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How does video playback acceleration work on AMD cards with VLC or mpv?

microcolonel 8y ago
> How does video playback acceleration work on AMD cards with VLC or mpv? It works great in MPV, I don't use VLC so I can't comment on that. The major problem right now with video acceleration is that Chromium (or maybe it's my distribution's build of it) seems to have enabled VA-API acceleration, but the Mesa VA-API state tracker (I think, I'd be glad to be corrected on this) I think is missing the API that would tell Chromium which pixel format to expect the decoder's output in; so Chromium assumes that it'll be in a certain format which it turns out not to be, and this leads to hideous corruption. I suspect that if and when there is any significant amount of HEVC content on the web, this issue will probably be resolved by then. For now there are configuration parameters which can be used to work around the issue by disabling the pixel format Chromium defaults to, and do so just in chromium, but a fix (which will be in Mesa 19) is required for that configuration to work with Chromium (due to its unusual process naming). I have used the MJPEG UVD decoder through ffmpeg to decode my 4K webcam's output and it works a treat.
- Melchizedek 8y ago
  So video acceleration works on Firefox?
  - microcolonel 8y ago
    It's kinda hard to tell, not sure Firefox supports any decode acceleration on Linux. If they do, it's not obvious when it's active, and Firefox uses quite a bit of CPU while playing video regardless.
- malvosenior 8y ago
  You've encountered another issue like the Nvidia/Wayland one. Google has closed the hardware acceleration issue in Chromium on Linux as "won't fix".
  - microcolonel 8y ago
    My reading of the situation is: That's because it's not theirs to fix. The API is missing in Mesa, and implementing it there would fix the issue. I don't begrudge Google and the broader Chromium developer community for closing it.

> How does video playback acceleration work on AMD cards with VLC or mpv? It works great in MPV, I don't use VLC so I can't comment on that. The major problem right now with video acceleration is that Chromium (or maybe it's my distribution's build of it) seems to have enabled VA-API acceleration, but the Mesa VA-API state tracker (I think, I'd be glad to be corrected on this) I think is missing the API that would tell Chromium which pixel format to expect the decoder's output in; so Chromium assumes that it'll be in a certain format which it turns out not to be, and this leads to hideous corruption. I suspect that if and when there is any significant amount of HEVC content on the web, this issue will probably be resolved by then. For now there are configuration parameters which can be used to work around the issue by disabling the pixel format Chromium defaults to, and do so just in chromium, but a fix (which will be in Mesa 19) is required for that configuration to work with Chromium (due to its unusual process naming). I have used the MJPEG UVD decoder through ffmpeg to decode my 4K webcam's output and it works a treat.

Melchizedek 8y ago
So video acceleration works on Firefox?
- microcolonel 8y ago
  It's kinda hard to tell, not sure Firefox supports any decode acceleration on Linux. If they do, it's not obvious when it's active, and Firefox uses quite a bit of CPU while playing video regardless.
malvosenior 8y ago
You've encountered another issue like the Nvidia/Wayland one. Google has closed the hardware acceleration issue in Chromium on Linux as "won't fix".
- microcolonel 8y ago
  My reading of the situation is: That's because it's not theirs to fix. The API is missing in Mesa, and implementing it there would fix the issue. I don't begrudge Google and the broader Chromium developer community for closing it.