Web audio codec guide - Web media technologies
codec name (short) full codec name container support aac advanced audio coding mp4, adts, 3gp alac apple lossless audio codec mp4, quicktime (mov) amr adaptive multi-rate 3gp flac free lossless audio codec mp4, ogg, flac g.711 pulse code modulation (pcm) of voice frequencies rtp / webrtc g.722 7 khz audio coding within 64 kbps (for telephony/voip) rtp / webrtc mp3 mpeg-1 audio layer iii mp4, adts, mpeg1, 3gp opus opus webm, mp4, ogg vorbis vorbis webm, ogg [1] when mpeg-1 audio layer iii codec data is stored in an mpeg file, and there is no video track on the file, the file is typically referred to as an mp3 file, even though it's still ...
...human speech generally resides within the audio frequency range of 300 hz to 18 khz.
... however, the vast majority of human vocalizations exist in the range 300 hz to 8 khz, and you can capture enough of human vocalizations in the frequency range 500 hz to 3 khz to still be understandable.
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Digital audio concepts - Web media technologies
at the common sample rate of 48 khz (48,000 samples per second), this means each second of audio occupies 192 kb of memory.
... the most common sample rates are: 8000 hz the international g.711 standard for audio used in telephony uses a sample rate of 8000 hz (8 khz).
... 44100 hz the 44.1 khz sample rate is used for compact disc (cd) audio.
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Rendering and the WebXR frame animation callback - Web APIs
this figure goes by a number of different names, but they're all equivalent or nearly so: refresh rate vertical refresh rate vertical blanking rate (vbl) vertical sync rate vertical refresh rate there are other similar terms used as well, but regardless of what it's called, the unit of measurement applied is the hertz, or hz.
... a display that refreshes 60 times per second has a 60 hz refresh rate.
... but not all displays run at 60 hz; nowadays, higher performance displays are beginning to use much higher refresh rates.
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Basic concepts behind Web Audio API - Web APIs
a frame, or sample frame, is the set of all values for all channels that will play at a specific point in time: all the samples of all the channels that play at the same time (two for a stereo sound, six for 5.1, etc.) the sample rate is the number of those samples (or frames, since all samples of a frame play at the same time) that will play in one second, measured in hz.
... let's look at a mono and a stereo audio buffer, each is one second long, and playing at 44100hz: the mono buffer will have 44100 samples, and 44100 frames.
... here's a couple of simple examples: var context = new audiocontext(); var buffer = context.createbuffer(2, 22050, 44100); note: in digital audio, 44,100 hz (alternately represented as 44.1 khz) is a common sampling frequency.
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<frequency> - CSS: Cascading Style Sheets
units hz represents a frequency in hertz.
... examples: 0hz, 1500hz, 10000hz.
... khz represents a frequency in kilohertz.
...And 6 more matches

attr() - CSS: Cascading Style Sheets
30.5khz).
... 0hz, or, if 0hz is not a valid value for the property, the property's minimum value.
... hz, khz <frequency> the attribute value is parsed as a css <number>, that is without the unit (e.g.
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Cooperative asynchronous JavaScript: Timeouts and intervals - Learn web development
since most screens have a refresh rate of 60hz, the fastest frame rate you can aim for is 60 frames per second (fps) when working with web browsers.
... if you have a monitor with a 60hz refresh rate and you want to achieve 60 fps you have about 16.7 milliseconds (1000 / 60) to execute your animation code to render each frame.
...we arrived at our final value of 17 via the formula 1000 milliseconds / 60hz, and then rounded it up.
...as we said before, 60hz is the standard refresh rate.

Power profiling overview
for example, the gecko profiler takes samples at 1000hz using a timer.
...1hz.) p-states intel processors also support multiple p-states.
...they are also updated frequently, at approximately 1,000 hz, though the variability in their update latency means that they are probably only accurate at lower frequencies, e.g.
... up to 20 hz or so.

AudioBufferSourceNode.playbackRate - Web APIs
consider a sound buffer containing audio sampled at 44.1 khz (44,100 samples per second).
... let's see what a few values of playbackrate do: a playbackrate of 1.0 plays the audio at full speed, or 44,100 hz.
... a playbackrate of 0.5 plays the audio at half speed, or 22,050 hz.
... a playbackrate of 2.0 doubles the audio's playback rate to 88,200 hz.

