Migrating from webkitAudioContext - Web APIs
the web audio api went through many iterations before reaching its current state.
...in this article, we cover the differences in web audio api since it was first implemented in webkit and how to update your code to use the modern web audio api.
... the web audio standard was first implemented in webkit, and the implementation was built in parallel with the work on the specification of the api.
...And 44 more matches

Advanced techniques: Creating and sequencing audio - Web APIs
if you're familiar with these terms and you're looking for an introduction to their application within with the web audio api, you've come to the right place.
... demo we're going to be looking at a very simple step sequencer: in practice this is easier to do with a library — the web audio api was built to be built upon.
...the techniques we are using are: name of voice technique associated web audio api feature "sweep" oscillator, periodic wave oscillatornode, periodicwave "pulse" multiple oscillators oscillatornode "noise" random noise buffer, biquad filter audiobuffer, audiobuffersourcenode, biquadfilternode "dial up" loading a sound sample to play audiocontext.decodeaudiodata(), audiobuffersourcenode note: this instru...
...And 39 more matches

Audio and Video Delivery - Developer guides
we can deliver audio and video on the web in a number of ways, ranging from 'static' media files to adaptive live streams.
... the audio and video elements whether we are dealing with pre-recorded audio files or live streams, the mechanism for making them available through the browser's <audio> and <video> elements remains pretty much the same.
... to deliver video and audio, the general workflow is usually something like this: check what format the browser supports via feature detection (usually a choice of two, as stated above).
...And 39 more matches

Basic concepts behind Web Audio API - Web APIs
this article explains some of the audio theory behind how the features of the web audio api work, to help you make informed decisions while designing how audio is routed through your app.
... it won't turn you into a master sound engineer, but it will give you enough background to understand why the web audio api works like it does.
... audio graphs the web audio api involves handling audio operations inside an audio context, and has been designed to allow modular routing.
...And 38 more matches

BaseAudioContext - Web APIs
the baseaudiocontext interface of the web audio api acts as a base definition for online and offline audio-processing graphs, as represented by audiocontext and offlineaudiocontext respectively.
... you wouldn't use baseaudiocontext directly — you'd use its features via one of these two inheriting interfaces.
... a baseaudiocontext can be a target of events, therefore it implements the eventtarget interface.
...And 33 more matches

AudioNode - Web APIs
the audionode interface is a generic interface for representing an audio processing module.
... examples include: an audio source (e.g.
... an html <audio> or <video> element, an oscillatornode, etc.), the audio destination, intermediate processing module (e.g.
...And 28 more matches

AudioListener - Web APIs
the audiolistener interface represents the position and orientation of the unique person listening to the audio scene, and is used in audio spatialization.
... all pannernodes spatialize in relation to the audiolistener stored in the baseaudiocontext.listener attribute.
... it is important to note that there is only one listener per context and that it isn't an audionode.
...And 27 more matches

AudioBufferSourceNode - Web APIs
the audiobuffersourcenode interface is an audioscheduledsourcenode which represents an audio source consisting of in-memory audio data, stored in an audiobuffer.
... it's especially useful for playing back audio which has particularly stringent timing accuracy requirements, such as for sounds that must match a specific rhythm and can be kept in memory rather than being played from disk or the network.
... to play sounds which require accurate timing but must be streamed from the network or played from disk, use a audioworkletnode to implement its playback.
...And 24 more matches

Introducing the Audio API extension - Archive of obsolete content
the audio data api extension extends the html5 specification of the <audio> and <video> media elements by exposing audio metadata and raw audio data.
... this enables users to visualize audio data, to process this audio data and to create new audio data.
...you should use the web audio api instead.
...And 23 more matches

Web Audio API best practices - Web APIs
in this article, we'll share a number of best practices — guidelines, tips, and tricks for working with the web audio api.
... loading sounds/files there are four main ways to load sound with the web audio api and it can be a little confusing as to which one you should use.
...an <audio> or <video> element), or you're looking to fetch the file and decode it into a buffer.
...And 22 more matches

AudioParam - Web APIs
the web audio api's audioparam interface represents an audio-related parameter, usually a parameter of an audionode (such as gainnode.gain).
... an audioparam can be set to a specific value or a change in value, and can be scheduled to happen at a specific time and following a specific pattern.
... there are two kinds of audioparam, a-rate and k-rate parameters: an a-rate audioparam takes the current audio parameter value for each sample frame of the audio signal.
...And 21 more matches

MediaStreamAudioSourceNode - Web APIs
the mediastreamaudiosourcenode interface is a type of audionode which operates as an audio source whose media is received from a mediastream obtained using the webrtc or media capture and streams apis.
... this media could be from a microphone (through getusermedia()) or from a remote peer on a webrtc call (using the rtcpeerconnection's audio tracks).
... a mediastreamaudiosourcenode has no inputs and exactly one output, and is created using the audiocontext.createmediastreamsource() method.
...And 20 more matches

AudioNode.connect() - Web APIs
the connect() method of the audionode interface lets you connect one of the node's outputs to a target, which may be either another audionode (thereby directing the sound data to the specified node) or an audioparam, so that the node's output data is automatically used to change the value of that parameter over time.
... syntax var destinationnode = audionode.connect(destination, outputindex, inputindex); audionode.connect(destination, outputindex); parameters destination the audionode or audioparam to which to connect.
... outputindex optional an index specifying which output of the current audionode to connect to the destination.
...And 19 more matches

AudioWorkletProcessor - Web APIs
the audioworkletprocessor interface of the web audio api represents an audio processing code behind a custom audioworkletnode.
... it lives in the audioworkletglobalscope and runs on the web audio rendering thread.
... in turn, an audioworkletnode based on it runs on the main thread.
...And 19 more matches

AudioContext - Web APIs
the audiocontext interface represents an audio-processing graph built from audio modules linked together, each represented by an audionode.
... an audio context controls both the creation of the nodes it contains and the execution of the audio processing, or decoding.
... you need to create an audiocontext before you do anything else, as everything happens inside a context.
...And 18 more matches

OfflineAudioContext - Web APIs
the offlineaudiocontext interface is an audiocontext interface representing an audio-processing graph built from linked together audionodes.
... in contrast with a standard audiocontext, an offlineaudiocontext doesn't render the audio to the device hardware; instead, it generates it, as fast as it can, and outputs the result to an audiobuffer.
...t="50" fill="#fff" stroke="#d4dde4" stroke-width="2px" /><text x="56" y="30" font-size="12px" font-family="consolas,monaco,andale mono,monospace" fill="#4d4e53" text-anchor="middle" alignment-baseline="middle">eventtarget</text></a><polyline points="111,25 121,20 121,30 111,25" stroke="#d4dde4" fill="none"/><line x1="121" y1="25" x2="151" y2="25" stroke="#d4dde4"/><a xlink:href="/docs/web/api/audiocontext" target="_top"><rect x="151" y="1" width="120" height="50" fill="#fff" stroke="#d4dde4" stroke-width="2px" /><text x="211" y="30" font-size="12px" font-family="consolas,monaco,andale mono,monospace" fill="#4d4e53" text-anchor="middle" alignment-baseline="middle">audiocontext</text></a><polyline points="271,25 281,20 281,30 271,25" stroke="#d4dde4" fill="none"/><line x1="281" y1="25" x2...
...And 18 more matches

Autoplay guide for media and Web Audio APIs - Web media technologies
automatically starting the playback of audio (or videos with audio tracks) immediately upon page load can be an unwelcome surprise to users.
...in this guide, we'll cover autoplay functionality in the various media and web audio apis, including a brief overview of how to use autoplay and how to work with browsers to handle autoplay blocking gracefully.
... autoplay blocking is not applied to <video> elements when the source media does not have an audio track, or if the audio track is muted.
...And 18 more matches

AudioWorkletProcessor.process - Web APIs
the process() method of an audioworkletprocessor-derived class implements the audio processing algorithm for the audio processor worklet.
... although the method is not a part of the audioworkletprocessor interface, any implementation of audioworkletprocessor must provide a process() method.
... the method is called synchronously from the audio rendering thread, once for each block of audio (also known as a rendering quantum) being directed through the processor's corresponding audioworkletnode.
...And 16 more matches

Audio and video manipulation - Developer guides
having native audio and video in the browser means we can use these data streams with technologies such as <canvas>, webgl or web audio api to modify audio and video directly, for example adding reverb/compression effects to audio, or grayscale/sepia filters to video.
... playback rate we can also adjust the rate that audio and video plays at using an attribute of the <audio> and <video> element called playbackrate.
... note that the playbackrate property works with both <audio> and <video>, but in both cases, it changes the playback speed but not the pitch.
...And 16 more matches

AudioWorkletNode - Web APIs
although the interface is available outside secure contexts, the baseaudiocontext.audioworklet property is not, thus custom audioworkletprocessors cannot be defined outside them.
... the audioworkletnode interface of the web audio api represents a base class for a user-defined audionode, which can be connected to an audio routing graph along with other nodes.
... it has an associated audioworkletprocessor, which does the actual audio processing in a web audio rendering thread.
...And 15 more matches

AudioBuffer - Web APIs
the audiobuffer interface represents a short audio asset residing in memory, created from an audio file using the audiocontext.decodeaudiodata() method, or from raw data using audiocontext.createbuffer().
... once put into an audiobuffer, the audio can then be played by being passed into an audiobuffersourcenode.
... objects of these types are designed to hold small audio snippets, typically less than 45 s.
...And 14 more matches

AudioParamDescriptor - Web APIs
the audioparamdescriptor dictionary of the web audio api specifies properties for an audioparam objects.
... it is used to create custom audioparams on an audioworkletnode.
... if the underlying audioworkletprocessor has a parameterdescriptors static getter, then the returned array of objects based on this dictionary is used internally by audioworkletnode constructor to populate its parameters property accordingly.
...And 12 more matches

AudioWorkletProcessor.parameterDescriptors (static getter) - Web APIs
the read-only parameterdescriptors property of an audioworkletprocessor-derived class is a static getter, which returns an iterable of audioparamdescriptor-based objects.
... the property is not a part of the audioworkletprocessor interface, but, if defined, it is called internally by the audioworkletprocessor constructor to create a list of custom audioparam objects in the parameters property of the associated audioworkletnode.
... syntax audioworkletprocessorsubclass.parameterdescriptors; value an iterable of audioparamdescriptor-based objects.
...And 12 more matches

BaseAudioContext.createBuffer() - Web APIs
the createbuffer() method of the baseaudiocontext interface is used to create a new, empty audiobuffer object, which can then be populated by data, and played via an audiobuffersourcenode for more details about audio buffers, check out the audiobuffer reference page.
...the asynchronous method decodeaudiodata() does the same thing — takes compressed audio, say, an mp3 file, and directly gives you back an audiobuffer that you can then set to play via in an audiobuffersourcenode.
... for simple uses like playing an mp3, decodeaudiodata() is what you should be using.
...And 12 more matches

MediaStreamTrackAudioSourceNode - Web APIs
the mediastreamtrackaudiosourcenode interface is a type of audionode which represents a source of audio data taken from a specific mediastreamtrack obtained through the webrtc or media capture and streams apis.
... the audio itself might be input from a microphone or other audio sampling device, or might be received through a rtcpeerconnection, among other posible options.
... a mediastreamtrackaudiosourcenode has no inputs and exactly one output, and is created using the audiocontext.createmediastreamtracksource() method.
...And 12 more matches

Web Audio Editor - Firefox Developer Tools
with the web audio api, developers create an audio context.
... within that context they then construct a number of audio nodes, including: nodes providing the audio source, such as an oscillator or a data buffer source nodes performing transformations such as delay and gain nodes representing the destination of the audio stream, such as the speakers each node has zero or more audioparam properties that configure its operation.
... the developer connects the nodes in a graph, and the complete graph defines the behavior of the audio stream.
...And 11 more matches

AudioTrack - Web APIs
the audiotrack interface represents a single audio track from one of the html media elements, <audio> or <video>.
... the most common use for accessing an audiotrack object is to toggle its enabled property in order to mute and unmute the track.
... properties enabled a boolean value which controls whether or not the audio track's sound is enabled.
...And 11 more matches

AudioWorkletGlobalScope - Web APIs
the audioworkletglobalscope interface of the web audio api represents a global execution context for user-supplied code, which defines custom audioworkletprocessor-derived classes.
... each baseaudiocontext has a single audioworklet available under the audioworklet property, which runs its code in a single audioworkletglobalscope.
... as the global execution context is shared across the current baseaudiocontext, it's possible to define any other variables and perform any actions allowed in worklets — apart from defining audioworkletprocessor-derived classes.
...And 11 more matches

AudioContext() - Web APIs
the audiocontext() constructor creates a new audiocontext object which represents an audio-processing graph, built from audio modules linked together, each represented by an audionode.
... syntax var audioctx = new audiocontext(); var audioctx = new audiocontext(options); parameters options optional an object based on the audiocontextoptions dictionary that contains zero or more optional properties to configure the new context.
... available properties are as follows: latencyhint optional the type of playback that the context will be used for, as a value from the audiocontextlatencycategory enum or a double-precision floating-point value indicating the preferred maximum latency of the context in seconds.
...And 10 more matches

AudioProcessingEvent - Web APIs
the web audio api audioprocessingevent represents events that occur when a scriptprocessornode input buffer is ready to be processed.
... note: as of the august 29 2014 web audio api spec publication, this feature has been marked as deprecated, and is soon to be replaced by audioworklet.
... playbacktime read only double the time when the audio will be played, as defined by the time of audiocontext.currenttime inputbuffer read only audiobuffer the buffer containing the input audio data to be processed.
...And 10 more matches

AudioWorkletProcessor() - Web APIs
the audioworkletprocessor() constructor creates a new audioworkletprocessor object, which represents an underlying audio processing mechanism of an audioworkletnode.
... syntax the audioworkletprocessor and classes that derive from it cannot be instantiated directly from a user-supplied code.
... instead, they are created only internally by the creation of an associated audioworkletnodes.
...And 10 more matches

msAudioCategory - Web APIs
the msaudiocategory property of the html <audio> element, is a read/write proprietary attribute, specific to internet explorer and microsoft edge.
... msaudiocategory specifies the purpose of the audio or video media, such as background audio or alerts.
... syntax <audio controls="controls" msaudiocategory="backgroundcapablemedia"> </audio> the msaudiocategory property offers a variety of values that can enhance the behavior of your audio-aware app.
...And 10 more matches

MediaElementAudioSourceNode - Web APIs
the mediaelementaudiosourcenode interface represents an audio source consisting of an html5 <audio> or <video> element.
... it is an audionode that acts as an audio source.
... a mediaelementsourcenode has no inputs and exactly one output, and is created using the audiocontext.createmediaelementsource() method.
...And 10 more matches

AudioBufferSourceNode.playbackRate - Web APIs
the playbackrate property of the audiobuffersourcenode interface is a k-rate audioparam that defines the speed at which the audio asset will be played.
... a value of 1.0 indicates it should play at the same speed as its sampling rate, values less than 1.0 cause the sound to play more slowly, while values greater than 1.0 result in audio playing faster than normal.
...when set to another value, the audiobuffersourcenode resamples the audio before sending it to the output.
...And 9 more matches

AudioListener.setPosition() - Web APIs
the setposition() method of the audiolistener interface defines the position of the listener.
...pannernode objects use this position relative to individual audio sources for spatialisation.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.setposition(1,1,1); returns void.
...And 9 more matches

AudioTrack.kind - Web APIs
the kind property contains a string indicating the category of audio contained in the audiotrack.
...see audio track kind strings for a list of the kinds available for audio tracks.
... syntax var trackkind = audiotrack.kind; value a domstring specifying the type of content the media represents.
...And 9 more matches

AudioTrackList - Web APIs
the audiotracklist interface is used to represent a list of the audio tracks contained within a given html media element, with each track represented by a separate audiotrack object in the list.
... retrieve an instance of this object with htmlmediaelement.audiotracks.
... event handlers onaddtrack an event handler to be called when the addtrack event is fired, indicating that a new audio track has been added to the media element.
...And 9 more matches

BaseAudioContext.createPanner() - Web APIs
the createpanner() method of the baseaudiocontext interface is used to create a new pannernode, which is used to spatialize an incoming audio stream in 3d space.
... the panner node is spatialized in relation to the audiocontext's audiolistener (defined by the audiocontext.listener attribute), which represents the position and orientation of the person listening to the audio.
... syntax baseaudioctx.createpanner(); returns a pannernode.
...And 9 more matches

DisplayMediaStreamConstraints.audio - Web APIs
the displaymediastreamconstraints dictionary's audio property is used to specify whether or not to request that the mediastream containing screen display contents also include an audio track.
... this value may simply be a boolean, where true indicates that an audio track should be included an false (the default) indicates that no audio should be included in the stream.
... more precise control over the audio data may be exercised by instead providing a mediatrackconstraints object, which is used to process the audio prior to adding it to the stream.
...And 9 more matches

MediaStreamConstraints.audio - Web APIs
the mediastreamconstraints dictionary's audio property is used to indicate what kind of audio track, if any, should be included in the mediastream returned by a call to getusermedia().
... syntax var audioconstraints = true | false | mediatrackconstraints; value the value of the audio property can be specified as either of two types: boolean if a boolean value is specified, it simply indicates whether or not an audio track should be included in the returned stream; if it's true, an audio track is included; if no audio source is available or if permission is not given to use the audio source, the call to getusermedia() will fail.
... if false, no audio track is included.
...And 9 more matches

Web audio spatialization basics - Web APIs
as if its extensive variety of sound processing (and other) options wasn't enough, the web audio api also includes facilities to allow you to emulate the difference in sound as a listener moves around a sound source, for example panning as you move around a sound source inside a 3d game.
... basics of spatialization in web audio, complex 3d spatializations are created using the pannernode, which in layman's terms is basically a whole lotta cool maths to make audio appear in 3d space.
...in 3d spaces, it's the only way to achieve realistic audio.
...And 9 more matches

AudioBufferSourceNode.start() - Web APIs
the start() method of the audiobuffersourcenode interface is used to schedule playback of the audio data contained in the buffer, or to begin playback immediately.
... syntax audiobuffersourcenode.start([when][, offset][, duration]); parameters when optional the time, in seconds, at which the sound should begin to play, in the same time coordinate system used by the audiocontext.
... if when is less than (audiocontext.currenttime, or if it's 0, the sound begins to play at once.
...And 8 more matches

AudioContext.createMediaStreamSource() - Web APIs
the createmediastreamsource() method of the audiocontext interface is used to create a new mediastreamaudiosourcenode object, given a media stream (say, from a mediadevices.getusermedia instance), the audio from which can then be played and manipulated.
... for more details about media stream audio source nodes, check out the mediastreamaudiosourcenode reference page.
... syntax audiosourcenode = audiocontext.createmediastreamsource(stream); parameters stream a mediastream to serve as an audio source to be fed into an audio processing graph for use and manipulation.
...And 8 more matches

AudioContextOptions - Web APIs
the audiocontextoptions dictionary is used to specify configuration options when constructing a new audiocontext object to represent a graph of web audio nodes.
... it is only used when calling the audiocontext() constructor.
... properties latencyhint optional the type of playback that the context will be used for, as a value from the audiocontextlatencycategory enum or a double-precision floating-point value indicating the preferred maximum latency of the context in seconds.
...And 8 more matches

AudioListener.forwardX - Web APIs
the forwardx read-only property of the audiolistener interface is an audioparam representing the x value of the direction vector defining the forward direction the listener is pointing in.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.forwardx.value = 0; value an audioparam.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

AudioListener.forwardY - Web APIs
the forwardy read-only property of the audiolistener interface is an audioparam representing the y value of the direction vector defining the forward direction the listener is pointing in.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.forwardy.value = 0; value an audioparam.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

AudioListener.forwardZ - Web APIs
the forwardz read-only property of the audiolistener interface is an audioparam representing the z value of the direction vector defining the forward direction the listener is pointing in.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.forwardz.value = 0; value an audioparam.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

AudioListener.positionX - Web APIs
the positionx read-only property of the audiolistener interface is an audioparam representing the x position of the listener in 3d cartesian space.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.positionx.value = 1; value an audioparam.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

AudioListener.positionY - Web APIs
the positiony read-only property of the audiolistener interface is an audioparam representing the y position of the listener in 3d cartesian space.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.positiony.value = 1; value an audioparam.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

AudioListener.positionZ - Web APIs
the positionz read-only property of the audiolistener interface is an audioparam representing the z position of the listener in 3d cartesian space.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.positionz.value = 1; value an audioparam.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

AudioListener.upX - Web APIs
the upx read-only property of the audiolistener interface is an audioparam representing the x value of the direction vector defining the up direction the listener is pointing in.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.upx.value = 0; value an audioparam.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

AudioListener.upY - Web APIs
the upy read-only property of the audiolistener interface is an audioparam representing the y value of the direction vector defining the up direction the listener is pointing in.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.upy.value = 0; value an audioparam.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

AudioListener.upZ - Web APIs
the upz read-only property of the audiolistener interface is an audioparam representing the z value of the direction vector defining the up direction the listener is pointing in.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.upz.value = 0; value an audioparam.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

AudioParam.value - Web APIs
the web audio api's audioparam interface property value gets or sets the value of this audioparam at the current time.
... initially, the value is set to audioparam.defaultvalue.
... setting value has the same effect as calling audioparam.setvalueattime with the time returned by the audiocontext's currenttime property..
...And 8 more matches

AudioTrack.enabled - Web APIs
the audiotrack property enabled specifies whether or not the described audio track is currently enabled for use.
... if the track is disabled by setting enabled to false, the track is muted and does not produce audio.
... syntax isaudioenabled = audiotrack.enabled; audiotrack.enabled = true | false; value the enabled property is a boolean whose value is true if the track is enabled; enabled tracks produce audio while the media is playing.
...And 8 more matches

AudioWorkletNode() - Web APIs
the audioworkletnode() constructor creates a new audioworkletnode object, which represents an audionode that uses a javascript function to perform custom audio processing.
... syntax var node = new audioworkletnode(context, name); var node = new audioworkletnode(context, name, options); parameters context the baseaudiocontext instance this node will be associated with.
... name a string, which represents the name of the audioworkletprocessor this node will be based on.
...And 8 more matches

BaseAudioContext.createScriptProcessor() - Web APIs
the createscriptprocessor() method of the baseaudiocontext interface creates a scriptprocessornode used for direct audio processing.
... note: as of the august 29 2014 web audio api spec publication, this feature has been marked as deprecated, and was replaced by audioworklet (see audioworkletnode).
... syntax var scriptprocessor = audioctx.createscriptprocessor(buffersize, numberofinputchannels, numberofoutputchannels); parameters buffersize the buffer size in units of sample-frames.
...And 8 more matches

Audio() - Web APIs
the audio() constructor creates and returns a new htmlaudioelement which can be either attached to a document for the user to interact with and/or listen to, or can be used offscreen to manage and play audio.
... syntax audioobj = new audio(url); parameters url optional an optional domstring containing the url of an audio file to be associated with the new audio element.
... return value a new htmlaudioelement object, configured to be used for playing back the audio from the file specified by url.the new object's preload property is set to auto and its src property is set to the specified url or null if no url is given.
...And 8 more matches

HTMLAudioElement - Web APIs
the htmlaudioelement interface provides access to the properties of <audio> elements, as well as methods to manipulate them.
...l="#fff" stroke="#d4dde4" stroke-width="2px" /><text x="411" y="94" font-size="12px" font-family="consolas,monaco,andale mono,monospace" fill="#4d4e53" text-anchor="middle" alignment-baseline="middle">htmlmediaelement</text></a><polyline points="331,89 321,84 321,94 331,89" stroke="#d4dde4" fill="none"/><line x1="321" y1="89" x2="291" y2="89" stroke="#d4dde4"/><a xlink:href="/docs/web/api/htmlaudioelement" target="_top"><rect x="131" y="65" width="160" height="50" fill="#f4f7f8" stroke="#d4dde4" stroke-width="2px" /><text x="211" y="94" font-size="12px" font-family="consolas,monaco,andale mono,monospace" fill="#4d4e53" text-anchor="middle" alignment-baseline="middle">htmlaudioelement</text></a></svg></div> a:hover text { fill: #0095dd; pointer-events: all;} constructor audio()...
... creates and returns a new htmlaudioelement object, optionally starting the process of loading an audio file into it if the file url is given.
...And 8 more matches

OfflineAudioContext.startRendering() - Web APIs
the startrendering() method of the offlineaudiocontext interface starts rendering the audio graph, taking into account the current connections and the current scheduled changes.
... the complete event (of type offlineaudiocompletionevent) is raised when the rendering is finished, containing the resulting audiobuffer in its renderedbuffer property.
... syntax event-based version: offlineaudioctx.startrendering(); offlineaudioctx.oncomplete = function(e) { // e.renderedbuffer contains the output buffer } promise-based version: offlineaudioctx.startrendering().then(function(buffer) { // buffer contains the output buffer }); parameters none.
...And 8 more matches

Writing Web Audio API code that works in every browser - Developer guides
you probably have already read the announcement on the web audio api coming to firefox, and are totally excited and ready to make your until-now-webkit-only sites work with firefox, which uses the unprefixed version of the spec.
... unfortunately, chrome, safari and opera still use the webkitaudiocontext prefixed name.
...in addition, not all features of web audio are already implemented in firefox yet.
...And 8 more matches

AudioContext.getOutputTimestamp() - Web APIs
the getoutputtimestamp() property of the audiocontext interface returns a new audiotimestamp object containing two audio timestamp values relating to the current audio context.
... the two values are as follows: audiotimestamp.contexttime: the time of the sample frame currently being rendered by the audio output device (i.e., output audio stream position), in the same units and origin as the context's audiocontext.currenttime.
... basically, this is the time after the audio context was first created.
...And 7 more matches

AudioDestinationNode - Web APIs
the audiodestinationnode interface represents the end destination of an audio graph in a given context — usually the speakers of your device.
... it can also be the node that will "record" the audio data when used with an offlineaudiocontext.
... audiodestinationnode has no output (as it is the output, no more audionode can be linked after it in the audio graph) and one input.
...And 7 more matches

AudioListener.dopplerFactor - Web APIs
the deprecated dopplerfactor property of the audiolistener interface is a double value representing the amount of pitch shift to use when rendering a doppler effect.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.dopplerfactor = 1; value a double indicating the doppler effect's pitch shift value.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 7 more matches

AudioListener.setOrientation() - Web APIs
the setorientation() method of the audiolistener interface defines the orientation of the listener.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.setorientation(0,0,-1,0,1,0); returns void.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 7 more matches

AudioListener.speedOfSound - Web APIs
the speedofsound property of the audiolistener interface is a double value representing the speed of sound, in meters per second.
... syntax var audioctx = new audiocontext(); var mylistener = audioctx.listener; mylistener.speedofsound = 343.3; value a double.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 7 more matches

AudioNode.disconnect() - Web APIs
the disconnect() method of the audionode interface lets you disconnect one or more nodes from the node on which the method is called.
... syntax audionode.disconnect(); audionode.disconnect(output); audionode.disconnect(destination); audionode.disconnect(destination, output); audionode.disconnect(destination, output, input); return value undefined parameters there are several versions of the disconnect() method, which accept different combinations of parameters to control which nodes to disconnect from.
... destination optional an audionode or audioparam specifying the node or nodes to disconnect from.
...And 7 more matches

AudioWorkletGlobalScope.registerProcessor - Web APIs
the registerprocessor method of the audioworkletglobalscope interface registers a class constructor derived from audioworkletprocessor interface under a specified name.
... syntax audioworkletglobalscope.registerprocessor(name, processorctor); parameters name a string representing the name under which the processor will be registered.
... processorctor the constructor of a class derived from audioworkletprocessor.
...And 7 more matches

AudioWorkletNode.parameters - Web APIs
the read-only parameters property of the audioworkletnode interface returns the associated audioparammap — that is, a map-like collection of audioparam objects.
... they are instantiated during creation of the underlying audioworkletprocessor according to its parameterdescriptors static getter.
... syntax audioworkletnodeinstance.parameters value the audioparammap object containing audioparam instances.
...And 7 more matches

AudioWorkletNodeOptions - Web APIs
the audioworkletnodeoptions dictionary of the web audio api is used to specify configuration options when constructing a new audioworkletnode object for custom audio processing.
... it is only used when calling the audioworkletnode() constructor.
... during internal instantiation of the underlying audioworkletprocessor, the the structured clone algorithm is applied to the options object and the result is passed into audioworkletprocessor's constructor.
...And 7 more matches

HTMLMediaElement.audioTracks - Web APIs
the read-only audiotracks property on htmlmediaelement objects returns an audiotracklist object listing all of the audiotrack objects representing the media element's audio tracks.
... the media element may be either an <audio> element or a <video> element.
...once you have a reference to the list, you can monitor it for changes to detect when new audio tracks are added or existing ones removed.
...And 7 more matches

Live streaming web audio and video - Developer guides
streaming audio and video on demand streaming technology is not used exclusively for live streams.
... it can also be used instead of the traditional progressive download method for audio and video on demand: there are several advantages to this: latency is generally lower so media will start playing more quickly adaptive streaming makes for better experiences on a variety of devices media is downloaded just in time which makes bandwidth usage more efficient streaming protocols while static media is usually served over http, there are several protocols for serving adaptive streams; let's take a look at the options.
... important: although the <audio> and <video> tags are protocol agnostic, no browser currently supports anything other than http without requiring plugins, although this looks set to change.
...And 7 more matches

