Mesa's VDPAU State Tracker Adds Support For AV1 Decoding

[ahrs]

I don't know the reasons in detail why certain applications prefer specific APIs like in the case of VLC. But speaking of browsers i really would like to see firefox finally switching to vulkan for more performance and being competitive again in terms of speed.

For Firefox I think that's difficult because they still use OpenGL everywhere unless the interop between Vulkan and GL is good enough for this? I know Chromium is ahead of them here. They already have a Vulkan renderer and working Vulkan Video Decoding.

[dec05eba]

One good thing about vdpau on nvidia is that vdpau uses far less power than nvdec because nvdec requires use of cuda which triggers forced p2 power state so the gpu cant go into low power state. Nvidia is aware of this issue but they refuse to fix it, it's intentionally using more power than necessary.

[Rovano]

For Firefox I think that's difficult because they still use OpenGL everywhere unless the interop between Vulkan and GL is good enough for this? I know Chromium is ahead of them here. They already have a Vulkan renderer and working Vulkan Video Decoding.

In which development version does it work? At Chromium 122 it gives me an error when looking for Vulkan 1.3 drivers. Which of course are installed.

I don't solve anything on Firefox. Video acceleration works there (but not on Vulkan).

[Rovano]

One good thing about vdpau on nvidia is that vdpau uses far less power than nvdec because nvdec requires use of cuda which triggers forced p2 power state so the gpu cant go into low power state. Nvidia is aware of this issue but they refuse to fix it, it's intentionally using more power than necessary.

It could be a design feature. Then it's hard to get around.

Nvidia has an experimental new way of managing power. Is it not resolved there?

[dec05eba]

It could be a design feature. Then it's hard to get around.

Nvidia has an experimental new way of managing power. Is it not resolved there?

Nvidia does this (on windows too) because when you use cuda in some extreme cases it causes corrupt memory (mostly enterprise level stuff). The nvidia driver has done this for 10 years or so. In the case of nvenc/nvdec cuda is only used for passing buffers around so it will never have this corrupt memory issue but the driver doesn't know if you are doing something extreme with the cuda driver or not, it just forces the power state the moment you create a cuda context regardless of what you are going to do with it.
Nvidia only disables this behavior for some proprietary applications on windows (such as discord (screen share) and nvidia shadowplay).
I wish they either added an option so you can opt out of this behavior or if they moved this forced power state to other functions, rather than the very basic cuda context creation. I believe they just went with the lazy and easy solution.
When you use vdpau or vulkan video you dont have this issue since those dont need to use cuda to pass buffers around.
Nvenc/nvdec has an opengl interface so you dont have to use cuda but nvidia went the lazy route and made that a wrapper around the cuda interface. If they didn't go with this lazy solution then nvenc/nvdec wouldn't have this power state issue.

And no, there is no workaround this issue except manually overclocking your gpu, but this only works on X11 and you need to run the xorg server as root and you need to set "coolbits" in xorg config file (yes, this forced power state will ignore your power state option in nvidia settings).