0

I work on a team that is developing a browser based video application. We have been experiencing an occasional severe degradation in the quality of our video starting around November 2022. It happens during a call and continues until the call is ended (the connection is ended), and appears to be a decoding issue (the screen looks pixelated/discolored but you retain some idea of the 'shape' of objects on the video feed).

We use Pexip which acts as an MCU between participants, and have validated from Pexip's outbound packets that it is sending a clear video stream, however on the browser we see the issue nonetheless. This is only seen on a single participants video stream.

The issue has only been seen on Chrome and Edge which default to VP8, and has not been reproduced on Firefox (defaults to H.264). This leads me to believe it is an issue with Chromium.

I have struggled to find any logs that relate to the start of the issue, and am asking if you have any suggestions on where to look on Chrome's logs to find any indication that an issue has started or to understand more about why the issue is happening?

We have tested on Chrome/Edge/Firefox browsers, and the issue only happens in Chrome or Edge (Chromium based). We have tested on a wireless or wired connections and the issue shows in both cases. We have tested on Windows and macOS and it happens on both. We have also tested on a freshly rebooted computer with no other applications running, and the issue still shows. There is nothing interesting happening on CPU/Memory/Network utilization when the issue begins.

Frankvideo
  • 1
  • 1
  • Did you reach out to the Pexip folks? They have a great deal of experience debugging such issues, the 2017 blog post https://webrtchacks.com/video_replay/ has aged very well (Chrome made some improvements to allow for easier capture (see comments section) – Philipp Hancke Jan 18 '23 at 19:53
  • 1
    You mention you have validated Pexip's outgoing traffic. How did you do so? Also, as @Philipp says, you could try with Chromium's replay tool https://chromium.googlesource.com/external/webrtc/+/refs/heads/lkgr/rtc_tools/video_replay.cc. if you see corruption then it could indicate a bug on the WebRTC stack. Lastly, one think to try out is to check If you have HW acceleration enabled on Chrome, and if so disable it and re-test. To put it mildly there have been multiple issues where there is a miscommunication with the drivers for HW decoding. – Camilo Celis Guzman Jan 19 '23 at 11:00
  • @PhilippHancke We have been working with the Pexip Team, we haven't been able to discover much on that, only that the outbound RTP are not corrupted. They have a tool that allowed them to play the video after unencrypting the outbound RTP for a specific call that had the issue, and on the replay the video did not have the issue. – Frankvideo Jan 19 '23 at 17:49
  • @CamiloCelisGuzman We captured the outbound RTP on the Pexip node and then check the previous comment I just made, the Pexip team helped to validate the outbound traffic wasn't corrupt. Thanks for the pointer to the Chromium replay tool, we will have to see if we can use it. It get's difficult trying to replay packets when they are encrypted. Also we looked into the HW acceleration and have had it disabled, same issue arises – Frankvideo Jan 19 '23 at 17:52
  • @Frankvideo if you have a ticket/case number with Pexip posting it here might help escalating it to the right folks like Camilo which should hopefully lead to a faster resolution! Or you drop a link to this and the suggestion to reach out internally to that ticket. – Philipp Hancke Jan 19 '23 at 20:36

0 Answers0