tree 4757f72891c0de721760f3313b01aa5d91d4fb3f
parent e127728445505df1828287b9c7f1d84dc9af2c11
author Marco Paniconi <marpan@google.com> 1660630581 -0700
committer Jerome Jiang <jianj@google.com> 1661964821 +0000

rtc: Fix to color artifacts under high motion

For RTC: the golden reference is used as longer-term
reference, but the color_sensitivity flags are
only defined relative to the last reference.
This can cause color artifacts for high motion
if golden is selected as the best reference and
has different uv-signal than the source.

The fix here is to define a color_sensitivity for
golden reference at the superblock level, and for
now skip testing the golden reference if this
color flag is set. Logic is also based on source_variance
and content_stats, to avoid any regression from too
much/unneeded skipping.

This reduces color artifacts in the issue below.
To reduce further: logic above on golden-ref can be better
tuned, and defining color_sensitivity for alt-ref would
also be needed, but since alt-ref is closer to last ref,
the impact from that is less.

Stats changed are neutral/small:
               avg-psnr  ovr-pnsr  ssim   IC-speedup
speed 7 derf:   0.03      0.03     0.05   -0.01
speed 9 derf:   0.15      0.18     0.18   -0.15
speed 9 rtc:    0.25      0.23     0.33    0.03
speed 10 rtc:  -0.01     -0.02    -0.03   -0.14
speed 10 screen:0.26      0.09     0.34    0.04

Bug: aomedia:3308
Bug: aomedia:3313

Change-Id: Ie23ab25d8189540ea11d95c46cf9ea4f549c583d
(cherry picked from commit c6a503f4b15da2ecef856f917d08473ea788ae00)