[FFmpeg-devel] H.264: Partially inline CABAC residual decode

[Jason Garrett-Glaser]

This is a port of a technique originally used in x264 (and later
ported to ffvp8).  It inlines the CBF portion of residual coding,
which improves performance by allowing more constant propagation and
because a huge number of residual blocks terminate on the CBF check.

Timing for CABAC mb decode:
Before: 6861 +/- 15 clocks
After: 6779 +/- 9 clocks

Jason