Video and Audio APIs - Learn web development
previous overview: client-side web apis next html5 comes with elements for embedding rich media in documents — <video> and <audio> — which in turn come with their own apis for controlling playback, seeking, etc.
... prerequisites: javascript basics (see first steps, building blocks, javascript objects), the basics of client-side apis objective: to learn how to use browser apis to control video and audio playback.
... html5 video and audio the <video> and <audio> elements allow us to embed video and audio into web pages.
...And 6 more matches

nsIDOMHTMLAudioElement
the nsidomhtmlaudioelement interface is used to implement the html5 <audio> element.
... dom/interfaces/html/nsidomhtmlaudioelement.idlscriptable please add a summary to this article.
... last changed in gecko 2.0 (firefox 4 / thunderbird 3.3 / seamonkey 2.1) inherits from: nsidomhtmlmediaelement method overview unsigned long long mozcurrentsampleoffset(); void mozsetup(in pruint32 channels, in pruint32 rate); [implicit_jscontext] unsigned long mozwriteaudio(in jsval data); methods mozcurrentsampleoffset() non-standard this feature is non-standard and is not on a standards track.
...And 6 more matches

AudioBufferSourceNode.loopStart - Web APIs
the loopstart property of the audiobuffersourcenode interface is a floating-point value indicating, in seconds, where in the audiobuffer the restart of the play must happen.
... syntax audiobuffersourcenode.loopstart = startoffsetinseconds; startoffsetinseconds = audiobuffersourcenode.loopstart; value a floating-point number indicating the offset, in seconds, into the audio buffer at which each loop should begin during playback.
... example in this example, the audiocontext.decodeaudiodata() function is used to decode an audio track and put it into an audiobuffersourcenode.
...And 6 more matches

AudioContext.close() - Web APIs
the close() method of the audiocontext interface closes the audio context, releasing any system audio resources that it uses.
... closed contexts cannot have new nodes created, but can decode audio data, create buffers, etc.
... this function does not automatically release all audiocontext-created objects, unless other references have been released as well; however, it will forcibly release any system audio resources that might prevent additional audiocontexts from being created and used, suspend the progression of audio time in the audio context, and stop processing audio data.
...And 6 more matches

AudioParam.setTargetAtTime() - Web APIs
the settargetattime() method of the audioparam interface schedules the start of a gradual change to the audioparam value.
... starttime the time that the exponential transition will begin, in the same time coordinate system as audiocontext.currenttime.
... if it is less than or equal to audiocontext.currenttime, the parameter will start changing immediately.
...And 6 more matches

AudioTrackList.getTrackById() - Web APIs
the audiotracklist method gettrackbyid() returns the first audiotrack object from the track list whose id matches the specified string.
... syntax var thetrack = audiotracklist.gettrackbyid(id); paramters id a domstring indicating the id of the track to locate within the track list.
... return value an audiotrack object indicating the first track found within the audiotracklist whose id matches the specified string.
...And 6 more matches

MediaStream.getAudioTracks() - Web APIs
the getaudiotracks() method of the mediastream interface returns a sequence that represents all the mediastreamtrack objects in this stream's track set where mediastreamtrack.kind is audio.
... syntax var mediastreamtracks = mediastream.getaudiotracks() parameters none.
... return value an array of mediastreamtrack objects, one for each audio track contained in the stream.
...And 6 more matches

MediaStreamAudioSourceNode() - Web APIs
the web audio api's mediastreamaudiosourcenode() constructor creates and returns a new mediastreamaudiosourcenode object which uses the first audio track of a given mediastream as its source.
... note: another way to create a mediastreamaudiosourcenode is to call theaudiocontext.createmediastreamsource() method, specifying the stream from which you want to obtain audio.
... syntax audiosourcenode = new mediastreamaudiosourcenode(context, options); parameters context an audiocontext representing the audio context you want the node to be associated with.
...And 6 more matches

MediaStreamTrackAudioSourceNode() - Web APIs
the web audio api's mediastreamtrackaudiosourcenode() constructor creates and returns a new mediastreamtrackaudiosourcenode object whose audio is taken from the mediastreamtrack specified in the given options object.
... another way to create a mediastreamtrackaudiosourcenode is to call theaudiocontext.createmediastreamtracksource() method, specifying the mediastreamtrack from which you want to obtain audio.
... syntax audiotracknode = new mediastreamtrackaudiosourcenode(context, options); parameters context an audiocontext representing the audio context you want the node to be associated with.
...And 6 more matches

ScriptProcessorNode.onaudioprocess - Web APIs
note: as of the august 29 2014 web audio api spec publication, this feature has been marked as deprecated, and is soon to be replaced by audio workers.
... the onaudioprocess event handler of the scriptprocessornode interface represents the eventhandler to be called for the audioprocess event that is dispatched to scriptprocessornode node types.
... an event of type audioprocessingevent will be dispatched to the event handler.
...And 6 more matches

AudioBuffer() - Web APIs
the audiobuffer constructor of the web audio api creates a new audiobuffer object.
... syntax var audiobuffer = new audiobuffer(options); parameters inherits parameters from the audionodeoptions dictionary.
... options options are as follows: length: the size of the audio buffer in sample-frames.
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AudioBufferSourceNode.loopEnd - Web APIs
the loopend property of the audiobuffersourcenode interface specifies is a floating point number specifying, in seconds, at what offset into playing the audiobuffer playback should loop back to the time indicated by the loopstart property.
... syntax audiobuffersourcenode.loopend = endoffsetinseconds; var endoffsetinseconds = audiobuffersourcenode.loopend; value a floating-point number indicating the offset, in seconds, into the audio buffer at which each loop will loop return to the beginning of the loop (that is, the current play time gets reset to audiobuffersourcenode.loopstart).
... example in this example, the audiocontext.decodeaudiodata() function is used to decode an audio track and put it into an audiobuffersourcenode.
...And 5 more matches

AudioContext.createMediaElementSource() - Web APIs
the createmediaelementsource() method of the audiocontext interface is used to create a new mediaelementaudiosourcenode object, given an existing html <audio> or <video> element, the audio from which can then be played and manipulated.
... for more details about media element audio source nodes, check out the mediaelementaudiosourcenode reference page.
... syntax var audioctx = new audiocontext(); var source = audioctx.createmediaelementsource(mymediaelement); parameters mymediaelement an htmlmediaelement object that you want to feed into an audio processing graph to manipulate.
...And 5 more matches

AudioContext.createMediaStreamDestination() - Web APIs
the createmediastreamdestination() method of the audiocontext interface is used to create a new mediastreamaudiodestinationnode object associated with a webrtc mediastream representing an audio stream, which may be stored in a local file or sent to another computer.
... the mediastream is created when the node is created and is accessible via the mediastreamaudiodestinationnode's stream attribute.
... for more details about media stream destination nodes, check out the mediastreamaudiodestinationnode reference page.
...And 5 more matches

AudioContext.createMediaStreamTrackSource() - Web APIs
the createmediastreamtracksource() method of the audiocontext interface creates and returns a mediastreamtrackaudiosourcenode which represents an audio source whose data comes from the specified mediastreamtrack.
... this differs from createmediastreamsource(), which creates a mediastreamaudiosourcenode whose audio comes from the audio track in a specified mediastream whose id is first, lexicographically (alphabetically).
... syntax var audioctx = new audiocontext(); var track = audioctx.createmediastreamtracksource(track); parameters track the mediastreamtrack to use as the source of all audio data for the new node.
...And 5 more matches

AudioParam.setValueCurveAtTime() - Web APIs
the setvaluecurveattime() method of the audioparam interface schedules the parameter's value to change following a curve defined by a list of values.
... syntax var paramref = param.setvaluecurveattime(values, starttime, duration); parameters values an array of floating-point numbers representing the value curve the audioparam will change through along the specified duration.
... starttime a double representing the time (in seconds) after the audiocontext was first created that the change in value will happen.
...And 5 more matches

AudioScheduledSourceNode - Web APIs
the audioscheduledsourcenode interface—part of the web audio api—is a parent interface for several types of audio source node interfaces which share the ability to be started and stopped, optionally at specified times.
... you can't create an audioscheduledsourcenode object directly.
... instead, use the interface which extends it, such as audiobuffersourcenode, oscillatornode, and constantsourcenode.
...And 5 more matches

AudioTrackList.length - Web APIs
the read-only audiotracklist property length returns the number of entries in the audiotracklist, each of which is an audiotrack representing one audio track in the media element.
... a value of 0 indicates that there are no audio tracks in the media.
... syntax var trackcount = audiotracklist.length; value a number indicating how many audio tracks are included in the audiotracklist.
...And 5 more matches

AudioTrackList.onaddtrack - Web APIs
the audiotracklist property onaddtrack is an event handler which is called when the addtrack event occurs, indicating that a new audio track has been added to the media element whose audio tracks the audiotracklist represents.
... syntax audiotracklist.onaddtrack = eventhandler; value set onaddtrack to a function that accepts as input a trackevent object which indicates in its track property which audio track has been added to the media.
... usage notes the addtrack event is called whenever a new track is added to the media element whose audio tracks are represented by the audiotracklist object.
...And 5 more matches

AudioWorklet - Web APIs
the audioworklet interface of the web audio api is used to supply custom audio processing scripts that execute in a separate thread to provide very low latency audio processing.
... the worklet's code is run in the audioworkletglobalscope global execution context, using a separate web audio thread which is shared by the worklet and other audio nodes.
... access the audio context's instance of audioworklet through the baseaudiocontext.audioworklet property.
...And 5 more matches

AudioWorkletNode.port - Web APIs
the read-only port property of the audioworkletnode interface returns the associated messageport.
... it can be used to communicate between the node and its associated audioworkletprocessor.
... syntax audioworkletnodeinstance.port; value the messageport object that is connecting the audioworkletnode and its associated audioworkletprocessor.
...And 5 more matches

AudioWorkletProcessor.port - Web APIs
the read-only port property of the audioworkletprocessor interface returns the associated messageport.
... it can be used to communicate between the processor and the audioworkletnode to which it belongs.
... syntax audioworkletprocessorinstance.port; value the messageport object that is connecting the audioworkletprocessor and the associated audioworkletnode.
...And 5 more matches

MediaStreamAudioDestinationNode - Web APIs
the mediastreamaudiodestinationnode interface represents an audio destination consisting of a webrtc mediastream with a single audiomediastreamtrack, which can be used in a similar way to a mediastream obtained from navigator.getusermedia.
... it is an audionode that acts as an audio destination, created using the audiocontext.createmediastreamdestination method.
... number of inputs 1 number of outputs 0 channel count 2 channel count mode "explicit" channel count interpretation "speakers" constructor mediastreamaudiodestinationnode.mediastreamaudiodestinationnode() creates a new mediastreamaudiodestinationnode object instance.
...And 5 more matches

AudioBuffer.getChannelData() - Web APIs
the getchanneldata() method of the audiobuffer interface returns a float32array containing the pcm data associated with the channel, defined by the channel parameter (with 0 representing the first channel).
... syntax var myarraybuffer = audioctx.createbuffer(2, framecount, audioctx.samplerate); var nowbuffering = myarraybuffer.getchanneldata(channel); parameters channel the channel property is an index representing the particular channel to get data for.
...if the channel index value is greater than of equal to audiobuffer.numberofchannels, an index_size_err exception will be thrown.
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AudioBufferSourceNode.loop - Web APIs
the loop property of the audiobuffersourcenode interface is a boolean indicating if the audio asset must be replayed when the end of the audiobuffer is reached.
... syntax var loopingenabled = audiobuffersourcenode.loop; audiobuffersourcenode.loop = true | false; value a boolean which is true if looping is enabled; otherwise, the value is false.
...when the time specified by the loopend property is reached, playback continues at the time specified by loopstart example in this example, the audiocontext.decodeaudiodata function is used to decode an audio track and put it into an audiobuffersourcenode.
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AudioConfiguration - Web APIs
the audioconfiguration dictionary of the media capabilities api defines the audio file being tested when calling mediacapabilities.encodinginfo() or mediacapabilities.decodinginfo() to query whether a specific audio configuration is supported, smooth, and/or power efficient.
... properties the audioconfiguration dictionary is made up of four audio properties, including: contenttype: a valid audio mime type, for information on possible values and what they mean, see the web audio codec guide.
... channels: the number of channels used by the audio track.
...And 4 more matches

AudioContextLatencyCategory - Web APIs
the audiocontextlatencycategory type is an enumerated set of strings which are used to select one of a number of default values for acceptable maximum latency of an audio context.
... by using these strings rather than a numeric value when specifying a latency to a audiocontext, you can allow the user agent to select an appropriate latency for your use case that makes sense on the device on which your content is being used.
... audiocontextlatencycategory can be used when constructing a new audiocontext by passing one of these values as the latencyhint option in the audiocontext() constructor's options dictionary.
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AudioNodeOptions - Web APIs
the audionodeoptions dictionary of the web audio api specifies options that can be used when creating new audionode objects.
... audionodeoptions is inherited from by the option objects of the different types of audio node constructors.
... syntax var audionodeoptions = { "channelcount" : 2, "channelcountmode" : "max", "channelinterpretation" : "discrete" } properties channelcount optional represents an integer used to determine how many channels are used when up-mixing and down-mixing connections to any inputs to the node.
...And 4 more matches

AudioParam.exponentialRampToValueAtTime() - Web APIs
the exponentialramptovalueattime() method of the audioparam interface schedules a gradual exponential change in the value of the audioparam.
... syntax var audioparam = audioparam.exponentialramptovalueattime(value, endtime) parameters value a floating point number representing the value the audioparam will ramp to by the given time.
... returns a reference to this audioparam object.
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AudioParam.linearRampToValueAtTime() - Web APIs
the linearramptovalueattime() method of the audioparam interface schedules a gradual linear change in the value of the audioparam.
... syntax var audioparam = audioparam.linearramptovalueattime(value, endtime) parameters value a floating point number representing the value the audioparam will ramp to by the given time.
... returns a reference to this audioparam object.
...And 4 more matches

AudioParam.setValueAtTime() - Web APIs
the setvalueattime() method of the audioparam interface schedules an instant change to the audioparam value at a precise time, as measured against audiocontext.currenttime.
... syntax var audioparam = audioparam.setvalueattime(value, starttime) parameters value a floating point number representing the value the audioparam will change to at the given time.
... starttime a double representing the time (in seconds) after the audiocontext was first created that the change in value will happen.
...And 4 more matches

AudioScheduledSourceNode.start() - Web APIs
the start() method on audioscheduledsourcenode schedules a sound to begin playback at the specified time.
... syntax audioscheduledsourcenode.start([when [, offset [, duration]]]); parameters when optional the time, in seconds, at which the sound should begin to play.
... this value is specified in the same time coordinate system as the audiocontext is using for its currenttime attribute.
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AudioTrackList.onremovetrack - Web APIs
the audiotracklist onremovetrack event handler is called when the removetrack event occurs, indicating that an audio track has been removed from the media element, and therefore also from the audiotracklist.
... the event is passed into the event handler in the form of a trackevent object, whose track property identifies the track that was removed from the media element's audiotracklist.
... syntax audiotracklist.onremovetrack = eventhandler; value set onremovetrack to a function that accepts as input a trackevent object which indicates in its track property which audio track has been removed from the media element.
...And 4 more matches

BaseAudioContext.createBufferSource() - Web APIs
the createbuffersource() method of the baseaudiocontext interface is used to create a new audiobuffersourcenode, which can be used to play audio data contained within an audiobuffer object.
... audiobuffers are created using baseaudiocontext.createbuffer or returned by baseaudiocontext.decodeaudiodata when it successfully decodes an audio track.
... syntax var source = baseaudiocontext.createbuffersource(); returns an audiobuffersourcenode.
...And 4 more matches

BaseAudioContext.createConvolver() - Web APIs
the createconvolver() method of the baseaudiocontext interface creates a convolvernode, which is commonly used to apply reverb effects to your audio.
... syntax baseaudiocontext.createconvolver(); returns a convolvernode.
... example the following example shows basic usage of an audiocontext to create a convolver node.
...And 4 more matches

BaseAudioContext.createStereoPanner() - Web APIs
the createstereopanner() method of the baseaudiocontext interface creates a stereopannernode, which can be used to apply stereo panning to an audio source.
... it positions an incoming audio stream in a stereo image using a low-cost equal-power panning algorithm.
... syntax baseaudiocontext.createstereopanner(); returns a stereopannernode.
...And 4 more matches

msAudioDeviceType - Web APIs
the msaudiodevicetype property of the html <audio> element, is a read/write proprietary attribute, specific to internet explorer and microsoft edge.
... msaudiodevicetype specifies the output device id that the audio will be sent to.
... syntax <audio src="sound.mp3" msaudiodevicetype="communications" /> by default, audio on your system will output to your default speakers and be considered a foreground element, meaning that the audio will play only when the element is active in the app.
...And 4 more matches

RTCRtpContributingSource.audioLevel - Web APIs
the read-only audiolevel property of the rtcrtpcontributingsource interface indicates the audio level contained in the last rtp packet played from the described source.
... audiolevel will be the level value defined in [rfc6465] if the rfc 6465 header extension is present, and otherwise null.
... syntax var audiolevel = rtcrtpcontributingsource.audiolevel value a double-precision floating-point number which indicates the volume level of the audio in the most recently received rtp packet from the source described by the rtcrtpcontributingsource.
...And 4 more matches

AudioBuffer.copyToChannel() - Web APIs
the copytochannel() method of the audiobuffer interface copies the samples to the specified channel of the audiobuffer, from the source array.
... channelnumber the channel number of the current audiobuffer to copy the channel data to.
... if channelnumber is greater than or equal to audiobuffer.numberofchannels, an index_size_err will be thrown.
...And 3 more matches

AudioContext.createJavaScriptNode() - Web APIs
the audiocontext.createjavascriptnode() method creates a javascriptnode which is used for directly manipulating audio data with javascript.
... important: this method is obsolete, and has been renamed to audiocontext.createscriptprocessor().
... syntax var jsnode = audioctx.createjavascriptnode(buffersize, numinputchannels, numoutputchannels); parameters buffersize the buffer size must be in units of sample frames, i.e., one of: 256, 512, 1024, 2048, 4096, 8192, or 16384.
...And 3 more matches

AudioContextOptions.latencyHint - Web APIs
the audiocontextoptions dictionary (used when instantiating an audiocontext) may contain a property named latencyhint, which indicates the preferred maximum latency in seconds for the audio context.
... the value is specified either as a member of the string enum audiocontextlatencycategory or a double-precision value.
... syntax audiocontextoptions.latencyhint = "interactive"; audiocontextoptions.latencyhint = 0.2; var latencyhint = audiocontextoptions.latencyhint; value the preferred maximum latency for the audiocontext.
...And 3 more matches

AudioContextOptions.sampleRate - Web APIs
the audiocontextoptions dictionary (used when instantiating an audiocontext) may contain a property named samplerate, which indicates the sample rate to use for the new context.
... the value must be a floating-point value indicating the sample rate, in samples per second, for which to configure the new context; additionally, the value must be one which is supported by audiobuffer.samplerate.
... syntax audiocontextoptions.samplerate = 44100; var samplerate = audiocontextoptions.samplerate; value the desired sample rate for the audiocontext, specified in samples per second.
...And 3 more matches

AudioDestinationNode.maxChannelCount - Web APIs
the maxchannelcount property of the audiodestinationnode interface is an unsigned long defining the maximum amount of channels that the physical device can handle.
... the audionode.channelcount property can be set between 0 and this value (both included).
... if maxchannelcount is 0, like in offlineaudiocontext, the channel count cannot be changed.
...And 3 more matches

AudioScheduledSourceNode.stop() - Web APIs
the stop() method on audioscheduledsourcenode schedules a sound to cease playback at the specified time.
... syntax audioscheduledsourcenode.stop([when]); parameters when optional the time, in seconds, at which the sound should stop playing.
... this value is specified in the same time coordinate system as the audiocontext is using for its currenttime attribute.
...And 3 more matches

AudioTrack.label - Web APIs
the read-only audiotrack property label returns a string specifying the audio track's human-readable label, if one is available; otherwise, it returns an empty string.
... syntax var audiotracklabel = audiotrack.label; value a domstring specifying the track's human-readable label, if one is available in the track metadata.
... example this example returns an array of track kinds and labels for potential use in a user interface to select audio tracks for a specified media element.
...And 3 more matches

AudioTrackList.onchange - Web APIs
the audiotracklist property onchange is an event handler which is called when the change event occurs, indicating that one or more of the audiotracks in the audiotracklist have been enabled or disabled.
...to determine the new state of media's tracks, you'll have to look at their audiotrack.enabled flags.
... syntax audiotracklist.onchange = eventhandler; value set onchange to a function that should be called whenever tracks are enabled or disabled on the media element.
...And 3 more matches

BaseAudioContext.createAnalyser() - Web APIs
the createanalyser() method of the baseaudiocontext interface creates an analysernode, which can be used to expose audio time and frequency data and create data visualisations.
... syntax var analysernode = baseaudiocontext.createanalyser(); returns an analysernode.
... example the following example shows basic usage of an audiocontext to create an analyser node, then use requestanimationframe() to collect time domain data repeatedly and draw an "oscilloscope style" output of the current audio input.
...And 3 more matches

BaseAudioContext.createChannelMerger() - Web APIs
the createchannelmerger() method of the baseaudiocontext interface creates a channelmergernode, which combines channels from multiple audio streams into a single audio stream.
... syntax baseaudiocontext.createchannelmerger(numberofinputs); parameters numberofinputs the number of channels in the input audio streams, which the output stream will contain; the default is 6 if this parameter is not specified.
...to use them, you need to use the second and third parameters of the audionode.connect(audionode) method, which allow you to specify both the index of the channel to connect from and the index of the channel to connect to.
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BaseAudioContext.createChannelSplitter() - Web APIs
the createchannelsplitter() method of the baseaudiocontext interface is used to create a channelsplitternode, which is used to access the individual channels of an audio stream and process them separately.
... syntax baseaudiocontext.createchannelsplitter(numberofoutputs); parameters numberofoutputs the number of channels in the input audio stream that you want to output separately; the default is 6 if this parameter is not specified.
...to use them, you need to use the second and third parameters of the audionode.connect(audionode) method, which allow you to specify the index of the channel to connect from and the index of the channel to connect to.
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BaseAudioContext.createDynamicsCompressor() - Web APIs
the createdynamicscompressor() method of the baseaudiocontext interface is used to create a dynamicscompressornode, which can be used to apply compression to an audio signal.
...it is especially important in games and musical applications where large numbers of individual sounds are played simultaneously, where you want to control the overall signal level and help avoid clipping (distorting) of the audio output.
... syntax baseaudioctx.createdynamicscompressor(); returns a dynamicscompressornode.
...And 3 more matches

BaseAudioContext.createGain() - Web APIs
the creategain() method of the baseaudiocontext interface creates a gainnode, which can be used to control the overall gain (or volume) of the audio graph.
... syntax var gainnode = audiocontext.creategain(); return value a gainnode which takes as input one or more audio sources and outputs audio whose volume has been adjusted in gain (volume) to a level specified by the node's gainnode.gain a-rate parameter.
... example the following example shows basic usage of an audiocontext to create a gainnode, which is then used to mute and unmute the audio when a mute button is clicked by changing the gain property value.
...And 3 more matches

BaseAudioContext.createWaveShaper() - Web APIs
the createwaveshaper() method of the baseaudiocontext interface creates a waveshapernode, which represents a non-linear distortion.
... it is used to apply distortion effects to your audio.
... syntax baseaudioctx.createwaveshaper(); returns a waveshapernode.
...And 3 more matches

BaseAudioContext.currentTime - Web APIs
the currenttime read-only property of the baseaudiocontext interface returns a double representing an ever-increasing hardware timestamp in seconds that can be used for scheduling audio playback, visualizing timelines, etc.
... syntax var curtime = baseaudiocontext.currenttime; example var audiocontext = window.audiocontext || window.webkitaudiocontext; var audioctx = new audiocontext(); // older webkit/blink browsers require a prefix ...
... console.log(audioctx.currenttime); reduced time precision to offer protection against timing attacks and fingerprinting, the precision of audioctx.currenttime might get rounded depending on browser settings.
...And 3 more matches

BaseAudioContext.sampleRate - Web APIs
the samplerate property of the baseaudiocontext interface returns a floating point number representing the sample rate, in samples per second, used by all nodes in this audio context.
... syntax baseaudiocontext.samplerate; value a floating point number indicating the audio context's sample rate, in samples per second.
... example note: for a full web audio example implementation, see one of our web audio demos on the mdn github repo, like panner-node.
...And 3 more matches

MediaElementAudioSourceNode() - Web APIs
the mediaelementaudiosourcenode() constructor creates a new mediaelementaudiosourcenode object instance.
... syntax var myaudiosource = new mediaelementaudiosourcenode(context, options); parameters inherits parameters from the audionodeoptions dictionary.
... context an audiocontext representing the audio context you want the node to be associated with.
...And 3 more matches

MediaStreamAudioSourceNode.mediaStream - Web APIs
the mediastreamaudiosourcenode interface's read-only mediastream property indicates the mediastream that contains the audio track from which the node is receiving audio.
... this stream was specified when the node was first created, either using the mediastreamaudiosourcenode() constructor or the audiocontext.createmediastreamsource() method.
... syntax audiosourcestream = mediastreamaudiosourcenode.mediastream; value a mediastream representing the stream which contains the mediastreamtrack serving as the source of audio for the node.
...And 3 more matches

NotifyAudioAvailableEvent - Web APIs
the non-standard, obsolete, notifyaudioavailableevent interface defines the event sent to audio elements when the audio buffer is full.
... properties framebuffer read only a float32array containing the raw 32-bit floating-point audio data obtained from decoding the audio (e.g., the raw data being sent to the audio hardware vs.
... encoded audio).
...And 3 more matches

Media type and format guide: image, audio, and video content - Web media technologies
some are audio-specific, while others may be used for either audio or combined audiovisual content such as movies.
... web audio codec guide a guide to the audio codecs allowed for by the common media containers, as well as by the major browsers.
... codecs used by webrtc webrtc doesn't use a container, but instead streams the encoded media itself from peer to peer using mediastreamtrack objects to represent each audio or video track.
...And 3 more matches

Visualizing an audio spectrum - Archive of obsolete content
this example calculates and displays fast fourier transform (fft) spectrum data for the playing audio.
... the function handling the loadedmetadata event stores the metadata of the audio element in global variables; the function for the mozaudioavailable event does an fft of the samples and displays them in a canvas.
... note: you can use the audionode called analysernode to perform real-time fft analysis on an audio stream, rather than the code shown below.
...And 2 more matches

AudioContext.resume() - Web APIs
the resume() method of the audiocontext interface resumes the progression of time in an audio context that has previously been suspended.
... this method will cause an invalid_state_err exception to be thrown if called on an offlineaudiocontext.
... syntax completepromise = audiocontext.resume(); parameters none.
...And 2 more matches

AudioContext.suspend() - Web APIs
the suspend() method of the audiocontext interface suspends the progression of time in the audio context, temporarily halting audio hardware access and reducing cpu/battery usage in the process — this is useful if you want an application to power down the audio hardware when it will not be using an audio context for a while.
... this method will cause an invalid_state_err exception to be thrown if called on an offlineaudiocontext.
... syntax var audioctx = new audiocontext(); audioctx.suspend().then(function() { ...
...And 2 more matches

AudioNode.channelCountMode - Web APIs
the channelcountmode property of the audionode interface represents an enumerated value describing the way channels must be matched between the node's inputs and outputs.
... the possible values of channelcountmode and their meanings are: value description the following audionode children default to this value max the number of channels is equal to the maximum number of channels of all connections.
... audiodestinationnode, analysernode, channelsplitternode in older versions of the spec, the default for a channelsplitternode was max.
...And 2 more matches

AudioNode.channelInterpretation - Web APIs
the channelinterpretation property of the audionode interface represents an enumerated value describing the meaning of the channels.
... this interpretation will define how audio up-mixing and down-mixing will happen.
...this can be somewhat controlled by setting the audionode.channelinterpretation property to speakers or discrete: interpretation input channels output channels mixing rules speakers 1 (mono) 2 (stereo) up-mix from mono to stereo.
...And 2 more matches

AudioScheduledSourceNode.onended - Web APIs
the onended event handler for the audioscheduledsourcenode interface specifies an eventhandler to be executed when the ended event occurs on the node.
... this event is sent to the node when the concrete interface (such as audiobuffersourcenode, oscillatornode, or constantsourcenode) determines that it has stopped playing.
...this is the case, for example, when using an audiobuffersourcenode with its loop property set to true.
...And 2 more matches

AudioTrack.id - Web APIs
the id property contains a string which uniquely identifies the track represented by the audiotrack.
... this id can be used with the audiotracklist.gettrackbyid() method to locate a specific track within the media associated with a media element.
... syntax var trackid = audiotrack.id; value a domstring which identifies the track, suitable for use when calling gettrackbyid() on an audiotracklist such as the one specified by a media element's audiotracks property.
...And 2 more matches

