tree 4bcc9ac1e24a8c47380a65a9b054611318f76ce7
parent 3774595577fdeb09e72df1e291c288d1c27aa953
author Yannis Guyon <yguyon@google.com> 1623325104 +0200
committer Yannis Guyon <yguyon@google.com> 1623326174 +0000

Replace PredictorScorer by BlockScorer

The goal is to merge all PredictorScorer, FindBestTf(),
FindBestPred(), FindBestPredTf(), FindBestSplit() for luma/chroma and
the alpha equivalents into a single BlockScorer class for clarity.

Some minor changes at default effort 5 due to predictor reordering and
score formula editing leading to floating point rounding differences.
Other efforts are more impacted because:
 - At effort 1, all predictors were tried but the score was only based
   on the prediction. Now a smaller subset of predictors are tested
   but with the regular rate-distortion analysis.
 - At effort 8+, splitting is now tested along predictors, not after.

Change-Id: Ide78b44945795b26069ee6b8aff7481828ab1aca
Reviewed-on: https://chromium-review.googlesource.com/c/codecs/libwebp2/+/2951005
Tested-by: WebM Builds <builds@webmproject.org>
Reviewed-by: Yannis Guyon <yguyon@google.com>