Make vaapi decoder compatible with latest libva changes
Modify vaapi decoder to choose the format used by vaapi.
This avoids possible double format conversions if the output or encoder expects a diffrent format.
Add vaapi h264 encoder
Disable DRM for now
Use fast cached SSE4.1 copying for vaapi-enc
Preparations for VPP
Add deinterlacing code
Finalize Deinterlacer
Fix trailing endings
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