avcodec/dsputil/huffyuv: move diff int16 and add int16 to dsputil

This also fixes masking the bits

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/x86/dsp: add_int16_mmx / add_int16_sse2

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Merge remote-tracking branch 'cehoyos/master'

* cehoyos/master:
  Allow decoding of slightly broken Nikon avi files.

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Fix compilation with --disable-hwaccel=mpeg1_xvmc,mpeg2_xvmc
Add h263dsp dependency to mpeg1video and mpeg2video encoders.

Fixes compilation with:
configure --disable-everything --enable-encoder=mpeg2video --disable-asm