The MediaTrackSettings
dictionary is used to return the current values configured for each of a MediaStreamTrack
's settings. These values will adhere as closely as possible to any constraints previously described using a MediaTrackConstraints
object and set using applyConstraints()
, and will adhere to the default constraints for any properties whose constraints haven't been changed, or whose customized constraints couldn't be matched.
To learn more about how constraints and settings work, see Capabilities, constraints, and settings.
Properties
Some or all of the following will be included in the object, either because it's not supported by the browser or because it's not available due to context. For example, because RTP doesn't provide some of these values during negotiation of a WebRTC connection, a track associated with a RTCPeerConnection
will not include certain values, such as facingMode
or groupId
.
Properties of all media tracks
deviceId
- A
DOMString
indicating the current value of the
property. The device ID is a origin-unique string identifying the source of the track; this is usually a GUID. This value is specific to the source of the track's data and is not usable for setting constraints; it can, however, be used for initially selecting media when callingdeviceId
MediaDevices.getUserMedia()
. groupId
- A
DOMString
indicating the current value of the
property. The group ID is a browsing session-unique string identifying the source group of the track. Two devices (as identified by thegroupId
deviceId
) are considered part of the same group if they are from the same physical device. 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. The microphone on a headset would have a different ID, though. This value is specific to the source of the track's data and is not usable for setting constraints; it can, however, be used for initially selecting media when callingMediaDevices.getUserMedia()
.
Properties of audio tracks
autoGainControl
- A Boolean which indicates the current value of the
autoGainControl
property, which istrue
if automatic gain control is enabled and isfalse
otherwise. channelCount
- A long integer value indicating the current value of the
property, specifying the number of audio channels present on the track (therefore indicating how many audio samples exist in each audio frame). This is 1 for mono, 2 for stereo, and so forth.channelCount
echoCancellation
- A Boolean indicating the current value of the
property, specifyingechoCancellation
true
if echo cancellation is enabled, otherwisefalse
. latency
- A double-precision floating point value indicating the current value of the
property, specifying the audio latency, in seconds. Latency is the amount of time which elapses between the start of processing the audio and the data being available to the next stop in the audio utilization process. This value is a target value; actual latency may vary to some extent for various reasons.latency
noiseSuppression
- A Boolean which indicates the current value of the
noiseSupression
property, which istrue
if noise suppression is enabled and isfalse
otherwise.
sampleRate
- A long integer value indicating the current value of the
property, specifying the sample rate in samples per second of the audio data. Standard CD-quality audio, for example, has a sample rate of 41,000 samples per second.sampleRate
sampleSize
- A long integer value indicating the current value of the
property, specifying the linear size, in bits, of each audio sample. CD-quality audio, for example, is 16-bit, so this value would be 16 in that case.sampleSize
volume
- A double-precision floating point value indicating the current value of the
property, specifying the volume level of the track. This value will be between 0.0 (silent) to 1.0 (maximum supported volume).volume
Properties of video tracks
aspectRatio
- A double-precision floating point value indicating the current value of the
property, specified precisely to 10 decimal places. This is the width of the image in pixels divided by its height in pixels. Common values include 1.3333333333 (for the classic television 4:3 "standard" aspect ratio, also used on tablets such as Apple's iPad), 1.7777777778 (for the 16:9 high-definition widescreen aspect ratio), and 1.6 (for the 16:10 aspect ratio common among widescreen computers and tablets).aspectRatio
facingMode
- A
DOMString
indicating the current value of the
property, specifying the direction the camera is facing. The value will be one of:facingMode
"user"
- A camera facing the user (commonly known as a "selfie cam"), used for self-portraiture and video calling.
"environment"
- A camera facing away from the user (when the user is looking at the screen). This is typically the highest quality camera on the device, used for general photography.
"left"
- A camera facing toward the environment to the user's left.
"right"
- A camera facing toward the environment to the user's right.
frameRate
- A double-precision floating point value indicating the current value of the
property, specifying how many frames of video per second the track includes. If the value can't be determined for any reason, the value will match the vertical sync rate of the device the user agent is running on.frameRate
height
- A long integer value indicating the current value of the
property, specifying the height of the track's video data in pixels.height
width
- A long integer value indicating the current value of the
width
property, specifying the width of the track's video data in pixels. resizeMode
- A
DOMString
indicating the current value of the
property, specifying the mode used by the user agent to derive the resolution of the track. The value will be one of:resizeMode
"none"
- The track has the resolution offered by the camera, its driver or the OS.
"crop-and-scale"
- The track's resolution might be the result of the user agent using cropping or downscaling from a higher camera resolution.
