nvidia-vaapi-driver

This is an VA-API implementation that uses NVDEC as a backend. This implementation is specifically designed to be used by Firefox for accelerated decode of web content, and may not operate correctly in other applications.

Table of contents

• nvidia-vaapi-driver
• Table of contents
• Codec Support
• Installation
  • Packaging status
  • Building
  • Removal
• Configuration
  • Upstream regressions
  • Kernel parameters
  • Environment Variables
  • Firefox
  • Chrome
  • MPV
  • Direct Backend
• Testing

Codec Support

Hardware decoding only, encoding is not supported.

YUV444 is supported but requires:

• >= Turing (20XX/16XX)
• HEVC
• Direct backend

To view which codecs your card is capable of decoding you can use the vainfo command with this driver installed, or visit the NVIDIA website here.

Installation

To install and use nvidia-vaapi-driver, follow the steps in installation and configuration. It is recommended to follow testing as well to verify hardware acceleration is working as intended.

Requirements

• NVIDIA driver series 470 or 500+

Packaging status

pkgs.org/nvidia-vaapi-driver pkgs.org/libva-nvidia-driver

openSUSE: 1, 2.

Feel free to add your distributions package in an issue/PR, if it isn't on these websites.

Building

You'll need meson, the gstreamer-plugins-bad library, and nv-codec-headers installed.

Then run the following commands:

meson setup build
meson install -C build

Removal

By default the driver installs itself as /usr/lib64/dri/nvidia_drv_video.so (this might be /usr/lib/x86_64-linux-gnu/dri/nvidia_drv_video.so on some distros). To uninstall the driver, simply remove this file. In addition, this file is usually symlinked to /usr/lib64/dri/vdpau_drv_video.so (or /usr/lib/x86_64-linux-gnu/dri/vdpau_drv_video.so) if the VDPAU to VA-API driver is installed, so this symlink will need to be restored for that driver to work normally again.

Configuration

Upstream regressions

The EGL backend is broken on driver versions 525 or later due to a regression. Users running these drivers should use the direct backend instead.

For more information read the upstream bug report or issue #126.

Kernel parameters

This library requires that the nvidia_drm kernel module is configured with the parameter nvidia-drm.modeset=1

Environment Variables

Environment variables used to control the behavior of this library.

Firefox

Due to license, Firefox on Linux does not support HEVC till now. To use the driver with firefox you will need at least Firefox 96, ffmpeg compiled with vaapi support (ffmpeg -hwaccels output should include vaapi), and the following config options need to be set in the about:config page:

In addition the following environment variables need to be set. For permanent configuration /etc/environment may suffice.

When libva is used it will log out some information, which can be excessive when Firefox initalises it multiple times per page. This logging can be suppressed by adding the following line to the /etc/libva.conf file:

LIBVA_MESSAGING_LEVEL=1

If you're using the Snap version of Firefox, it will be unable to access the host version of the driver that is installed.

Chrome

Chrome is currently unsupported, and will not function.

MPV

Currently this only works with a recent MPV version (at least 0.36.0).

There's no real reason to run it with mpv except for testing, as mpv already supports using nvdec directly. The test.sh script will run mpv with the file provided and various environment variables set to use the newly built driver

Direct Backend

The direct backend is a experimental backend that accesses the NVIDIA kernel driver directly, rather than using EGL to share the buffers. This allows us a greater degree of control over buffer allocation and freeing.

The direct backend has been tested on a variety of hardware from the Kepler to Lovelace generations, and seems to be working fine. If you find any compatibility issues, please leave a comment here.

Given this backend accesses the NVIDIA driver directly, via NVIDIA's unstable API, this module is likely to break often with new versions of the kernel driver. If you encounter issues using this backend raise an issue and including logs generated by NVD_LOG=1.

This backend uses headers files from the NVIDIA open-gpu-kernel-modules project. The extract_headers.sh script, along with the headers.in file list which files we need, and will copy them from a checked out version of the NVIDIA project to the nvidia-include directory. This is done to prevent everyone needing to checkout that project.

Testing

To verify that the driver is being used to decode video, you can use nvidia-settings or nvidia-smi.

• nvidia-settings

  By selecting the relevant GPU on the left of the nvidia-settings window, it will show Video Engine Utilization on the right. While playing a video this value should be non-zero.

• nvidia-smi

  Running nvidia-smi while decoding a video should show a Firefox process with C in the Type column. In addition nvidia-smi pmon will show the usage of the decode engine per-process, and nvidia-smi dmon will show the usage per-GPU. When using nvidia open gpu kernel modules, the usage of the decode engine may not be displayed correctly.