Closed Bug 1652249 Opened 4 years ago Closed 3 years ago

VAAPI decoding tries to use dGPU by default


(Core :: Audio/Video: Playback, defect, P5)

80 Branch



Tracking Status
firefox80 --- disabled


(Reporter: matejm98, Unassigned)


(Blocks 1 open bug)



(2 files)

Attached file The log from the link

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0

Steps to reproduce:

I have a laptop with two GPUs:

  1. iGPU identified as: AMD RAVEN (DRM 3.38.0, 5.8.0-rc4-10-mainline, LLVM 10.0.0) - supports VP9
  2. dGPU identified as Radeon RX 560 Series (POLARIS11, DRM 3.38.0, 5.8.0-rc4-10-mainline, LLVM 10.0.0) - doesn't support VP9

I tried playing a youtube video in VP9 and noticed in the log that VAAPI decode is not used.

Actual results:

As seen in the log, for some reason, FF tries to use my dGPU for video decoding and fails because VP9 is not supported.

Expected results:

I would expect that the iGPU is used by default or maybe it tries to use all GPUs before going back to CPU decoding. During this test DRI_PRIME=1 or similar is NOT set.

The report says FF 78 but I tested this issue on FF 80 Nightly and Gnome Wayland.

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

Component: Untriaged → Audio/Video: Playback
Product: Firefox → Core

Which graphics card is used to render your desktop? If your monitor is attached to the RX 560, this is the expected behavior.

OS: Unspecified → Linux
Hardware: Unspecified → x86_64

about:support shows AMD RAVEN as the one GPU being used and doesn't show any other GPU (Windows shows both, iGPU as active). I am guessing the laptop screen is connected to the iGPU since that is usually the case in laptops with switchable graphics.

Which one GPU is mentioned on about:support page?

The integrated one - AMD RAVEN.

Severity: -- → S4
Priority: -- → P5

I have noticed, that for some reason the dGPU is not always used, sometimes the iGPU is used and works correctly. I will test this with mpv, if it is a Firefox issue or VAAPI? issue.

On both my laptops iGPU's (as VAAPI devices) are available at /dev/dri/renderD128 so I am guessing it is usually the same everywhere. If FF used the GPU at /dev/dri/renderD128 by default it would solve the issue. Or in another words, FF should try the device at /dev/dri/renderD128 first.

I noticed today that this issue is only present on FF Nightly. FF Stable works correctly / uses the iGPU.

Please open about:support in Nightly, click on "Copy text to clipboard" and paste it here.
Which VAAPI prefs do you have enabled? Only media.ffmpeg.vaapi.enabled, or media.ffmpeg.vaapi-drm-display.enabled as well?
Which env vars do you use to start Nightly, if any?

Attached file From about:config

Both are enabled, output from env looks like this:

Oh, and it looks like enabling only "media.ffmpeg.vaapi.enabled" and leaving "media.ffmpeg.vaapi-drm-display.enabled" disabled fixes this issue. But only on Wayland. On Xorg the issue remains the same.

X11 might need bug 1588904 comment 8.

Closed: 3 years ago
Resolution: --- → DUPLICATE

(In reply to mthw0 from comment #8)

On both my laptops iGPU's (as VAAPI devices) are available at /dev/dri/renderD128 so I am guessing it is usually the same everywhere.

Ordering of /dev/dri/renderDNNN nodes is not stable. On one boot iGPU may be renderD128, on another boot it may become renderD129 while renderD128 is assigned to dGPU.

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