AudioTrack.language - Web APIs
the read-only audiotrack property language returns a string identifying the language used in the audio track.
... syntax var audiotracklanguage = audiotrack.language; value a domstring specifying the bcp 47 (rfc 5646) format language tag of the primary language used in the audio track, or an empty string ("") if the language is not specified or known, or if the track doesn't contain speech.
... example this example locates all of a media element's primary language and translated audio tracks and returns a list of objects containing each of those tracks' id, kind, and language.
...And 2 more matches

BaseAudioContext.createBiquadFilter() - Web APIs
the createbiquadfilter() method of the baseaudiocontext interface creates a biquadfilternode, which represents a second order filter configurable as several different common filter types.
... syntax baseaudiocontext.createbiquadfilter(); returns a biquadfilternode.
... example the following example shows basic usage of an audiocontext to create a biquad filter node.
...And 2 more matches

BaseAudioContext.createDelay() - Web APIs
the createdelay() method of the baseaudiocontext interface is used to create a delaynode, which is used to delay the incoming audio signal by a certain amount of time.
... syntax var delaynode = audioctx.createdelay(maxdelaytime); parameters maxdelaytime optional the maximum amount of time, in seconds, that the audio signal can be delayed by.
... var audiocontext = window.audiocontext || window.webkitaudiocontext; var audioctx = new audiocontext(); var synthdelay = audioctx.createdelay(5.0); ...
...And 2 more matches

BaseAudioContext.destination - Web APIs
the destination property of the baseaudiocontext interface returns an audiodestinationnode representing the final destination of all audio in the context.
... it often represents an actual audio-rendering device such as your device's speakers.
... syntax baseaudiocontext.destination; value an audiodestinationnode.
...And 2 more matches

BaseAudioContext.listener - Web APIs
the listener property of the baseaudiocontext interface returns an audiolistener object that can then be used for implementing 3d audio spatialization.
... syntax baseaudiocontext.listener; value an audiolistener object.
... example note: for a full web audio spatialization example, see our panner-node demo.
...And 2 more matches

BaseAudioContext.state - Web APIs
the state read-only property of the baseaudiocontext interface returns the current state of the audiocontext.
... syntax baseaudiocontext.state; value a domstring.
... possible values are: suspended: the audio context has been suspended (with the audiocontext.suspend() method.) running: the audio context is running normally.
...And 2 more matches

OfflineAudioCompletionEvent - Web APIs
the web audio api offlineaudiocompletionevent interface represents events that occur when the processing of an offlineaudiocontext is terminated.
... note: this interface is marked as deprecated; it is still supported for legacy reasons, but it will soon be superseded when the promise version of offlineaudiocontext.startrendering is supported in browsers, which will no longer need it.
... constructor offlineaudiocompletionevent.offlineaudiocompletionevent creates a new offlineaudiocompletionevent object instance.
...And 2 more matches

Visualizations with Web Audio API - Web APIs
one of the most interesting features of the web audio api is the ability to extract frequency, waveform, and other data from your audio source, which can then be used to create visualizations.
... basic concepts to extract data from your audio source, you need an analysernode, which is created using the audiocontext.createanalyser() method, for example: var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); var analyser = audioctx.createanalyser(); this node is then connected to your audio source at some point between your source and your destination, for example: source = audioctx.createmediastreamsource(stream); source.connect(analyser); analyser.connect(distortion); distortion.connect(audioctx.destination); note: you don't need to connect the analyser's output to another node for it to work, a...
... the analyser node will then capture audio data using a fast fourier transform (fft) in a certain frequency domain, depending on what you specify as the analysernode.fftsize property value (if no value is specified, the default is 2048.) note: you can also specify a minimum and maximum power value for the fft data scaling range, using analysernode.mindecibels and analysernode.maxdecibels, and different data averaging constants using analysernode.smoothingtimeconstant.
...And 2 more matches

Web Audio playbackRate explained - Developer guides
the playbackrate property of the <audio> and <video> elements allows us to change the speed, or rate, at which a piece of web audio or video is playing.
... playbackrate basics let's starting by looking at a brief example of playbackrate usage: var myaudio = document.createelement('audio'); myaudio.setattribute('src','audiofile.mp3'); myaudio.playbackrate = 0.5; here we create an <audio> element, and set its src to a file of our choice.
... browser support chrome 20+ ✔ firefox 20+ ✔ ie 9+ ✔ safari 6+ ✔ opera 15+ ✔ mobile chrome (android) ✖ mobile firefox 24+ ✔ ie mobile ✖ mobile safari 6+ (ios) ✔ opera mobile ✖ notes most browsers stop playing audio outside playbackrate bounds of 0.5 and 4, leaving the video playing silently.
...And 2 more matches

Displaying a graphic with audio samples - Archive of obsolete content
the following example shows how to take samples from an audio stream and display them behind an image (in this case, the mozilla logo), giving the impression that the image is built from the samples.
... <!doctype html> <html> <head> <title>javascript spectrum example</title> </head> <body> <audio id="audio-element" src="revolve.ogg" controls="true" style="width: 512px;"> </audio> <div><canvas id="fft" width="512" height="200"></canvas></div> <img id="mozlogo" style="display:none" src="mozilla2.png"></img> <script> var canvas = document.getelementbyid('fft'), ctx = canvas.getcontext('2d'), channels, rate, framebufferlength, fft; function loadedmetadata() { channels = audio.mozchannels; rate = audio.mozsamplerate; framebufferlength = audio.mozframebufferlength; fft = new fft(framebufferlength / channels, r...
...ate); } function audioavailable(event) { var fb = event.framebuffer, t = event.time, /* unused, but it's there */ signal = new float32array(fb.length / channels), magnitude; for (var i = 0, fbl = framebufferlength / 2; i < fbl; i++ ) { // assuming interlaced stereo channels, // need to split and merge into a stero-mix mono signal signal[i] = (fb[2*i] + fb[2*i+1]) / 2; } // clear the canvas before drawing spectrum ctx.fillstyle = "rgb(0,0,0)"; ctx.fillrect (0,0, canvas.width, canvas.height); ctx.fillstyle = "rgb(255,255,255)"; for (var i = 0; i < signal.length; i++ ) { // multiply spectrum by a zoom value magnitude = signal[i] * ...
...1000; // draw rectangle bars for each frequency bin ctx.fillrect(i * 4, canvas.height, 3, -magnitude); } ctx.drawimage(document.getelementbyid('mozlogo'),0,0, canvas.width, canvas.height); } var audio = document.getelementbyid('audio-element'); audio.addeventlistener('mozaudioavailable', audioavailable, false); audio.addeventlistener('loadedmetadata', loadedmetadata, false); </script> </body> </html> ...

AudioBuffer.copyFromChannel() - Web APIs
the copyfromchannel() method of the audiobuffer interface copies the audio sample data from the specified channel of the audiobuffer to a specified float32array.
... channelnumber the channel number of the current audiobuffer to copy the channel data from.
... example this example creates a new audio buffer, then copies the samples from another channel into it.
... var myarraybuffer = audioctx.createbuffer(2, framecount, audioctx.samplerate); var anotherarray = new float32array(length); myarraybuffer.copyfromchannel(anotherarray, 1, 0); specification specification status comment web audio apithe definition of 'copyfromchannel' in that specification.

AudioBuffer.duration - Web APIs
the duration property of the audiobuffer interface returns a double representing the duration, in seconds, of the pcm data stored in the buffer.
... syntax var myarraybuffer = audioctx.createbuffer(2, framecount, audioctx.samplerate); myarraybuffer.duration; value a double.
... example // stereo var channels = 2; // create an empty two second stereo buffer at the // sample rate of the audiocontext var framecount = audioctx.samplerate * 2.0; var myarraybuffer = audioctx.createbuffer(2, framecount, audioctx.samplerate); button.onclick = function() { // fill the buffer with white noise; // just random values between -1.0 and 1.0 for (var channel = 0; channel < channels; channel++) { // this gives us the actual arraybuffer that contains the data var nowbuffering = myarraybuffer.getchanneldata(channel); for (var i = 0; i < framecount; i++) { // math.random() is in [0; 1.0] // audio needs to be in [-1.0; 1.0] nowbuffering[i] = math.random() * 2 - 1; } } console.log(myarraybuffer.duration); } specification specifi...
...cation status comment web audio apithe definition of 'duration' in that specification.

AudioBuffer.length - Web APIs
the length property of the audiobuffer interface returns an integer representing the length, in sample-frames, of the pcm data stored in the buffer.
... syntax var myarraybuffer = audioctx.createbuffer(2, framecount, audioctx.samplerate); myarraybuffer.length; value an integer.
... example // stereo var channels = 2; // create an empty two second stereo buffer at the // sample rate of the audiocontext var framecount = audioctx.samplerate * 2.0; var myarraybuffer = audioctx.createbuffer(2, framecount, audioctx.samplerate); button.onclick = function() { // fill the buffer with white noise; // just random values between -1.0 and 1.0 for (var channel = 0; channel < channels; channel++) { // this gives us the actual arraybuffer that contains the data var nowbuffering = myarraybuffer.getchanneldata(channel); for (var i = 0; i < framecount; i++) { // math.random() is in [0; 1.0] // audio needs to be in [-1.0; 1.0] nowbuffering[i] = math.random() * 2 - 1; } } console.log(myarraybuffer.length); } specification specificat...
...ion status comment web audio apithe definition of 'length' in that specification.

AudioBuffer.numberOfChannels - Web APIs
the numberofchannels property of the audiobuffer interface returns an integer representing the number of discrete audio channels described by the pcm data stored in the buffer.
... syntax var myarraybuffer = audioctx.createbuffer(2, framecount, audioctx.samplerate); myarraybuffer.numberofchannels; value an integer.
... example // stereo var channels = 2; // create an empty two second stereo buffer at the // sample rate of the audiocontext var framecount = audioctx.samplerate * 2.0; var myarraybuffer = audioctx.createbuffer(2, framecount, audioctx.samplerate); button.onclick = function() { // fill the buffer with white noise; // just random values between -1.0 and 1.0 for (var channel = 0; channel < channels; channel++) { // this gives us the actual arraybuffer that contains the data var nowbuffering = myarraybuffer.getchanneldata(channel); for (var i = 0; i < framecount; i++) { // math.random() is in [0; 1.0] // audio needs to be in [-1.0; 1.0] nowbuffering[i] = math.random() * 2 - 1; } } console.log(myarraybuffer.numberofchannels); } specification ...
...specification status comment web audio apithe definition of 'numberofchannels' in that specification.

AudioBuffer.sampleRate - Web APIs
the samplerate property of the audiobuffer interface returns a float representing the sample rate, in samples per second, of the pcm data stored in the buffer.
... syntax var myarraybuffer = audioctx.createbuffer(2, framecount, audioctx.samplerate); myarraybuffer.samplerate; value a floating-point value indicating the current sample rate of the buffers data, in samples per second.
... example // stereo var channels = 2; // create an empty two second stereo buffer at the // sample rate of the audiocontext var framecount = audioctx.samplerate * 2.0; var myarraybuffer = audioctx.createbuffer(2, framecount, audioctx.samplerate); button.onclick = function() { // fill the buffer with white noise; // just random values between -1.0 and 1.0 for (var channel = 0; channel < channels; channel++) { // this gives us the actual arraybuffer that contains the data var nowbuffering = myarraybuffer.getchanneldata(channel); for (var i = 0; i < framecount; i++) { // math.random() is in [0; 1.0] // audio needs to be in [-1.0; 1.0] nowbuffering[i] = math.random() * 2 - 1; } } console.log(myarraybuffer.samplerate); } specification specif...
...ication status comment web audio apithe definition of 'samplerate' in that specification.

AudioBufferSourceNode.buffer - Web APIs
the buffer property of the audiobuffersourcenode interface provides the ability to play back audio using an audiobuffer as the source of the sound data.
... syntax audiobuffersourcenode.buffer = soundbuffer; value an audiobuffer which contains the data representing the sound which the node will play.
... var myarraybuffer = audioctx.createbuffer(2, framecount, audioctx.samplerate); button.onclick = function() { // fill the buffer with white noise; //just random values between -1.0 and 1.0 for (var channel = 0; channel < channels; channel++) { // this gives us the actual arraybuffer that contains the data var nowbuffering = myarraybuffer.getchanneldata(channel); for (var i = 0; i < framecount; i++) { // math.random() is in [0; 1.0] // audio needs to be in [-1.0; 1.0] nowbuffering[i] = math.random() * 2 - 1; } } // get an audiobuffersourcenode.
... // this is the audionode to use when we want to play an audiobuffer var source = audioctx.createbuffersource(); // set the buffer in the audiobuffersourcenode source.buffer = myarraybuffer; specifications specification status comment web audio apithe definition of 'buffer' in that specification.

AudioBufferSourceNode.detune - Web APIs
the detune property of the audiobuffersourcenode interface is a k-rate audioparam representing detuning of oscillation in cents.
... syntax var source = audioctx.createbuffersource(); source.detune.value = 100; // value in cents note: though the audioparam returned is read-only, the value it represents is not.
... value a k-rate audioparam whose value indicates the detuning of oscillation in cents.
... example const audioctx = new audiocontext(); const channelcount = 2; const framecount = audioctx.samplerate * 2.0; // 2 seconds const myarraybuffer = audioctx.createbuffer(channelcount, framecount, audioctx.samplerate); for (let channel = 0; channel < channelcount; channel++) { const nowbuffering = myarraybuffer.getchanneldata(channel); for (let i = 0; i < framecount; i++) { nowbuffering[i] = math.random() * 2 - 1; } } const source = audioctx.createbuffersource(); source.buffer = myarraybuffer; source.connect(audioctx.destination); source.detune.value = 100; // value in cents source.start(); specifications specification status comment web audio apithe definition of 'detune' in that specification.

AudioContext.baseLatency - Web APIs
the baselatency read-only property of the audiocontext interface returns a double that represents the number of seconds of processing latency incurred by the audiocontext passing an audio buffer from the audiodestinationnode — i.e.
... the end of the audio graph — into the host system's audio subsystem ready for playing.
... syntax var baselatency = audioctx.baselatency; value a double representing the base latency in seconds.
... example // default latency ("interactive") const audioctx1 = new audiocontext(); console.log(audioctx1.baselatency); // 0.00 // higher latency ("playback") const audioctx2 = new audiocontext({ latencyhint: 'playback' }); console.log(audioctx2.baselatency); // 0.15 specifications specification status comment web audio apithe definition of 'baselatency' in that specification.

AudioContext.outputLatency - Web APIs
the outputlatency read-only property of the audiocontext interface provides an estimation of the output latency of the current audio context.
... this is the time, in seconds, between the browser passing an audio buffer out of an audio graph over to the host system's audio subsystem to play, and the time at which the first sample in the buffer is actually processed by the audio output device.
... syntax var outputlatency = audioctx.outputlatency; value a double representing the output latency in seconds.
... example const audioctx = new audiocontext(); console.log(audioctx.outputlatency); specifications specification status comment web audio apithe definition of 'outputlatency' in that specification.

AudioNode.channelCount - Web APIs
the channelcount property of the audionode interface represents an integer used to determine how many channels are used when up-mixing and down-mixing connections to any inputs to the node.
... channelcount's usage and precise definition depend on the value of audionode.channelcountmode: it is ignored if the channelcountmode value is max.
... syntax var oscillator = audioctx.createoscillator(); var channels = oscillator.channelcount; value an integer.
... example var audiocontext = window.audiocontext || window.webkitaudiocontext; var audioctx = new audiocontext(); var oscillator = audioctx.createoscillator(); var gainnode = audioctx.creategain(); oscillator.connect(gainnode); gainnode.connect(audioctx.destination); oscillator.channelcount; specifications specification status comment web audio apithe definition of 'channelcount' in that specification.

AudioNode.numberOfOutputs - Web APIs
the numberofoutputs property of the audionode interface returns the number of outputs coming out of the node.
... destination nodes — like audiodestinationnode — have a value of 0 for this attribute.
... syntax var numoutputs = audionode.numberofoutputs; value an integer ≥ 0.
... example const audioctx = new audiocontext(); const oscillator = audioctx.createoscillator(); const gainnode = audioctx.creategain(); oscillator.connect(gainnode).connect(audioctx.destination); console.log(oscillator.numberofoutputs); // 1 console.log(gainnode.numberofoutputs); // 1 console.log(audioctx.destination.numberofoutputs); // 0 specifications specification status comment web audio apithe definition of 'numberofoutputs' in that specification.

AudioParam.cancelAndHoldAtTime() - Web APIs
the cancelandholdattime() property of the audioparam interface cancels all scheduled future changes to the audioparam but holds its value at a given time until further changes are made using other methods.
... syntax var audioparam = audioparam.cancelandholdattime(canceltime) parameters canceltime a double representing the time (in seconds) after the audiocontext was first created after which all scheduled changes will be cancelled.
... return value a reference to the audioparam it was called on.
... specifications specification status comment web audio apithe definition of 'cancelandholdattime()' in that specification.

AudioParam.cancelScheduledValues() - Web APIs
the cancelscheduledvalues() method of the audioparam interface cancels all scheduled future changes to the audioparam.
... syntax var audioparam = audioparam.cancelscheduledvalues(starttime) parameters starttime a double representing the time (in seconds) after the audiocontext was first created after which all scheduled changes will be cancelled.
... returns a reference to this audioparam object.
... examples var gainnode = audioctx.creategain(); gainnode.gain.setvaluecurveattime(wavearray, audioctx.currenttime, 2); //'gain' is the audioparam gainnode.gain.cancelscheduledvalues(audioctx.currenttime); specifications specification status comment web audio apithe definition of 'cancelscheduledvalues' in that specification.

AudioScheduledSourceNode: ended event - Web APIs
the ended event of the audioscheduledsourcenode interface is fired when the source node has stopped playing.
... bubbles no cancelable no interface event event handler property audioscheduledsourcenode.onended usage notes this event occurs when a audioscheduledsourcenode has stopped playing, either because it's reached a predetermined stop time, the full duration of the audio has been performed, or because the entire buffer has been played.
... examples in this simple example, an event listener for the ended event is set up to enable a "start" button in the user interface when the node stops playing: node.addeventlistener('ended', () => { document.getelementbyid("startbutton").disabled = false; }) you can also set up the event handler using the audioscheduledsourcenode.onended property: node.onended = function() { document.getelementbyid("startbutton").disabled = false; } for an example of the ended event in use, see our audio-buffer example on github.
... specifications specification status comment web audio apithe definition of 'onended' in that specification.

AudioWorkletNode.onprocessorerror - Web APIs
the onprocessorerror property of the audioworkletnode interface defines an event handler function to be called when the processorerror event fires.
... this occurs when the underlying audioworkletprocessor behind the node throws an exception in its constructor, the process method, or any user-defined class method.
... syntax audioworkletnode.onprocessorerror = function() { ...
... }; examples // fill in example snippet specifications specification status comment web audio apithe definition of 'onprocessorerror' in that specification.

BaseAudioContext.createOscillator() - Web APIs
the createoscillator() method of the baseaudiocontext interface creates an oscillatornode, a source representing a periodic waveform.
... syntax var oscillatornode = audioctx.createoscillator(); returns an oscillatornode.
... example the following example shows basic usage of an audiocontext to create an oscillator node.
... // create web audio api context var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); // create oscillator node var oscillator = audioctx.createoscillator(); oscillator.type = 'square'; oscillator.frequency.setvalueattime(3000, audioctx.currenttime); // value in hertz oscillator.connect(audioctx.destination); oscillator.start(); specifications specification status comment web audio apithe definition of 'createoscillator' in that specification.

BaseAudioContext.createPeriodicWave() - Web APIs
the createperiodicwave() method of the baseaudiocontext interface is used to create a periodicwave, which is used to define a periodic waveform that can be used to shape the output of an oscillatornode.
... syntax var wave = audiocontext.createperiodicwave(real, imag[, constraints]); returns a periodicwave.
... var real = new float32array(2); var imag = new float32array(2); var ac = new audiocontext(); var osc = ac.createoscillator(); real[0] = 0; imag[0] = 0; real[1] = 1; imag[1] = 0; var wave = ac.createperiodicwave(real, imag, {disablenormalization: true}); osc.setperiodicwave(wave); osc.connect(ac.destination); osc.start(); osc.stop(2); this works because a sound that contains only a fundamental tone is by definition a sine wave here, we create a periodicwave with two value...
... specifications specification status comment web audio apithe definition of 'createperiodicwave' in that specification.

BaseAudioContext.onstatechange - Web APIs
the onstatechange property of the baseaudiocontext interface defines an event handler function to be called when the statechange event fires: this occurs when the audio context's state changes.
... syntax baseaudiocontext.onstatechange = function() { ...
... }; example the following snippet is taken from our audiocontext states demo (see it running live.) the onstatechange hander is used to log the current state to the console every time it changes.
... audioctx.onstatechange = function() { console.log(audioctx.state); } specifications specification status comment web audio apithe definition of 'onstatechange' in that specification.

MediaElementAudioSourceNode.mediaElement - Web APIs
the mediaelementaudiosourcenode interface's read-only mediaelement property indicates the htmlmediaelement that contains the audio track from which the node is receiving audio.
... this stream was specified when the node was first created, either using the mediaelementaudiosourcenode() constructor or the audiocontext.createmediaelementsource() method.
... syntax audiosourceelement = mediaelementaudiosourcenode.mediaelement; value an htmlmediaelement representing the element which contains the source of audio for the node.
... examples const audioctx = new window.audiocontext(); const audioelem = document.queryselector('audio'); let options = { mediaelement: audioelem } let source = new mediaelementaudiosourcenode(audioctx, options); console.log(source.mediaelement); specifications specification status comment web audio apithe definition of 'mediaelementaudiosourcenode.mediaelement' in that specification.

MediaRecorder.audioBitsPerSecond - Web APIs
the audiobitspersecond read-only property of the mediarecorder interface returns the audio encoding bit rate in use.
... syntax var audiobitspersecond = mediarecorder.audiobitspersecond value a number (unsigned long).
... specifications specification status comment mediastream recordingthe definition of 'audiobitspersecond' in that specification.
... desktopmobilechromeedgefirefoxinternet exploreroperasafariandroid webviewchrome for androidfirefox for androidopera for androidsafari on iossamsung internetaudiobitspersecond experimentalchrome full support 49edge full support 79firefox full support 71ie no support noopera full support 36safari no support ...

MediaStreamAudioDestinationNode.stream - Web APIs
the stream property of the audiocontext interface represents a mediastream containing a single audiomediastreamtrack with the same number of channels as the node itself.
... you can use this property to get a stream out of the audio graph and feed it into another construct, such as a media recorder.
... syntax var audioctx = new audiocontext(); var destination = audioctx.createmediastreamdestination(); var mystream = destination.stream; value a mediastream.
... example specifications specification status comment web audio apithe definition of 'stream' in that specification.

MediaStreamAudioSourceOptions - Web APIs
the mediastreamaudiosourceoptions dictionary provides configuration options used when creating a mediastreamaudiosourcenode using its constructor.
... it is not needed when using the audiocontext.createmediastreamsource() method.
... properties mediastream a required property which specifies the mediastream from which to obtain audio for the node.
... specifications specification status comment web audio apithe definition of 'mediastreamaudiosourceoptions' in that specification.

MediaStreamTrackAudioSourceOptions.mediaStreamTrack - Web APIs
the mediastreamtrackaudiosourceoptions dictionary's mediastreamtrack property must contain a reference to the mediastreamtrack from which the mediastreamtrackaudiosourcenode being created using the mediastreamtrackaudiosourcenode() constructor.
... syntax mediastreamtrackaudiosourceoptions = { mediastreamtrack: audiosourcetrack; } mediastreamtrackaudiosourceoptions.mediastreamtrack = audiosourcetrack; value a mediastreamtrack from which the audio output of the new mediastreamtrackaudiosourcenode will be taken.
... example this example uses getusermedia() to obtain access to the user's camera, then creates a new mediastreamaudiosourcenode from the first audio track provided by the device.
... let audioctx = new (window.audiocontext || window.webkitaudiocontext)(); if (navigator.mediadevices.getusermedia) { navigator.mediadevices.getusermedia ( { audio: true, video: false }).then(function(stream) { let options = { mediastreamtrack: stream.getaudiotracks()[0]; } let source = new mediastreamtrackaudiosourcenode(audioctx, options); source.connect(audioctx.destination); }).catch(function(err) { console.log('the following gum error occured: ' + err); }); } else { console.log('new getusermedia not supported on your browser!'); } specifications specification status comment web audio apithe definition of 'mediastreamtrackaudiosourceoptions.mediastream' in that specification.

MediaStreamTrackAudioSourceOptions - Web APIs
the mediastreamtrackaudiosourceoptions dictionary is used when specifying options to the mediastreamtrackaudiosourcenode() constructor.
... it isn't needed when using the audiocontext.createmediastreamtracksource() method.
... properties mediastreamtrack the mediastreamtrack from which to take audio data for this node's output.
... specifications specification status comment web audio apithe definition of 'mediastreamtrackaudiosourceoptions' in that specification.

OfflineAudioContext.oncomplete - Web APIs
the oncomplete event handler of the offlineaudiocontext interface is called when the audio processing is terminated, that is when the complete event (of type offlineaudiocompletionevent) is raised.
... syntax var offlineaudioctx = new offlineaudiocontext(); offlineaudioctx.oncomplete = function() { ...
... } example when processing is complete, you might want to use the oncomplete handler the prompt the user that the audio can now be played, and enable the play button.
... offlineaudioctx.oncomplete = function() { console.log('offline audio processing now complete'); showmodaldialog('song processed and ready to play'); playbtn.disabled = false; } specifications specification status comment web audio apithe definition of 'oncomplete' in that specification.

OfflineAudioContext.resume() - Web APIs
the resume() method of the offlineaudiocontext interface resumes the progression of time in an audio context that has been suspended.
... the promise resolves immediately because the offlineaudiocontext does not require the audio hardware.
... syntax offlineaudiocontext.resume().then(function() { ...
... specifications specification status comment web audio apithe definition of 'resume()' in that specification.

OfflineAudioContext.suspend() - Web APIs
the suspend() method of the offlineaudiocontext interface schedules a suspension of the time progression in the audio context at the specified time and returns a promise.
... this is generally useful at the time of manipulating the audio graph synchronously on offlineaudiocontext.
... syntax offlineaudiocontext.suspend(suspendtime).then(function() { ...
... invalidstateerror if the quantized frame number is one of the following: a negative number is less than or equal to the current time is greater than or equal to the total render duration is scheduled by another suspend for the same time specifications specification status comment web audio apithe definition of 'suspend()' in that specification.

ScriptProcessorNode: audioprocess event - Web APIs
the audioprocess event of the scriptprocessornode interface is fired when an input buffer of a script processor is ready to be processed.
... bubbles no cancelable no default action none interface audioprocessingevent event handler property scriptprocessornode.onaudioprocess examples scriptnode.addeventlistener('audioprocess', function(audioprocessingevent) { // the input buffer is a song we loaded earlier var inputbuffer = audioprocessingevent.inputbuffer; // the output buffer contains the samples that will be modified and played var outputbuffer = audioprocessingevent.outputbuffer; // loop through the output channels (in this case there is only one) for (var channel = 0; channel < outputbuffer.numberofchannels; channel++) { var inputdata = inputbuffer.getchanneldata(channel); var outputdata = outputbuffer.getchanneldata(channel); // loo...
...p through the 4096 samples for (var sample = 0; sample < inputbuffer.length; sample++) { // make output equal to the same as the input outputdata[sample] = inputdata[sample]; // add noise to each output sample outputdata[sample] += ((math.random() * 2) - 1) * 0.2; } } }) you could also set up the event handler using the scriptprocessornode.onaudioprocess property: scriptnode.onaudioprocess = function(audioprocessingevent) { ...
... } specifications specification status comment web audio apithe definition of 'audioprocessingevent' in that specification.

mozbrowseraudioplaybackchange
the mozbrowseraudioplaybackchange event is fired when audio starts or stops playing within a browser <iframe>.
... details read only boolean indicates whether audio is playing in the browser.
... examples var browser = document.queryselector("iframe"); browser.addeventlistener("mozbrowseraudioplaybackchange", function(event) { console.log(event.details); }); related events mozbrowserclose mozbrowsercontextmenu mozbrowsererror mozbrowsericonchange mozbrowserloadend mozbrowserloadstart mozbrowserlocationchange mozbrowseropenwindow mozbrowsersecuritychange mozbrowsertitlechange mozbrowserusernameandpasswordrequired ...

AudioNode.context - Web APIs
the read-only context property of the audionode interface returns the associated baseaudiocontext, that is the object representing the processing graph the node is participating in.
... syntax var acontext = anaudionode.context; value the audiocontext or offlineaudiocontext object that was used to construct this audionode.
... example const audiocontext = window.audiocontext || window.webkitaudiocontext; const audioctx = new audiocontext(); const oscillator = audioctx.createoscillator(); const gainnode = audioctx.creategain(); oscillator.connect(gainnode).connect(audioctx.destination); console.log(oscillator.context); // audiocontext console.log(oscillator.context === audioctx); // true specifications specification status comment web audio apithe definition of 'context' in that specification.

