Add some missing "const".

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36483 b3059339-0415-0410-9bf9-f77b7e298cf2
Remove pointless casts.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36484 b3059339-0415-0410-9bf9-f77b7e298cf2
Use sizeof(*var) instead of sizeof(type), prefer calloc.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36485 b3059339-0415-0410-9bf9-f77b7e298cf2
vd_ffmpeg: disable DR also for HEVC.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36486 b3059339-0415-0410-9bf9-f77b7e298cf2
Add some "const" to input-only pointers.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36487 b3059339-0415-0410-9bf9-f77b7e298cf2