h264: add videodsp dependency.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec_align_dimensions2: Ensure cinepak has large enough buffers.

This is partly redundant with the following patches, but its safer

Found-by: u-bo1b@0w.se
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
cinepak: Use correct colorspace.

The new code is also faster and more robust.

As for the performance:

old decoder + conversion to rgb:         fps = 2618
old decoder, without converting to rgb:  fps = 4012

new decoder, producing rgb:              fps = 4502

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

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
cinepak: More correct Cinepak decoder.

change the treatment of the strip y coordinates which previously did
not follow the description (nor did it behave like the binary decoder
on files with absolute strip offsets).

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