dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-17 22:39:52 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

Increase the transform bits if possible.

Browse Source 
This brings minor size improvements because repetitive values in
the transform images are easily explainable through LZ77. Still,
it makes an upcoming pull request a bit more stable.

This is a rollforward of
7ec51c5916
ee26766a89

Change-Id: I254ab3ccd5053344f89099280e8d994ecd55aee0
This commit is contained in:
Vincent Rabaud
2024-07-19 15:27:49 +02:00
parent 6296cc8d0d
commit f2d6dc1eef
3 changed files with 97 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
src/enc/vp8l_enc.c
View File

@ -1071,26 +1071,27 @@ static int ApplyPredictFilter(VP8LEncoder* const enc, int width, int height,
int quality, int low_effort,
int used_subtract_green, VP8LBitWriter* const bw,
int percent_range, int* const percent) {
const int pred_bits = enc->predictor_transform_bits_;
const int transform_width = VP8LSubSampleSize(width, pred_bits);
const int transform_height = VP8LSubSampleSize(height, pred_bits);
const int min_bits = enc->predictor_transform_bits_;
int best_bits;
// we disable near-lossless quantization if palette is used.
const int near_lossless_strength =
enc->use_palette_ ? 100 : enc->config_->near_lossless;
if (!VP8LResidualImage(
width, height, pred_bits, low_effort, enc->argb_, enc->argb_scratch_,
enc->transform_data_, near_lossless_strength, enc->config_->exact,
used_subtract_green, enc->pic_, percent_range / 2, percent)) {
if (!VP8LResidualImage(width, height, min_bits, low_effort, enc->argb_,
enc->argb_scratch_, enc->transform_data_,
near_lossless_strength, enc->config_->exact,
used_subtract_green, enc->pic_, percent_range / 2,
percent, &best_bits)) {
return 0;
}
VP8LPutBits(bw, TRANSFORM_PRESENT, 1);
VP8LPutBits(bw, PREDICTOR_TRANSFORM, 2);
assert(pred_bits >= MIN_TRANSFORM_BITS && pred_bits <= MAX_TRANSFORM_BITS);
VP8LPutBits(bw, pred_bits - MIN_TRANSFORM_BITS, NUM_TRANSFORM_BITS);
assert(best_bits >= MIN_TRANSFORM_BITS && best_bits <= MAX_TRANSFORM_BITS);
VP8LPutBits(bw, best_bits - MIN_TRANSFORM_BITS, NUM_TRANSFORM_BITS);
enc->predictor_transform_bits_ = best_bits;
return EncodeImageNoHuffman(
bw, enc->transform_data_, (VP8LHashChain*)&enc->hash_chain_,
(VP8LBackwardRefs*)&enc->refs_[0], transform_width, transform_height,
bw, enc->transform_data_, &enc->hash_chain_, &enc->refs_[0],
VP8LSubSampleSize(width, best_bits), VP8LSubSampleSize(height, best_bits),
quality, low_effort, enc->pic_, percent_range - percent_range / 2,
percent);
}
@ -1099,24 +1100,22 @@ static int ApplyCrossColorFilter(VP8LEncoder* const enc, int width, int height,
int quality, int low_effort,
VP8LBitWriter* const bw, int percent_range,
int* const percent) {
const int ccolor_transform_bits = enc->cross_color_transform_bits_;
const int transform_width = VP8LSubSampleSize(width, ccolor_transform_bits);
const int transform_height = VP8LSubSampleSize(height, ccolor_transform_bits);
const int min_bits = enc->cross_color_transform_bits_;
int best_bits;
if (!VP8LColorSpaceTransform(width, height, ccolor_transform_bits, quality,
enc->argb_, enc->transform_data_, enc->pic_,
percent_range / 2, percent)) {
if (!VP8LColorSpaceTransform(width, height, min_bits, quality, enc->argb_,
enc->transform_data_, enc->pic_,
percent_range / 2, percent, &best_bits)) {
return 0;
}
VP8LPutBits(bw, TRANSFORM_PRESENT, 1);
VP8LPutBits(bw, CROSS_COLOR_TRANSFORM, 2);
assert(ccolor_transform_bits >= MIN_TRANSFORM_BITS &&
ccolor_transform_bits <= MAX_TRANSFORM_BITS);
VP8LPutBits(bw, ccolor_transform_bits - MIN_TRANSFORM_BITS,
NUM_TRANSFORM_BITS);
assert(best_bits >= MIN_TRANSFORM_BITS && best_bits <= MAX_TRANSFORM_BITS);
VP8LPutBits(bw, best_bits - MIN_TRANSFORM_BITS, NUM_TRANSFORM_BITS);
enc->cross_color_transform_bits_ = best_bits;
return EncodeImageNoHuffman(
bw, enc->transform_data_, (VP8LHashChain*)&enc->hash_chain_,
(VP8LBackwardRefs*)&enc->refs_[0], transform_width, transform_height,
bw, enc->transform_data_, &enc->hash_chain_, &enc->refs_[0],
VP8LSubSampleSize(width, best_bits), VP8LSubSampleSize(height, best_bits),
quality, low_effort, enc->pic_, percent_range - percent_range / 2,
percent);
}