The restructure moves the decision into the rd pick
modes loop and makes a decision based at the 16x16
block level instead of only the 64x64 level.
This gives finer granularity and better visual results
on the clips I have tested. Metrics results are worse
than the old AQ2 especially for PSNR and this mode
now falls between AQ0 and AQ1 in terms of visual
impact and metrics results.
Further tuning of this to follow.
It should be noted that if there are multiple iterations
of the recode loop the segment for a MB could change
in each loop if the previous loop causes a change in the
complexity / variance bin of the block. Also where a block
gets a delta Q this will alter the rd multiplier for this block
in subsequent recode iterations and frames where the
segmentation is applied.
Change-Id: I20256c125daa14734c16f7cc9aefab656ab808f7
AQ2 modified to use mb_av_energy in defining variance
thresholds used alongside complexity when defining the
segment to be used for an SB64.
Slight improvements in metrics (ssim and PSNR).
Change-Id: Idb9cb73f7d9c4f7118cd7e84ac77b0f25cacbf81
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
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