Advanced techniques: Creating and sequencing audio - Web APIs
one will change the tone and the other will change how the pulse modulates the first wave: <label for="hz">hz</label> <input name="hz" id="hz" type="range" min="660" max="1320" value="880" step="1" /> <label for="lfo">lfo</label> <input name="lfo" id="lfo" type="range" min="20" max="40" value="30" step="1" /> as before, we'll vary the parameters when the range input values are changed by the user.
... let pulsehz = 880; const hzcontrol = document.queryselector('#hz'); hzcontrol.addeventlistener('input', function() { pulsehz = number(this.value); }, false); let lfohz = 30; const lfocontrol = document.queryselector('#lfo'); lfocontrol.addeventlistener('input', function() { lfohz = number(this.value); }, false); the final playpulse() function here's the entire playpulse() function: let pulsetime = 1; function playpulse() { let osc = audioctx.createoscillator(); osc.type = 'sine'; osc.frequency.setvalueattime(pulsehz, audioctx.currenttime); let amp = audioctx.creategain(); amp.gain.setvalueattime(1, audioctx.currenttime); let lfo = audioctx.createoscillator(); lfo.type = 'square'; lfo.frequency.setvalueattime(lfohz, audioctx.currenttime); l...
...input name="duration" id="duration" type="range" min="0" max="2" value="1" step="0.1" /> <label for="band">band</label> <input name="band" id="band" type="range" min="400" max="1200" value="1000" step="5" /> let noiseduration = 1; const durcontrol = document.queryselector('#duration'); durcontrol.addeventlistener('input', function() { noiseduration = number(this.value); }, false); let bandhz = 1000; const bandcontrol = document.queryselector('#band'); bandcontrol.addeventlistener('input', function() { bandhz = number(this.value); }, false); the final playnoise() function here's the entire playnoise() function: function playnoise() { const buffersize = audioctx.samplerate * noiseduration; // set the time of the note const buffer = audioctx.createbuffer(1, buffersize, au...
...getchanneldata(0); // get data // fill the buffer with noise for (let i = 0; i < buffersize; i++) { data[i] = math.random() * 2 - 1; } // create a buffer source for our created data let noise = audioctx.createbuffersource(); noise.buffer = buffer; let bandpass = audioctx.createbiquadfilter(); bandpass.type = 'bandpass'; bandpass.frequency.value = bandhz; // connect our graph noise.connect(bandpass).connect(audioctx.destination); noise.start(); } "dial up" — loading a sound sample it's straightforward enough to emulate phone dial (dtmf) sounds, by playing a couple of oscillators together using the methods we've already looked at, however, in this section, we'll load in a sample file instead so we can take a look at what's involve...

Tamarin-central rev 703:2cee46be9ce0 - Archive of obsolete content
osdefault-jitinterpretedaggressive jit mac (os/x 10.4 intel, 2ghz dual core)tc-703 vs tc-700: 0.0%tc-703 vs flash10: 1.1% slowertc-703 vs tc-700: 17.4% fastertc-703 vs flash10: 165.3% fastertc-703 vs tc-700: 0.1% fastertc-703 vs flash10: 0.8% slower windows (xp pro, 2.13ghz dual core)tc-703 vs tc-700: 0.6% fastertc-703 vs flash10: 0.8% fastertc-703 vs tc-700: 16.4% fastertc-703 vs flash10: 148.7% fastertc-703 vs tc-700: 0.1% slowertc-703 vs flash10: 5.
...2% faster linux (ubuntu linux, 2.13 ghz dual core)tc-703 vs tc-700: 6.0% fastertc-703 vs flash10: 1.7% fastertc-703 vs tc-700: 89.5% fastertc-703 vs flash10: 182.0% fastertc-703 vs tc-700: 6.1% fastertc-703 vs flash10: 1.4% faster performance testuite memory metric the following is a comparison of the current tamarin-central (tc-703) versus the prior build (tc-700).
... osdefault-jitinterpretedaggressive jit mac (os/x 10.4 intel, 2ghz dual core)tc-703 vs tc-700: 2.0% smallertc-703 vs tc-663: 7.8% smallertc-703 vs tc-700: 7.1% largertc-703 vs tc-663: 14.6% largertc-703 vs tc-700: 16.4% largertc-703 vs tc-663: 2.1% larger windows (xp pro, 2.13ghz dual core)tc-703 vs tc-700: 3.2% largertc-703 vs tc-663: 7.6% largertc-703 vs tc-700: 3.9% largertc-703 vs tc-663: 12.4% largertc-703 vs tc-700: 3.3% largertc-703 vs tc-663: 21.4% larger linux (ubuntu linux, 2.13 ghz dual core)n/an/an/a vm code size the following is a comparison of the current tamarin-central compiled size (...

