VLC VAAPI

Introduction to GPU decoding in VLC

The VLC framework can use your graphic card (aka GPU) to decode H.264 streams (wrongly called HD videos) under certain circumstances.

VLC, in its modular approach and its transcoding/streaming capabilities, does decoding in GPU at the decoding stage only and then gets the data back to go to the other stages (streaming, filtering or plug any video output after that).

What that means is that, compared to some other implementation, GPU decoding in VLC can be slower because it needs to get the data back from the GPU. But you can plug ANY video output (sink) to it and use all the VLC video filters.

Introduction to compilation of VAAPI in VLC

This page is about compiling VLC with support of GPU acceleration on Linux. For Windows, look at VLC_DxVA2.

This howto has been written by Jean-Baptiste Kempf and tested with nVidia GPU.

http://en.wikipedia.org/wiki/Video_Acceleration_API

http://www.freedesktop.org/wiki/Software/vaapi

Before starting

libva

Install libva from http://www.splitted-desktop.com/~gbeauchesne/libva/ . We do not support other libraries than the one from Mr Beauchesne.

Drivers

nVidia

http://www.splitted-desktop.com/~gbeauchesne/vdpau-video/ for nVidia. Use at least version 0.6.2.

ATI

http://www.splitted-desktop.com/~gbeauchesne/xvba-video/ for ATI. Use at least 0.6.4.

Check if LIBVA environment variables are correctly configured:

set | grep LIBVA

Should output something like:

LIBVA_DRIVER_NAME=xvba
LIBVA_DRIVERS_PATH=/usr/lib64/va/drivers

If not, add these, according to your library path, to your system environment variables (/etc/environment ?)

Then run

vainfo

which should return something like:

VAProfileH264High               :	VAEntrypointVLD
VAProfileVC1Advanced            :	VAEntrypointVLD

To check if everything works.

FFmpeg trunk

Get the latest FFmpeg trunk as of 2010-January. Compile it with vaapi hwaccel support.

./configure --enable-gpl --enable-postproc --prefix=/path/to/ --enable-shared --enable-vaapi
make
make install

Copy vaapi.h to the includes, if not done (newer FFmpeg should do that automagically)

VLC

Get VLC from Git. Get the necessary external libraries (on debian/*buntu: apt-get build-dep vlc)

./bootstrap
./configure
make

Compile VLC with vaapi

Configure VLC.

Edit vlc-config and add

-lX11 -lva-x11

to the avcodec line. (Step no longer required with recent builds)

Mine looks like this:

avcodec)
     cflags="${cflags} -I/home/jb/VideoLAN/vlc/vlc/extras/ffmpeg"
     libs="${libs} /home/jb/vlc/extras/ffmpeg/libavcodec/libavcodec.a /home/jb/vlc/extras/ffmpeg/libavutil/libavutil.a -lz -lm -lva -ldl -ljack -lasound -lm -lX11 -lva-x11"

Recompile VLC

make clean && make

Check

That everything went ok:

./vlc --list | grep avcodec

should return something.

Activate

Activate acceleration in the preferences.

Or directly on command line

vlc --ffmpeg-hw

Exemple: on playback log output (with -v debug and ATI VAAPI)

[0x7f8c4cc03ba8] avcodec decoder: Using VA API version 0.32 for hardware decoding.

Profit