avcodec/vc1_mc: use the same reference as luma does in ff_vc1_mc_4mv_chroma()

Fixes Ticket3230

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
vf_scale: Use correct chroma positions for YUV420P

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/segment: Use av_freep() avoid leaving stale pointers in memory

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/wtvdec: Use av_freep() avoid leaving stale pointers in memory

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/smoothstreamingenc: Use av_freep() avoid leaving stale pointers in memory

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/nvenc: Remove special cases for cygwin

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/cache: support non continuous caching

This allows using the cache protocol on top of seekable but slow protocols to
speed them up

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>