AudioNode.numberOfInputs - Web APIs
the numberofinputs property of the audionode interface returns the number of inputs feeding the node.
... syntax var numinputs = audionode.numberofinputs; value an integer ≥ 0.
... example const audioctx = new audiocontext(); const oscillator = audioctx.createoscillator(); const gainnode = audioctx.creategain(); oscillator.connect(gainnode).connect(audioctx.destination); console.log(oscillator.numberofinputs); // 0 console.log(gainnode.numberofinputs); // 1 console.log(audioctx.destination.numberofinputs); // 1 specifications specification status comment web audio apithe definition of 'numberofinputs' in that specification.

AudioParam.defaultValue - Web APIs
the defaultvalue read-only property of the audioparam interface represents the initial value of the attributes as defined by the specific audionode creating the audioparam.
... syntax var defaultval = audioparam.defaultvalue; value a floating-point number.
... example const audioctx = new audiocontext(); const gainnode = audioctx.creategain(); const defaultval = gainnode.gain.defaultvalue; console.log(defaultval); // 1 console.log(defaultval === gainnode.gain.value); // true specifications specification status comment web audio apithe definition of 'defaultvalue' in that specification.

AudioParam.maxValue - Web APIs
the maxvalue read-only property of the audioparam interface represents the maximum possible value for the parameter's nominal (effective) range.
... syntax var maxval = audioparam.maxvalue; value a floating-point number indicating the maximum value permitted for the parameter's nominal range.
... example const audioctx = new audiocontext(); const gainnode = audioctx.creategain(); console.log(gainnode.gain.maxvalue); // 3.4028234663852886e38 specifications specification status comment web audio apithe definition of 'maxvalue' in that specification.

AudioParam.minValue - Web APIs
the minvalue read-only property of the audioparam interface represents the minimum possible value for the parameter's nominal (effective) range.
... syntax var minval = audioparam.minvalue; value a floating-point number indicating the minimum value permitted for the parameter's nominal range.
... example const audioctx = new audiocontext(); const gainnode = audioctx.creategain(); console.log(gainnode.gain.minvalue); // -3.4028234663852886e38 specifications specification status comment web audio apithe definition of 'minvalue' in that specification.

AudioTrack.sourceBuffer - Web APIs
the read-only audiotrack property sourcebuffer returns the sourcebuffer that created the track, or null if the track was not created by a sourcebuffer or the sourcebuffer has been removed from the mediasource.sourcebuffers attribute of its parent media source.
... syntax var sourcebuffer = audiotrack.sourcebuffer; value a sourcebuffer or null.
... specifications specification status comment media source extensionsthe definition of 'audiotrack: sourcebuffer' in that specification.

AudioTrackList: change event - Web APIs
the change event is fired when an audio track is enabled or disabled, for example by changing the track's enabled property.
... bubbles no cancelable no interface event event handler property onchange examples using addeventlistener(): const videoelement = document.queryselector('video'); videoelement.audiotracks.addeventlistener('change', (event) => { console.log(`'${event.type}' event fired`); }); // changing the value of `enabled` will trigger the `change` event const toggletrackbutton = document.queryselector('.toggle-track'); toggletrackbutton.addeventlistener('click', () => { const track = videoelement.audiotracks[0]; track.enabled = !track.enabled; }); using the onchange event handler property: const videoelement = document.queryselector('video'); videoelement.audiotracks.onchange = (event) => { console.log(`'${event.type}' event fired`); ...
...}; // changing the value of `enabled` will trigger the `change` event const toggletrackbutton = document.queryselector('.toggle-track'); toggletrackbutton.addeventlistener('click', () => { const track = videoelement.audiotracks[0]; track.enabled = !track.enabled; }); specifications specification status html living standardthe definition of 'change' in that specification.

BaseAudioContext.createConstantSource() - Web APIs
the createconstantsource() property of the baseaudiocontext interface creates a constantsourcenode object, which is an audio source that continuously outputs a monaural (one-channel) sound signal whose samples all have the same value.
... syntax var constantsourcenode = audiocontext.createconstantsource() parameters none.
... specifications specification status comment web audio apithe definition of 'createconstantsource()' in that specification.

BaseAudioContext.createIIRFilter() - Web APIs
the createiirfilter() method of the baseaudiocontext interface creates an iirfilternode, which represents a general infinite impulse response (iir) filter which can be configured to serve as various types of filter.
... syntax var iirfilter = audiocontext.createiirfilter(feedforward, feedback); parameters feedforward an array of floating-point values specifying the feedforward (numerator) coefficients for the transfer function of the iir filter.
... specifications specification status comment web audio apithe definition of 'createiirfilter()' in that specification.

HTMLMediaElement.msInsertAudioEffect() - Web APIs
the htmlmediaelement.msinsertaudioeffect() method inserts the specified audio effect into the media pipeline.
... syntax htmlmediaelement.msinsertaudioeffect(activatableclassid: domstring, effectrequired: boolean, config); parameters activatableclassid a domstring defining the audio effects class.
... effectrequired a boolean which if set to true requires an audio effect to be defined.

MediaStreamAudioSourceOptions.mediaStream - Web APIs
the mediastreamaudiosourceoptions dictionary's mediastream property must specify the mediastream from which to retrieve audio data when instantiating a mediastreamaudiosourcenode using the mediastreamaudiosourcenode() constructor.
... syntax mediastreamaudiosourceoptions = { mediastream: audiosourcestream; } mediastreamaudiosourceoptions.mediastream = audiosourcestream; value a mediastream representing the stream from which to use a mediastreamtrack as the source of audio for the node.
... example specifications specification status comment web audio apithe definition of 'mediastreamaudiosourceoptions.mediastream' in that specification.

OfflineAudioCompletionEvent.renderedBuffer - Web APIs
the renderedbuffer read-only property of the offlineaudiocompletionevent interface is an audiobuffer containing the result of processing an offlineaudiocontext.
... syntax var buffer = offlineaudiocompletioneventinstance.renderedbuffer; value an audiobuffer.
... specifications specification status comment web audio apithe definition of 'renderedbuffer' in that specification.

OfflineAudioContext: complete event - Web APIs
the complete event of the offlineaudiocontext interface is fired when the rendering of an offline audio context is complete.
... bubbles no cancelable no default action none interface offlineaudiocompletionevent event handler property offlineaudiocontext.oncomplete examples when processing is complete, you might want to use the oncomplete handler the prompt the user that the audio can now be played, and enable the play button: let offlineaudioctx = new offlineaudiocontext(); offlineaudioctx.addeventlistener('complete', () => { console.log('offline audio processing now complete'); showmodaldialog('song processed and ready to play'); playbtn.disabled = false; }) you can also set up the event handler using the offlineaudiocontext.oncomplete property: let offlineaudioctx = new offlineaudiocontext(); offlineaudioctx.oncomplete = function() { co...
...nsole.log('offline audio processing now complete'); showmodaldialog('song processed and ready to play'); playbtn.disabled = false; } specifications specification status comment web audio apithe definition of 'offlineaudiocompletionevent' in that specification.

OfflineAudioContext.length - Web APIs
the length property of the offlineaudiocontext interface returns an integer representing the size of the buffer in sample-frames.
... syntax var length = offlineaudiocontext.length; value an integer representing the size of the buffer in sample-frames.
... specifications specification status comment web audio apithe definition of 'length' in that specification.

SourceBuffer.audioTracks - Web APIs
the audiotracks read-only property of the sourcebuffer interface returns a list of the audio tracks currently contained inside the sourcebuffer.
... syntax var myaudiotracks = sourcebuffer.audiotracks; value an audiotracklist object.
... example tbd specifications specification status comment media source extensionsthe definition of 'audiotracks' in that specification.

Tools for analyzing Web Audio usage - Web APIs
while working on your web audio api code, you may find that you need tools to analyze the graph of nodes you create or to otherwise debug your work.
... chrome a handy web audio inspector can be found in the chrome web store.
... firefox firefox offers a native web audio editor.

MozAudioAvailable - Archive of obsolete content
the mozaudioavailable event is fired when the audio buffer is full and the corresponding raw samples are available.
... framebuffer read only framebuffer (array) the decoded audio sample data (i.e., floats).

Media (Audio-visual presentation) - MDN Web Docs Glossary: Definitions of Web-related terms
the term media (more accurately, multimedia) refers to audio, video, or combined audio-visual material such as music, recorded speech, movies, tv shows, or any other form of content that is presented over a period of time.
... learn more general knowledge multimedia on wikipedia technical reference web media technologies: a guide to all the ways media can be used in web content multimedia and embedding in the mdn learning area <audio> and <video> elements, used to present media in html documents ...

AudioParamMap - Web APIs
the web audio api interface audioparammap represents a set of multiple audio parameters, each described as a mapping of a domstring identifying the parameter to the audioparam object representing its value.
... properties the audioparammap object is accessed as a map in which each parameter is identified by a name string which is mapped to an audioparam containing the value of that parameter.

AudioTrackList: addtrack event - Web APIs
the addtrack event is fired when a track is added to an audiotracklist.
... bubbles no cancelable no interface trackevent event handler property onaddtrack examples using addeventlistener(): const videoelement = document.queryselector('video'); videoelement.audiotracks.addeventlistener('addtrack', (event) => { console.log(`audio track: ${event.track.label} added`); }); using the onaddtrack event handler property: const videoelement = document.queryselector('video'); videoelement.audiotracks.onaddtrack = (event) => { console.log(`audio track: ${event.track.label} added`); }; specifications specification status html living standardthe definition of 'addtrack' in that specification.

AudioTrackList: removetrack event - Web APIs
the removetrack event is fired when a track is removed from an audiotracklist.
... bubbles no cancelable no interface trackevent event handler property onremovetrack examples using addeventlistener(): const videoelement = document.queryselector('video'); videoelement.audiotracks.addeventlistener('removetrack', (event) => { console.log(`audio track: ${event.track.label} removed`); }); using the onremovetrack event handler property: const videoelement = document.queryselector('video'); videoelement.audiotracks.onremovetrack = (event) => { console.log(`audio track: ${event.track.label} removed`); }; specifications specification status html living standardthe definition of 'removetrack' in that specification.

audioCapabilities - Web APIs
the mediakeysystemconfiguration.audiocapabilities read-only property returns an array of supported audio type and capability pairs.
... syntax var audiocapabilities[ {contenttype: 'contenttype', robustness:'robustness'}] = mediasystemconfiguration.audiocapabilities; specifications specification status comment encrypted media extensionsthe definition of 'audiocapabilities' in that specification.

SpeechRecognition: audioend event - Web APIs
the audioend event of the web speech api is fired when the user agent has finished capturing audio for speech recognition.
... bubbles no cancelable no interface event event handler onaudioend examples you can use the audioend event in an addeventlistener method: var recognition = new webkitspeechrecognition() || new speechrecognition(); recognition.addeventlistener('audioend', function() { console.log('audio capturing ended'); }); or use the onaudioend event handler property: recognition.onaudioend = function() { console.log('audio capturing ended'); } specifications specification status comment web speech apithe definition of 'speech recognition events' in that specification.

SpeechRecognition: audiostart event - Web APIs
the audiostart event of the web speech api is fired when the user agent has started to capture audio for speech recognition.
... bubbles no cancelable no interface event event handler onaudiostart examples you can use the audiostart event in an onaudiostart method: var recognition = new webkitspeechrecognition() || new speechrecognition(); recognition.addeventlistener('audiostart', function() { console.log('audio capturing started'); }); or use the onaudiostart event handler property: recognition.onaudiostart = function() { console.log('audio capturing started'); } specifications specification status comment web speech apithe definition of 'speech recognition events' in that specification.

SpeechRecognition.onaudioend - Web APIs
the onaudioend property of the speechrecognition interface represents an event handler that will run when the user agent has finished capturing audio (when the audioend event fires.) syntax myspeechrecognition.onaudioend = function() { ...
... }; examples var recognition = new speechrecognition(); recognition.onaudioend = function() { console.log('audio capturing ended'); } specifications specification status comment web speech apithe definition of 'onaudioend' in that specification.

SpeechRecognition.onaudiostart - Web APIs
the onaudiostart property of the speechrecognition interface represents an event handler that will run when the user agent has started to capture audio (when the audiostart event fires.) syntax myspeechrecognition.onaudiostart = function() { ...
... }; examples var recognition = new speechrecognition(); recognition.onaudiostart = function() { console.log('audio capturing started'); } specifications specification status comment web speech apithe definition of 'onaudiostart' in that specification.

Using audio and video in HTML - Web media technologies
the html <audio> and <video> elements let you embed audio and video content into a web page.
... we don't have a particularly good guide to using these objects offscreen at this time, although audio and video manipulation may be a good start.

Guide to streaming audio and video - Web media technologies
in this guide, we'll examine the techniques used to stream audio and/or video media on the web, and how you can optimize your code, your media, your server, and the options you use while performing the streaming to bring out the best quality and performance possible.
...for example, hls lets the server stream a video with multiple audio streams which the user can choose from, in order to hear their own language.

AudioContext.createWaveTable() - Web APIs
the audiocontext method createwavetable() is now obsolete; you should instead use the method createperiodicwave().

Index - Web APIs
51 analysernode api, analysernode, interface, reference, web audio api the analysernode interface represents a node able to provide real-time frequency and time-domain analysis information.
... it is an audionode that passes the audio stream unchanged from the input to the output, but allows you to take the generated data, process it, and create audio visualizations.
... 52 analysernode.analysernode() api, analysernode, audio, constructor, media, reference, web audio api the analysernode constructor of the web audio api creates a new analysernode object instance.
...And 528 more matches

Media container formats (file types) - Web media technologies
the format of audio and video media files is defined in two parts (three if a file has both audio and video in it, of course): the audio and/or video codecs used and the media container format (or file type) used.
...instead, it streams the encoded audio and video tracks directly from one peer to another using mediastreamtrack objects to represent each track.
...some support only audio while others support both audio and video.
...And 48 more matches

Key Values - Web APIs
learn how to use these key values in javascript using keyboardevent.key special values | modifier keys | whitespace keys | navigation keys | editing keys | ui keys | device keys | ime and composition keys | function keys | phone keys | multimedia keys | audio control keys | tv control keys | media controller keys | speech recognition keys | document keys | application selector keys | browser control keys | numeric keypad keys special values values of key which have special meanings other than identifying a specific key or character.
... appcommand_media_fast_forward gdk_key_audioforward (0x1008ff97) qt:key_audioforward (0x01000102) keycode_media_fast_forward (90) "mediapause" pauses the currently playing media.
... appcommand_media_pause gdk_key_audiopause (0x1008ff31) qt::key_mediapause (0x1000085) keycode_media_pause (127) "mediaplay" starts or continues playing media at normal speed, if not already doing so.
...And 36 more matches

PannerNode - Web APIs
the pannernode interface represents the position and behavior of an audio source signal in space.
... it is an audionode audio-processing module describing its position with right-hand cartesian coordinates, its movement using a velocity vector and its directionality using a directionality cone.
... a pannernode always has exactly one input and one output: the input can be mono or stereo but the output is always stereo (2 channels); you can't have panning effects without at least two audio channels!
...And 31 more matches

The "codecs" parameter in common media types - Web media technologies
at a fundamental level, you can specify the type of a media file using a simple mime type, such as video/mp4 or audio/mpeg.
...this information may include things like the profile of the video codec, the type used for the audio tracks, and so forth.
... this guide briefly examines the syntax of the media type codecs parameter and how it's used with the mime type string to provide details about the contents of audio or video media beyond simply indicating the container type.
...And 28 more matches

Accessible multimedia - Learn web development
previous overview: accessibility next another category of content that can create accessibility problems is multimedia — video, audio, and image content need to be given proper textual alternatives so they can be understood by assistive technologies and their users.
... for example: <img src="dinosaur.png" alt="a red tyrannosaurus rex: a two legged dinosaur standing upright like a human, with small arms, and a large head with lots of sharp teeth."> accessible audio and video controls implementing controls for web-based audio/video shouldn't be a problem, right?
... the problem with native html5 controls html5 video and audio instances even come with a set of inbuilt controls that allow you to control the media straight out of the box.
...And 23 more matches

Capabilities, constraints, and settings - Web APIs
the constraint exerciser lets you experiment with the results of different constraint sets being applied to the audio and video tracks coming from the computer's a/v input devices (such as its webcam and microphone).
... applying constraints the first and most common way to use constraints is to specify them when you call getusermedia(): navigator.mediadevices.getusermedia({ video: { width: { min: 640, ideal: 1920 }, height: { min: 400, ideal: 1080 }, aspectratio: { ideal: 1.7777777778 } }, audio: { samplesize: 16, channelcount: 2 } }).then(stream => { videoelement.srcobject = stream; }).catch(handleerror); in this example, constraints are applied at getusermedia() time, asking for an ideal set of options with fallbacks for the video.
... example: constraint exerciser in this example, we create an exerciser which lets you experiment with media constraints by editing the source code describing the constraint sets for audio and video tracks.
...And 23 more matches

Perceivable - Accessibility
non-text content refers to multimedia such as images, audio, and video.
... multimedia content (i.e., audio or video) should at least have a descriptive identification available, such as a caption or similar.
... see text alternatives for static caption options, and audio transcripts, video text tracks, and other multimedia content for other alternatives.
...And 21 more matches

Using DTMF with WebRTC - Web APIs
in order to more fully support audio/video conferencing, webrtc supports sending dtmf to the remote peer on an rtcpeerconnection.
... webrtc doesn't send dtmf codes as audio data.
...webrtc currently ignores these payloads; this is because webrtc's dtmf support is primarily intended for use with legacy telephone services that rely on dtmf tones to perform tasks such as: teleconferencing systems menu systems voicemail systems entry of credit card or other payment information passcode entry note: while the dtmf is not sent to the remote peer as audio, browsers may choose to play the corresponding tone to the local user as part of their user experience, since users are typically used to hearing their phone play the tones audibly.
...And 19 more matches

Introduction to web APIs - Learn web development
for example, the web audio api provides javascript constructs for manipulating audio in the browser — taking an audio track, altering its volume, applying effects to it, etc.
...c++ or rust) to do the actual audio processing.
... audio and video apis like htmlmediaelement, the web audio api, and webrtc allow you to do really interesting things with multimedia such as creating custom ui controls for playing audio and video, displaying text tracks like captions and subtitles along with your videos, grabbing video from your web camera to be manipulated via a canvas (see above) or displayed on someone else's computer in a web confe...
...And 18 more matches

<video>: The Video Embed element - HTML: Hypertext Markup Language
you can use <video> for audio content as well, but the <audio> element may provide a more appropriate user experience.
... note: sites that automatically play audio (or videos with an audio track) can be an unpleasant experience for users, so should be avoided when possible.
... muted a boolean attribute that indicates the default setting of the audio contained in the video.
...And 18 more matches

HTMLMediaElement - Web APIs
the htmlmediaelement interface adds to htmlelement the properties and methods needed to support basic media-related capabilities that are common to audio and video.
... the htmlvideoelement and htmlaudioelement elements both inherit this interface.
... htmlmediaelement.audiotracks a audiotracklist that lists the audiotrack objects contained in the element.
...And 17 more matches

MIME types (IANA media types) - HTTP
audio list at iana audio or music data.
... examples include audio/mpeg, audio/vorbis.
...example can also be used as a subtype; for instance, in an example related to working with audio on the web, the mime type audio/example can be used to indicate that the type is a placeholder and should be replaced with an appropriate one when using the code in the real world.
...And 17 more matches

Codecs used by WebRTC - Web media technologies
the webrtc api makes it possible to construct web sites and apps that let users communicate in real time, using audio and/or video as well as optional data and other information.
...of secondary importance is the need to keep the video and audio synchronized, so that the movements and any ancillary information (such as slides or a projection) are presented at the same time as the audio that corresponds.
... supported audio codecs the audio codecs which rfc 7874 mandates that all webrtc-compatible browsers must support are shown in the table below.
...And 16 more matches

Introduction to the Real-time Transport Protocol (RTP) - Web APIs
rtp isn't limited to use in audiovisual communication.
...among the simplest things you can do is to implement a "hold" feature, wherein a participant in a call can click a button and turn off their microphone, begin sending music to the other peer instead, and stop accepting incoming audio.
...it accepts as input a mediastream containing the audio to play while the call is on hold.
...And 15 more matches

ScriptProcessorNode - Web APIs
the scriptprocessornode interface allows the generation, processing, or analyzing of audio using javascript.
... note: as of the august 29 2014 web audio api spec publication, this feature has been marked as deprecated, and was replaced by audioworklet (see audioworkletnode).
... the scriptprocessornode interface is an audionode audio-processing module that is linked to two buffers, one containing the input audio data, one containing the processed output audio data.
...And 12 more matches

Using IIR filters - Web APIs
the iirfilternode interface of the web audio api is an audionode processor that implements a general infinite impulse response (iir) filter; this type of filter can be used to implement tone control devices and graphic equalizers, and the filter response parameters can be specified, so that it can be tuned as needed.
... demo our simple example for this guide provides a play/pause button that starts and pauses audio play, and a toggle that turns an iir filter on and off, altering the tone of the sound.
... it also provides a canvas on which is drawn the frequency response of the audio, so you can see what effect the iir filter has.
...And 12 more matches

Web media technologies
over the years, the web's ability to present, create, and manage audio, video, and other media has grown at an increasing pace.
... <audio> the <audio> element is used to play audio in a web context.
... these can be used invisibly as a destination for more complex media, or with visible controls for user-controlled playback of audio files.
...And 12 more matches

BiquadFilterNode - Web APIs
the biquadfilternode interface represents a simple low-order filter, and is created using the audiocontext.createbiquadfilter() method.
... it is an audionode that can represent different kinds of filters, tone control devices, and graphic equalizers.
... properties inherits properties from its parent, audionode.
...And 9 more matches

ConstantSourceNode - Web APIs
the constantsourcenode interface—part of the web audio api—represents an audio source (based upon audioscheduledsourcenode) whose output is single unchanging value.
... this makes it useful for cases in which you need a constant value coming in from an audio source.
... in addition, it can be used like a constructible audioparam by automating the value of its offset or by connecting another node to it; see controlling multiple parameters with constantsourcenode.
...And 9 more matches

DynamicsCompressorNode - Web APIs
this is often used in musical production and game audio.
... dynamicscompressornode is an audionode that has exactly one input and one output; it is created using the audiocontext.createdynamicscompressor() method.
... properties inherits properties from its parent, audionode.
...And 9 more matches

GainNode - Web APIs
it is an audionode audio-processing module that causes a given gain to be applied to the input data before its propagation to the output.
...if modified, the new gain is instantly applied, causing unaesthetic 'clicks' in the resulting audio.
... to prevent this from happening, never change the value directly but use the exponential interpolation methods on the audioparam interface.
...And 9 more matches

Using the MediaStream Recording API - Web APIs
the mediastream recording api makes it easy to record audio and/or video streams.
...both audio and video may be recorded, separately or together.
...it allows you to record snippets of audio and then play them back.
...And 9 more matches

Controlling multiple parameters with ConstantSourceNode - Web APIs
you may have times when you want to have multiple audio parameters be linked so they share the same value even while being changed in some way.
...you could use a loop and change the value of each affected audioparam one at a time, but there are two drawbacks to doing it that way: first, that's extra code that, as you're about to see, you don't have to write; and second, that loop uses valuable cpu time on your thread (likely the main thread), and there's a way to offload all that work to the audio rendering thread, which is optimized for this kind of work and may run at a more appropriate priority level than your code.
... the solution is simple, and it involves using an audio node type which, at first glance, doesn't look all that useful: constantsourcenode.
...And 9 more matches

Media buffering, seeking, and time ranges - Developer guides
sometimes it's useful to know how much <audio> or <video> has downloaded or is playable without delay — a good example of this is the buffered progress bar of an audio or video player.
... this will work with <audio> or <video>; for now let's consider a simple audio example: <audio id="my-audio" controls src="music.mp3"> </audio> we can access these attributes like so: var myaudio = document.getelementbyid('my-audio'); var bufferedtimeranges = myaudio.buffered; timeranges object timeranges are a series of non-overlapping ranges of time, with start and stop times.
... ------------------------------------------------------ |=============| |===========| | ------------------------------------------------------ 0 5 15 19 21 for this audio instance, the associated timeranges object would have the following available properties: myaudio.buffered.length; // returns 2 myaudio.buffered.start(0); // returns 0 myaudio.buffered.end(0); // returns 5 myaudio.buffered.start(1); // returns 15 myaudio.buffered.end(1); // returns 19 to try out and visualize buffered time ranges we can write a little bit of html: <p> <audio id="my-aud...
...And 9 more matches

Web video codec guide - Web media technologies
not only is the required storage space enormous, but the network bandwidth needed to transmit an uncompressed video like that would be enormous, at 249 mb/sec—not including audio and overhead.
...just as audio codecs do for the sound data, video codecs compress the video data and encode it into a format that can later be decoded and played back or edited.
... its primary purpose is to be used to stream mpeg-4 audio and video over an rtp session.
...And 9 more matches

Index - Archive of obsolete content
212 stringview as web applications become more and more powerful, adding features such as audio and video manipulation, access to raw data using websockets, and so forth, it has become clear that there are times when it would be helpful for javascript code to be able to quickly and easily manipulate raw binary data.
...the actual keys are: 489 introducing the audio api extension deprecated the audio data api extension extends the html5 specification of the <audio> and <video> media elements by exposing audio metadata and raw audio data.
... this enables users to visualize audio data, to process this audio data and to create new audio data.
...And 8 more matches

MediaDevices.getUserMedia() - Web APIs
that stream can include, for example, a video track (produced by either a hardware or virtual video source such as a camera, video recording device, screen sharing service, and so forth), an audio track (similarly, produced by a physical or virtual audio source like a microphone, a/d converter, or the like), and possibly other track types.
... the constraints parameter is a mediastreamconstraints object with two members: video and audio, describing the media types requested.
... the following requests both audio and video without any specific requirements: { audio: true, video: true } if true is specified for a media type, the resulting stream is required to have that type of track in it.
...And 8 more matches

PannerNode.distanceModel - Web APIs
the distancemodel property of the pannernode interface is an enumerated value determining which algorithm to use to reduce the volume of the audio source as it moves away from the listener.
... syntax var audioctx = new audiocontext(); var panner = audioctx.createpanner(); panner.distancemodel = 'inverse'; value a enum — see distancemodeltype.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

PannerNode.maxDistance - Web APIs
the maxdistance property of the pannernode interface is a double value representing the maximum distance between the audio source and the listener, after which the volume is not reduced any further.
... syntax var audioctx = new audiocontext(); var panner = audioctx.createpanner(); panner.maxdistance = 10000; value a double.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

PannerNode.panningModel - Web APIs
the panningmodel property of the pannernode interface is an enumerated value determining which spatialisation algorithm to use to position the audio in 3d space.
... syntax var audioctx = new audiocontext(); var panner = audioctx.createpanner(); panner.panningmodel = 'hrtf'; value a enum — see panningmodeltype.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

PannerNode.setOrientation() - Web APIs
the setorientation() method of the pannernode interface defines the direction the audio source is playing in.
... syntax var audioctx = new audiocontext(); var panner = audioctx.createpanner(); panner.setorientation(1,0,0); returns void.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

PannerNode.setPosition() - Web APIs
the setposition() method of the pannernode interface defines the position of the audio source relative to the listener (represented by an audiolistener object stored in the audiocontext.listener attribute.) the three parameters x, y and z are unitless and describe the source's position in 3d space using the right-hand cartesian coordinate system.
... syntax var audioctx = new audiocontext(); var panner = audioctx.createpanner(); panner.setposition(0,0,0); returns void.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 8 more matches

Example and tutorial: Simple synth keyboard - Web APIs
this example makes use of the following web api interfaces: audiocontext, oscillatornode, periodicwave, and gainnode.
... because oscillatornode is based on audioscheduledsourcenode, this is to some extent an example for that as well.
... let audiocontext = new (window.audiocontext || window.webkitaudiocontext)(); let osclist = []; let mastergainnode = null; audiocontext is set to reference the global audiocontext object (or webkitaudiocontext if necessary).
...And 8 more matches

Event reference
media events event name fired when audioprocess the input buffer of a scriptprocessornode is ready to be processed.
... complete the rendering of an offlineaudiocontext is terminated.
... audioprocess audioprocessingevent web audio apithe definition of 'audioprocess' in that specification.
...And 8 more matches

Index - MDN Web Docs Glossary: Definitions of Web-related terms
47 cms cms, composing, content management system, glossary a cms (content management system) is software that allows users to publish, organize, change, or remove various kinds of content, not only text but also embedded images, video, audio, and interactive code.
...the most common examples of continuous media are audio and motion video.
... 213 ice codingscripting, glossary, networking, protocols, webrtc ice (interactive connectivity establishment) is a framework used by webrtc (among other technologies) for connecting two peers to each other, regardless of network topology (usually for audio and/or video chat).
...And 7 more matches

PannerNode.setVelocity() - Web APIs
the setvelocity() method of the pannernode interface defines the velocity vector of the audio source — how fast it is moving and in what direction.
... syntax var audioctx = new audiocontext(); var panner = audioctx.createpanner(); panner.setvelocity(0,0,17); returns void.
... example in the following example, you can see an example of how the createpanner() method, audiolistener and pannernode would be used to control audio spatialisation.
...And 7 more matches

