Originally committed as revision 10395 to svn://svn.ffmpeg.org/ffmpeg/trunk
try the MV length as context for coding the residual coefficients
use extradata for stuff which is in the keyframes now?
the MV median predictor is patented IIRC
+change MC so per picture halfpel interpolation can be done and finish the implementation of it
+compare the 6 tap and 8 tap hpel filters (psnr/bitrate and subjective quality)
+try different range coder state transition tables for different contexts
Not Important:
spatial_scalability b vs u (!= 0 breaks syntax anyway so we can add a u later)