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Speedup WebP lossless compression for low effort (m=0) mode with following:

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- Disable Cross-Color transform.
- Evaluate predictors #11 (paeth), #12 and #13 only.

Change-Id: I857264c85c61c3957d4fb45ae32d261d947c8bed
This commit is contained in:
Pascal Massimino
2014-12-17 11:52:11 +01:00
parent 9275d91c79
commit 31a9cf6417
3 changed files with 16 additions and 10 deletions
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15
src/enc/vp8l.c
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@ -341,7 +341,7 @@ static int AnalyzeAndInit(VP8LEncoder* const enc, WebPImageHint image_hint) {
if (!enc->use_palette_) {
if (image_hint == WEBP_HINT_PHOTO) {
enc->use_predict_ = 1;
enc->use_cross_color_ = 1;
enc->use_cross_color_ = (method > 0);
} else {
double non_pred_entropy, pred_entropy;
if (!AnalyzeEntropy(pic->argb, width, height, pic->argb_stride,
@ -350,7 +350,7 @@ static int AnalyzeAndInit(VP8LEncoder* const enc, WebPImageHint image_hint) {
}
if (pred_entropy < 0.95 * non_pred_entropy) {
enc->use_predict_ = 1;
enc->use_cross_color_ = 1;
enc->use_cross_color_ = (method > 0);
}
}
}
@ -919,14 +919,15 @@ static void ApplySubtractGreen(VP8LEncoder* const enc, int width, int height,
}
static WebPEncodingError ApplyPredictFilter(const VP8LEncoder* const enc,
int width, int height, int quality,
int width, int height,
int quality, int low_effort,
VP8LBitWriter* const bw) {
const int pred_bits = enc->transform_bits_;
const int transform_width = VP8LSubSampleSize(width, pred_bits);
const int transform_height = VP8LSubSampleSize(height, pred_bits);
VP8LResidualImage(width, height, pred_bits, enc->argb_, enc->argb_scratch_,
enc->transform_data_);
VP8LResidualImage(width, height, pred_bits, low_effort, enc->argb_,
enc->argb_scratch_, enc->transform_data_);
VP8LPutBits(bw, TRANSFORM_PRESENT, 1);
VP8LPutBits(bw, PREDICTOR_TRANSFORM, 2);
assert(pred_bits >= 2);
@ -1207,6 +1208,7 @@ WebPEncodingError VP8LEncodeStream(const WebPConfig* const config,
VP8LBitWriter* const bw) {
WebPEncodingError err = VP8_ENC_OK;
const int quality = (int)config->quality;
const int low_effort = (config->method == 0);
const int width = picture->width;
const int height = picture->height;
VP8LEncoder* const enc = VP8LEncoderNew(config, picture);
@ -1279,7 +1281,8 @@ WebPEncodingError VP8LEncodeStream(const WebPConfig* const config,
}
}
#endif // WEBP_EXPERIMENTAL_FEATURES
err = ApplyPredictFilter(enc, enc->current_width_, height, quality, bw);
err = ApplyPredictFilter(enc, enc->current_width_, height, quality,
low_effort, bw);
if (err != VP8_ENC_OK) {
WebPSafeFree(copy_buffer);
goto Error;