Re: [mediacapture-transform] What is the impact of timestamp for video frames enqueued in VideoTrackGenerator? (#96)

Chrome's internal VideoFrames have their timestamp directly sourced from `VideoFrame.timestamp`, but also an optional absolute capture time which is set from some sources.

Both RtpSender and MediaRecorder prefers to use the capture time if present, otherwise
- RtpSender will use an estimation of the capture time based on frame submit time and `timestamp` [code ref](https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/platform/peerconnection/webrtc_video_track_source.cc;l=227).
- MediaRecorder will use roughly the submit time and ignore timestamp [code ref](https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/modules/mediarecorder/video_track_recorder.cc;l=511)

I think HTMLVideoElement uses the internal timestamp to smooth out playback, @drkron can you shed some light?

-- 
GitHub Notification of comment by handellm
Please view or discuss this issue at https://github.com/w3c/mediacapture-transform/issues/96#issuecomment-2375395856 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Wednesday, 25 September 2024 22:42:19 UTC