RTCPeerConnection.createOffer() - Web APIs
offertoreceiveaudio optional (legacy) a legacy boolean option which used to control whether or not to offer to the remote peer the opportunity to try to send audio.
... if this value is false, the remote peer will not be offered to send audio data, even if the local side will be sending audio data.
... if this value is true, the remote peer will be offered to send audio data, even if the local side will not be sending audio data.
...And 7 more matches

Creating a Web based tone generator - Archive of obsolete content
the function mozwriteaudio() is called to write those samples produced in the audio stream.
...the function mozcurrentsampleoffset() is used to know the position of the samples being played so that we can fill a 500 ms buffer of audio samples.
... <!doctype html> <html> <head> <title>javascript audio write example</title> </head> <body> <input type="text" size="4" id="freq" value="440"><label for="hz">hz</label> <button onclick="start()">play</button> <button onclick="stop()">stop</button> <script type="text/javascript"> function audiodatadestination(samplerate, readfn) { // initialize the audio output.
...And 6 more matches

AnalyserNode - Web APIs
it is an audionode that passes the audio stream unchanged from the input to the output, but allows you to take the generated data, process it, and create audio visualizations.
...t="50" fill="#fff" stroke="#d4dde4" stroke-width="2px" /><text x="56" y="30" font-size="12px" font-family="consolas,monaco,andale mono,monospace" fill="#4d4e53" text-anchor="middle" alignment-baseline="middle">eventtarget</text></a><polyline points="111,25 121,20 121,30 111,25" stroke="#d4dde4" fill="none"/><line x1="121" y1="25" x2="151" y2="25" stroke="#d4dde4"/><a xlink:href="/docs/web/api/audionode" target="_top"><rect x="151" y="1" width="90" height="50" fill="#fff" stroke="#d4dde4" stroke-width="2px" /><text x="196" y="30" font-size="12px" font-family="consolas,monaco,andale mono,monospace" fill="#4d4e53" text-anchor="middle" alignment-baseline="middle">audionode</text></a><polyline points="241,25 251,20 251,30 241,25" stroke="#d4dde4" fill="none"/><line x1="251" y1="25" x2="281" ...
... properties inherits properties from its parent, audionode.
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MediaTrackSettings - Web APIs
for instance, the audio input and output devices for the speaker and microphone built into a phone would share the same group id, since they're part of the same physical device.
... properties of audio tracks autogaincontrol a boolean which indicates the current value of the autogaincontrol property, which is true if automatic gain control is enabled and is false otherwise.
... channelcount a long integer value indicating the current value of the channelcount property, specifying the number of audio channels present on the track (therefore indicating how many audio samples exist in each audio frame).
...And 6 more matches

OscillatorNode - Web APIs
it is an audioscheduledsourcenode audio-processing module that causes a specified frequency of a given wave to be created—in effect, a constant tone.
... an oscillatornode is created using the baseaudiocontext.createoscillator() method.
...its basic property defaults (see audionode for definitions) are: number of inputs 0 number of outputs 1 channel count mode max channel count 2 (not used in the default count mode) channel interpretation speakers constructor oscillatornode() creates a new instance of an oscillatornode object, optionally providing an object specifying default values for the node's properties.
...And 6 more matches

SpeechRecognition - Web APIs
your audio is sent to a web service for recognition processing, so it won't work offline.
... speechrecognition.abort() stops the speech recognition service from listening to incoming audio, and doesn't attempt to return a speechrecognitionresult.
... speechrecognition.start() starts the speech recognition service listening to incoming audio with intent to recognize grammars associated with the current speechrecognition.
...And 6 more matches

StereoPannerNode - Web APIs
the stereopannernode interface of the web audio api represents a simple stereo panner node that can be used to pan an audio stream left or right.
... it is an audionode audio-processing module that positions an incoming audio stream in a stereo image using a low-cost equal-power panning algorithm.
... properties inherits properties from its parent, audionode.
...And 6 more matches

Index - Learn web development
3 accessible multimedia accessibility, article, audio, beginner, codingscripting, html, images, javascript, learn, multimedia, video, captions, subtitles, text tracks this chapter has provided a summary of accessibility concerns for multimedia content, along with some practical solutions.
... 63 video and audio apis api, article, audio, beginner, codingscripting, guide, javascript, learn, video i think we've taught you enough in this article.
... the htmlmediaelement api makes a wealth of functionality available for creating simple video and audio players, and that's only the tip of the iceberg.
...And 5 more matches

Multimedia: video - Learn web development
optimizing video delivery it's best to compress all video, optimize <source> order, set autoplay, remove audio from muted video, optimize video preload, and consider streaming the video.
... remove audio from muted hero videos for hero-video or other video without audio, removing audio is smart.
...there are no controls, so there is no way to hear audio.
...And 5 more matches

ChannelMergerNode - Web APIs
if channelmergernode has one single output, but as many inputs as there are channels to merge; the number of inputs is defined as a parameter of its constructor and the call to audiocontext.createchannelmerger.
...in that case, when the signal is sent to the audiocontext.listener object, supernumerary channels will be ignored.
... properties no specific property; inherits properties from its parent, audionode.
...And 5 more matches

ChannelSplitterNode - Web APIs
the channelsplitternode interface, often used in conjunction with its opposite, channelmergernode, separates the different channels of an audio source into a set of mono outputs.
... if your channelsplitternode always has one single input, the amount of outputs is defined by a parameter on its constructor and the call to audiocontext.createchannelsplitter().
... properties no specific property; inherits properties from its parent, audionode.
...And 5 more matches

DelayNode - Web APIs
the delaynode interface represents a delay-line; an audionode audio-processing module that causes a delay between the arrival of an input data and its propagation to the output.
...alternatively, you can use the baseaudiocontext.createdelay() factory method.
... properties inherits properties from its parent, audionode.
...And 5 more matches

MediaConfiguration - Web APIs
the mediaconfiguration mediacapabilities dictionary of the media capabilities api describes how media and audio files must be configured, or defined, to be passed as a parameter of the mediacapabilities.encodinginfo() and mediacapabilities.encodinginfo() methods.
... properties a valid configuration includes a valid encoding configuration type or decoding configuration type and a valid audio configuration or video configuration.
... if the media is an audio file, the audio configuration must include a valid audio mime type as contenttype, the number of channels, the bitrate, and the sample rate.
...And 5 more matches

MediaDevices.ondevicechange - Web APIs
it displays in the browser window two lists: one of audio devices and one of video devices, with both the device's label (name) and whether it's an input or an output device.
... html content <p>click the start button below to begin the demonstration.</p> <div id="startbutton" class="button"> start </div> <video id="video" width="160" height="120" autoplay></video><br> <div class="left"> <h2>audio devices:</h2> <ul class="devicelist" id="audiolist"></ul> </div> <div class="right"> <h2>video devices:</h2> <ul class="devicelist" id="videolist"></ul> </div> <div id="log"></div> css content body { font: 14px "open sans", "arial", sans-serif; } video { margin-top: 20px; border: 1px solid black; } .button { cursor: pointer; width: 160px; border: 1px solid black; font-siz...
... let videoelement = document.getelementbyid("video"); let logelement = document.getelementbyid("log"); function log(msg) { logelement.innerhtml += msg + "<br>"; } document.getelementbyid("startbutton").addeventlistener("click", function() { navigator.mediadevices.getusermedia({ video: { width: 160, height: 120, framerate: 30 }, audio: { samplerate: 44100, samplesize: 16, volume: 0.25 } }).then(stream => { videoelement.srcobject = stream; updatedevicelist(); }) .catch(err => log(err.name + ": " + err.message)); }, false); we set up global variables that contain references to the <ul> elements that are used to list the audio and video devices: let audiolist = document.getelementbyi...
...And 5 more matches

Media Capabilities API - Web APIs
examples detect audio file support and expected performance this example defines a audio configuration then checks to see if the user agent supports decoding that media configuration, and whether it will perform well in terms of smoothness and power efficiency.
... if ('mediacapabilities' in navigator) { const audiofileconfiguration = { type : 'file', audio : { contenttype: "audio/mp3", channels: 2, bitrate: 132700, samplerate: 5200 } }; navigator.mediacapabilities.decodinginfo(audiofileconfiguration).then(result => { console.log('this configuration is ' + (result.supported ?
...'' : 'not ') + 'power efficient.') }) .catch(() => { console.log("decodinginfo error: " + contenttype) }); } media capabilities api concepts and usage there are a myriad of video and audio codecs.
...And 5 more matches

Using the Screen Capture API - Web APIs
capturing shared audio getdisplaymedia() is most commonly used to capture video of a user's screen (or parts thereof).
... however, user agents may allow the capture of audio along with the video content.
... the source of this audio might be the selected window, the entire computer's audio system, or the user's microphone (or a combination of all of the above).
...And 5 more matches

HTML attribute reference - HTML: Hypertext Markup Language
autoplay <audio>, <video> the audio or video should play as soon as possible.
... buffered <audio>, <video> contains the time range of already buffered media.
... controls <audio>, <video> indicates whether the browser should show playback controls to the user.
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HTML documentation index - HTML: Hypertext Markup Language
property values are either a string or a url and can be associated with a very wide range of elements including <audio>, <embed>, <iframe>, <img>, <link>, <object>, <source> , <track>, and <video>.
... 39 html attribute: crossorigin advanced, attribute, cors, html, needscontent, reference, security the crossorigin attribute, valid on the <audio>, <img>, <link>, <script>, and <video> elements, provides support for cors, defining how the element handles crossorigin requests, thereby enabling the configuration of the cors requests for the element's fetched data.
... 63 <audio>: the embed audio element audio, element, html, html embedded content, html5, html:embedded content, html:flow content, html:phrasing content, media, multimedia, reference, web, sound the html <audio> element is used to embed sound content in documents.
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2D maze game with device orientation - Game development
audio: the sound files used in the game.
...boot will take care of initializing a few settings, preloader will load all of the assets like graphics and audio, mainmenu is the menu with the start button, howto shows the "how to play" instructions and the game state lets you actually play the game.
... this.load.audio('audio-bounce', ['audio/bounce.ogg', 'audio/bounce.mp3', 'audio/bounce.m4a']); }, create: function() { this.game.state.start('mainmenu'); } }; there are single images, spritesheets and audio files loaded by the framework.
...And 4 more matches

ConvolverNode.buffer - Web APIs
the buffer property of the convolvernode interface represents a mono, stereo, or 4-channel audiobuffer containing the (possibly multichannel) impulse response used by the convolvernode to create the reverb effect.
...that audio recording could then be used as the buffer.
... this audiobuffer must have the same sample-rate as the audiocontext or an exception will be thrown.
...And 4 more matches

ConvolverNode - Web APIs
the convolvernode interface is an audionode that performs a linear convolution on a given audiobuffer, often used to achieve a reverb effect.
... properties inherits properties from its parent, audionode.
... convolvernode.buffer a mono, stereo, or 4-channel audiobuffer containing the (possibly multichannel) impulse response used by the convolvernode to create the reverb effect.
...And 4 more matches

DelayNode.delayTime - Web APIs
the delaytime property of the delaynode interface is an a-rate audioparam representing the amount of delay to apply.
... delaytime is expressed in seconds, its minimal value is 0, and its maximum value is defined by the maxdelaytime argument of the audiocontext.createdelay() method that created it.
... syntax var audioctx = new audiocontext(); var mydelay = audioctx.createdelay(5.0); mydelay.delaytime.value = 3.0; note: though the audioparam returned is read-only, the value it represents is not.
...And 4 more matches

GainNode.gain - Web APIs
the gain property of the gainnode interface is an a-rate audioparam representing the amount of gain to apply.
... syntax var audioctx = new audiocontext(); var gainnode = audioctx.creategain(); gainnode.gain.value = 0.5; value an audioparam.
... note: though the audioparam returned is read-only, the value it represents is not.
...And 4 more matches

The HTML DOM API - Web APIs
management of media connected to the html media elements (<audio> and <video>).
...for example, the <audio> and <video> elements both present audiovisual media.
... the corresponding types, htmlaudioelement and htmlvideoelement, are both based upon the common type htmlmediaelement, which in turn is based upon htmlelement and so forth.
...And 4 more matches

MediaRecorder() - Web APIs
this source media can come from a stream created using navigator.mediadevices.getusermedia() or from an <audio>, <video> or <canvas> element.
... options optional a dictionary object that can contain the following properties: mimetype: a mime type specifying the format for the resulting media; you may simply specify the container format (the browser will select its preferred codecs for audio and/or video), or you may use the codecs parameter and/or the profiles parameter to provide detailed information about which codecs to use and how to configure them.
... audiobitspersecond: the chosen bitrate for the audio component of the media.
...And 4 more matches

Media Capture and Streams API (Media Stream) - Web APIs
the media capture and streams api, often called the media streams api or simply mediastream api, is an api related to webrtc which provides support for streaming audio and video data.
... concepts and usage the api is based on the manipulation of a mediastream object representing a flux of audio- or video-related data.
... a mediastream consists of zero or more mediastreamtrack objects, representing various audio or video tracks.
...And 4 more matches

ScriptProcessorNode.bufferSize - Web APIs
note: as of the august 29 2014 web audio api spec publication, this feature has been marked as deprecated, and is soon to be replaced by audio workers.
... syntax var audioctx = new audiocontext(); var scriptnode = audioctx.createscriptprocessor(4096, 1, 1); console.log(scriptnode.buffersize); value an integer.
... example the following example shows basic usage of a scriptprocessornode to take a track loaded via audiocontext.decodeaudiodata(), process it, adding a bit of white noise to each audio sample of the input track (buffer) and play it through the audiodestinationnode.
...And 4 more matches

StereoPannerNode.pan - Web APIs
the pan property of the stereopannernode interface is an a-rate audioparam representing the amount of panning to apply.
... syntax var audioctx = new audiocontext(); var pannode = audioctx.createstereopanner(); pannode.pan.value = -0.5; returned value an a-rate audioparam containing the panning to apply.
... note: though the audioparam returned is read-only, the value it represents is not.
...And 4 more matches

WaveShaperNode - Web APIs
it is an audionode that uses a curve to apply a wave shaping distortion to the signal.
... properties inherits properties from its parent, audionode.
...oversampling is a technique for creating more samples (up-sampling) before applying the distortion effect to the audio signal.
...And 4 more matches

Web APIs
s mediastream recordingnnavigation timingnetwork information api ppage visibility apipayment request apiperformance apiperformance timeline apipermissions apipointer eventspointer lock apiproximity events push api rresize observer apiresource timing apisserver sent eventsservice workers apistoragestorage access apistreams ttouch eventsuurl apivvibration apivisual viewport wweb animationsweb audio apiweb authentication apiweb crypto apiweb notificationsweb storage apiweb workers apiwebglwebrtcwebvttwebxr device apiwebsockets api interfaces this is a list of all the interfaces (that is, types of objects) that are available.
... a angle_instanced_arrays abortcontroller abortsignal absoluteorientationsensor abstractrange abstractworker accelerometer addresserrors aescbcparams aesctrparams aesgcmparams aeskeygenparams ambientlightsensor analysernode animation animationeffect animationevent animationplaybackevent animationtimeline arraybufferview attr audiobuffer audiobuffersourcenode audioconfiguration audiocontext audiocontextlatencycategory audiocontextoptions audiodestinationnode audiolistener audionode audionodeoptions audioparam audioparamdescriptor audioparammap audioprocessingevent audioscheduledsourcenode audiotrack audiotracklist audioworklet audioworkletglobalscope audioworkletnode audioworkletnodeoptions audioworkletprocessor authenticatorassertionresponse authenticatorattestationresponse au...
...thenticatorresponse b baseaudiocontext basiccardrequest basiccardresponse batterymanager beforeinstallpromptevent beforeunloadevent biquadfilternode blob blobbuilder blobevent bluetooth bluetoothadvertisingdata bluetoothcharacteristicproperties bluetoothdevice bluetoothremotegattcharacteristic bluetoothremotegattdescriptor bluetoothremotegattserver bluetoothremotegattservice body broadcastchannel budgetservice budgetstate buffersource bytelengthqueuingstrategy bytestring c cdatasection css cssconditionrule csscounterstylerule cssgroupingrule cssimagevalue csskeyframerule csskeyframesrule csskeywordvalue cssmathproduct cssmathsum cssmathvalue cssmediarule cssnamespacerule cssnumericvalue cssomstring csspagerule csspositionvalue cssprimitivevalu...
...And 4 more matches

Index - Developer guides
6 audio and video delivery audio, guide, html, html5, media, video whether we are dealing with pre-recorded audio files or live streams, the mechanism for making them available through the browser's <audio> and <video> elements remains pretty much the same.
... 9 cross-browser audio basics apps, audio, guide, html5, media, events this article provides: a basic guide to creating a cross-browser html5 audio player with all the associated attributes, properties, and events explained a guide to custom controls created using the media api 10 live streaming web audio and video guide, adaptive streaming live streaming technology is often employ...
... 11 media buffering, seeking, and time ranges apps, buffer, html5, timeranges, video, buffering, seeking sometimes it's useful to know how much <audio> or <video> has downloaded or is playable without delay — a good example of this is the buffered progress bar of an audio or video player.
...And 4 more matches

HTML elements reference - HTML: Hypertext Markup Language
image and multimedia html supports various multimedia resources such as images, audio, and video.
... <audio> the html <audio> element is used to embed sound content in documents.
... it may contain one or more audio sources, represented using the src attribute or the <source> element: the browser will choose the most suitable one.
...And 4 more matches

Configuring servers for Ogg media - HTTP
html <audio> and <video> elements allow media presentation without the need for the user to install any plug-ins or other software to do so.
... serve media with the correct mime type *.ogg and *.ogv files containing video (possibly with an audio track as well, of course), should be served with the video/ogg mime type.
... *.oga and *.ogg files containing only audio should be served with the audio/ogg mime type.
...And 4 more matches

XUL accessibility guidelines - Archive of obsolete content
avoid using audio or visual alerts alone to signal urgent events.
... users who have audio turned down or off and users who are deaf or hard of hearing may not be able to recognize audio only alerts.
... media audio informative audio files such as podcasts can be made accessible by supplying a word-for-word transcript.
...And 3 more matches

Handling common JavaScript problems - Learn web development
typed arrays allow javascript code to access and manipulate raw binary data, which is necessary as browser apis for example start to manipulate streams of raw video and audio data.
... web audio api for advanced audio manipulation.
... webrtc api for multi-person, real-time video/audio connectivity (e.g.
...And 3 more matches

AnalyserNode.getFloatFrequencyData() - Web APIs
syntax var audioctx = new audiocontext(); var analyser = audioctx.createanalyser(); var dataarray = new float32array(analyser.frequencybincount); // float32array should be the same length as the frequencybincount void analyser.getfloatfrequencydata(dataarray); // fill the float32array with data returned from getfloatfrequencydata() parameters array the float32array that the frequency domain data will be co...
... example const audioctx = new audiocontext(); const analyser = audioctx.createanalyser(); // float32array should be the same length as the frequencybincount const mydataarray = new float32array(analyser.frequencybincount); // fill the float32array with data returned from getfloatfrequencydata() analyser.getfloatfrequencydata(mydataarray); drawing a spectrum the following example shows basic usage of an audiocontext to connect a mediaelementaudiosourcenode to an analysernode.
... while the audio is playing, we collect the frequency data repeatedly with requestanimationframe() and draw a "winamp bargraph style" to a <canvas> element.
...And 3 more matches

BiquadFilterNode.Q - Web APIs
the q property of the biquadfilternode interface is an a-rate audioparam, a double representing a q factor, or quality factor.
... syntax var audioctx = new audiocontext(); var biquadfilter = audioctx.createbiquadfilter(); biquadfilter.q.value = 100; note: though the audioparam returned is read-only, the value it represents is not.
... value an audioparam.
...And 3 more matches

BiquadFilterNode.detune - Web APIs
the detune property of the biquadfilternode interface is an a-rate audioparam representing detuning of the frequency in cents.
... syntax var audioctx = new audiocontext(); var biquadfilter = audioctx.createbiquadfilter(); biquadfilter.detune.value = 100; note: though the audioparam returned is read-only, the value it represents is not.
... value an a-rate audioparam.
...And 3 more matches

BiquadFilterNode.frequency - Web APIs
the frequency property of the biquadfilternode interface is a k-rate audioparam, a double representing a frequency in the current filtering algorithm measured in hertz (hz).
... syntax var audioctx = new audiocontext(); var biquadfilter = audioctx.createbiquadfilter(); biquadfilter.frequency.value = 3000; note: though the audioparam returned is read-only, the value it represents is not.
... value an audioparam.
...And 3 more matches

BiquadFilterNode.gain - Web APIs
the gain property of the biquadfilternode interface is a a-rate audioparam, a double representing the gain used in the current filtering algorithm.
... syntax var audioctx = new audiocontext(); var biquadfilter = audioctx.createbiquadfilter(); biquadfilter.gain.value = 25; note: though the audioparam returned is read-only, the value it represents is not.
... value an audioparam.
...And 3 more matches

ConstantSourceNode() - Web APIs
the constantsourcenode() constructor creates a new constantsourcenode object instance, representing an audio source which constantly outputs samples whose values are always the same.
... syntax var constantsourcenode = new constantsourcenode(context, options); parameters context an audiocontext representing the audio context you want the node to be associated with.
... options a constantsourceoptions dictionary object defining the properties you want the constantsourcenode to have: offset: a read-only audioparam specifying the constant value generated by the source.
...And 3 more matches

ConstantSourceNode.offset - Web APIs
the read-only offset property of the constantsourcenode interface returns a audioparam object indicating the numeric a-rate value which is always returned by the source when asked for the next sample.
... while the audioparam named offset is read-only, the value property within is not.
... so you can change the value of offset by setting the value of constantsourcenode.offset.value: myconstantsourcenode.offset.value = newvalue; syntax let offsetparameter = constantaudionode.offset; let offset = constantsourcenode.offset.value; constantsourcenode.offset.value = newvalue; value an audioparam object indicating the a-rate value returned for every sample by this node.
...And 3 more matches

ConvolverNode() - Web APIs
the convolvernode() constructor of the web audio api creates a new convolvernode object instance.
... syntax var convolvernode = new convolvernode(context, options) parameters inherits parameters from the audionodeoptions dictionary.
... context a reference to an audiocontext.
...And 3 more matches

DynamicsCompressorNode.attack - Web APIs
the attack property of the dynamicscompressornode interface is a k-rate audioparam representing the amount of time, in seconds, required to reduce the gain by 10 db.
... syntax var audioctx = new audiocontext(); var compressor = audioctx.createdynamicscompressor(); compressor.attack.value = 0; value an audioparam.
... note: though the audioparam returned is read-only, the value it represents is not.
...And 3 more matches

DynamicsCompressorNode.knee - Web APIs
the knee property of the dynamicscompressornode interface is a k-rate audioparam containing a decibel value representing the range above the threshold where the curve smoothly transitions to the compressed portion.
... syntax var audioctx = new audiocontext(); var compressor = audioctx.createdynamicscompressor(); compressor.knee.value = 40; value an audioparam.
... note: though the audioparam returned is read-only, the value it represents is not.
...And 3 more matches

DynamicsCompressorNode.ratio - Web APIs
the ratio property of the dynamicscompressornode interface is a k-rate audioparam representing the amount of change, in db, needed in the input for a 1 db change in the output.
... syntax var audioctx = new audiocontext(); var compressor = audioctx.createdynamicscompressor(); compressor.ratio.value = 12; value an audioparam.
... note: though the audioparam returned is read-only, the value it represents is not.
...And 3 more matches

DynamicsCompressorNode.release - Web APIs
the release property of the dynamicscompressornode interface is a k-rate audioparam representing the amount of time, in seconds, required to increase the gain by 10 db.
... syntax var audioctx = new audiocontext(); var compressor = audioctx.createdynamicscompressor(); compressor.release.value = 0.25; value an audioparam.
... note: though the audioparam returned is read-only, the value it represents is not.
...And 3 more matches

DynamicsCompressorNode.threshold - Web APIs
the threshold property of the dynamicscompressornode interface is a k-rate audioparam representing the decibel value above which the compression will start taking effect.
... syntax var audioctx = new audiocontext(); var compressor = audioctx.createdynamicscompressor(); compressor.threshold.value = -50; value an audioparam.
... note: though the audioparam returned is read-only, the value it represents is not.
...And 3 more matches

MediaRecorder - Web APIs
options are available to do things like set the container's mime type (such as "video/webm" or "video/mp4") and the bit rates of the audio and video tracks or a single overall bit rate.
...if this attribute is false, mediarecorder will record silence for audio and black frames for video.
... mediarecorder.audiobitspersecond read only returns the audio encoding bit rate in use.
...And 3 more matches

Transcoding assets for Media Source Extensions - Web APIs
if you don't need it, add --audio-codec=aac to the mp4-dash-encode.py command line.
... to check if the browser supports a particular container, you can pass a string of the mime type to the mediasource.istypesupported method: mediasource.istypesupported('audio/mp3'); // false mediasource.istypesupported('video/mp4'); // true mediasource.istypesupported('video/mp4; codecs="avc1.4d4028, mp4a.40.2"'); // true the string is the mime type of the container, optionally followed by a list of codecs.
... currently, mp4 containers with h.264 video and aac audio codecs have support across all modern browsers, while others don't.
...And 3 more matches

PannerNode.orientationX - Web APIs
the orientationx property of the pannernode interface indicates the x (horizontal) component of the direction in which the audio source is facing, in a 3d cartesian coordinate space.
... the complete vector is defined by the position of the audio source, given as (positionx, positiony, positionz), and the orientation of the audio source (that is, the direction in which it's facing), given as (orientationx, orientationy, orientationz).
... the audioparam contained by this property is read only; however, you can still change the value of the parameter by assigning a new value to its audioparam.value property.
...And 3 more matches

PannerNode.orientationY - Web APIs
the orientationy property of the pannernode interface indicates the y (vertical) component of the direction the audio source is facing, in 3d cartesian coordinate space.
... the complete vector is defined by the position of the audio source, given as (positionx, positiony, positionz), and the orientation of the audio source (that is, the direction in which it's facing), given as (orientationx, orientationy, orientationz).
... the audioparam contained by this property is read only; however, you can still change the value of the parameter by assigning a new value to its audioparam.value property.
...And 3 more matches

PannerNode.orientationZ - Web APIs
the orientationz property of the pannernode interface indicates the z (depth) component of the direction the audio source is facing, in 3d cartesian coordinate space.
... the complete vector is defined by the position of the audio source, given as (positionx, positiony, positionz), and the orientation of the audio source (that is, the direction in which it's facing), given as (orientationx, orientationy, orientationz).
... the audioparam contained by this property is read only; however, you can still change the value of the parameter by assigning a new value to its audioparam.value property.
...And 3 more matches

PeriodicWave.PeriodicWave() - Web APIs
the periodicwave() constructor of the web audio api creates a new periodicwave object instance.
... syntax var mywave = new periodicwave(context, options); parameters inherits parameters from the audionodeoptions dictionary.
... context a baseaudiocontext representing the audio context you want the node to be associated with.
...And 3 more matches

Signaling and video calling - Web APIs
webrtc is a fully peer-to-peer technology for the real-time exchange of audio, video, and data, with one central caveat.
...the "local_video" <video> element presents a preview of the user's camera; specifiying the muted attribute, as we don't need to hear local audio in this preview panel.
... starting a call when the user clicks on a username they want to call, the invite() function is invoked as the event handler for that click event: var mediaconstraints = { audio: true, // we want an audio track video: true // ...and we want a video track }; function invite(evt) { if (mypeerconnection) { alert("you can't start a call because you already have one open!"); } else { var clickedusername = evt.target.textcontent; if (clickedusername === myusername) { alert("i'm afraid i can't let you talk to yourself.
...And 3 more matches

WebRTC API - Web APIs
webrtc (web real-time communication) is a technology which enables web applications and sites to capture and optionally stream audio and/or video media, as well as to exchange arbitrary data between browsers without requiring an intermediary.
... webrtc concepts and usage webrtc serves multiple purposes; together with the media capture and streams api, they provide powerful multimedia capabilities to the web, including support for audio and video conferencing, file exchange, screen sharing, identity management, and interfacing with legacy telephone systems including support for sending dtmf (touch-tone dialing) signals.
... media streams can consist of any number of tracks of media information; tracks, which are represented by objects based on the mediastreamtrack interface, may contain one of a number of types of media data, including audio, video, and text (such as subtitles or even chapter names).
...And 3 more matches

<source>: The Media or Image Source element - HTML: Hypertext Markup Language
the html <source> element specifies multiple media resources for the <picture>, the <audio> element, or the <video> element.
... permitted parents a media element—<audio> or <video>—and it must be placed before any flow content or <track> element.
... src required for <audio> and <video>, address of the media resource.
...And 3 more matches

Index - Game development
26 audio for web games audio, games, web audio api, audio sprites, spatialization, syncing tracks audio is an important part of any game; it adds feedback and atmosphere.
... web-based audio is maturing fast, but there are still many browser differences to navigate.
... we often need to decide which audio parts are essential to our games' experience and which are nice to have but not essential, and devise a strategy accordingly.
...And 2 more matches

Introduction to game development for the Web - Game development
as we like to say, "the web is the platform." let's take a look at the core of the web platform: function technology audio web audio api graphics webgl (opengl es 2.0) input touch events, gamepad api, device sensors, webrtc, full screen api, pointer lock api language javascript (or c/c++ using emscripten to compile to javascript) networking webrtc and/or websockets storage indexeddb or the "cloud" web html, css, svg (and much more!) the...
... html audio the <audio> element lets you easily play simple sound effects and music.
... if your needs are more involved, check out the web audio api for real audio processing power!
...And 2 more matches

