diff options
Diffstat (limited to 'src/3rdparty/libwebp/src/enc/filter_enc.c')
| -rw-r--r-- | src/3rdparty/libwebp/src/enc/filter_enc.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/src/3rdparty/libwebp/src/enc/filter_enc.c b/src/3rdparty/libwebp/src/enc/filter_enc.c new file mode 100644 index 0000000..4bc3672 --- /dev/null +++ b/src/3rdparty/libwebp/src/enc/filter_enc.c @@ -0,0 +1,219 @@ +// Copyright 2011 Google Inc. All Rights Reserved. +// +// Use of this source code is governed by a BSD-style license +// that can be found in the COPYING file in the root of the source +// tree. An additional intellectual property rights grant can be found +// in the file PATENTS. All contributing project authors may +// be found in the AUTHORS file in the root of the source tree. +// ----------------------------------------------------------------------------- +// +// Selecting filter level +// +// Author: somnath@google.com (Somnath Banerjee) + +#include <assert.h> +#include "./vp8i_enc.h" +#include "../dsp/dsp.h" + +// This table gives, for a given sharpness, the filtering strength to be +// used (at least) in order to filter a given edge step delta. +// This is constructed by brute force inspection: for all delta, we iterate +// over all possible filtering strength / thresh until needs_filter() returns +// true. +#define MAX_DELTA_SIZE 64 +static const uint8_t kLevelsFromDelta[8][MAX_DELTA_SIZE] = { + { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, + 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, + 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, + 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63 }, + { 0, 1, 2, 3, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 17, 18, + 20, 21, 23, 24, 26, 27, 29, 30, 32, 33, 35, 36, 38, 39, 41, 42, + 44, 45, 47, 48, 50, 51, 53, 54, 56, 57, 59, 60, 62, 63, 63, 63, + 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63 }, + { 0, 1, 2, 3, 5, 6, 7, 8, 9, 11, 12, 13, 14, 16, 17, 19, + 20, 22, 23, 25, 26, 28, 29, 31, 32, 34, 35, 37, 38, 40, 41, 43, + 44, 46, 47, 49, 50, 52, 53, 55, 56, 58, 59, 61, 62, 63, 63, 63, + 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63 }, + { 0, 1, 2, 3, 5, 6, 7, 8, 9, 11, 12, 13, 15, 16, 18, 19, + 21, 22, 24, 25, 27, 28, 30, 31, 33, 34, 36, 37, 39, 40, 42, 43, + 45, 46, 48, 49, 51, 52, 54, 55, 57, 58, 60, 61, 63, 63, 63, 63, + 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63 }, + { 0, 1, 2, 3, 5, 6, 7, 8, 9, 11, 12, 14, 15, 17, 18, 20, + 21, 23, 24, 26, 27, 29, 30, 32, 33, 35, 36, 38, 39, 41, 42, 44, + 45, 47, 48, 50, 51, 53, 54, 56, 57, 59, 60, 62, 63, 63, 63, 63, + 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63 }, + { 0, 1, 2, 4, 5, 7, 8, 9, 11, 12, 13, 15, 16, 17, 19, 20, + 22, 23, 25, 26, 28, 29, 31, 32, 34, 35, 37, 38, 40, 41, 43, 44, + 46, 47, 49, 50, 52, 53, 55, 56, 58, 59, 61, 62, 63, 63, 63, 63, + 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63 }, + { 0, 1, 2, 4, 5, 7, 8, 9, 11, 12, 13, 15, 16, 18, 19, 21, + 22, 24, 25, 27, 28, 30, 31, 33, 34, 36, 37, 39, 40, 42, 43, 45, + 46, 48, 49, 51, 52, 54, 55, 57, 58, 60, 61, 63, 63, 63, 63, 63, + 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63 }, + { 0, 1, 2, 4, 5, 7, 8, 9, 11, 12, 14, 15, 17, 18, 20, 21, + 23, 24, 26, 27, 29, 30, 32, 33, 35, 36, 38, 39, 41, 42, 44, 45, + 47, 48, 50, 51, 53, 54, 56, 57, 59, 60, 62, 63, 63, 63, 63, 63, + 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63 } +}; + +int VP8FilterStrengthFromDelta(int sharpness, int delta) { + const int pos = (delta < MAX_DELTA_SIZE) ? delta : MAX_DELTA_SIZE - 1; + assert(sharpness >= 0 && sharpness <= 7); + return kLevelsFromDelta[sharpness][pos]; +} + +//------------------------------------------------------------------------------ +// Paragraph 15.4: compute the inner-edge filtering strength + +static int GetILevel(int sharpness, int level) { + if (sharpness > 0) { + if (sharpness > 4) { + level >>= 2; + } else { + level >>= 1; + } + if (level > 9 - sharpness) { + level = 9 - sharpness; + } + } + if (level < 1) level = 1; + return level; +} + +static void DoFilter(const VP8EncIterator* const it, int level) { + const VP8Encoder* const enc = it->enc_; + const int ilevel = GetILevel(enc->config_->filter_sharpness, level); + const int limit = 2 * level + ilevel; + + uint8_t* const y_dst = it->yuv_out2_ + Y_OFF_ENC; + uint8_t* const u_dst = it->yuv_out2_ + U_OFF_ENC; + uint8_t* const v_dst = it->yuv_out2_ + V_OFF_ENC; + + // copy current block to yuv_out2_ + memcpy(y_dst, it->yuv_out_, YUV_SIZE_ENC * sizeof(uint8_t)); + + if (enc->filter_hdr_.simple_ == 1) { // simple + VP8SimpleHFilter16i(y_dst, BPS, limit); + VP8SimpleVFilter16i(y_dst, BPS, limit); + } else { // complex + const int hev_thresh = (level >= 40) ? 