Adapt the use of segmentation in AQ mode 2 based on
the ambient kf/arf/gf Q.
Disable segmentation where the rate per SB is very
low and overheads are likely to outweigh the benefits.
This patch reduces the -ve average metrics impact
of AQ mode 2 while allowing stronger 3 segment AQ
in some cases. Average improvement ~0.5-1.0%.
Change-Id: I5892dfcc7507c5cc6444531cc7fe17554cf8d0c7
In Aq mode 2 for kf/arf/gf the segment q delta
is calculated and then applied by re-quantization without
going through the rd loop again. If the base Q != 0
but the segment Q == 0 (lossless) this can could give rise
to a situation where we have an illegal combination of
transform size and Q. (Q == 0 requires that all blocks
are coded 4x4 WHT).
Change-Id: I241a58c6494ed442e9e4630070b0cde0fb99ae45
