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.


var rtcRtpContributingSources = rtcRtpReceiver.getContributingSources()



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 timestampsource, and audioLevel.

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


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

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