Test your skills: Multimedia and embedding - Learn web development
this aim of this skill test is to assess whether you've understood our video and audio content and from object to iframe — other embedding technologies articles.
... multimedia and embedding 1 in this task we want you to embed a simple audio file onto the page.
... you need to: add the path to the audio file to an appropriate attribute to embed it on the page.
...And 2 more matches

Third-party APIs - Learn web development
for example, the web audio api we saw in the introductory article is accessed using the native audiocontext object.
... for example: const audioctx = new audiocontext(); ...
... const audioelement = document.queryselector('audio'); ...
...And 2 more matches

Embedding API for Accessibility
it's a w3c uaag requirement */ setboolpref("browser.selection.use_system_colors", usesystemcolors); no content waiting alerts setcharpref("alert.audio.mail_waiting", pathtosoundfile); setcharpref("alert.audio.background_image_waiting", pathtosoundfile); setcharpref("alert.audio.popup_waiting", pathtosoundfile); setcharpref("alert.audio.applet_waiting", pathtosoundfile); setcharpref("alert.audio.script_waiting", pathtosoundfile); se...
...tcharpref("alert.audio.redirect_waiting", pathtosoundfile); setcharpref("alert.audio.refresh_waiting", pathtosoundfile); setcharpref("alert.audio.plugin_content_waiting", pathtosoundfile); setcharpref("alert.audio.video_waiting", pathtosoundfile); setcharpref("alert.audio.audio_waiting", pathtosoundfile); setcharpref("alert.audio.timed_event_waiting", pathtosoundfile); /* these alerts will also be mirrored visually, either on the status bar or elsewhere */ no background images setboolpref("browser.accept.background_images", acceptbackgroundimages); no ...
...f("browser.accept.refreshes", acceptrefreshes); no plugin content setboolpref("browser.accept.plugin_content.[plugin_name_goes_here]", acceptplugincontent); no video setboolpref("browser.accept.video", acceptvideo); no audio setboolpref("browser.accept.audio", acceptaudio); no timed events setboolpref("browser.accept.timed_events", accepttimedevents); no timer speed setintpref("timer.relative_speed", percent); /* 100 corresponds to norm...
...And 2 more matches

Experimental features in Firefox
nightly 74 no developer edition 74 no beta 74 no release 74 no preference name dom.input_events.beforeinput.enabled htmlmediaelement method: setsinkid() htmlmediaelement.setsinkid() allows you to set the sink id of an audio output device on an htmlmediaelement, thereby changing where the audio is being output.
... nightly 64 no developer edition 64 no beta 64 no release 64 no preference name media.setsinkid.enabled htmlmediaelement properties: audiotracks and videotracks enabling this feature adds the htmlmediaelement.audiotracks and htmlmediaelement.videotracks properties to all html media elements.
... however, because firefox doesn't currently suport multiple audio and video tracks, the most common use cases for these properties don't work, so they're both disabled by default.
...And 2 more matches

AnalyserNode.getByteTimeDomainData() - Web APIs
syntax const audioctx = new audiocontext(); const analyser = audioctx.createanalyser(); const dataarray = new uint8array(analyser.fftsize); // uint8array should be the same length as the fftsize analyser.getbytetimedomaindata(dataarray); // fill the uint8array with data returned from getbytetimedomaindata() parameters array the uint8array that the time domain data will be copied to.
... return value void | none example the following example shows basic usage of an audiocontext to create an analysernode, then requestanimationframe and <canvas> to collect time domain data repeatedly and draw an "oscilloscope style" output of the current audio input.
... const audioctx = new (window.audiocontext || window.webkitaudiocontext)(); const analyser = audioctx.createanalyser(); ...
...And 2 more matches

Body.arrayBuffer() - Web APIs
note that before playing full audio file will be downloaded.
... if you need to play ogg during downloading (stream it) - consider htmlaudioelement: new audio("music.ogg").play(); in getdata() we create a new request using the request() constructor, then use it to fetch an ogg music track.
... we also use audiocontext.createbuffersource to create an audio buffer source.
...And 2 more matches

ChannelSplitterNode.ChannelSplitterNode() - Web APIs
the channelsplitternode() constructor of the web audio api creates a new channelsplitternode object instance, representing a node that splits the input into a separate output for each of the source node's audio channels.
... syntax var splitter = new channelspitternode(context, options); parameters inherits parameters from the audionodeoptions dictionary.
... context a baseaudiocontext representing the audio context you want the node to be associated with.
...And 2 more matches

GainNode() - Web APIs
the gainnode() constructor of the web audio api creates a new gainnode object which an audionode that represents a change in volume.
... note: you should typically call audiocontext.creategain() to create a gain node.
... syntax var gainnode = new gainnode(context, options) parameters inherits parameters from the audionodeoptions dictionary.
...And 2 more matches

IIRFilterNode() - Web APIs
the iirfilternode() constructor of the web audio api creates a new iirfilternode object which an audionode processor which implements a general infinite impulse response filter.
... syntax var iirfilternode = new iirfilternode(context, options) parameters inherits parameters from the audionodeoptions dictionary.
... context a reference to an audiocontext.
...And 2 more matches

IIRFilterNode - Web APIs
the iirfilternode interface of the web audio api is a audionode processor which implements a general infinite impulse response (iir) filter; this type of filter can be used to implement tone control devices and graphic equalizers as well.
... iirfilternodes have a tail-time reference; they continue to output non-silent audio with zero input.
... properties this interface has no properties of its own; however, it inherits properties from its parent, audionode.
...And 2 more matches

KeyboardEvent: code values - Web APIs
ut" 0xe018 "unidentified" "copy" 0xe019 "mediatracknext" "mediatracknext" 0xe01a, 0xe01b "unidentified" "" 0xe01c "numpadenter" "numpadenter" 0xe01d "controlright" "controlright" 0xe01e "unidentified" "launchmail" 0xe01f "unidentified" "" 0xe020 "audiovolumemute" "audiovolumemute" 0xe021 "launchapp2" "" 0xe022 "mediaplaypause" "mediaplaypause" 0xe023 "unidentified" "" 0xe024 "mediastop" "mediastop" 0xe025 ～ 0xe02b "unidentified" "" 0xe02c "unidentified" "eject" 0xe02d "unidentified" "" 0xe02e...
... "audiovolumedown" "volumedown" (was "volumedown" until chrome 50) 0xe02f "unidentified" "" 0xe030 "audiovolumeup" "volumeup" (was "volumeup" until chrome 50) 0xe031 "unidentified" "" 0xe032 "browserhome" "browserhome" 0xe033, 0xe034 "unidentified" "" 0xe035 "numpaddivide" "numpaddivide" 0xe036 "unidentified" "" 0xe037 "printscreen" "printscreen" 0xe038 "altright" "altright" 0xe039, 0xe03a "unidentified" "" 0xe03b "unidentified" "help" 0xe03c～ 0xe044 "unidentified" "" 0xe045 "numlock" "numlock" 0xe046 (ctrl...
...ally) "" (no events fired actually) kvk_f17 (0x40) "f17" "f17" kvk_ansi_keypaddecimal (0x41) "numpaddecimal" "numpaddecimal" kvk_ansi_keypadmultiply (0x43) "numpadmultiply" "numpadmultiply" kvk_ansi_keypadplus (0x45) "numpadadd" "numpadadd" kvk_ansi_keypadclear (0x47) "numlock" "numlock" kvk_volumeup (0x48) "audiovolumeup" (was "volumeup" until firefox 48) "audiovolumeup" (was "volumeup" until chrome 50) kvk_volumedown (0x49) "audiovolumedown" (was "volumedown" until firefox 49) "audiovolumedown" (was "volumedown" until chrome 50) kvk_mute (0x4a) "audiovolumemute" (was "volumemute" until firefox 49) "audiovolumemute" (was "volumemute" until chrome 50) kvk_ansi_keyp...
...And 2 more matches

MediaError.message - Web APIs
example this example creates a <audio> element, establishes an error handler for it, then lets the user click buttons to choose whether to assign a valid audio file or a missing file to the element's src attribute.
... the example creates an <audio> element and lets the user assign either a valid music file to it, or a link to a file which doesn't exist.
... this lets us see the behavior of the error event handler, which is received by an event handler we add to the <audio> element itself.
...And 2 more matches

MediaStream Recording API - Web APIs
overview of the recording process the process of recording a stream is simple: set up a mediastream or htmlmediaelement (in the form of an <audio> or <video> element) to serve as the source of the media data.
... in this code snippet, enumeratedevices() is used to examine the available input devices, locate those which are audio input devices, and create <option> elements that are then added to a <select> element representing an input source picker.
... navigator.mediadevices.enumeratedevices() .then(function(devices) { devices.foreach(function(device) { let menu = document.getelementbyid("inputdevices"); if (device.kind == "audioinput") { let item = document.createelement("option"); item.innerhtml = device.label; item.value = device.deviceid; menu.appendchild(item); } }); }); code similar to this can be used to let the user restrict the set of devices they wish to use.
...And 2 more matches

MediaTrackSettings.sampleSize - Web APIs
syntax var samplesize = mediatracksettings.samplesize; value an integer value indicating how many bits each audio sample is represented by.
... the most commonly used sample size for many years now is 16 bits per sample, which was used for cd audio among others.
... other common sample sizes are 8 (for reduced bandwidth requirements) and 24 (for high-resolution professional audio).
...And 2 more matches

OscillatorNode.OscillatorNode() - Web APIs
the oscillatornode() constructor of the web audio api creates a new oscillatornode object which is an audionode that represents a periodic waveform, like a sine wave, optionally setting the node's properties' values to match values in a specified object.
... if the default values of the properties are acceptable, you can optionally use the audiocontext.createoscillator() factory method instead.
... syntax var oscillatornode = new oscillatornode(context, options) parameters inherits parameters from the audionodeoptions dictionary.
...And 2 more matches

OscillatorNode.detune - Web APIs
the detune property of the oscillatornode interface is an a-rate audioparam representing detuning of oscillation in cents.
... syntax var oscillator = audioctx.createoscillator(); oscillator.detune.setvalueattime(100, audioctx.currenttime); // value in cents note: though the audioparam returned is read-only, the value it represents is not.
... value an a-rate audioparam.
...And 2 more matches

OscillatorNode.frequency - Web APIs
the frequency property of the oscillatornode interface is an a-rate audioparam representing the frequency of oscillation in hertz.
... syntax var oscillator = audioctx.createoscillator(); oscillator.frequency.setvalueattime(440, audioctx.currenttime); // value in hertz note: though the audioparam returned is read-only, the value it represents is not.
... value an a-rate audioparam.
...And 2 more matches

PannerNode.PannerNode() - Web APIs
the pannernode() constructor of the web audio api creates a new pannernode object instance.
... syntax var mypanner = new pannernode(context, options); parameters inherits parameters from the audionodeoptions dictionary.
... context a baseaudiocontext representing the audio context you want the node to be associated with.
...And 2 more matches

PannerNode.positionX - Web APIs
the positionx property of the pannernode interface specifies the x coordinate of the audio source's position in 3d cartesian coordinates, corresponding to the horizontal axis (left-right).
... the complete vector is defined by the position of the audio source, given as (positionx, positiony, positionz), and the orientation of the audio source (that is, the direction in which it's facing), given as (orientationx, orientationy, orientationz).
... the audioparam contained by this property is read only; however, you can still change the value of the parameter by assigning a new value to its audioparam.value property.
...And 2 more matches

PannerNode.positionY - Web APIs
the positiony property of the pannernode interface specifies the y coordinate of the audio source's position in 3d cartesian coordinates, corresponding to the vertical axis (top-bottom).
... the complete vector is defined by the position of the audio source, given as (positionx, positiony, positionz), and the orientation of the audio source (that is, the direction in which it's facing), given as (orientationx, orientationy, orientationz).
... the audioparam contained by this property is read only; however, you can still change the value of the parameter by assigning a new value to its audioparam.value property.
...And 2 more matches

PannerNode.positionZ - Web APIs
the positionz property of the pannernode interface specifies the z coordinate of the audio source's position in 3d cartesian coordinates, corresponding to the depth axis (behind-in front of the listener).
... the complete vector is defined by the position of the audio source, given as (positionx, positiony, positionz), and the orientation of the audio source (that is, the direction in which it's facing), given as (orientationx, orientationy, orientationz).
... the audioparam contained by this property is read only; however, you can still change the value of the parameter by assigning a new value to its audioparam.value property.
...And 2 more matches

RTCPeerConnection.addTrack() - Web APIs
for example, if all you're sharing with the remote peer is a single stream with an audio track and a video track, you don't need to deal with managing what track is in what stream, so you might as well just let the transceiver handle it for you.
... here's an example showing a function that uses getusermedia() to obtain a stream from a user's camera and microphone, then adds each track from the stream to the peer connection, without specifying a stream for each track: async opencall(pc) { const gumstream = await navigator.mediadevices.getusermedia( {video: true, audio: true}); for (const track of gumstream.gettracks()) { pc.addtrack(track); } } the result is a set of tracks being sent to the remote peer, with no stream associations.
... for example, consider this function that an application might use to begin streaming a device's camera and microphone input over an rtcpeerconnection to a remote peer: async opencall(pc) { const gumstream = await navigator.mediadevices.getusermedia( {video: true, audio: true}); for (const track of gumstream.gettracks()) { pc.addtrack(track, gumstream); } } the remote peer might then use a track event handler that looks like this: pc.ontrack = ({streams: [stream]} => videoelem.srcobject = stream; this sets the video element's current stream to the one that contains the track that's been added to the connection.
...And 2 more matches

StereoPannerNode.StereoPannerNode() - Web APIs
the stereopannernode() constructor of the web audio api creates a new stereopannernode object which is an audionode that represents a simple stereo panner node that can be used to pan an audio stream left or right.
... syntax var stereopannernode = stereopannernode(context, options) parameters inherits parameters from the audionodeoptions dictionary.
... context a reference to an audiocontext.
...And 2 more matches

ARIA: button role - Accessibility
as an example, the mute button on an audio player labeled "mute" could indicate that sound is muted by setting the aria-pressed state true.
...if the button alters the current context, then focus typically remains on the button, such as muting and unmuting an audio file.
... html <button type="button" onclick="handlebtnclick()" onkeydown="handlebtnkeydown()"> mute audio </button> <span role="button" tabindex="0" aria-pressed="false" onclick="handlebtnclick(event)" onkeydown="handlebtnkeydown(event)"> mute audio </span> <audio id="audio" src="https://udn.realityripple.com/samples/41/191d072707.mp3"> your browser does not support the <code>audio</code> element.
...And 2 more matches

DASH Adaptive Streaming for HTML 5 Video - HTML: Hypertext Markup Language
to start with you'll only need the ffpmeg program from ffmpeg.org, with libvpx and libvorbis support for webm video and audio, at least version 2.5 (probably; this was tested ith 3.2.5).
...use your existing webm file to create one audio file and multiple video files.
... for example: the file in.video can be any container with at least one audio and one video stream that can be decoded by ffmpeg, create the audio using: ffmpeg -i in.video -vn -acodec libvorbis -ab 128k -dash 1 my_audio.webm create each video variant.
...And 2 more matches

<track>: The Embed Text Track element - HTML: Hypertext Markup Language
the html <track> element is used as a child of the media elements, <audio> and <video>.
... permitted parents a media element, <audio> or <video>.
... captions closed captions provide a transcription and possibly a translation of audio.
...And 2 more matches

Common MIME types - HTTP
this table lists some important mime types for the web: extension kind of document mime type .aac aac audio audio/aac .abw abiword document application/x-abiword .arc archive document (multiple files embedded) application/x-freearc .avi avi: audio video interleave video/x-msvideo .azw amazon kindle ebook format application/vnd.amazon.ebook .bin any kind of binary data application/octet-stream .bmp windows os/2 bit...
...https://html.spec.whatwg.org/multipage/#scriptinglanguages https://html.spec.whatwg.org/multipage/#dependencies:willful-violation https://datatracker.ietf.org/doc/draft-ietf-dispatch-javascript-mjs/ .json json format application/json .jsonld json-ld format application/ld+json .mid .midi musical instrument digital interface (midi) audio/midi audio/x-midi .mjs javascript module text/javascript .mp3 mp3 audio audio/mpeg .mpeg mpeg video video/mpeg .mpkg apple installer package application/vnd.apple.installer+xml .odp opendocument presentation document application/vnd.oasis.opendocument.presentation .ods opendocument spreadsheet document appli...
...cation/vnd.oasis.opendocument.spreadsheet .odt opendocument text document application/vnd.oasis.opendocument.text .oga ogg audio audio/ogg .ogv ogg video video/ogg .ogx ogg application/ogg .opus opus audio audio/opus .otf opentype font font/otf .png portable network graphics image/png .pdf adobe portable document format (pdf) application/pdf .php hypertext preprocessor (personal home page) application/x-httpd-php .ppt microsoft powerpoint application/vnd.ms-powerpoint .pptx microsoft powerpoint (openxml) application/vnd.openxmlformats-officedocument.presentationml.presentation .rar rar archive application/vnd.rar ...
...And 2 more matches

HTTP Index - HTTP
10 incomplete list of mime types audio, file types, files, http, mime, mime types, php, reference, text, types, video here is a list of mime types, associated by type of documents, ordered by their common extensions.
... 14 configuring servers for ogg media audio, http, media, ogg, video this guide covers a few server configuration changes that may be necessary for your web server to correctly serve ogg media files.
... 88 csp: media-src csp, content-security-policy, directive, http, media, reference, security, media-src, source the http content-security-policy (csp) media-src directive specifies valid sources for loading media using the <audio> and <video> elements.
...And 2 more matches

Techniques for game development - Game development
using webrtc peer-to-peer data channels in addition to providing support for audio and video communication, webrtc lets you set up peer-to-peer data channels to exchange text or binary data actively between your players.
... audio for web games audio is an important part of any game — it adds feedback and atmosphere.
... web-based audio is maturing fast, but there are still many browser differences to negotiate.
... this article provides a detailed guide to implementing audio for web games, looking at what works currently across as wide a range of platforms as possible.

Plug-in Development Overview - Gecko Plugin API Reference
e plug-in dll should contain the following set of string/value pairs: mimetype: for mime types fileextents: for file extensions fileopenname: for file open template productname: for plug-in name filedescription: for description language: for language in use in the mime types and file extensions strings, multiple values are separated by the "|" character, for example: video/quicktime|audio/aiff|image/jpeg the version stamp will be loaded only if it has been created with the language set to "us english" and the character set to "windows multilingual" in your development environment.
...for example: str 128 mime type string 1 video/quicktime string 2 mov, moov string 3 audio/aiff string 4 aiff string 5 image/jpeg string 6 jpg several other optional strings may contain useful information about the plug-in.
...for example, this description list corresponds to the types in the previous example: string 1: "quicktime video", string 4: "aiff audio", and string 5: "jpeg image format." str#' 126: string 1 can contain a descriptive message about the plug-in.
...consider the following example, where a media player plug-in can be controlled with an advancetonextsong() method called inside the script element: <object id="myplugin" type="audio/wav" data="music.wav"> </object> <script type="application/javascript"> var theplugin = document.getelementbyid('myplugin'); if (theplugin && theplugin.advancetonextsong) theplugin.advancetonextsong(); else alert("plugin not installed correctly"); </script> in the past, liveconnect and later xpconnect were used to make plug-ins scriptable.

How can we design for all types of users? - Learn web development
if you want an elastic/responsive website, and you don't know what the browser's default width is, you can use the max-width property to allow up to 70 characters per line and no more: div.container { max-width:70em; } alternative content for images, audio, and video websites often include stuff besides plain text.
... audio/video you must also provide alternatives to multimedia content.
... subtitling/close-captioning you should include captions in your video to cater to visitors who can't hear the audio.
...for all these reasons, please provide a text transcript of the video/audio file.

How much does it cost to do something on the Web? - Learn web development
media editors if you want to include video or audio into your website, you can either embed online services (for example youtube, vimeo, or dailymotion), or include your own videos (see below for bandwidth costs).
... for audio files, you can find free software (audacity, wavosaur), or paying up to a few hundred dollars (sony sound forge, adobe audition).
... of course, you'll need a more serious computer if you want to produce complicated designs, touch up photos, or produce audio and video files.
... on the other hand, you'll need a high-bandwidth connection, such as dsl, cable, or fiber access, if you want a more advanced website with hundreds of files, or if you want to deliver heavy video/audio files directly from your web server.

HTML Cheatsheet - Learn web development
embedded audio <audio controls="controls" src="https://udn.realityripple.com/samples/b7/193cb038d0.mp3">your browser does not support the html5 audio element.</audio> your browser does not support the html5 audio element.
... embedded audio with alternative sources <audio controls="controls"><source src="https://udn.realityripple.com/samples/b7/193cb038d0.mp3" type="audio/mpeg"><source src="https://udn.realityripple.com/samples/f7/14a4179ee6.ogg" type="audio/ogg"> your browser does not support audio.
... </audio> your browser does not support audio.
... <h1> this is heading 1 </h1> <h2> this is heading 2 </h2> <h3> this is heading 3 </h3> <h4> this is heading 4 </h4> <h5> this is heading 5 </h5> <h6> this is heading 6 </h6> this is heading 1 this is heading 2 this is heading 3 this is heading 4 this is heading 5 this is heading 6 your browser does not support the audio element.

Browser API
audio-related methods the following methods allow direct control of sound in the browser element.
... htmliframeelement.mute() mutes any audio playing in the browser <iframe>.
... htmliframeelement.unmute() unmutes any audio playing in the browser <iframe>.
... mozbrowseraudioplaybackchange sent when audio starts or stops playing within the browser <iframe> content.

Plug-in Development Overview - Plugins
e plug-in dll should contain the following set of string/value pairs: mimetype: for mime types fileextents: for file extensions fileopenname: for file open template productname: for plug-in name filedescription: for description language: for language in use in the mime types and file extensions strings, multiple values are separated by the "|" character, for example: video/quicktime|audio/aiff|image/jpeg the version stamp will be loaded only if it has been created with the language set to "us english" and the character set to "windows multilingual" in your development environment.
...for example: str 128 mime type string 1 video/quicktime string 2 mov, moov string 3 audio/aiff string 4 aiff string 5 image/jpeg string 6 jpg several other optional strings may contain useful information about the plug-in.
...for example, this description list corresponds to the types in the previous example: string 1: "quicktime video", string 4: "aiff audio", and string 5: "jpeg image format." str#' 126: string 1 can contain a descriptive message about the plug-in.
...consider the following example, where a media player plug-in can be controlled with an advancetonextsong() method called inside the script element: <object id="myplugin" type="audio/wav" data="music.wav"> </object> <script type="application/javascript"> var theplugin = document.getelementbyid('myplugin'); if (theplugin && theplugin.advancetonextsong) theplugin.advancetonextsong(); else alert("plugin not installed correctly"); </script> in the past, liveconnect and later xpconnect were used to make plug-ins scriptable.

Deprecated tools - Firefox Developer Tools
web audio editor bugzilla issue: bug 1403944 removed as of firefox 67 description the web audio editor allowed you to examine an audio context constructed in the page and provided a visualization of its graph.
...it was possible to edit the audioparam properties for each node in the graph.
... some non-audioparam properties, like an oscillatornode's type property, were displayed and editable as well.
... more details about the web audio editor alternatives alternatives include audion and https://github.com/spite/webaudioextension web extensions.

AnalyserNode.AnalyserNode() - Web APIs
the analysernode constructor of the web audio api creates a new analysernode object instance.
... syntax var analysernode = new analysernode(context, ?options); parameters inherits parameters from the audionodeoptions dictionary.
... context a reference to an audiocontext or offlineaudiocontext.
... specifications specification status comment web audio apithe definition of 'analysernode() constructor' in that specification.

AnalyserNode.fftSize - Web APIs
example the following example shows basic usage of an audiocontext to create an analysernode, then requestanimationframe and <canvas> to collect time domain data repeatedly and draw an "oscilloscope style" output of the current audio input.
... var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); var analyser = audioctx.createanalyser(); ...
... analyser.fftsize = 2048; var bufferlength = analyser.frequencybincount ; var dataarray = new uint8array(bufferlength); analyser.getbytetimedomaindata(dataarray); // draw an oscilloscope of the current audio source function draw() { drawvisual = requestanimationframe(draw); analyser.getbytetimedomaindata(dataarray); canvasctx.fillstyle = 'rgb(200, 200, 200)'; canvasctx.fillrect(0, 0, width, height); canvasctx.linewidth = 2; canvasctx.strokestyle = 'rgb(0, 0, 0)'; canvasctx.beginpath(); var slicewidth = width * 1.0 / bufferlength; var x = 0; for(var i = 0; i < bufferlength; i++) { var v = dataarray[i] / 128.0; var y = v * height/2; if(i === 0) { canvasctx.moveto(x, y); } else { ...
... canvasctx.lineto(x, y); } x += slicewidth; } canvasctx.lineto(canvas.width, canvas.height/2); canvasctx.stroke(); }; draw(); specifications specification status comment web audio apithe definition of 'fftsize' in that specification.

AnalyserNode.getByteFrequencyData() - Web APIs
syntax var audioctx = new audiocontext(); var analyser = audioctx.createanalyser(); var dataarray = new uint8array(analyser.frequencybincount); // uint8array should be the same length as the frequencybincount void analyser.getbytefrequencydata(dataarray); // fill the uint8array with data returned from getbytefrequencydata() parameters array the uint8array that the frequency domain data will be copied to.
... example the following example shows basic usage of an audiocontext to create an analysernode, then requestanimationframe and <canvas> to collect frequency data repeatedly and draw a "winamp bargraph style" output of the current audio input.
... var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); var analyser = audioctx.createanalyser(); ...
... specifications specification status comment web audio apithe definition of 'getbytefrequencydata()' in that specification.

AnalyserNode.getFloatTimeDomainData() - Web APIs
syntax var audioctx = new audiocontext(); var analyser = audioctx.createanalyser(); var dataarray = new float32array(analyser.fftsize); // float32array needs to be the same length as the fftsize analyser.getfloattimedomaindata(dataarray); // fill the float32array with data returned from getfloattimedomaindata() parameters array the float32array that the time domain data will be copied to.
... example the following example shows basic usage of an audiocontext to create an analysernode, then requestanimationframe and <canvas> to collect time domain data repeatedly and draw an "oscilloscope style" output of the current audio input.
... var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); var analyser = audioctx.createanalyser(); ...
... specifications specification status comment web audio apithe definition of 'getfloattimedomaindata()' in that specification.

BiquadFilterNode() - Web APIs
the biquadfilternode() constructor of the web audio api creates a new biquadfilternode object, which represents a simple low-order filter, and is created using the audiocontext.createbiquadfilter() method.
... syntax var biquadfilternode = new biquadfilternode(context, options) parameters inherits parameters from the audionodeoptions dictionary.
... context a reference to an audiocontext.
... specifications specification status comment web audio apithe definition of 'biquadfilternode()' in that specification.

BiquadFilterNode.getFrequencyResponse() - Web APIs
for any frequency in frequencyarray whose value is outside the range 0.0 to samplerate/2 (where samplerate is the sample rate of the audiocontext), the corresponding value in this array is nan.
...for any frequency in frequencyarray whose value is outside the range 0.0 to samplerate/2 (where samplerate is the sample rate of the audiocontext), the corresponding value in this array is nan.
...lter frequency response for: </p> <ul class="freq-response-output"> </ul> var freqresponseoutput = document.queryselector('.freq-response-output'); finally, after creating our biquad filter, we use getfrequencyresponse() to generate the response data and put it in our arrays, then loop through each data set and output them in a human-readable list at the bottom of the page: var biquadfilter = audioctx.createbiquadfilter(); biquadfilter.type = "lowshelf"; biquadfilter.frequency.value = 1000; biquadfilter.gain.value = range.value; ...
...i <= myfrequencyarray.length-1;i++){ var listitem = document.createelement('li'); listitem.innerhtml = '<strong>' + myfrequencyarray[i] + 'hz</strong>: magnitude ' + magresponseoutput[i] + ', phase ' + phaseresponseoutput[i] + ' radians.'; freqresponseoutput.appendchild(listitem); } } calcfrequencyresponse(); specifications specification status comment web audio apithe definition of 'getfrequencyresponse()' in that specification.

BiquadFilterNode.type - Web APIs
syntax var audioctx = new audiocontext(); var biquadfilter = audioctx.createbiquadfilter(); biquadfilter.type = 'lowpass'; value a string (enum) representing a biquadfiltertype.
... not used example the following example shows basic usage of an audiocontext to create a biquad filter node.
... var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); //set up the different audio nodes we will use for the app var analyser = audioctx.createanalyser(); var distortion = audioctx.createwaveshaper(); var gainnode = audioctx.creategain(); var biquadfilter = audioctx.createbiquadfilter(); var convolver = audioctx.createconvolver(); // connect the nodes together source = audioctx.createmediastreamsource(stream); source.connect(analyser); analyser.connect(distortion); distortion.connect(biquadfilter); biquadfilter.connect(convolver); convolver.connect(gainnode); gainnode.connect(audioctx.destination); // manipulate the biquad filter biquadfilter.type = "lowshelf"; biquad...
...filter.frequency.value = 1000; biquadfilter.gain.value = 25; specifications specification status comment web audio apithe definition of 'type' in that specification.

