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Remove the post-transform near-lossless heuristic.

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Remove the post-transform (prediction, subtract green & cross-color)
near-lossless heuristic, that's not ready yet and produces unacceptable visual
(banding) artifacts.

Change-Id: I9b606a790ce0344c588f2ef83a09c57ac19c2fc1
This commit is contained in:
Vikas Arora
2015-01-26 13:18:17 -08:00
parent f2ebc4a836
commit 9814ddb601
2 changed files with 9 additions and 146 deletions
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45
src/enc/vp8l.c
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@ -1240,12 +1240,14 @@ WebPEncodingError VP8LEncodeStream(const WebPConfig* const config,
goto Error;
}
// If no prediction transform just apply near-lossless preprocessing.
// Apply near-lossless preprocessing.
use_near_lossless = !enc->use_palette_ && config->near_lossless;
if (!enc->use_predict_ && use_near_lossless &&
!VP8ApplyNearLossless(width, height, picture->argb,
config->near_lossless)) {
goto Error;
if (use_near_lossless) {
if (!VP8ApplyNearLossless(width, height, picture->argb,
config->near_lossless)) {
err = VP8_ENC_ERROR_OUT_OF_MEMORY;
goto Error;
}
}
if (enc->use_palette_) {
@ -1275,40 +1277,9 @@ WebPEncodingError VP8LEncodeStream(const WebPConfig* const config,
}
if (enc->use_predict_) {
uint32_t* copy_buffer = NULL;
#ifdef WEBP_EXPERIMENTAL_FEATURES
if (use_near_lossless) {
// Copy image to temporary buffer.
int y;
copy_buffer = WebPSafeMalloc(height * enc->current_width_,
sizeof(*copy_buffer));
if (copy_buffer == NULL) {
err = VP8_ENC_ERROR_OUT_OF_MEMORY;
goto Error;
}
for (y = 0; y < height; ++y) {
memcpy(copy_buffer + y * enc->current_width_,
enc->argb_ + y * enc->current_width_,
enc->current_width_ * sizeof(*enc->argb_));
}
}
#endif // WEBP_EXPERIMENTAL_FEATURES
err = ApplyPredictFilter(enc, enc->current_width_, height, quality,
low_effort, bw);
if (err != VP8_ENC_OK) {
WebPSafeFree(copy_buffer);
goto Error;
}
#ifdef WEBP_EXPERIMENTAL_FEATURES
if (use_near_lossless) {
VP8ApplyNearLosslessPredict(enc->current_width_, height,
enc->transform_bits_, copy_buffer, enc->argb_,
enc->argb_scratch_, enc->transform_data_,
config->near_lossless,
enc->use_subtract_green_);
WebPSafeFree(copy_buffer);
}
#endif // WEBP_EXPERIMENTAL_FEATURES
if (err != VP8_ENC_OK) goto Error;
}
if (enc->use_cross_color_) {