Merge commit 'd1d9efaae6c7e8466b06c30ca21c6b569dd2e480'
* commit 'd1d9efaae6c7e8466b06c30ca21c6b569dd2e480':
avcodec: split avpicture from imgconvert
pixdesc: add PIX_FMT_ALPHA flag
Conflicts:
libavcodec/imgconvert.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>