ConvolverNode.normalize - Web APIs
syntax var audioctx = new audiocontext(); var convolver = audioctx.createconvolver(); convolver.normalize = false; value a boolean.
... example var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); var convolver = audioctx.createconvolver(); ...
... // grab audio track via xhr for convolver node var soundsource, concerthallbuffer; ajaxrequest = new xmlhttprequest(); ajaxrequest.open('get', 'concert-crowd.ogg', true); ajaxrequest.responsetype = 'arraybuffer'; ajaxrequest.onload = function() { var audiodata = ajaxrequest.response; audioctx.decodeaudiodata(audiodata, function(buffer) { concerthallbuffer = buffer; soundsource = audioctx.createbuffersource(); soundsource.buffer = concerthallbuffer; }, function(e){"error with decoding audio data" + e.err}); } ajaxrequest.send(); ...
... convolver.normalize = false; // must be set before the buffer, to take effect convolver.buffer = concerthallbuffer; specifications specification status comment web audio apithe definition of 'normalize' in that specification.

DelayNode() - Web APIs
the delaynode() constructor of the web audio api creates a new delaynode object with a delay-line; an audionode audio-processing module that causes a delay between the arrival of an input data, and its propagation to the output.
... syntax var delaynode = new delaynode(context); var delaynode = new delaynode(context, options); parameters inherits parameters from the audionodeoptions dictionary.
... context a reference to an audiocontext or offlineaudiocontext.
... example const audioctx = new audiocontext(); const delaynode = new delaynode(audioctx, { delaytime: 0.5, maxdelaytime: 2, }); specifications specification status comment web audio apithe definition of 'delaynode()' in that specification.

HTMLMediaElement.defaultMuted - Web APIs
the htmlmediaelement.defaultmuted property reflects the muted html attribute, which indicates whether the media element's audio output should be muted by default.
...to mute and unmute the audio output, use the muted property.
... syntax var dmuted = video.defaultmuted; audio.defaultmuted = true; value a boolean.
... a value of true means that the audio output will be muted by default.

HTMLMediaElement.readyState - Web APIs
syntax var readystate = audioorvideo.readystate; value an unsigned short.
... examples this example will listen for audio data to be loaded for the element `example`.
...if it has, the audio will play.
... <audio id="example" preload="auto"> <source src="sound.ogg" type="audio/ogg" /> </audio> var obj = document.getelementbyid('example'); obj.addeventlistener('loadeddata', function() { if(obj.readystate >= 2) { obj.play(); } }); specifications specification status comment html living standardthe definition of 'htmlmediaelement.readystate' in that specification.

MediaStreamTrack.enabled - Web APIs
in the case of audio, a disabled track generates frames of silence (that is, frames in which every sample's value is 0).
... empty audio frames have every sample's value set to 0.
... pausebutton.onclick = function(evt) { const newstate = !myaudiotrack.enabled; pausebutton.innerhtml = newstate ?
... "&#x25b6;&#xfe0f;" : "&#x23f8;&#xfe0f;"; myaudiotrack.enabled = newstate; } this creates a variable, newstate, which is the opposite of the current value of enabled, then uses that to select either the emoji character for the "play" icon or the character for the "pause" icon as the new innerhtml of the pause button's element.

Recording a media element - Web APIs
while the article using the mediastream recording api demonstrates using the mediarecorder interface to capture a mediastream generated by a hardware device, as returned by navigator.mediadevices.getusermedia(), you can also use an html media element (namely <audio> or <video>) as the source of the mediastream to be recorded.
... getting an input stream and setting up the recorder now let's look at the most intricate piece of code in this example: our event handler for clicks on the start button: startbutton.addeventlistener("click", function() { navigator.mediadevices.getusermedia({ video: true, audio: true }).then(stream => { preview.srcobject = stream; downloadbutton.href = stream; preview.capturestream = preview.capturestream || preview.mozcapturestream; return new promise(resolve => preview.onplaying = resolve); }).then(() => startrecording(preview.capturestream(), recordingtimems)) .then (recordedchunks => { let recordedblob = new blob(recordedchunks, { type: "vi...
... downloadbutton.href = recording.src; downloadbutton.download = "recordedvideo.webm"; log("successfully recorded " + recordedblob.size + " bytes of " + recordedblob.type + " media."); }) .catch(log); }, false); when a click event occurs, here's what happens: lines 2-4 navigator.mediadevices.getusermedia() is called to request a new mediastream that has both video and audio tracks.
...since the <video> element is muted, the audio won't play.

Media Source API - Web APIs
using mse, media streams can be created via javascript, and played using <audio> and <video> elements.
... media source extensions concepts and usage playing video and audio has been available in web applications without plugins for a few years now, but the basic features offered have really only been useful for playing single whole tracks.
...while browser support for the various media containers with mse is spotty, usage of the h.264 video codec, aac audio codec, and mp4 container format is a common baseline.
... audiotrack.sourcebuffer, videotrack.sourcebuffer, texttrack.sourcebuffer returns the sourcebuffer that created the track in question.

Navigator.getUserMedia() - Web APIs
the deprecated navigator.getusermedia() method prompts the user for permission to use up to one video input device (such as a camera or shared screen) and up to one audio input device (such as a microphone) as the source for a mediastream.
... if permission is granted, a mediastream whose video and/or audio tracks come from those devices is delivered to the specified success callback.
...your callback can then assign the stream to the desired object (such as an <audio> or <video> element), as shown in the following example: function(stream) { var video = document.queryselector('video'); video.srcobject = stream; video.onloadedmetadata = function(e) { // do something with the video here.
... navigator.getusermedia = navigator.getusermedia || navigator.webkitgetusermedia || navigator.mozgetusermedia; if (navigator.getusermedia) { navigator.getusermedia({ audio: true, video: { width: 1280, height: 720 } }, function(stream) { var video = document.queryselector('video'); video.srcobject = stream; video.onloadedmetadata = function(e) { video.play(); }; }, function(err) { console.log("the following error occurred: " + err.name); } ); } else { console.log("getusermedia not ...

OscillatorNode.onended - Web APIs
syntax var oscillator = audioctx.createoscillator(); oscillator.onended = function() { ...
... }; example the following example shows basic usage of an audiocontext to create an oscillator node.
... // create web audio api context var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); // create oscillator node var oscillator = audioctx.createoscillator(); oscillator.type = 'square'; oscillator.frequency.value = 440; // value in hertz oscillator.start(); // start the tone playing oscillator.stop(5); // the tone will stop again in 5 seconds.
... specifications specification status comment web audio apithe definition of 'onended' in that specification.

OscillatorNode.stop() - Web APIs
syntax oscillator.stop(when); // stop playing oscillator at when parameters when optional an optional double representing the audio context time when the oscillator should stop.
...if the time is equal to or before the current audio context time, the oscillator will stop playing immediately.
... example the following example shows basic usage of an audiocontext to create an oscillator node.
... // create web audio api context var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); // create oscillator node var oscillator = audioctx.createoscillator(); oscillator.connect(audioctx.destination); oscillator.start(); oscillator.stop(audioctx.currenttime + 2); // stop 2 seconds after the current time specifications specification status comment web audio apithe definition of 'stop' in that specification.

PannerNode.refDistance - Web APIs
the refdistance property of the pannernode interface is a double value representing the reference distance for reducing volume as the audio source moves further from the listener – i.e.
... syntax var audioctx = new audiocontext(); var panner = audioctx.createpanner(); panner.refdistance = 1; value a non-negative number.
... const context = new audiocontext(); // all our test tones will last this many seconds const note_length = 6; // this is how far we'll move the sound const z_distance = 20; // this function creates a graph for the test tone with a given refdistance // and schedules it to move away from the listener along the z (depth-wise) axis // at the given start time, resulting in a decrease in volume (decay) const scheduletesttone = ...
...ld decay slower and later than the previous one scheduletesttone(4, context.currenttime + note_length); // this tone should decay only slightly, and only start decaying fairly late scheduletesttone(7, context.currenttime + note_length * 2); after running this code, the resulting waveforms should look something like this: specifications specification status comment web audio apithe definition of 'refdistance' in that specification.

PeriodicWave - Web APIs
the periodicwave itself is created/returned by audiocontext.createperiodicwave().
...if you wish to establish custom property values at the outset, use the audiocontext.createperiodicwave() factory method instead.
... var real = new float32array(2); var imag = new float32array(2); var ac = new audiocontext(); var osc = ac.createoscillator(); real[0] = 0; imag[0] = 0; real[1] = 1; imag[1] = 0; var wave = ac.createperiodicwave(real, imag, {disablenormalization: true}); osc.setperiodicwave(wave); osc.connect(ac.destination); osc.start(); osc.stop(2); this works because a sound that contains only a fundamental tone is by definition a sine wave here, we create a periodicwave with two values.
... specifications specification status comment web audio apithe definition of 'periodicwave' in that specification.

TrackEvent - Web APIs
events based on trackevent are always sent to one of the media track list types: events involving video tracks are always sent to the videotracklist found in htmlmediaelement.videotracks events involving audio tracks are always sent to the audiotracklist specified in htmlmediaelement.audiotracks events affecting text tracks are sent to the texttracklist object indicated by htmlmediaelement.texttracks.
...if not null, this is always an object of one of the media track types: audiotrack, videotrack, or texttrack).
... var videoelem = document.queryselector("video"); videoelem.videotracks.addeventlistener("addtrack", handletrackevent, false); videoelem.videotracks.addeventlistener("removetrack", handletrackevent, false); videoelem.audiotracks.addeventlistener("addtrack", handletrackevent, false); videoelem.audiotracks.addeventlistener("removetrack", handletrackevent, false); videoelem.texttracks.addeventlistener("addtrack", handletrackevent, false); videoelem.texttracks.addeventlistener("removetrack", handletrackevent, false); function handletrackevent(event) { var trackkind; if (event.target instanceof(videotracklist)) { ...
... trackkind = "video"; } else if (event.target instanceof(audiotracklist)) { trackkind = "audio"; } else if (event.target instanceof(texttracklist)) { trackkind = "text"; } else { trackkind = "unknown"; } switch(event.type) { case "addtrack": console.log("added a " + trackkind + " track"); break; case "removetrack": console.log("removed a " + trackkind + " track"); break; } } the event handler uses the javascript instanceof operator to determine which type of track the event occurred on, then outputs to console a message indicating what kind of track it is and whether it's being added to or removed from the element.

WaveShaperNode.WaveShaperNode() - Web APIs
the waveshapernode() constructor of the web audio api creates a new waveshapernode object which is an audionode that represents a non-linear distorter.
... syntax var waveshapernode = new waveshapernode(context, options) parameters inherits parameters from the audionodeoptions dictionary.
... context a reference to an audiocontext.
... specifications specification status comment web audio apithe definition of 'waveshapernode()' in that specification.

WaveShaperNode.curve - Web APIs
syntax var audioctx = new audiocontext(); var distortion = audioctx.createwaveshaper(); distortion.curve = mycurvedataarray; // mycurvedataarray is a float32array value a float32array.
... example the following example shows basic usage of an audiocontext to create a wave shaper node.
... var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); var distortion = audioctx.createwaveshaper(); ...
... distortion.curve = makedistortioncurve(400); distortion.oversample = '4x'; specifications specification status comment web audio apithe definition of 'curve' in that specification.

WaveShaperNode.oversample - Web APIs
oversampling is a technique for creating more samples (up-sampling) before applying a distortion effect to the audio signal.
... example the following example shows basic usage of an audiocontext to create a wave shaper node.
... var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); var distortion = audioctx.createwaveshaper(); ...
... distortion.curve = makedistortioncurve(400); distortion.oversample = '4x'; specifications specification status comment web audio apithe definition of 'oversample' in that specification.

WebRTC Statistics API - Web APIs
rtcaudiosourcestats or rtcvideosourcestats rtcmediasourcestats rtcstats rtcaudiosourcestats or rtcvideosourcestats outbound-rtp statistics describing the state of one of the outbound data streams on this connection.
... rtcaudioreceiverstats or rtcvideoreceiverstats rtcaudiohandlerstats or rtcvideohandlerstats rtcmediahandlerstats rtcstats remote-candidate statistics about a remote ice candidate associated with the connection's rtcicetransports.
... rtcaudiosenderstats or rtcvideosenderstats rtcaudiohandlerstats or rtcvideohandlerstats rtcmediahandlerstats rtcstats stream statistics about a particular media mediastream.
... rtcsendervideotrackattachmentstats or rtcsenderaudiotrackattachmentstats or rtcreceivervideotrackattachmentstats or rtcreceiveraudiotrackattachmentstats rtcmediahandlerstats rtcstats transceiver statistics related to a specific rtcrtptransceiver.

Setting up adaptive streaming media sources - Developer guides
here's a simple example that provides an audio track representation and four separate video representations.
....0" encoding="utf-8"?> <mpd xmlns:xsi="http://www.w3.org/2001/xmlschema-instance" xmlns="urn:mpeg:dash:schema:mpd:2011" xsi:schemalocation="urn:mpeg:dash:schema:mpd:2011 dash-mpd.xsd" type="static" mediapresentationduration="pt654s" minbuffertime="pt2s" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011"> <baseurl>http://example.com/ondemand/</baseurl> <period> <!-- english audio --> <adaptationset mimetype="audio/mp4" codecs="mp4a.40.5" lang="en" subsegmentalignment="true" subsegmentstartswithsap="1"> <representation id="1" bandwidth="64000"> <baseurl>elephantsdream_aac48k_064.mp4.dash</baseurl> </representation> </adaptationset> <!-- video --> <adaptationset mimetype="video/mp4" codecs="avc1.42401e" subsegmentalignment="true" subsegme...
... note: you can also split out your audio and video streams into separate files, which can then be prioritised and served separately depending on bandwidth.
... media is usually encoded as mpeg-4 (h.264 video and aac audio) and packaged into an mpeg-2 transport stream, which is then broken into segments and saved as one or more .ts media files.

Content categories - Developer guides
they are: <a>, <abbr>, <address>, <article>, <aside>, <audio>, <b>,<bdo>, <bdi>, <blockquote>, <br>, <button>, <canvas>, <cite>, <code>, <command>, <data>, <datalist>, <del>, <details>, <dfn>, <div>, <dl>, <em>, <embed>, <fieldset>, <figure>, <footer>, <form>, <h1>, <h2>, <h3>, <h4>, <h5>, <h6>, <header>, <hgroup>, <hr>, <i>, <iframe>, <img>, <input>, <ins>, <kbd>, <keygen>, <label>, <main>, <map>, <mark>, <math>, <menu>, <meter>, <nav>, <noscript>, <obj...
... elements belonging to this category are <abbr>, <audio>, <b>, <bdo>, <br>, <button>, <canvas>, <cite>, <code>, <command>, <data>, <datalist>, <dfn>, <em>, <embed>, <i>, <iframe>, <img>, <input>, <kbd>, <keygen>, <label>, <mark>, <math>, <meter>, <noscript>, <object>, <output>, <picture>, <progress>, <q>, <ruby>, <samp>, <script>, <select>, <small>, <span>, <strong>, <sub>, <sup>, <svg>, <textarea>, <time>, <var>, <video>, <wbr> and plain text (not ...
...elements that belong to this category include: <audio>, <canvas>, <embed>, <iframe>, <img>, <math>, <object>, <picture>, <svg>, <video>.
... some elements belong to this category only under specific conditions: <audio>, if the controls attribute is present <img>, if the usemap attribute is present <input>, if the type attribute is not in the hidden state <menu>, if the type attribute is in the toolbar state <object>, if the usemap attribute is present <video>, if the controls attribute is present palpable content content is palpable when it's neither empty or hidden; it is content that is rendered and is substantive.

<bgsound>: The Background Sound element (obsolete) - HTML: Hypertext Markup Language
the internet explorer only html background sound element (<bgsound>) sets up a sound file to play in the background while the page is used; use <audio> instead.
...in order to embed audio in a web page, you should be using the <audio> element.
... example <bgsound src="sound1.mid"> <bgsound src="sound2.au" loop="infinite"> usage notes historically, the <embed> element could be used with audio player plug-ins to play audio in the background in most browsers.
... however, even this is no longer appropriate, and you should use <audio> instead, since it's more capable, more compatible, and doesn't require plug-ins.

Index of archived content - Archive of obsolete content
on gecko coding help wanted http class overview hacking wiki help viewer creating a help content pack helper apps (and a bit of save as) hidden prefs how to write and land nanojit patches io guide/directory keys introducing the audio api extension isp data java in firefox extensions javascript os.shared javascript crypto crmf request object generatecrmfrequest() importusercertificates popchallengeresponse jetpack basics co...
...owsers on windows mcd, mission control desktop, aka autoconfig monitoring wifi access points no proxy for configuration notes on html reflow same-origin policy for file: uris source navigator source code directories overview using xml data islands in mozilla using content preferences visualizing an audio spectrum working with bfcache cert_override.txt mozilla release faq newsgroup summaries format mozilla.dev.apps.firefox-2006-09-29 mozilla.dev.apps.firefox-2006-10-06 mozilla-dev-accessibility 2006-10-06 2006-11-10 2006-11-2...
... references summary of changes using the w3c dom using workers in extensions web standards choosing standards compliance over proprietary practices community correctly using titles with external stylesheets describing microformats in javascript displaying a graphic with audio samples fixing incorrectly sized list item markers fixing table inheritance in quirks mode issues arising from arbitrary-element hover mozilla's doctype sniffing parsing microformats in javascript popup window controls rdf in fifty words or less rdf in mozilla faq styling abbreviations and acronyms ...

Assessment: Accessibility troubleshooting - Learn web development
the audio player the <audio> player isn't accessible to hearing impaired (deaf) people — can you add some kind of accessible alternative for these users?
... the <audio> player isn't accessible to those using older browsers that don't support html5 audio.
... how can you allow them to still access the audio?

What is a URL? - Learn web development
on an html document, for example, the browser will scroll to the point where the anchor is defined; on a video or audio document, the browser will try to go to the time the anchor represents.
... the html language — which will be discussed later on — makes extensive use of urls: to create links to other documents with the <a> element; to link a document with its related resources through various elements such as <link> or <script>; to display media such as images (with the <img> element), videos (with the <video> element), sounds and music (with the <audio> element), etc.; to display other html documents with the <iframe> element.
... note: when specifying urls to load resources as part of a page (such as when using the <script>, <audio>, <img>, <video>, and the like), you should generally only use http and https urls, with few exceptions (one notable one being data:; see data urls).

Images in HTML - Learn web development
a figure could be several images, a code snippet, audio, video, equations, a table, or something else.
...in the next article we'll move it up a gear, looking at how to use html to embed video and audio in web pages.
... overview: multimedia and embedding next in this module images in html video and audio content from <object> to <iframe> — other embedding technologies adding vector graphics to the web responsive images mozilla splash page ...

From object to iframe — other embedding technologies - Learn web development
previous overview: multimedia and embedding next by now you should really be getting the hang of embedding things into your web pages, including images, video and audio.
...we saw some in earlier articles, such as <video>, <audio>, and <img>, but there are others to discover, such as <canvas> for javascript-generated 2d and 3d graphics, and <svg> for embedding vector graphics.
... previous overview: multimedia and embedding next in this module images in html video and audio content from <object> to <iframe> — other embedding technologies adding vector graphics to the web responsive images mozilla splash page ...

Graceful asynchronous programming with Promises - Learn web development
the code that the video chat application would use might look something like this: function handlecallbutton(evt) { setstatusmessage("calling..."); navigator.mediadevices.getusermedia({video: true, audio: true}) .then(chatstream => { selfviewelem.srcobject = chatstream; chatstream.gettracks().foreach(track => mypeerconnection.addtrack(track, chatstream)); setstatusmessage("connected"); }).catch(err => { setstatusmessage("failed to connect"); }); } this function starts by using a function called setstatusmessage() to update a status display with the message "c...
...it then calls getusermedia(), asking for a stream that has both video and audio tracks, then once that's been obtained, sets up a video element to show the stream coming from the camera as a "self view," then takes each of the stream's tracks and adds them to the webrtc rtcpeerconnection representing a connection to another user.
...among those apis are webrtc, web audio api, media capture and streams, and many more.

Handling common accessibility problems - Learn web development
people with hearing impairments relying on captions/subtitles or other text alternatives for audio/video content.
... alt text is slightly more complex for video and audio content.
...browser compatibility for these features is fairly good, but if you want to provide text alternatives for audio or support older browsers, a simple text transcript presented somewhere on the page or on a separate page might be a good idea.

Handling common HTML and CSS problems - Learn web development
for example .audio-player ul a.
...in general, most core html and css functionality (such as basic html elements, css basic colors and text styling) works across most browsers you'll want to support; more problems are uncovered when you start wanting to use newer features such as flexbox, or html5 video/audio, or even more nascent, css grids or -webkit-background-clip: text.
... more complex elements like html <video>, <audio>, and <canvas> (and other features besides) have natural mechanisms for fallbacks to be added, which work on the same principle as described above.

Mozilla's Section 508 Compliance
gnopernicus support in beta no screen reader support on mac os x b) at least one mode of operation and information retrieval that does not require visual acuity greater than 20/70 shall be provided in audio and enlarged print output working together or independently, or support for assistive technology used by people who are visually impaired shall be provided.
... unknown d) where audio information is important for the use of a product, at least one mode of operation and information retrieval shall be provided in an enhanced auditory fashion, or support for assistive hearing devices shall be provided.
...audio is not a core part of mozilla -- plugins or the os take care of audio playback.

Index
495 nsidomhtmlaudioelement interfaces, interfaces:scriptable, xpcom interface reference the nsidomhtmlaudioelement interface is used to implement the html5 <audio> element.
... 498 nsidomhtmlsourceelement dom, html, html5, interfaces, interfaces:scriptable, media, xpcom, xpcom interface reference the nsidomhtmlsourceelement interface is the dom interface to the source child of the audio and video media elements in html.
... 512 nsidomprogressevent interfaces, interfaces:scriptable, reference, xmlhttprequest, xpcom interface reference, nsidomprogressevent, progress the nsidomprogressevent is used in the media elements (<video> and <audio>) to inform interested code of the progress of the media download.

nsIDOMWindowUtils
audiomuted boolean with this it's possible to mute all the mediaelements in this window.
... we have audiomuted and audiovolume to preserve the volume across mute/umute.
... audiovolume float range: greater or equal to 0.

Plug-in Basics - Plugins
if you are browsing a page that has several embedded realaudio clips, for example, the browser will create as many instances of the realplayer plug-in as are needed (though of course playing several realaudio files at the same time would seldom be a good idea).
...here's an example: <embed src="audiplay.aiff" type="audio/x-aiff" hidden="true"> note: whether a plug-in is windowed or windowless is not meaningful if the plug-in is invoked with the hidden attribute.
...using the class attribute and the css block above, you can simulate the behavior of the hidden plug-in in the embed element: <object data="audiplay.aiff" type="audio/x-aiff" class="hiddenobject"></object> a full-page plug-in is a visible plug-in that is not part of an html page.

AnalyserNode.frequencyBinCount - Web APIs
example the following example shows basic usage of an audiocontext to create an analysernode, then requestanimationframe and <canvas> to collect frequency data repeatedly and draw a "winamp bargraph style" output of the current audio input.
... var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); var analyser = audioctx.createanalyser(); analyser.mindecibels = -90; analyser.maxdecibels = -10; ...
...); var barwidth = (width / bufferlength) * 2.5 - 1; var barheight; var x = 0; for(var i = 0; i < bufferlength; i++) { barheight = dataarray[i]; canvasctx.fillstyle = 'rgb(' + (barheight+100) + ',50,50)'; canvasctx.fillrect(x,height-barheight/2,barwidth,barheight/2); x += barwidth; } }; draw(); specifications specification status comment web audio apithe definition of 'frequencybincount' in that specification.

AnalyserNode.maxDecibels - Web APIs
example the following example shows basic usage of an audiocontext to create an analysernode, then requestanimationframe and <canvas> to collect frequency data repeatedly and draw a "winamp bargraph style" output of the current audio input.
... var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); var analyser = audioctx.createanalyser(); analyser.mindecibels = -90; analyser.maxdecibels = -10; ...
...); var barwidth = (width / bufferlength) * 2.5; var barheight; var x = 0; for(var i = 0; i < bufferlength; i++) { barheight = dataarray[i]; canvasctx.fillstyle = 'rgb(' + (barheight+100) + ',50,50)'; canvasctx.fillrect(x,height-barheight/2,barwidth,barheight/2); x += barwidth + 1; } }; draw(); specifications specification status comment web audio apithe definition of 'maxdecibels' in that specification.

AnalyserNode.minDecibels - Web APIs
example the following example shows basic usage of an audiocontext to create an analysernode, then requestanimationframe and <canvas> to collect frequency data repeatedly and draw a "winamp bargraph style" output of the current audio input.
... var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); var analyser = audioctx.createanalyser(); analyser.mindecibels = -90; analyser.maxdecibels = -10; ...
...); var barwidth = (width / bufferlength) * 2.5; var barheight; var x = 0; for(var i = 0; i < bufferlength; i++) { barheight = dataarray[i]; canvasctx.fillstyle = 'rgb(' + (barheight+100) + ',50,50)'; canvasctx.fillrect(x,height-barheight/2,barwidth,barheight/2); x += barwidth + 1; } }; draw(); specifications specification status comment web audio apithe definition of 'mindecibels' in that specification.

AnalyserNode.smoothingTimeConstant - Web APIs
example the following example shows basic usage of an audiocontext to create an analysernode, then requestanimationframe and <canvas> to collect frequency data repeatedly and draw a "winamp bargraph style" output of the current audio input.
... var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); var analyser = audioctx.createanalyser(); analyser.mindecibels = -90; analyser.maxdecibels = -10; analyser.smoothingtimeconstant = 0.85; ...
...); var barwidth = (width / bufferlength) * 2.5; var barheight; var x = 0; for(var i = 0; i < bufferlength; i++) { barheight = dataarray[i]; canvasctx.fillstyle = 'rgb(' + (barheight+100) + ',50,50)'; canvasctx.fillrect(x,height-barheight/2,barwidth,barheight/2); x += barwidth + 1; } }; draw(); specifications specification status comment web audio apithe definition of 'smoothingtimeconstant' in that specification.

ChannelMergerNode() - Web APIs
syntax var mynode = new channelmergernode(context, options); parameters context a baseaudiocontext representing the audio context you want the node to be associated with.
... options optional a channelmergeroptions dictionary object defining the properties you want the channelmergernode to have (also inherits parameters from the audionodeoptions dictionary): numberofinputs: a number defining the number of inputs the channelmergernode should have.
... example var ac = new audiocontext(); var options = { numberofinputs : 2 } var mymerger = new channelmergernode(ac, options); specifications specification status comment web audio apithe definition of 'channelmergernode' in that specification.

DisplayMediaStreamConstraints - Web APIs
the displaymediastreamconstraints dictionary is used to specify whether or not to include video and/or audio tracks in the mediastream to be returned by getdisplaymedia(), as well as what type of processing must be applied to the tracks.
... properties audio a boolean or mediatrackconstraints value; if a boolean, this value simply indicates whether or not to include an audio track in the mediastream returned by getdisplaymedia().
... if a mediatrackconstraints object is provided here, an audio track is included in the stream, but the audio is processed to match the specified constraints after being retrieved from the hardware but before being added to the mediastream.

HTMLMediaElement.autoplay - Web APIs
note: sites which automatically play audio (or videos with an audio track) can be an unpleasant experience for users, so it should be avoided when possible.
... for a much more in-depth look at autoplay, autoplay blocking, and how to respond whena autoplay is blocked by the user's browser, see our article autoplay guide for media and web audio apis.
... note: some browsers offer users the ability to override autoplay in order to prevent disruptive audio or video from playing without permission or in the background.

HTMLMediaElement.networkState - Web APIs
syntax var networkstate = audioorvideo.networkstate; value an unsigned short.
... examples this example will listen for the audio element to begin playing and then check if it is still loading data.
... <audio id="example" preload="auto"> <source src="sound.ogg" type="audio/ogg" /> </audio> var obj = document.getelementbyid('example'); obj.addeventlistener('playing', function() { if (obj.networkstate === 2) { // still loading...

HTMLMediaElement.playbackRate - Web APIs
the audio is muted when the fast forward or slow motion is outside a useful range (for example, gecko mutes the sound outside the range 0.25 to 5.0).
... the pitch of the audio is corrected by default and is the same for every speed.
... syntax // video video.playbackrate = 1.5; // audio audio.playbackrate = 1.0; value a double.

HTMLMediaElement.setSinkId() - Web APIs
the htmlmediaelement.setsinkid() method sets the id of the audio device to use for output and returns a promise.
... parameters sinkid the mediadeviceinfo.deviceid of the audio output device.
... exceptions exception explanation domexception no permission to use the requested device examples const devices = await navigator.mediadevices.enumeratedevices(); const audiodevices = devices.filter(device => device.kind === 'audiooutput'); const audio = document.createelement('audio'); await audio.setsinkid(audiodevices[0].deviceid); console.log('audio is being played on ' + audio.sinkid); specifications specification status comment audio output devices apithe definition of 'sinkid' in that specification.

