User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:100.0) Gecko/20100101 Firefox/100.0

Steps to reproduce:

1 create new firefox profile
2 set media.ffmpeg.vaapi.enabled to true in about:config
3 restart firefox
4 go to https://yewtu.be/watch?v=5U2bTS4O-5U
5 click setting on the site at the right (the small gear icon)
6 set "proxy video" and set video quality to dash and set dash quality to 480p
7 at the bottom click save.
8 you get back to the video. click play
9 after some video play the picture stops and sound continue and then video continue too but then some seconds later video stop.

this happened after firefox update to 100.
I didnt have this issue before.
this doesn't always happen and I think it happens when the video steam cuts in middle and then tries to resume. if I set the dash quality to auto, this doesn't seem to happen.
if I disable media.ffmpeg.vaapi.enabled I dont get this behavior.

I test with this page too and it happens with that too
https://bitmovin.com/demos/stream-test?format=dash&manifest=https%3A%2F%2Fbitmovin-a.akamaihd.net%2Fcontent%2FMI201109210084_1%2Fmpds%2Ff08e80da-bf1d-4e3d-8899-f0f6155f6efa.mpd

the error I get is this in console:

Media resource blob:https://bitmovin.com/451d2a80-415e-4ef8-ae29-5f44f6643d16 could not be decoded.
Media resource blob:https://bitmovin.com/451d2a80-415e-4ef8-ae29-5f44f6643d16 could not be decoded, error: Error Code: NS_ERROR_DOM_MEDIA_FATAL_ERR (0x806e0005)
VIDEOJS: ERROR: (CODE:3 MEDIA_ERR_DECODE) The media playback was aborted due to a corruption problem or because the media used features your browser did not support. <unavailable> video.js:163:49

03:25:31.229 Media resource blob:https://yewtu.be/91db02f7-49df-4970-b218-c82d95cb4641 could not be decoded.
Media resource blob:https://yewtu.be/91db02f7-49df-4970-b218-c82d95cb4641 could not be decoded, error: Error Code: NS_ERROR_DOM_MEDIA_FATAL_ERR (0x806e0005)

I have a
OS: Arch Linux x86_64
CPU: AMD Ryzen 7 5700U with Radeon Graphics (16) @ 1.800GHz
GPU: AMD ATI 04:00.0 Lucienne

The Bugbug bot thinks this bug should belong to the 'Core::Audio/Video: Playback' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

This seems VAAPI related.

Can you please run with va-api enabled on terminal with MOZ_LOG="PlatformDecoderModule:5" env variable and attach the log here?
Thanks.

Also please test latest nightly:
https://fedoraproject.org/wiki/How_to_debug_Firefox_problems#Testing_Mozilla_binaries
Thanks.

I tried with the way you recommenced.
and I got tab crashes.

Please run with MOZ_DISABLE_RDD_SANDBOX=1 env variable and check if you see the crashes.
Thanks.

I dont seem to be able to reproduce it with the new nightly I downloaded. with or without the sandbox thing.

Thanks.

should I know what fixed it?

I remember years ago firefox has a tool to test regression commit finding by downloading different nightly (or their diff maybe) and testing those.

(In reply to emailsaddres from comment #13)

should I know what fixed it?

I remember years ago firefox has a tool to test regression commit finding by downloading different nightly (or their diff maybe) and testing those.

Yes, the tool is available and there's a howto here:
https://fedoraproject.org/wiki/How_to_debug_Firefox_problems#Use_Mozregression_tool