Laggy screensharing when VP9 is enabled. about lib-jitsi-meet

[NewEraCracker]

Looks like this issue is known since 2021:

https://stackoverflow.com/questions/68741890/webrtc-screen-sharing-with-vp9-low-fps
https://bugs.chromium.org/p/webrtc/issues/detail?id=13016

PS: Leaving this here, no warranties express or implied, as a workaround:

--- a/modules/RTC/ScreenObtainer.js
+++ b/modules/RTC/ScreenObtainer.js
@@ -322,7 +322,7 @@ const ScreenObtainer = {
 
         // Set contentHint on the desktop track based on the fps requested.
         if ('contentHint' in desktopTrack) {
-            desktopTrack.contentHint = desktopSharingFrameRate?.max > SS_DEFAULT_FRAME_RATE ? 'motion' : 'detail';
+            desktopTrack.contentHint = (browser.supportsVP9() || desktopSharingFrameRate?.max > SS_DEFAULT_FRAME_RATE) ? 'motion' : 'detail';
         } else {
             logger.warn('MediaStreamTrack contentHint attribute not supported');
         }

Adding here the following:

We never go beyond 1080p screensharing in our application, and the quality is okay with this hack in non-e2ee sessions (vp9) and e2ee sessions (vp8). The contentHint motion would be applied in both cases as chrome supports vp9.

As the workaround seems okay for our usage, I will leave the issue here for maintainer review.

[saghul]

Ping @jallamsetty1

[jallamsetty1]

This is because of https://bugs.chromium.org/p/webrtc/issues/detail?id=13016. If you want higher fps, you can set the desktopSharingFrameRate.max to > 5 and this is configurable via config.js, settings menu and through JitsiConference:setDesktopSharingFrameRate() API.