tree a3b0d44f5093e6ba059bc2d42b3a9d362e3da1bb
parent 3057d6a94721bdabeec5434bebce74baad08dad4
author Urvang Joshi <urvang@google.com> 1541548362 -0800
committer Urvang Joshi <urvang@google.com> 1542145788 +0000

Improved coding for static content.

Use a much better 'q' for the 1st (unforced) keyframes.

This vastly improves PSNR for static content like slideshows, audio-only
music videos with static thumbnails etc.

Exactly neutral on regular videos like lowres and midres sets.

Note: This is a cherry-pick of these two VP9 changes:
https://chromium-review.googlesource.com/c/webm/libvpx/+/1108202
and
https://chromium-review.googlesource.com/c/webm/libvpx/+/1203975

But also some other changes:
- Correctly handle condition to break from loop for FIXED_GF_LENGTH.
- Change condition for using alt-ref frame.
- Allow q = 0 (lossless) preventing quality loss for some non-static
clips at high bitrates.
- No max capping for kf_boost, but use a minimum for static content.

STATS_CHANGED for very static videos

BUG=b/119104564

Change-Id: Ia4e7f7c1d7d5aa3a2b5962b6e1c5d5067bacc2d9