This patch modified struct VP9_COMP. Created a struct ThreadData
to include data that need to be copied for each thread. In
multiple thread case, one thread processes one tile. all threads
share one copy of VP9_COMP,
(refer to VP9_COMP *cpi in the code)
but each thread has its own copy of ThreadData,
(refer to ThreadData *td in the code).
Therefore, within the scope of encode_tiles(), both cpi and td
need to be passed as function parameters.
In single thread case, the FRAME_COUNTS pointer in ThreadData
points to "counts" in VP9_COMMON.
Change-Id: Ib37908b2d8e2c0f4f9c18f38017df5ce60e8b13e
Add an additional restriction to bit/complexity based
segmentation based on spatial variance.
Only lower Q when both the number of bits spent
in the initial encoding pass and the spatial complexity are
below a threshold. This will prevent the low Q segments
being used just because there is a surfeit of bits.
Small metrics gains especially opsnr.
derf ~0.2% std-hd ~0.3%
Change-Id: I6a8496d466d673f9b0e2b2ca6304ea7b6d8e1cce
