RTCOutboundRtpStreamStats.framesEncoded - Web APIs
the framesencoded property of the rtcoutboundrtpstreamstats dictionary indicates the total number of frames that have been encoded by this rtcrtpsender for this media source.
... syntax var framesencoded = rtcoutboundrtpstreamstats.framesencoded; value an integer value indicating the total number of video frames that this sender has encoded so far for this stream.
... specifications specification status comment identifiers for webrtc's statistics apithe definition of 'rtcoutboundrtpstreamstats.framesencoded' in that specification.

RTCInboundRtpStreamStats.qpSum - Web APIs
you can, for example, use the value of rtcreceivedrtpstreamstats.framesdecoded if receiving the media or rtcsentrtpstreamstats.framesencoded if sending it to get the number of frames handled so far, and compute an average from there.
... function calculateaverageqp(stats) { let framecount = 0; switch(stats.type) { case "inbound-rtp": case "remote-inbound-rtp": framecount = stats.framesdecoded; break; case "outbound-rtp": case "remote-outbound-rtp": framecount = stats.framesencoded; break; default: return 0; } return status.qpsum / framecount; } specifications specification status comment identifiers for webrtc's statistics apithe definition of 'rtcinboundrtpstreamstats.qpsum' in that specification.

RTCOutboundRtpStreamStats.qpSum - Web APIs
you can use the value of rtcsentrtpstreamstats.framesencoded to get the number of frames that have been encoded so far, and compute an average from there.
... function calculateaverageqp(stats) { let framecount = 0; switch(stats.type) { case "inbound-rtp": case "remote-inbound-rtp": framecount = stats.framesdecoded; break; case "outbound-rtp": case "remote-outbound-rtp": framecount = stats.framesencoded; break; default: return 0; } return status.qpsum / framecount; } specifications specification status comment identifiers for webrtc's statistics apithe definition of 'rtcoutboundrtpstreamstats.qpsum' in that specification.

RTCRtpStreamStats.qpSum - Web APIs
you can, for example, use the value of rtcreceivedrtpstreamstats.framesdecoded if receiving the media or rtcsentrtpstreamstats.framesencoded if sending it to get the number of frames handled so far, and compute an average from there.
... function calculateaverageqp(stats) { let framecount = 0; switch(stats.type) { case "inbound-rtp": case "remote-inbound-rtp": framecount = stats.framesdecoded; break; case "outbound-rtp": case "remote-outbound-rtp": framecount = stats.framesencoded; break; default: return 0; } return status.qpsum / framecount; } specifications specification status comment identifiers for webrtc's statistics apithe definition of 'rtcinboundrtpstreamstats: qpsum' in that specification.

Index - Web APIs
3395 rtcoutboundrtpstreamstats.framesencoded api, encoding, frames, media, property, rtcoutboundrtpstreamstats, reference, statistics, stats, video, webrtc, webrtc api, encode, framesencoded, stream the framesencoded property of the rtcoutboundrtpstreamstats dictionary indicates the total number of frames that have been encoded by this rtcrtpsender for this media source.

RTCOutboundRtpStreamStats - Web APIs
framesencoded the number of frames that have been successfully encoded so far for sending on this rtp stream.

RTCRtpStreamStats - Web APIs
combined with rtcreceivedrtpstreamstats.framesdecoded or rtcsentrtpstreamstats.framesencoded, you can approximate the average qp over those frames, keeping in mind that codecs often vary the quantizer values even within frames.