2 : (level >= 15) ? 1 : 0; + VP8HFilter16i(y_dst, BPS, limit, ilevel, hev_thresh); + VP8HFilter8i(u_dst, v_dst, BPS, limit, ilevel, hev_thresh); + VP8VFilter16i(y_dst, BPS, limit, ilevel, hev_thresh); + VP8VFilter8i(u_dst, v_dst, BPS, limit, ilevel, hev_thresh); + } +} + +//------------------------------------------------------------------------------ +// SSIM metric for one macroblock + +static double GetMBSSIM(const uint8_t* yuv1, const uint8_t* yuv2) { + int x, y; + double sum = 0.; + + // compute SSIM in a 10 x 10 window + for (y = VP8_SSIM_KERNEL; y < 16 - VP8_SSIM_KERNEL; y++) { + for (x = VP8_SSIM_KERNEL; x < 16 - VP8_SSIM_KERNEL; x++) { + sum += VP8SSIMGetClipped(yuv1 + Y_OFF_ENC, BPS, yuv2 + Y_OFF_ENC, BPS, + x, y, 16, 16); + } + } + for (x = 1; x < 7; x++) { + for (y = 1; y < 7; y++) { + sum += VP8SSIMGetClipped(yuv1 + U_OFF_ENC, BPS, yuv2 + U_OFF_ENC, BPS, + x, y, 8, 8); + sum += VP8SSIMGetClipped(yuv1 + V_OFF_ENC, BPS, yuv2 + V_OFF_ENC, BPS, + x, y, 8, 8); + } + } + return sum; +} + +//------------------------------------------------------------------------------ +// Exposed APIs: Encoder should call the following 3 functions to adjust +// loop filter strength + +void VP8InitFilter(VP8EncIterator* const it) { + if (it->lf_stats_ != NULL) { + int s, i; + for (s = 0; s < NUM_MB_SEGMENTS; s++) { + for (i = 0; i < MAX_LF_LEVELS; i++) { + (*it->lf_stats_)[s][i] = 0; + } + } + VP8SSIMDspInit(); + } +} + +void VP8StoreFilterStats(VP8EncIterator* const it) { + int d; + VP8Encoder* const enc = it->enc_; + const int s = it->mb_->segment_; + const int level0 = enc->dqm_[s].fstrength_; + + // explore +/-quant range of values around level0 + const int delta_min = -enc->dqm_[s].quant_; + const int delta_max = enc->dqm_[s].quant_; + const int step_size = (delta_max - delta_min >= 4) ? 4 : 1; + + if (it->lf_stats_ == NULL) return; + + // NOTE: Currently we are applying filter only across the sublock edges + // There are two reasons for that. + // 1. Applying filter on macro block edges will change the pixels in + // the left and top macro blocks. That will be hard to restore + // 2. Macro Blocks on the bottom and right are not yet compressed. So we + // cannot apply filter on the right and bottom macro block edges. + if (it->mb_->type_ == 1 && it->mb_->skip_) return; + + // Always try filter level zero + (*it->lf_stats_)[s][0] += GetMBSSIM(it->yuv_in_, it->yuv_out_); + + for (d = delta_min; d <= delta_max; d += step_size) { + const int level = level0 + d; + if (level <= 0 || level >= MAX_LF_LEVELS) { + continue; + } + DoFilter(it, level); + (*it->lf_stats_)[s][level] += GetMBSSIM(it->yuv_in_, it->yuv_out2_); + } +} + +void VP8AdjustFilterStrength(VP8EncIterator* const it) { + VP8Encoder* const enc = it->enc_; + if (it->lf_stats_ != NULL) { + int s; + for (s = 0; s < NUM_MB_SEGMENTS; s++) { + int i, best_level = 0; + // Improvement over filter level 0 should be at least 1e-5 (relatively) + double best_v = 1.00001 * (*it->lf_stats_)[s][0]; + for (i = 1; i < MAX_LF_LEVELS; i++) { + const double v = (*it->lf_stats_)[s][i]; + if (v > best_v) { + best_v = v; + best_level = i; + } + } + enc->dqm_[s].fstrength_ = best_level; + } + } else if (enc->config_->filter_strength > 0) { + int max_level = 0; + int s; + for (s = 0; s < NUM_MB_SEGMENTS; s++) { + VP8SegmentInfo* const dqm = &enc->dqm_[s]; + // this '>> 3' accounts for some inverse WHT scaling + const int delta = (dqm->max_edge_ * dqm->y2_.q_[1]) >> 3; + const int level = + VP8FilterStrengthFromDelta(enc->filter_hdr_.sharpness_, delta); + if (level > dqm->fstrength_) { + dqm->fstrength_ = level; + } + if (max_level < dqm->fstrength_) { + max_level = dqm->fstrength_; + } + } + enc->filter_hdr_.level_ = max_level; + } +} + +// ----------------------------------------------------------------------------- |