- a lot less overflows when decoding frames

- no more error with norm6 codes
- almost skipped frames (~110 bits) are not overflowed
However:
- there are very few bits left in those frames, so I wonder if enough MB
data is actually left
- NORM6/DIFF6 (4/5) bitplanes are a lot more present, which I don't find
obvious.
patch by anonymous

Originally committed as revision 3915 to svn://svn.ffmpeg.org/ffmpeg/trunk