[Beignet] Use OpenCL to do video post processing for libva.

[ykzhao]

On Wed, 2013-10-30 at 02:02 -0600, Zou, Nanhai wrote:
> In the previous versions of libva intel-driver, video post processing
> features are mostly developed by GEN assembly.
> 
> Those assembly are extremely hard to write/debug and understand, could
> not be reused across different GEN platform.
> 
> This limited developers to develop their video processing algorithm
> over libva.
> 
>  
> 
> Now we have setup an experimental branch in libva to use OpenCL as the
> video post processing language.
> 
> This branch can share video buffer with beignet driver as bo, then
> call OpenCL to process the video buffer as an image object.
> 
> So that people develop high performance VPP with high level language
> on GPU with zero copy. (in current stage, beignet only support
> HD4000).
> 
>  
> 
> For those who are interested in develop their own VPP algorithm, you
> may try it and give feedback to us.
> 
> We have put 4 example post processing kernels in that branch.
> 
>  
> 
> 1.      Make and Install Beignet from
> git://anongit.freedesktop.org/beignet with opencl-1.2 branch.
> 
> 2.      Install ocl-icd driver
> 
> 3  Make and Install libva driver and libva intel-driver from
> 
>          git://people.freedesktop.org/~yakuiz/libva
> 
> git://people.freedesktop.org/~yakuiz/intel-driver
> 
> Please add  --enable-opencl when configuring libva intel-driver.

It is noted that the cl_branch should be used for libva/intel-driver.

The intel-driver also includes the README that describes how to use the
OpenCL for the video post-processing.


> 
>  
> 
> export INTEL_OCL="gray" to specify which opencl kernel to use.
> 
> We have put 4 sample opencl kernels in the branch, "gray", "blur",
> "mirror" and "pixelated".
> 
>  
> 
> Use a vaapi enabled mplayer to playback a video.
> 
> mplayer -vo vaapi:scaling=fast -va vaapi  <your-mp4-video-file>
> 
>  
> 
> Then you will see the post processing effect.
> 
>  
> 
> TODOs.
> 
> Extend the API to a more flexible version, so that OpenCL can handle
> more than 1 reference buffer or used in other video processing
> function.
> 
> E.g. video-encoding processing and camera pipeline.
> 
>  
> 
> Expose more ways to access video buffer, to access video buffer as raw
> data or with other pixel format.
> 
> Expose the hardware media sampler function to OCL as built-in. 
> 
>  
> 
> Thanks
> 
> Zou Nanhai
> 
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> 
>