Properties of shared screen tracks
Tracks containing video shared from a user's screen (regardless of whether the screen data comes from the entire screen or a portion of a screen, like a window or tab) are generally treated like video tracks, with the exception that they also support the following added settings:
cursor
-
A
DOMString
which indicates whether or not the mouse cursor is being included in the generated stream and under what conditions. Possible values are:always
- The mouse is always visible in the video content of the {domxref("MediaStream"), unless the mouse has moved outside the area of the content.
motion
- The mouse cursor is always included in the video if it's moving, and for a short time after it stops moving.
never
- The mouse cursor is never included in the shared video.
displaySurface
-
A
DOMString
which specifies the type of source the track contains; one of:application
- The stream contains all of the windows of the application chosen by the user rendered into the one video track.
browser
- The stream contains the contents of a single browser tab selected by the user.
monitor
- The stream's video track contains the entire contents of one or more of the user's screens.
window
- The stream contains a single window selected by the user for sharing.
logicalSurface
- A Boolean value which, if
true
, indicates that the video contained in the stream's video track contains a background rendering context, rather than a user-visible one. This isfalse
if the video being captured is coming from a foreground (user-visible) source.
Specifications
Specification | Status | Comment |
---|---|---|
Screen Capture The definition of 'MediaTrackSettings' in that specification. |
Working Draft | Initial definition |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
MediaTrackSettings | Chrome Full support 59 | Edge Full support ≤79 | Firefox Full support Yes | IE ? | Opera Full support Yes | Safari ? | WebView Android Full support 59 | Chrome Android Full support 59 | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support 7.0 |
aspectRatio | Chrome Full support Yes | Edge Full support ≤79 | Firefox No support No | IE ? | Opera Full support Yes | Safari ? | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android No support No | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
autoGainControl | Chrome Full support Yes | Edge Full support ≤79 | Firefox
Full support
55
| IE ? | Opera Full support Yes | Safari ? | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android
Full support
55
| Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
channelCount | Chrome No support No | Edge No support No | Firefox No support No | IE ? | Opera No support No | Safari ? | WebView Android No support No | Chrome Android No support No | Firefox Android No support No | Opera Android No support No | Safari iOS ? | Samsung Internet Android No support No |
cursor | Chrome Full support 71 | Edge Full support ≤79 | Firefox No support No | IE No support No | Opera Full support Yes | Safari ? | WebView Android Full support 71 | Chrome Android Full support 71 | Firefox Android No support No | Opera Android ? | Safari iOS ? | Samsung Internet Android Full support 10.0 |
deviceId | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support 69 | IE ? | Opera Full support Yes | Safari ? | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android No support No | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
displaySurface | Chrome Full support 71 | Edge Full support ≤79 | Firefox No support No | IE No support No | Opera Full support Yes | Safari ? | WebView Android Full support 71 | Chrome Android Full support 71 | Firefox Android No support No | Opera Android ? | Safari iOS ? | Samsung Internet Android Full support 10.0 |
echoCancellation | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support 50 | IE ? | Opera Full support Yes | Safari ? | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 50 | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
facingMode | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support 69 | IE ? | Opera Full support Yes | Safari ? | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android No support No | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
frameRate | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support 36 | IE ? | Opera Full support Yes | Safari ? | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 36 | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
groupId | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support 69 | IE ? | Opera Full support Yes | Safari ? | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android No support No | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
height | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support 36 | IE ? | Opera Full support Yes | Safari ? | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 36 | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
latency | Chrome No support No | Edge No support No | Firefox No support No | IE ? | Opera No support No | Safari ? | WebView Android No support No | Chrome Android No support No | Firefox Android No support No | Opera Android No support No | Safari iOS ? | Samsung Internet Android No support No |
logicalSurface | Chrome Full support 71 | Edge Full support ≤79 | Firefox No support No | IE No support No | Opera Full support Yes | Safari ? | WebView Android Full support 71 | Chrome Android Full support 71 | Firefox Android No support No | Opera Android ? | Safari iOS ? | Samsung Internet Android Full support 10.0 |
noiseSuppression | Chrome Full support Yes | Edge Full support ≤79 | Firefox
Full support
55
| IE ? | Opera Full support Yes | Safari ? | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android
Full support
55
| Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
resizeMode | Chrome No support No | Edge No support No | Firefox No support No | IE ? | Opera No support No | Safari ? | WebView Android No support No | Chrome Android No support No | Firefox Android No support No | Opera Android No support No | Safari iOS ? | Samsung Internet Android No support No |
sampleRate | Chrome No support No | Edge No support No | Firefox No support No | IE ? | Opera No support No | Safari ? | WebView Android No support No | Chrome Android No support No | Firefox Android No support No | Opera Android No support No | Safari iOS ? | Samsung Internet Android No support No |
sampleSize | Chrome Full support Yes | Edge Full support ≤79 | Firefox No support No | IE ? | Opera Full support Yes | Safari ? | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android No support No | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
volume | Chrome No support No | Edge No support No | Firefox No support No | IE ? | Opera No support No | Safari ? | WebView Android No support No | Chrome Android No support No | Firefox Android No support No | Opera Android No support No | Safari iOS ? | Samsung Internet Android No support No |
width | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support 36 | IE ? | Opera Full support Yes | Safari ? | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 36 | Opera Android Full support Yes | Safari iOS ? | Samsung Internet Android Full support Yes |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
- Non-standard. Expect poor cross-browser support.
- Non-standard. Expect poor cross-browser support.
- Deprecated. Not for use in new websites.
- Deprecated. Not for use in new websites.
- Requires a vendor prefix or different name for use.
- Requires a vendor prefix or different name for use.