Hello,

With Firefox 84 Beta, some tabs with video streams crash. It was fine with Firefox <=83.

I think I have issues only when I have multiple video streams, e.g. when having a meeting with GMeet and there are multiple streams.
It doesn't crash right away, some times after a few seconds, sometimes after a few minutes.

I have a couple of extensions enabled. In "safe mode" or with a new profile, I don't have any issues.
I turn off a few extensions -- µblock, privacy badger, Decentraleyes, Privacy Possum -- for this GMeet website but it continued to crash. After a restart of Firefox and these extensions off for GMeet only -- but still on for other websites -- it looks OK now. But still I guess it should not cause Firefox tab to crash :)

Also as written in the crash reports, I am on Ubuntu Linux with X11. I also turned on some settings to force the hardware accelerations for the videos decoding. It might be linked.

Crash report: https://crash-stats.mozilla.org/report/index/19460ed2-996a-4ecc-852c-d05790201202

But also see reports ID:

• 10e59a07-7b00-76e7-76b1-1438733dbd05
• 509fa089-100a-3d50-d47d-402cd44a6552
• 69e5c3b5-f51e-7df4-f957-a06e58bdb854

Reason: SIGSEGV /SEGV_MAPERR

Top 10 frames of crashing thread:

0 libgallium_dri.so u_transfer_helper_transfer_unmap src/gallium/auxiliary/util/u_transfer_helper.c:494
1 libgbm.so.1 gbm_dri_bo_unmap src/gbm/backends/dri/gbm_dri.c:1251
2 libxul.so DMABufSurfaceYUV::UpdateYUVData /build/firefox-9yZhbt/firefox-84.0~b6+build1/widget/gtk/DMABufSurface.cpp:802
3 libxul.so mozilla::FFmpegVideoDecoder<58>::CreateImageDMABuf /build/firefox-9yZhbt/firefox-84.0~b6+build1/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp:801
4 libxul.so mozilla::FFmpegVideoDecoder<58>::DoDecode /build/firefox-9yZhbt/firefox-84.0~b6+build1/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp:498
5 libxul.so mozilla::FFmpegDataDecoder<58>::DoDecode /build/firefox-9yZhbt/firefox-84.0~b6+build1/dom/media/platforms/ffmpeg/FFmpegDataDecoder.cpp:182
6 libxul.so mozilla::FFmpegDataDecoder<58>::ProcessDecode /build/firefox-9yZhbt/firefox-84.0~b6+build1/dom/media/platforms/ffmpeg/FFmpegDataDecoder.cpp:138
7 libxul.so mozilla::detail::ProxyRunnable<mozilla::MozPromise<nsTArray<RefPtr<mozilla::MediaData> >, mozilla::MediaResult, true>, RefPtr<mozilla::MozPromise<nsTArray<RefPtr<mozilla::MediaData> >, mozilla::MediaResult, true> >  /build/firefox-9yZhbt/firefox-84.0~b6+build1/obj-x86_64-linux-gnu/dist/include/mozilla/MozPromise.h:1457
8 libxul.so mozilla::TaskQueue::Runner::Run /build/firefox-9yZhbt/firefox-84.0~b6+build1/xpcom/threads/TaskQueue.cpp:158
9 libxul.so nsThreadPool::Run /build/firefox-9yZhbt/firefox-84.0~b6+build1/xpcom/threads/nsThreadPool.cpp:299

Please tell me if anything else could help!

I forgot to mention: thank you for developing and maintaining this great software! :)

Also I checked a few other bug reports before but I didn't see much more details on them to confirm it is the same issue as the one I have here.
So I don't know if it could be linked to bug 1679579, bug 1677279, bug 1678007 and bug 1678653.

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Reporter, would you mind telling us what pref you've flipped? This is caused by flipping the prefs to accelerate video decoding indeed, if it was ready for all configurations it would be enabled, but it can be helpful to know what you've tried.

I guess the raw data from about:support might help, because this might very well be hardware or driver dependant.

Thanks for the report in any case!

Hi Paul,

Thank you for your reply!

(In reply to Paul Adenot (:padenot) from comment #4)

Reporter, would you mind telling us what pref you've flipped? This is caused by flipping the prefs to accelerate video decoding indeed, if it was ready for all configurations it would be enabled, but it can be helpful to know what you've tried.

I set some env vars:

MOZ_X11_EGL=1
MOZ_ENABLE_WAYLAND=1
MOZ_WEBRENDER=1

(Note that I was on Wayland before and I recently switched to X11 due to some other issues)

And some settings:

dom.webgpu.enabled=true
gfx.webrender.all=true
gfx.webrender.enabled=true
media.eme.enabled=true
media.ffmpeg.vaapi-drm-display.enabled=false
media.ffmpeg.vaapi.enabled=true
media.ffvpx.enabled=false
media.webrtc.hw.h264.enabled=true
widget.wayland-dmabuf-vaapi.enabled=true

I can share the full list in private to your email address.

I guess the raw data from about:support might help, because this might very well be hardware or driver dependant.

My GPU is Intel(R) UHD Graphics 620 (KBL GT2) with Mesa 20.2.2

Closing because no crashes reported for 12 weeks.