Hardware-accelerated Video Decoding in Chrome

Current State

In 2022, most video comes with H265 and AV1. For now, only MPEG, H264, VC1, and VP9 are supported in the transformation driver

vdpau-va-driver-vp9

has a lot of potential. It bases on NVDEC, which is a new API provided by Nvidia. But it will crash Chrome because of limited support

The fundamental reason that we are in this stage is Nvidia and Google are both too stubborn to support each other.

Here it is again. Google doesn't want to add specific code for Nvidia's GPUs because there are so many other GPUs on the market that it would be a lot of work to support all of them. Meanwhile, Nvidia wants to provide specific functionality through its own unique API.

We need an abstraction layer for GPUs! Luckily we have DirectX in Windows, Metal in macOS, and Vulkan in Linux. And Vulkan is expected to support AV1 in 2023. So I believe Chrome will have a good hardware-accelerated video decode solution soon or later.

Developers of Chrome also said in June 2022, “VaapiVideoDecoder is in the process of shipping with Vulkan support now.”

VP9 & AV1 Vulkan Video Extensions Expected Next Year

While this week saw the ratification of the Vulkan Video 1.0 extensions in stable form after being out as provisional extensions since early 2021, one of the sad aspects of it is still lacking support for the popular royalty-free VP9 and AV1 codecs

https://www.phoronix.com/news/VP9-AV1-Vulkan-2023

bugs.chromium.org

https://bugs.chromium.org/p/chromium/issues/detail?id=1200559

But before that, let’s see how we can add limited support for hardware video decoding to Chrome in 2022.

VA_API transformation driver

⚠️ 2022-12-24 UPDATE: The hardware decoder is extremely unstable. I gave up.

First, install the VDPAU→VA_API transform driver


yay -S libva-vdpau-driver-vp9-git

Use vainfo, you shall see the driver.


❯ vainfo
Trying display: wayland
Trying display: x11
vainfo: VA-API version: 1.16 (libva 2.16.0)
vainfo: Driver version: Splitted-Desktop Systems VDPAU backend for VA-API - 0.7.4
vainfo: Supported profile and entrypoints
      VAProfileMPEG2Simple            :	VAEntrypointVLD
      VAProfileMPEG2Main              :	VAEntrypointVLD
      VAProfileMPEG4Simple            :	VAEntrypointVLD
      VAProfileMPEG4AdvancedSimple    :	VAEntrypointVLD
      VAProfileH264ConstrainedBaseline:	VAEntrypointVLD
      VAProfileH264Main               :	VAEntrypointVLD
      VAProfileH264High               :	VAEntrypointVLD
      VAProfileVC1Simple              :	VAEntrypointVLD
      VAProfileVC1Main                :	VAEntrypointVLD
      VAProfileVC1Advanced            :	VAEntrypointVLD
      VAProfileVP9Profile0            :	VAEntrypointVLD

Chrome settings

Use the following command to start Chrome (I use the beta version, you can use the stable version as well):


google-chrome-beta --use-gl=desktop \
                   --use-vulkan \
                   --enable-features=VaapiVideoDecoder,VaapiVideoEncoder,VaapiIgnoreDriverChecks \
                   --disable-features=UseChromeOSDirectVideoDecoder

In the Chrome flag settings, enable these:

Override software rendering list

GPU rasterization

Zero-copy rasterizer

Hardware decode acceleration for k-SVC VP9

Check

Relaunch Chrome, and open chrome://gpu to check if Video Decode is hardware accelerated.

That’s not enough. Play a Youtube video and press F12. Click More Options > More tools > Media to open the Media panel. Check if the hardware decoder is true.

💡

Notice that the hardware decoder won’t always be available due to the limitation of GPU-supported decoding formats. But it should work in most cases.