tree 862e4ce7d903c2f39e01705c040670c616b9e6d0
parent 19b1f4457a9207c47e3a85ccf23572896bfbf36f
author Marco Paniconi <marpan@google.com> 1662952033 -0700
committer Marco Paniconi <marpan@google.com> 1663085612 +0000

rtc: Allow for split to 8x8 blocks for speed >=9 low-resoln

For sf.prefer_large_partition_blocks >= 3 (speed >= 9) and
low-resolutions: split to 8x8 is disallowed. This can
cause visual quality artifacts near moving boundary, as
seen in, for example, desktopqvga_320_240.y4m.

This patch allows for split to 8x8 for some superblocks,
depending on sb source_sad content metrics. The content
metrics are selected try to target superblocks with motion,
but excluding very high motion or lighting changes, etc.

This is a simplified
version of https://aomedia-review.googlesource.com/c/aom/+/162007,
which was reverted due to 4x4 avg function.

This significantly reduces artifact in desktopqvga,
overall small bdrate change, and small speed loss.

Stats changed for speed 9/10 rtc_derf.
avg_psnr/ovr_psnr/ssim,  IC speedup
speed 9:  -0.15/-0.17/-0.17, -1.2
speed 10: -0.09/-0.10/-0.15, -1.1

Change-Id: I80908c2d281f3e411a920c2095c4758a9dd810e3