RTCRtpReceiver.getSynchronizationSources()

The getSynchronizationSources() method of the RTCRtpReceiver interface returns an array of RTCRtpContributingSource instances, each corresponding to one SSRC (synchronization source) identifier received by the current RTCRtpReceiver in the last ten seconds.

Syntax

var rtcRtpContributingSources = rtcRtpReceiver.getContributingSources()

Parameters

None.

Return value

An array of RTCRtpSynchronizationSource instances. Each instance describes one of the synchronization sources that provided data to the incoming stream in the past ten seconds.

As you'll see in the documentarion for RTCRtpSynchronizationSource, it inherits the properties of RTCRtpContributingSource, including timestamp, source, and audioLevel.

The synchronization source objects add a voiceActivityFlag property, which indicates if the last RTP packet received contained voice activity.

Specifications

Specification Status Comment
WebRTC 1.0: Real-time Communication Between Browsers
The definition of 'getSynchronizationSources()' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
getSynchronizationSourcesChrome Full support 73Edge Full support ≤79Firefox Full support 59IE No support NoOpera Full support 60Safari ? WebView Android Full support 73Chrome Android Full support 73Firefox Android Full support 59
Disabled
Full support 59
Disabled
Disabled From version 59: this feature is behind the media.peerconnection.rtpsourcesapi.enable preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 52Safari iOS ? Samsung Internet Android Full support 11.0
Audio tracks supportedChrome Full support 73Edge Full support 79Firefox Full support 59IE No support NoOpera Full support 60Safari ? WebView Android Full support 73Chrome Android Full support 73Firefox Android Full support 59
Disabled
Full support 59
Disabled
Disabled From version 59: this feature is behind the media.peerconnection.rtpsourcesapi.enable preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 52Safari iOS ? Samsung Internet Android Full support 11.0
Video tracks supportedChrome Full support 73Edge Full support ≤79Firefox Full support 68IE No support NoOpera Full support 60Safari ? WebView Android Full support 73Chrome Android Full support 73Firefox Android Full support 68
Disabled
Full support 68
Disabled
Disabled From version 68: this feature is behind the media.peerconnection.rtpsourcesapi.enable preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 52Safari iOS ? Samsung Internet Android Full support 11.0

Legend

Full support
Full support
No support
No support
Compatibility unknown
Compatibility unknown
User must explicitly enable this feature.
User must explicitly enable this feature.