gstreamer-vaapi-patches

There are three LGPL-licensed patches for gstreamer-vaapi plugins:

  • Peek VADisplay and VaSurface The patch is based on gstreamer-vaapi merge request #435. It allows other MIT-licences plugins to obtain VADisplay from GstContext created by VAAPI elements. It also allows to get VASurfaceID from GstBuffer created by VAAPI elements. This patch is required to enable VAAPI preprocessor of inference elements.

  • video-format-mapping.patch Patch to improve the mapping between VA and GST formats. The new map will be generated dynamically, based on the query result of ab image format in VA driver. Also consider the ambiguity of RGB color format in LSB mode.

  • dma-vaapiencode.patch Patch enables DMA memory input in VAAPI elements thus expanding its capabilities.

How to use these patches

To build gstreamer-vaapi with these patches you have to proceed following steps:

  1. Install meson and ninja. We need them to configure and build gstreamer-vaapi project

pip3 install meson ninja

  1. Create working directory:

mkdir -p $HOME/mygst-vaapi

  1. Move into working directory

cd $HOME/mygst-vaapi

  1. Download patches (usually, you can take last version of file from master -branch of DL Streamer’s repository)

wget https://gitlab.freedesktop.org/gstreamer/gstreamer-vaapi/-/merge_requests/435.patch -O gst-vaapi-peek-vadisplay.patch
wget https://raw.githubusercontent.com/openvinotoolkit/dlstreamer_gst/master/patches/gstreamer-vaapi/dma-vaapiencode.patch
wget https://raw.githubusercontent.com/openvinotoolkit/dlstreamer_gst/master/patches/gstreamer-vaapi/video-format-mapping.patch

  1. Download appropriate version of gstreamer-vaapi’s sources (e.g. 1.18.4)

wget https://gstreamer.freedesktop.org/src/gstreamer-vaapi/gstreamer-vaapi-1.18.4.tar.xz

  1. Unpack downloaded archive

tar xf gstreamer-vaapi-1.18.4.tar.xz

  1. Move into unpacked directory

cd gstreamer-vaapi-1.18.4

  1. Apply patches

patch -p1 < ../gst-vaapi-peek-vadisplay.patch
patch -p1 < ../video-format-mapping.patch
patch -p1 < ../dma-vaapiencode.patch

  1. Configure for building gstreamer-vaapi with applied patches (disable examples, docs and test because we don’t need them)

meson \
    -Dexamples=disabled \
    -Dtests=disabled \
    -Dgtk_doc=disabled \
    build/

Note

If you are experiencing troubles configuring gstreamer-vaapi consider rebooting machine if you haven’t done it after installing OpenVINO™ Toolkit. Otherwise:

sudo apt install libudev-dev

  • If the libva dependency cannot be found:

    export PKG_CONFIG_PATH=/opt/intel/mediasdk/lib64/pkgconfig:$PKG_CONFIG_PATH

  • If you are facing the error Neither a subproject directory nor a gst-plugins-bad.wrap file was found install the gstreamer-plugins-bad developer package:

    sudo apt install libgstreamer-plugins-bad1.0-dev

    Reconfigure gstreamer-vaapi after the steps above.

  1. Build configured gstreamer-vaapi project

ninja -C build/

  1. Install into desired directory (let’s use $HOME/mygst-vaapi/install for example):

mkdir -p $HOME/mygst-vaapi/install
DESTDIR=$HOME/mygst-vaapi/install meson install -C build/

  1. As output of previous command you should see path to installed libgstvaapi.so library. depending on your system this path may be different, as example we use path that most likely you will see in Ubuntu. To start using this library you have to add directory containing that libgstvaapi.so to your GST_PLUGIN_PATH as leading path :

export GST_PLUGIN_PATH=$HOME/mygst-vaapi/install/usr/local/lib/x86_64-linux-gnu/gstreamer-1.0/:$GST_PLUGIN_PATH

  1. Available VA-API plugins can be shown by:

gst-inspect-1.0 vaapi

Note

If the library is found but the command above shows 0 features refer to the note section in step 9. Then repeat steps 9, 10, 11 to reconfigure your gstreamer-vaapi.

VAAPI preprocessing backend

To enable VAAPI preprocessing backend you have to pass to cmake that configures gst-video-analytics following parameter -DENABLE_VAAPI=ON