RTCRtpStreamStats.codecId - Web APIs
the rtcrtpstreamstats dictionary's codecid property is a string which uniquely identifies the object that was inspected to produce the data in the rtccodecstats for the rtp stream.
... syntax var codecid = rtcrtpstreamstats.codecid; value a domstring which uniquely identifies the object from which the contents of the stream's rtccodecstats are derived.

RTCRtpStreamStats - Web APIs
standard fields included for all media types codecid a domstring which uniquely identifies the object which was inspected to produce the rtccodecstats object associated with this rtp stream.
...this value will match that of the media type indicated by rtccodecstats.codec, as well as the track's kind property.

Index - Web APIs
3502 rtcrtpstreamstats.codecid api, codec, dictionary, interface, property, rtcrtpstreamstats, rtp, reference, statistics, webrtc, webrtc api, webrtc statistics, codecid, id, rtc the rtcrtpstreamstats dictionary's codecid property is a string which uniquely identifies the object that was inspected to produce the data in the rtccodecstats for the rtp stream.

RTCRtpStreamStats.kind - Web APIs
it will also match the statistics object's rtccodecstats.codec property's media type.

RTCStatsReport - Web APIs
codec an rtccodecstats object containing statistics about a codec currently being used by rtp streams to send or receive data for the rtcpeerconnection.

RTCStatsType - Web APIs
codec an rtccodecstats object containing statistics about a codec currently being used by rtp streams to send or receive data for the rtcpeerconnection.

WebRTC Statistics API - Web APIs
rtccodecstats rtcstats csrc statistics for a single contributing source (csrc) that contributed to one of the connection's inbound rtp streams.