更新libva及V4l2 Buffer Sharing
https://cgit.freedesktop.org/vaapi/libva/
https://cgit.freedesktop.org/vaapi/intel-driver
https://www.mythtv.org/wiki/VAAPI
https://freedesktop.org/wiki/Software/Beignet/howto/v4l2-buffer-sharing-howto/
在编译Beignet的V4l2Buffer Sharing的demo时需要安装libva库，并且该库的版本需要libva>= 0.39.4。
若采用以下方法安装libva，则不能安装最新版本。
sudo apt-get update
sudo apt-get install libva-dev
sudo apt-get install i965-va-driverlibva-intel-vaapi-driver vainfo
vainfo
所以，需要自己手动安装libva：先安装libva，再安装vaapi的intel-dirver
cd ~
mkdir Libva_build
cd Libva_build
sudo apt-get build-dep libva1
git clone https://cgit.freedesktop.org/vaapi/libva/
cd libva
./autogen.sh [--enable-va-messaging=no]
./configure [--enable-va-messaging=no]
make
sudo make install
cd ..
git clone https://cgit.freedesktop.org/vaapi/intel-driver
cd intel-driver
./autogen.sh
./configure
make
sudo make install
在beignet的examples中加入libva源码VA-API
https://www.freedesktop.org/wiki/Software/vaapi/
in the url to git clone:https://cgit.freedesktop.org/libva/
liuhanglh@liuhang-dev:~/beignet/examples/thirdparty$git clone https://anongit.freedesktop.org/git/libva.git
V4l2 Buffer Sharing HowTo Sample code:
https://www.freedesktop.org/wiki/Software/Beignet/howto/v4l2-buffer-sharing-howto/
然后在以前安装的beignet文件下的build文件中
cmake -DBUILD_EXAMPLES=ON ../
make
cd examples
. ../utests/setenv.sh
./example-v4l2_buffer_sharing