tree 45809ea8c821776a5cf4ff9379ab23e62e34ee1f
parent 62698b879a82eb8e61ad894c65c6c4c09e434e5c
author Paul Wilkins <paulwilkins@google.com> 1565873657 +0100
committer Paul Wilkins <paulwilkins@google.com> 1565959818 +0000

Remove ediv_size_correction.

Removes the frame size correction to the error divisor used when
estimating the active worst quality in 2-pass vbr. In fact in VP9 the
adjustment based on frame size went the other way, but this could
be part of an interaction with other changes in VP9 not yet ported
over.

Change the default ERROR_DIVISOR to 96 such that the change is
neutral for 1080P.

Substantial metric gains for lowres and ugc360p.
Results more mixed for midres.
? Small net gains for hdres (720p) but not all test points completed.

lowres  -0.597	-0.637	-0.866	-0.640
midres  -0.027	-0.031	-0.259	 0.183
ugc360p -0.785	-0.599	-1.435	-0.581
hdres   -0.077	-0.132	 0.009	-0.106

Note that this change alters the active q range calculation.
For small image formats in particular it may often result in a
higher minQ value, especially for early key frames and alt ref
frames. This may lower both the rate and quality somewhat
even if overall bdrate metrics improve. The tweaks to certain
unit test thresholds reflect this and it is likely that these may
need further tweaking in response to other rate control and
bit distribution changes.

STATS_CHANGED

Change-Id: I5053861baf0c9a215865485f1c47884fe64b5727