tree c0a57fc9891d337b91857947583192126038d8fc
parent d8cfe16d9034fa91ff2a4db2f1eef5db866892d3
author Angie Chiang <angiebird@google.com> 1627692626 -0700
committer Angie Chiang <angiebird@google.com> 1628189596 +0000

Let define_kf_interval detect current key frame

This is needed for one pass mode.

We made several other changes.
1) Move end-of-gop define_kf_interval() call before
find_next_key_frame. This way, when define_kf_interval()
return 0, it means current frame should be key frame.
Then since frames_to_key will stay zero. We will call
find_next_key_frame to try to find the next key after
current frame.

2) Compute kf_group_err in one place.

After this CL, encoder is able to detect key frame locations
of mixedformat1080.y4m properly in one-pass mode

Including two previous CLs,
https://aomedia-review.googlesource.com/c/aom/+/142541
https://aomedia-review.googlesource.com/c/aom/+/142941,
The overall performance improvement is as follows.

One pass:
        ovr_psnr avg_psnr ssim
ugc360p -1.495%  -1.423%  -1.453%
lowres  -0.080%  -0.139%  -0.094%
hdres   -0.056%  -0.059%  -0.067%

Two pass:
        ovr_psnr avg_psnr ssim
ugc360p 0.002%   0.009%   0.010%
lowres  0%       0%       0%
hdres   0%       0%       0%

For two pass, almost all video's coding stats remain unchanged,
only UgcVert_360-aeaabeaad9a88ca3-723.33.y4m has slightly changed
0.085% drop in avg_psnr and 0.452% drop in ovr_psnr
I will investigate this change later.

BUG=aomedia:3069
BUG=aomedia:3070

Change-Id: Ia7c85f2b8caabbdb135e86cc259b36fef9e1a21f