Anatomy of a video game - Game development
all of the above steps must take place every 16-and-a-half milliseconds to keep up with a 60 hz display.
...it is 20 hz (50ms) here.
... mygame.ticklength = 50; // this sets your simulation to run at 20hz (50ms) setinitialstate(); main(performance.now()); // start the cycle })(); another alternative is to simply do certain things less often.

BaseAudioContext.createBuffer() - Web APIs
all browsers must support sample rates in at least the range 8,000 hz to 96,000 hz.
... examples first, a couple of simple trivial examples, to help explain how the parameters are used: var audioctx = new audiocontext(); var buffer = audioctx.createbuffer(2, 22050, 44100); if you use this call, you will get a stereo buffer (two channels), that, when played back on an audiocontext running at 44100hz (very common, most normal sound cards run at this rate), will last for 0.5 seconds: 22050 frames / 44100hz = 0.5 seconds.
... var audioctx = new audiocontext(); var buffer = audioctx.createbuffer(1, 22050, 22050); if you use this call, you will get a mono buffer (one channel), that, when played back on an audiocontext running at 44100hz, will be automatically *resampled* to 44100hz (and therefore yield 44100 frames), and last for 1.0 second: 44100 frames / 44100hz = 1 second.

OfflineAudioContext.OfflineAudioContext() - Web APIs
for example, a 5-second buffer with a samplerate of 48000hz would have a length of 5 * 48000 = 240000 sample-frames.
...all user agents are required to support a range of 22050hz to 96000hz, and may support a wider range than that.
... the most commonly-used rate is 44100hz, which is the sample rate used by cd audio.

SubtleCrypto.importKey() - Web APIs
a pem-encoded privatekeyinfo looks like this: -----begin private key----- mig2ageambagbyqgsm49agegbsubbaaibigemigbagebbdau9bd0jxdff5ov380z 9vieun2w5kjdz3hbuadencxliamsoquktffaou71eldn0tshzaniaarmuhcee/cp xmjgc1roj0d0k6vluqta+jvcwigxciaukoethcngzdkcrd4pkxdbvbcijdzkvo+l ml2fikoovzh/8yetkmjumb804g6omjuc9vvojcrv0ydasmykkjmjblg= -----end private key----- to get this into a format you can give to importkey() you need to do two things: base64-decode the part between header and footer, using window.atob().
...buffer-to-and-from-string */ function str2ab(str) { const buf = new arraybuffer(str.length); const bufview = new uint8array(buf); for (let i = 0, strlen = str.length; i < strlen; i++) { bufview[i] = str.charcodeat(i); } return buf; } const pemencodedkey = `-----begin private key----- 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...
... bufview[i] = str.charcodeat(i); } return buf; } const pemencodedkey = `-----begin public key----- miibijanbgkqhkig9w0baqefaaocaq8amiibcgkcaqeay3xo3u13dc+xojwqywojlcboq5fovy8llnqcjm1w1bftxihoajwohihuirmctv7dzx47tllmarskvtrjd0df92jx/xy20lz+dxp8yl5yuwafga3xko3lsjgeoex10nb8jfkmgsb7qiudtvvbbudfd5fwibmctacwwx7nyewwdb7a9cfxj7ejrdrdak3ux/tomlhfxvlqsl341tkcf4zqoz96rfpugpplofvn0x66cm1pqckdhzje6u5xge964zkkyuppsy6dcie4obhw4vdjgumlzv0z7ud010rlineugde2fqbfy/c+uwignpbpkkq+bv/uigs6dhqtcved5wgybqidaqab -----end public key-----`; function importrsakey(pem) { // fetch the part of the pem string between header and footer const pemheader = "-----begin public key-----"; const pemfooter = "-----end public key-----"; const pemcontents = pem.substring(pemheader.length, pem.length...