MediaCapabilities.decodingInfo() - Web APIs
syntax mediacapabilities.decodinginfo(mediadecodingconfiguration) parameters mediadecodingconfiguration a valid mediadecodingconfiguration dictionary containing a valid media decoding type of file or media-source and a valid media configuration: either an audioconfiguration or a videoconfiguration.
... return value a promise fulfilling with a mediacapabilitiesinfo interface containing three boolean attributes: supported smooth powerefficient exceptions a typeerror is raised if the mediaconfiguration passed to the decodinginfo() method is invalid, either because the type is not video or audio, the contenttype is not a valid codec mime type, the media decoding configuration is not a valid value for the media decoding type, or any other error in the media configuration passed to the method, including omitting values required in the media decoding configuration.
... example //create media configuration to be tested const mediaconfig = { type : 'file', // or 'media-source' audio : { contenttype : "audio/ogg", // valid content type channels : 2, // audio channels used by the track bitrate : 132700, // number of bits used to encode 1s of audio samplerate : 5200 // number of audio samples making up that 1s.

MediaSession.setActionHandler() - Web APIs
examples adding action handlers this example implements seek forward and backward actions for an audio player by setting up the seekforward and seekbackward action handlers.
... audio.currenttime = math.min(audio.currenttime + skiptime, audio.duration); }); navigator.mediasession.setactionhandler('seekbackward', evt => { // user clicked "seek backward" media notification icon.
... audio.currenttime = math.max(audio.currenttime - skiptime, 0); }); supporting multiple actions in one handler function you can also, if you prefer, use a single function to handle multiple action types, by checking the value of the mediasessionactiondetails object's action property: let skiptime = 7; navigator.mediasession.setactionhandler("seekforward", handleseek); navigator.mediasession.setactionhandler("seekbackward", handleseek); function handleseek(details) { switch(details.action) { case "seekforward": audio.currenttime = math.min(audio.currenttime + skiptime, audio.duration); break; case "seekbackward": audio.currenttime = math.max(audio.currenttime - skiptime, 0); break; } } here, the handleseek() function handles both seekbac...

Media Session action types - Web APIs
examples adding action handlers this example implements seek forward and backward actions for an audio player by setting up the seekforward and seekbackward action handlers.
... audio.currenttime = math.min(audio.currenttime + skiptime, audio.duration); }); navigator.mediasession.setactionhandler('seekbackward', evt => { // user clicked "seek backward" media notification icon.
... audio.currenttime = math.max(audio.currenttime - skiptime, 0); }); supporting multiple actions in one handler function you can also, if you prefer, use a single function to handle multiple action types, by checking the value of the mediasessionactiondetails object's action property: let skiptime = 7; navigator.mediasession.setactionhandler("seekforward", handleseek); navigator.mediasession.setactionhandler("seekbackward", handleseek); function handleseek(details) { switch(details.action) { case "seekforward": audio.currenttime = math.min(audio.currenttime + skiptime, audio.duration); break; case "seekbackward": audio.currenttime = math.max(audio.currenttime - skiptime, 0); break; } } here, the handleseek() function handles both seekbac...

MediaSessionActionDetails - Web APIs
examples adding action handlers this example implements seek forward and backward actions for an audio player by setting up the seekforward and seekbackward action handlers.
... audio.currenttime = math.min(audio.currenttime + skiptime, audio.duration); }); navigator.mediasession.setactionhandler('seekbackward', evt => { // user clicked "seek backward" media notification icon.
... audio.currenttime = math.max(audio.currenttime - skiptime, 0); }); supporting multiple actions in one handler function you can also, if you prefer, use a single function to handle multiple action types, by checking the value of the mediasessionactiondetails object's action property: let skiptime = 7; navigator.mediasession.setactionhandler("seekforward", handleseek); navigator.mediasession.setactionhandler("seekbackward", handleseek); function handleseek(details) { switch(details.action) { case "seekforward": audio.currenttime = math.min(audio.currenttime + skiptime, audio.duration); break; case "seekbackward": audio.currenttime = math.max(audio.currenttime - skiptime, 0); break; } } here, the handleseek() function handles both seekbac...

MediaStreamConstraints - Web APIs
track constraints audio either a boolean (which indicates whether or not an audio track is requested) or a mediatrackconstraints object providing the constraints which must be met by the audio track included in the returned mediastream.
... if constraints are specified, an audio track is inherently requested.
...streams isolated in this way can only be displayed in a media element (<audio> or <video>) where the content is protected just as if cors cross-origin rules were in effect.

MediaTrackSettings.sampleRate - Web APIs
the mediatracksettings dictionary's samplerate property is an integer indicating how many audio samples per second the mediastreamtrack is currently configured for.
... syntax var samplerate = mediatracksettings.samplerate; value an integer value indicating how many samples each second of audio data includes.
... common values include 44,100 (standard cd audio), 48,000 (standard digital audio), 96,000 (commonly used in audio mastering and post-production), and 192,000 (used for high-resolution audio in professional recording and mastering sessions).

Using the Media Capabilities API - Web APIs
you can also test audio decoding as well as video and audio encoding.
... const videoconfiguration = { type: "file", video: { contenttype: "video/webm;codecs=vp8", width: 800, height: 600, bitrate: 10000, framerate: 15 } }; had we been querying the decodability of an audio file, we would create an audio configuration including the number of channels and sample rate, leaving out the properties that apply only to video—namely, the dimensions and the frame rate: const audioconfiguration = { type: "file", audio: { contenttype: "audio/ogg", channels: 2, bitrate: 132700, samplerate: 5200 } }; had we been testing encoding capabilities,...
...a mediarecorder object) or transmission (for media transmitted over electronic means like rtcpeerconnection) — plus either an audio or video configuration as described above.

Media Session API - Web APIs
the following example adds a pointerup event to an on-page play button, which is then used to kick off the media session code: playbutton.addeventlistener('pointerup', function(event) { var audio = document.queryselector('audio'); // user interacted with the page.
... let's play audio...
... audio.play() .then(_ => { /* set up media session controls, as shown above.

OscillatorNode.start() - Web APIs
syntax oscillator.start(when); // start playing oscillator at the point in time specified by when parameters when optional an optional double representing the time (in seconds) when the oscillator should start, in the same coordinate system as audiocontext's currenttime attribute.
... example the following example shows basic usage of an audiocontext to create an oscillator node.
... // create web audio api context var audioctx = new (window.audiocontext || window.webkitaudiocontext)(); // create oscillator node var oscillator = audioctx.createoscillator(); oscillator.type = 'square'; oscillator.frequency.setvalueattime(3000, audioctx.currenttime); // value in hertz oscillator.start(); specifications specification status comment web audio apithe definition of 'start' in that specification.

PannerNode.coneInnerAngle - Web APIs
syntax var audioctx = new audiocontext(); var panner = audioctx.createpanner(); panner.coneinnerangle = 360; value a double.
...they range between -1 and 1 const x = math.cos(radians); const z = math.sin(radians); // we hard-code the y component to 0, as y is the axis of rotation return [x, 0, z]; }; now we can create our audiocontext, an oscillator and a pannernode: const context = new audiocontext(); const osc = new oscillatornode(context); osc.type = 'sawtooth'; const panner = new pannernode(context); panner.panningmodel = 'hrtf'; next, we set up the cone of our spatialised sound, determining the area in which it can be heard: // this value determines the size of the area in which the sound volume is constant //...
... osc.connect(panner) .connect(context.destination); osc.start(0); specifications specification status comment web audio apithe definition of 'coneinnerangle' in that specification.

PannerNode.coneOuterAngle - Web APIs
syntax var audioctx = new audiocontext(); var panner = audioctx.createpanner(); panner.coneouterangle = 0; value a double.
...they range between -1 and 1 const x = math.cos(radians); const z = math.sin(radians); // we hard-code the y component to 0, as y is the axis of rotation return [x, 0, z]; }; now we can create our audiocontext, an oscillator and a pannernode: const context = new audiocontext(); const osc = new oscillatornode(context); osc.type = 'sawtooth'; const panner = new pannernode(context); panner.panningmodel = 'hrtf'; next, we set up the cone of our spatialised sound, determining the area in which it can be heard: // this value determines the size of the area in which the sound volume is constant //...
... osc.connect(panner) .connect(context.destination); osc.start(0); specifications specification status comment web audio apithe definition of 'coneouterangle' in that specification.

PannerNode.coneOuterGain - Web APIs
syntax var audioctx = new audiocontext(); var panner = audioctx.createpanner(); panner.coneoutergain = 0; value a double.
...they range between -1 and 1 const x = math.cos(radians); const z = math.sin(radians); // we hard-code the y component to 0, as y is the axis of rotation return [x, 0, z]; }; now we can create our audiocontext, an oscillator and a pannernode: const context = new audiocontext(); const osc = new oscillatornode(context); osc.type = 'sawtooth'; const panner = new pannernode(context); panner.panningmodel = 'hrtf'; next, we set up the cone of our spatialised sound, determining the area in which it can be heard: // this value determines the size of the area in which the sound volume is constant //...
... osc.connect(panner) .connect(context.destination); osc.start(0); specifications specification status comment web audio apithe definition of 'coneoutergain' in that specification.

PannerNode.rolloffFactor - Web APIs
syntax var audioctx = new audiocontext(); var panner = audioctx.createpanner(); panner.rollofffactor = 1; value a number whose range depends on the distancemodel of the panner as follows (negative values are not allowed): "linear" the range is 0 to 1.
... example this example demonstrates how different rollofffactor values affect how the volume of the test tone decreases with increasing distance from the listener: const context = new audiocontext(); // all our test tones will last this many seconds const note_length = 4; // this is how far we'll move the sound const z_distance = 20; // this function creates a graph for the test tone with a given rollofffactor // and schedules it to move away from the listener along the z (depth-wise) axis // at the given start time, resulting in a decrease in volume (decay) const scheduletesttone = (rollofffactor, s...
...(1, context.currenttime); // this tone should decay slower than the previous one scheduletesttone(0.5, context.currenttime + note_length); // this tone should decay only slightly scheduletesttone(0.1, context.currenttime + note_length * 2); after running this code, the resulting waveforms should look something like this: specifications specification status comment web audio apithe definition of 'rollofffactor' in that specification.

RTCOfferAnswerOptions.voiceActivityDetection - Web APIs
the voiceactivitydetection property of the rtcofferansweroptions dictionary is used to specify whether or not to use automatic voice detection for the audio on an rtcpeerconnection.
... the default value, true, indicates that voice detection should be used and that if possible, the user agent should automatically disable or mute outgoing audio when the audio source is not sensing a human voice.
...the default value, true, indicates that the user agent should monitor the audio coming from the microphone or other audio source and automatically cease transmitting data or mute when the user isn't speaking into the microphone, a value of false indicates that the audio should continue to be transmitted regardless of whether or not speech is detected.

RTCPeerConnection.addStream() - Web APIs
the obsolete rtcpeerconnection method addstream() adds a mediastream as a local source of audio or video.
... example this simple example adds the audio and video stream coming from the user's camera to the connection.
... navigator.mediadevices.getusermedia({video:true, audio:true}, function(stream) { var pc = new rtcpeerconnection(); pc.addstream(stream); }); migrating to addtrack() compatibility allowing, you should update your code to instead use the addtrack() method: navigator.getusermedia({video:true, audio:true}, function(stream) { var pc = new rtcpeerconnection(); stream.gettracks().foreach(function(track) { pc.addtrack(track, stream); }); }); the newer addtrack() api avoids confusion over whether later changes to the track-makeup of a stream affects a peer connection (they do not).

RTCPeerConnection - Web APIs
lso inherits methods from: eventtargetaddicecandidate()when a web site or app using rtcpeerconnection receives a new ice candidate from the remote peer over its signaling channel, it delivers the newly-received candidate to the browser's ice agent by calling rtcpeerconnection.addicecandidate().addstream() the obsolete rtcpeerconnection method addstream() adds a mediastream as a local source of audio or video.
...if no stream matches, it returns null.gettransceivers()the rtcpeerconnection interface's gettransceivers() method returns a list of the rtcrtptransceiver objects being used to send and receive data on the connection.removestream() the rtcpeerconnection.removestream() method removes a mediastream as a local source of audio or video.
... constant description "balanced" the ice agent initially creates one rtcdtlstransport for each type of content added: audio, video, and data channels.

RTCRtpStreamStats.kind - Web APIs
the kind property of the rtcrtpstreamstats dictionary is a string indicating whether the described rtp stream contains audio or video media.
... its value is always either "audio" or "video".
... syntax mediakind = rtcrtpstreamstats.kind; value a domstring whose value is "audio" if the track whose statistics are given by the rtcrtpstreamstats object contains audio, or "video" if the track contains video media.

RTCStatsReport - Web APIs
the statistics object is an rtcaudioreceiverstats object if kind is audio; if kind is video, the object is an rtcvideoreceiverstats object.
...if kind is "audio", this object is of type rtcaudiosenderstats; if kind is "video", this is an rtcvideosenderstats object.
... track the object is one of the types based on rtcmediahandlerstats: for audio tracks, the type is rtcsenderaudiotrackattachmentstats and for video tracks, the type is rtcsendervideotrackattachmentstats.

RTCStatsType - Web APIs
the statistics object is an rtcaudioreceiverstats object if kind is audio; if kind is video, the object is an rtcvideoreceiverstats object.
...if kind is "audio", this object is of type rtcaudiosenderstats; if kind is "video", this is an rtcvideosenderstats object.
... track the object is one of the types based on rtcmediahandlerstats: for audio tracks, the type is rtcsenderaudiotrackattachmentstats and for video tracks, the type is rtcsendervideotrackattachmentstats.

Establishing a connection: The WebRTC perfect negotiation pattern - Web APIs
const constraints = { audio: true, video: true }; const config = { iceservers: [{ urls: "stun:stun.mystunserver.tld" }] }; const selfvideo = document.queryselector("video.selfview"); const remotevideo = document.queryselector("video.remoteview"); const signaler = new signalingchannel(); const pc = new rtcpeerconnection(config); this code also gets the <video> elements using the classes "selfview" and "remoteview"; the...
... handling incoming tracks we next need to set up a handler for track events to handle inbound video and audio tracks that have been negotiatied to be received by this peer connection.
...the former is either the video track or the audio track being received.

Worklet - Web APIs
with worklets, you can run javascript and webassembly code to do graphics rendering or audio processing where high performance is required.
... chrome: main thread gecko: paint thread css painting api audioworklet for audio processing with custom audionodes.
... web audio render thread web audio api animationworklet for creating scroll-linked and other high performance procedural animations.

Media events - Developer guides
various events are sent when handling media that are embedded in html documents using the <audio> and <video> elements; this section lists them and provides some helpful information about using them.
... mozaudioavailable sent when an audio buffer is provided to the audio layer for processing; the buffer contains raw audio samples that may or may not already have been played by the time you receive the event.
... volumechange sent when the audio volume changes (both when the volume is set and when the muted attribute is changed).

HTML5 - Developer guides
multimedia: making video and audio first-class citizens in the open web.
... using html5 audio and video the <audio> and <video> elements embed and allow the manipulation of new multimedia content.
... multimedia using html5 audio and video the <audio> and <video> elements embed and allow the manipulation of new multimedia content.

Developer guides
audio and video delivery we can deliver audio and video on the web in several ways, ranging from 'static' media files to adaptive live streams.
... audio and video manipulation the beauty of the web is that you can combine technologies to create new forms.
... having native audio and video in the browser means we can use these data streams with technologies such as <canvas>, webgl or web audio api to modify audio and video directly, for example adding reverb/compression effects to audio, or grayscale/sepia filters to video.

HTML attribute: accept - HTML: Hypertext Markup Language
microsoft word files can be identified, so a site that accepts word files might use an <input> like this: <input type="file" id="docpicker" accept=".doc,.docx,application/msword,application/vnd.openxmlformats-officedocument.wordprocessingml.document"> whereas if you're accepting a media file, you may want to be include any format of that media type: <input type="file" id="soundfile" accept="audio/*"> <input type="file" id="videofile" accept="video/*"> <input type="file" id="imagefile" accept="image/*"> the accept attribute doesn't validate the types of the selected files; it simply provides hints for browsers to guide users towards selecting the correct file types.
... <p> <label for="soundfile">select an audio file:</label> <input type="file" id="soundfile" accept="audio/*"> </p> <p> <label for="videofile">select a video file:</label> <input type="file" id="videofile" accept="video/*"> </p> <p> <label for="imagefile">select some images:</label> <input type="file" id="imagefile" accept="image/*" multiple> </p> note the last example allows you to select multiple iamges.
... the string audio/* meaning "any audio file".

itemprop - HTML: Hypertext Markup Language
property values are either a string or a url and can be associated with a very wide range of elements including <audio>, <embed>, <iframe>, <img>, <link>, <object>, <source> , <track>, and <video>.
... if the element is a meta element the value is the value of the element's content attribute if the element is an audio, embed, iframe, img, source, track, or video element the value is the resulting url string that results from parsing the value of the element's src attribute relative to the node document (part of the microdata dom api) of the element at the time the attribute is set if the element is an a, area, or link element the value is the resulting url string that results from parsing the...
...the url property elements are the a, area, audio, embed, iframe, img, link, object, source, track, and video elements.

HTML: Hypertext Markup Language
html markup includes special "elements" such as <head>, <title>, <body>, <header>, <footer>, <article>, <section>, <p>, <div>, <span>, <img>, <aside>, <audio>, <canvas>, <datalist>, <details>, <embed>, <nav>, <output>, <progress>, <video>, <ul>, <ol>, <li> and many others.
... multimedia and embedding this module explores how to use html to include multimedia in your web pages, including the different ways that images can be included, and how to embed video, audio, and even entire other webpages.
... guide to media types and formats on the web the <audio> and <video> elements allow you to play audio and video media natively within your content without the need for external software support.

Index - HTTP
40 csp: media-src csp, directive, http, reference, security the http content-security-policy (csp) media-src directive specifies valid sources for loading media using the <audio> and <video> elements.
...the autoplay attribute on <audio> and <video> elements will be ignored.
... 69 feature-policy: microphone feature policy, feature-policy, http, header, microphone the http feature-policy header microphone directive controls whether the current document is allowed to use audio input devices.

List of Mozilla-Based Applications - Archive of obsolete content
tform uses mozilla rhino javalikescript javascript extensible tooling framework uses nspr and spidermonkey jaxer ajax server jslibs javascript development runtime environment uses spidermonkey (note: this is separate from the javascript library jslib) joybidder ebay auction tool standalone version uses xulrunner just (fr) audio a tool for setting temporal tags in audio documents jsdoc toolkit documentation tool uses mozilla rhino k-meleon gecko-based web browser for windows embeds gecko in mfc kairo.at mandelbrot creates images of mandelbrot sets xulrunner application kazehakase gecko-based web browser for unix kirix strata data browser ...
... makes use of some mpl files such as libsecurity_asn1 maemo browser browser for maemo internet tablet development name is microb magooclient business process management tool uses mozilla rhino mantra security tool mccoy secure update tool for add-ons xulrunner application mediacoder media converter transcoder for video, audio, and even devices such as zen, zune, pocketpcs, ipods, and psps mekhala browser part of the khmeros linux distro midbrowser mobile web browser mockery mockup creation tool built on xulrunner mongodb database project uses spidermonkey moyura email client part of the khmeros linux distro mozcards, jolistopwatc...

nsIContentPolicy - Archive of obsolete content
type_media 15 indicates a video or audio load.
... type_internal_audio 30 an internal constant used to represent content loaded from <audio> elements.

Archived Mozilla and build documentation - Archive of obsolete content
introducing the audio api extension the audio data api extension extends the html5 specification of the <audio> and <video> media elements by exposing audio metadata and raw audio data.
... this enables users to visualize audio data, to process this audio data and to create new audio data.

NP_GetMIMEDescription - Archive of obsolete content
#include <libgnomevfs/gnome-vfs-mime-handlers.h> #include <libgnomevfs/gnome-vfs-mime-info.h> #include <libgnomevfs/gnome-vfs-utils.h> // const char* gnome_vfs_mime_get_description (const char *mime_type); const char* desc = gnome_vfs_mime_get_description ("audio/ogg"); if you use gnome gio (gio-2.0), you can get the mime type description too.
... #include <gio/gio.h> const char* desc = g_content_type_get_description("audio/ogg"); javascript inside a web page, you can retrieve these informations with this code: var mimetype = navigator.mimetypes['application/basic-example-plugin']; if (mimetype) { alert(mimetype.type + ':' + mimetype.suffixes + ':' + mimetype.description); } ...

SDP - MDN Web Docs Glossary: Definitions of Web-related terms
sdp contains the codec, source address, and timing information of audio and video.
... here is a typical sdp message: v=0 o=alice 2890844526 2890844526 in ip4 host.anywhere.com s= c=in ip4 host.anywhere.com t=0 0 m=audio 49170 rtp/avp 0 a=rtpmap:0 pcmu/8000 m=video 51372 rtp/avp 31 a=rtpmap:31 h261/90000 m=video 53000 rtp/avp 32 a=rtpmap:32 mpv/90000 sdp is never used alone, but by protocols like rtp and rtsp.

HTML: A good basis for accessibility - Learn web development
text alternatives whereas textual content is inherently accessible, the same cannot necessarily be said for multimedia content — image and video content cannot be seen by visually-impaired people, and audio content cannot be heard by hearing-impaired people.
... we cover video and audio content in detail in the accessible multimedia, but for this article we'll look at accessibility for the humble <img> element.

HTML: A good basis for accessibility - Learn web development
text alternatives whereas textual content is inherently accessible, the same cannot necessarily be said for multimedia content — image and video content cannot be seen by visually-impaired people, and audio content cannot be heard by hearing-impaired people.
... we cover video and audio content in detail in the accessible multimedia, but for this article we'll look at accessibility for the humble <img> element.

Pseudo-classes and pseudo-elements - Learn web development
:playing matches an element representing an audio, video, or similar resource that is capable of being “played” or “paused”, when that element is “playing”.
... :paused matches an element representing an audio, video, or similar resource that is capable of being “played” or “paused”, when that element is “paused”.

Creating hyperlinks - Learn web development
note: a url can point to html files, text files, images, text documents, video and audio files, or anything else that lives on the web.
... linking to non-html resources — leave clear signposts when linking to a resource that will be downloaded (like a pdf or word document), streamed (like video or audio), or has another potentially unexpected effect (opens a popup window, or loads a flash movie), you should add clear wording to reduce any confusion.

Multimedia and Embedding - Learn web development
this module explores how to use html to include multimedia in your web pages, including the different ways that images can be included, and how to embed video, audio, and even entire webpages.
... video and audio content next, we'll look at how to use the html5 <video> and <audio> elements to embed video and audio on our pages, including basics, providing access to different file formats to different browsers, adding captions and subtitles, and how to add fallbacks for older browsers.

Introduction to events - Learn web development
the media recorder api, for example, has a dataavailable event, which fires when some audio or video has been recorded and is available for doing something with (for example saving it, or playing it back).
... the corresponding ondataavailable handler's event object has a data property available containing the recorded audio or video data to allow you to access it and do something with it.

Software accessibility: Where are we today?
this tends to be somewhat less of a limitation in that most software doesn't rely exclusively on audio to relay feedback.
... refreshable braille displays of various sizes a braille embosser audio- and braille- based user interfaces are concepts that software designers are historically untrained for.

Mozilla’s UAAG evaluation report
(p1) c preferences, appearance, colors - "use my chosen colors, ignoring the colors and background image specified" 3.2 toggle audio, video, animated images.
... (p1) p animated images can be made still with the escape key animated images can be made still as a preference under preferences, privacy & security, images - "animated images should loop" mozilla has no preference or command to toggle audio or video 3.3 toggle animated/blinking text.

nsIDOMHTMLSourceElement
the nsidomhtmlsourceelement interface is the dom interface to the source child of the audio and video media elements in html.
...note that dynamically manipulating this value after the page has loaded has no effect on the containing element; instead, change the src attribute of that element (audio or video) instead.

nsISound
please use the html 5 <audio> tag instead.
...please use the html 5 <audio> tag instead.

Index - Firefox Developer Tools
to activate view source: 145 web audio editor firefox, mozilla, tools, web audio api with the web audio api, developers create an audio context.
... within that context they then construct a number of audio nodes, including: 146 web console debugging, guide, security, tools, web development, web development:tools, l10n:priority, web console the web console: 147 console messages most of the web console is occupied by the message display pane: 148 invoke getters from autocomplete no summary!

Using channel messaging - Web APIs
use cases channel messaging is mainly useful in cases where you've got a social site that embeds capabilities from other sites into its main interface via iframes, such as games, address book, or an audio player with personalized music choices.
...for example, what if you wanted to add a contact to the address book from the main site, add high scores from your game into your main profile, or add new background music choices from the audio player onto the game?

DynamicsCompressorNode() - Web APIs
syntax var dynamicscompressornode = new dynamicscompressornode(context, options) parameters context a reference to an audiocontext.
... specifications specification status comment web audio apithe definition of 'dynamicscompressornode()' in that specification.

Event - Web APIs
animationevent audioprocessingevent beforeinputevent beforeunloadevent blobevent clipboardevent closeevent compositionevent cssfontfaceloadevent customevent devicelightevent devicemotionevent deviceorientationevent deviceproximityevent domtransactionevent dragevent editingbeforeinputevent errorevent fetchevent focusevent gamepadevent hashchangeevent idbversionchangeevent inputevent keyboardeven...
...t mediastreamevent messageevent mouseevent mutationevent offlineaudiocompletionevent overconstrainederror pagetransitionevent paymentrequestupdateevent pointerevent popstateevent progressevent relatedevent rtcdatachannelevent rtcidentityerrorevent rtcidentityevent rtcpeerconnectioniceevent sensorevent storageevent svgevent svgzoomevent timeevent touchevent trackevent transitionevent uievent userproximityevent webglcontextevent wheelevent constructor event() creates an event object, returning it to the caller.

Introduction to the File and Directory Entries API - Web APIs
audio or photo editor with offline access or local cache (great for performance and speed) the app can write to files in place (for example, overwriting just the id3/exif tags and not the entire file).
...a blob can be an image or an audio file.

HTMLMediaElement: ended event - Web APIs
this event occurs based upon htmlmediaelement (<audio> and <video>) fire ended when playback of the media reaches the end of the media.
... bubbles no cancelable no interface event target element default action none event handler property globaleventhandlers.onended specification html5 media this event is also defined in media capture and streams and web audio api examples these examples add an event listener for the htmlmediaelement's ended event, then post a message when that event handler has reacted to the event firing.

HTMLMediaElement.load() - Web APIs
usage notes calling load() aborts all ongoing operations involving this media element, then begins the process of selecting and loading an appropriate media resource given the options specified in the <audio> or <video> element and its src attribute or child <source> element(s).
... this is described in more detail in supporting multiple formats in video and audio content.

HTMLMediaElement.sinkId - Web APIs
the htmlmediaelement.sinkid read-only property returns a domstring that is the unique id of the audio device delivering output.
... syntax var sinkid = htmlmediaelement.sinkid specifications specification status comment audio output devices apithe definition of 'sinkid' in that specification.

IIRFilterNode.getFrequencyResponse() - Web APIs
ocument.queryselector('.freq-response-output'); finally, after creating our filter, we use getfrequencyresponse() to generate the response data and put it in our arrays, then loop through each data set and output them in a human-readable list at the bottom of the page: var feedforwardcoefficients = [0.1, 0.2, 0.3, 0.4, 0.5]; var feedbackcoefficients = [0.5, 0.4, 0.3, 0.2, 0.1]; var iirfilter = audioctx.createiirfilter(feedforwardcoefficients, feedbackcoefficients); ...
...i <= myfrequencyarray.length-1;i++){ var listitem = document.createelement('li'); listitem.innerhtml = '<strong>' + myfrequencyarray[i] + 'hz</strong>: magnitude ' + magresponseoutput[i] + ', phase ' + phaseresponseoutput[i] + ' radians.'; freqresponseoutput.appendchild(listitem); } } calcfrequencyresponse(); specifications specification status comment web audio apithe definition of 'getfrequencyresponse()' in that specification.

MediaCapabilities.encodingInfo() - Web APIs
syntax mediacapabilities.encodinginfo(mediaencodingconfiguration) parameters mediaencodingconfiguration a valid mediaencodingconfiguration dictionary containing a valid media encoding type of record or transmission and a valid media configuration: either an audioconfiguration or videoconfiguration dictionary.
... return value a promise fulfilling with a mediacapabilitiesinfo interface containing three boolean attributes: supported smooth powerefficient exceptions a typeerror is raised if the mediaconfiguration passed to the encodinginfo() method is invalid, either because the type is not video or audio, the contenttype is not a valid codec mime type, or any other error in the media configuration passed to the method, including omitting any of the media encoding configuration elements.

MediaCapabilitiesInfo - Web APIs
all supported audio codecs are reported to be power efficient.
... example // mediaconfiguration to be tested const mediaconfig = { type : 'file', audio : { contenttype : "audio/ogg", channels : 2, bitrate : 132700, samplerate : 5200 }, }; // check support and performance navigator.mediacapabilities.decodinginfo(mediaconfig).then(result => { // result contains the media capabilities information console.log('this configuration is ' + (result.supported ?