VLC tables should only be initialized from one place.
This initializes/calculates more VLC tables than necessary for VC1 decoding,
but this is only done once and only a small overhead in time and space (maybe
30 kB) it seems not worth adding a separate function.
Originally committed as revision 20010 to svn://svn.ffmpeg.org/ffmpeg/trunk
These are only supposed to be called once per row, not once per macroblock.
~1.5% faster according to oprofile.
Originally committed as revision 19213 to svn://svn.ffmpeg.org/ffmpeg/trunk
~8% faster VC-1 decoding.
Possible future optimization: clear blocks after use instead of before, and for
DC-only blocks, only clear the DC coefficient.
Originally committed as revision 19205 to svn://svn.ffmpeg.org/ffmpeg/trunk
Includes mmx2 asm for the various functions.
Note that the actual idct still does not have an x86 SIMD implemtation.
For wmv3 files using regular idct, the decoder just falls back to simple_idct,
since simple_idct_dc doesn't exist (yet).
Originally committed as revision 19204 to svn://svn.ffmpeg.org/ffmpeg/trunk