Reduce reference MV candidates for separate list

[jianle973]

In this PR, when encoder flag reduce_max_drl_refmvs is set to 1 (i.e. speed >= 2), the encoder searches less reference MV candidate for the compound mode with separate DRL.

Test results of 33f RA (speed 2), based on commit ae462edd194e201c44270e503e4aca297ed9c5ac, are as folllows:
PSNR-Y PSNR-U PSNR-V PSNR-YUV EncTime DecTime
A1: +0.04% +0.01% +0.21% +0.05% 96.47% 98.30%
A2: +0.07% +0.28% -0.05% +0.07% 96.48% 98.14%

[yeqing-wu]

What is the anchor commit ID? Could you please update the commit message and the PR body with the anchor commit ID of this PR?

Meanwhile, @kslu-aom has submitted a PR titled ‘Conditionally reduce max DRL ref MVs for speeds >= 2’. I believe it may have significant overlap with this PR. If this PR is already based on Lester’s reduce max DRL ref MVs for speeds >= 2, we are safe. Otherwise, it would be better to test the performance on top of that.

[jianle973]

What is the anchor commit ID? Could you please update the commit message and the PR body with the anchor commit ID of this PR?

Meanwhile, @kslu-aom has submitted a PR titled ‘Conditionally reduce max DRL ref MVs for speeds >= 2’. I believe it may have significant overlap with this PR. If this PR is already based on Lester’s reduce max DRL ref MVs for speeds >= 2, we are safe. Otherwise, it would be better to test the performance on top of that.

The results are on top of
ae462ed .

The anchor contains Lester's PR.