[Webkit-unassigned] [Bug 261266] New: WebRTC maintain-framerate degradationPreference does not apply to resolution adaptation

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=261266

            Bug ID: 261266
           Summary: WebRTC maintain-framerate degradationPreference does
                    not apply to resolution adaptation
           Product: WebKit
           Version: WebKit Nightly Build
          Hardware: All
                OS: All
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: WebRTC
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: coin_st at hotmail.com
                CC: youennf at gmail.com

By configuring video sender's degradationPreference as maintain-framerate according to standard (https://www.w3.org/TR/mst-content-hint/#degradation-preference-when-encoding), resolution adaptation is expected to be adaptive when certain limitation reasons are satisfied such as lack of compute resources or bandwidth. But safari does not work with this setting under any circumstance even at the beginning, sending resolution usually starts with lower dimensions then ramps up to the target resolution, chromium and firefox both work and we can observe this behavior under maintain-framerate.

We set degradationPreference by following code snippet:

  s = pc.getSenders()[1];
  p = s.getParameters();
  p.degradationPreference = "maintain-framerate";
  s.setParameters(p);

Chromium and firefox will have distinct resolution adaptation at beginning and you may check getStats() outbound qualityLimitationReason which should be "bandwidth" and slow resolution ramp up can be observed, but nothing would happen on safari, plus seems qualityLimitationReason is not supported by safari.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20230907/a881a0a5/attachment.htm>