The RTCRtpContributingSource dictionary of the WebRTC API is used by getContributingSources() to provide information about a given contributing source (CSRC), including the most recent time a packet that the source contributed was played out.

The information provided is based on the last ten seconds of media received.


audioLevel Optional
A double-precision floating-point value between 0 and 1 specifying the audio level contained in the last RTP packet played from this source.
rtpTimestamp Optional
The RTP timestamp of the media played out at the time indicated by timestamp. This value is a source-generated time value which can be used to help with sequencing and synchronization.
source Optional
A 32-bit unsigned integer value specifying the CSRC identifier of the contributing source.
timestamp Optional
A DOMHighResTimeStamp indicating the most recent time at which a frame originating from this source was delivered to the receiver's MediaStreamTrack


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

Browser compatibility

BCD tables only load in the browser