[webrtc-stats] Additional Audio/Video Quality Metrics (#431)

aboba has just created a new issue for https://github.com/w3c/webrtc-stats:

== Additional Audio/Video Quality Metrics ==
Some additional audio/video quality metrics may be useful, such as:

o       Video packet loss rate measured on the outbound stream (%)
o       Number of IDRs sent per stream per minute
o       The number of IDR recoveries per minute sent
o       The number of IDR recoveries per minute received
o       The RMS across the QP values of the received frames
o       Mean of audio/video rendering to capture delay distance
o       Mean of audio/video rendering to capture delay distance in the last 10s of the call
o       Number of Sync Frame Request sent per Minute

Please view or discuss this issue at https://github.com/w3c/webrtc-stats/issues/431 using your GitHub account