1634991 - Hardware VP9 decoder often no longer used.

Status: NEW

(Core :: Audio/Video: Playback, defect, P3)

Description

[Jean-Yves Avenard [:jya]]

I noticed that none of my machines with VP9 hardware decoding capabilities are now using the vp9 HW decoder.

Only ffvp9 appears to be used (you can verify with the media devtools add-on).

This leads to higher CPU usage than needed and lower performance.

Comment 1

[Virtual_ManPL [:Virtual] 🇵🇱 - (please needinfo? me - so I will see your comment/reply/question/etc.)]

It could be same issue as in bug #1570046. When you will be opening simultaneously more than 3 tabs with video, VP9 hardware decoding will be disabled.

Comment 2

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

Could you see if you can find a regression range for this?

Comment 3

[Jean-Yves Avenard [:jya]]

(In reply to Virtual_ManPL [:Virtual] 🇵🇱 - (please needinfo? me - so I will see your comment/reply/question/etc.) from comment #1)

It could be same issue as in bug #1570046. When you will be opening simultaneously more than 3 tabs with video, VP9 hardware decoding will be disabled.

it isn't.

Comment 4

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

Can you provide any more details about this? I'm still seeing hardware decoding on the Windows machines I've tested. A regression range would be ideal. Is your vpx crashguard getting triggered?

Comment 5

[Jean-Yves Avenard [:jya]]

(In reply to Virtual_ManPL [:Virtual] 🇵🇱 - (please needinfo? me - so I will see your comment/reply/question/etc.) from comment #1)

It could be same issue as in bug #1570046. When you will be opening simultaneously more than 3 tabs with video, VP9 hardware decoding will be disabled.

I investigated the issue today, and for some reasons today it is, in about:support I get plenty of

(#0) Error	WMF VPX video decoding is disabled due to a previous crash.
(#1) 	CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#2) Error	WMF VPX video decoding is disabled due to a previous crash.
(#3) 	CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#4) Error	WMF VPX video decoding is disabled due to a previous crash.
(#5) 	CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#6) Error	WMF VPX video decoding is disabled due to a previous crash.
(#7) 	CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#8) Error	WMF VPX video decoding is disabled due to a previous crash.
(#9) 	CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#10) Error	WMF VPX video decoding is disabled due to a previous crash.
(#11) 	CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#12) Error	WMF VPX video decoding is disabled due to a previous crash.
(#13) 	CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.
(#14) Error	WMF VPX video decoding is disabled due to a previous crash.
(#15) 	CP+[GFX1-]: WMF VPX video decoding is disabled due to a previous crash.

can't reproduce on my local build

Comment 6

[Gian-Carlo Pascutto [:gcp]]

Bryce, this is an S2, but it has no priority nor assignee. Are you able to find an owner for this bug?

Comment 7

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

I'm trying to reproduce the crash that leads to the log spam. I'm interested in what is causing the initial Error: WMF VPX decoder just crashed; hardware video will be disabled. message, less so in WMF VPX video decoding is disabled due to a previous crash. I've tried opening many videos in different tabs and windows, but so far no luck.

For people encountering the issue I would also be interested in the values of your gfx.crash-guard.status.wmfvpxvideo and gfx.crash-guard.wmfvpxvideo.* prefs.

Comment 8

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

We've added markers to the Firefox profiler to help detect failures in Window's decoding pipeline. If you're encountering this issue it would be helpful if you could gather a profile using the 'Media' config on Firefox Nightly from after 2020-10-20, then share it and paste the link here.

Comment 9

[Jean-Yves Avenard [:jya]]

The cause for this is that under some circumstances we attempt to initialize the WMFDecoderModule in the GPU process before receiving the update for gfxVars::CanUseHardwareVideoDecoding()

So this testForVpx https://searchfox.org/mozilla-central/rev/8698fade12984b9a6a43a85a287a5f17e8fd4ddf/dom/media/platforms/wmf/WMFDecoderModule.cpp#128 will be false ; and HW VP9 decoding will be disabled.