Line data Source code
1 : /*
2 : * Copyright (c) 2014 The WebM project authors. All Rights Reserved.
3 : *
4 : * Use of this source code is governed by a BSD-style license
5 : * that can be found in the LICENSE file in the root of the source
6 : * tree. An additional intellectual property rights grant can be found
7 : * in the file PATENTS. All contributing project authors may
8 : * be found in the AUTHORS file in the root of the source tree.
9 : */
10 :
11 : #include <limits.h>
12 : #include <math.h>
13 : #include "vpx_dsp/vpx_dsp_common.h"
14 : #include "vpx_ports/system_state.h"
15 :
16 : #include "vp9/encoder/vp9_aq_complexity.h"
17 : #include "vp9/encoder/vp9_aq_variance.h"
18 : #include "vp9/encoder/vp9_encodeframe.h"
19 : #include "vp9/common/vp9_seg_common.h"
20 : #include "vp9/encoder/vp9_segmentation.h"
21 :
22 : #define AQ_C_SEGMENTS 5
23 : #define DEFAULT_AQ2_SEG 3 // Neutral Q segment
24 : #define AQ_C_STRENGTHS 3
25 : static const double aq_c_q_adj_factor[AQ_C_STRENGTHS][AQ_C_SEGMENTS] = {
26 : { 1.75, 1.25, 1.05, 1.00, 0.90 },
27 : { 2.00, 1.50, 1.15, 1.00, 0.85 },
28 : { 2.50, 1.75, 1.25, 1.00, 0.80 }
29 : };
30 : static const double aq_c_transitions[AQ_C_STRENGTHS][AQ_C_SEGMENTS] = {
31 : { 0.15, 0.30, 0.55, 2.00, 100.0 },
32 : { 0.20, 0.40, 0.65, 2.00, 100.0 },
33 : { 0.25, 0.50, 0.75, 2.00, 100.0 }
34 : };
35 : static const double aq_c_var_thresholds[AQ_C_STRENGTHS][AQ_C_SEGMENTS] = {
36 : { -4.0, -3.0, -2.0, 100.00, 100.0 },
37 : { -3.5, -2.5, -1.5, 100.00, 100.0 },
38 : { -3.0, -2.0, -1.0, 100.00, 100.0 }
39 : };
40 :
41 0 : static int get_aq_c_strength(int q_index, vpx_bit_depth_t bit_depth) {
42 : // Approximate base quatizer (truncated to int)
43 0 : const int base_quant = vp9_ac_quant(q_index, 0, bit_depth) / 4;
44 0 : return (base_quant > 10) + (base_quant > 25);
45 : }
46 :
47 0 : void vp9_setup_in_frame_q_adj(VP9_COMP *cpi) {
48 0 : VP9_COMMON *const cm = &cpi->common;
49 0 : struct segmentation *const seg = &cm->seg;
50 :
51 : // Make SURE use of floating point in this function is safe.
52 0 : vpx_clear_system_state();
53 :
54 0 : if (frame_is_intra_only(cm) || cm->error_resilient_mode ||
55 0 : cpi->refresh_alt_ref_frame || cpi->force_update_segmentation ||
56 0 : (cpi->refresh_golden_frame && !cpi->rc.is_src_frame_alt_ref)) {
57 : int segment;
58 0 : const int aq_strength = get_aq_c_strength(cm->base_qindex, cm->bit_depth);
59 :
60 : // Clear down the segment map.
61 0 : memset(cpi->segmentation_map, DEFAULT_AQ2_SEG, cm->mi_rows * cm->mi_cols);
62 :
63 0 : vp9_clearall_segfeatures(seg);
64 :
65 : // Segmentation only makes sense if the target bits per SB is above a
66 : // threshold. Below this the overheads will usually outweigh any benefit.
67 0 : if (cpi->rc.sb64_target_rate < 256) {
68 0 : vp9_disable_segmentation(seg);
69 0 : return;
70 : }
71 :
72 0 : vp9_enable_segmentation(seg);
73 :
74 : // Select delta coding method.
75 0 : seg->abs_delta = SEGMENT_DELTADATA;
76 :
77 : // Default segment "Q" feature is disabled so it defaults to the baseline Q.
78 0 : vp9_disable_segfeature(seg, DEFAULT_AQ2_SEG, SEG_LVL_ALT_Q);
79 :
80 : // Use some of the segments for in frame Q adjustment.
81 0 : for (segment = 0; segment < AQ_C_SEGMENTS; ++segment) {
82 : int qindex_delta;
83 :
84 0 : if (segment == DEFAULT_AQ2_SEG) continue;
85 :
86 0 : qindex_delta = vp9_compute_qdelta_by_rate(
87 0 : &cpi->rc, cm->frame_type, cm->base_qindex,
88 : aq_c_q_adj_factor[aq_strength][segment], cm->bit_depth);
89 :
90 : // For AQ complexity mode, we dont allow Q0 in a segment if the base
91 : // Q is not 0. Q0 (lossless) implies 4x4 only and in AQ mode 2 a segment
92 : // Q delta is sometimes applied without going back around the rd loop.
93 : // This could lead to an illegal combination of partition size and q.
94 0 : if ((cm->base_qindex != 0) && ((cm->base_qindex + qindex_delta) == 0)) {
95 0 : qindex_delta = -cm->base_qindex + 1;
96 : }
97 0 : if ((cm->base_qindex + qindex_delta) > 0) {
98 0 : vp9_enable_segfeature(seg, segment, SEG_LVL_ALT_Q);
99 0 : vp9_set_segdata(seg, segment, SEG_LVL_ALT_Q, qindex_delta);
100 : }
101 : }
102 : }
103 : }
104 :
105 : #define DEFAULT_LV_THRESH 10.0
106 : #define MIN_DEFAULT_LV_THRESH 8.0
107 : // Select a segment for the current block.
108 : // The choice of segment for a block depends on the ratio of the projected
109 : // bits for the block vs a target average and its spatial complexity.
110 0 : void vp9_caq_select_segment(VP9_COMP *cpi, MACROBLOCK *mb, BLOCK_SIZE bs,
111 : int mi_row, int mi_col, int projected_rate) {
112 0 : VP9_COMMON *const cm = &cpi->common;
113 :
114 0 : const int mi_offset = mi_row * cm->mi_cols + mi_col;
115 0 : const int bw = num_8x8_blocks_wide_lookup[BLOCK_64X64];
116 0 : const int bh = num_8x8_blocks_high_lookup[BLOCK_64X64];
117 0 : const int xmis = VPXMIN(cm->mi_cols - mi_col, num_8x8_blocks_wide_lookup[bs]);
118 0 : const int ymis = VPXMIN(cm->mi_rows - mi_row, num_8x8_blocks_high_lookup[bs]);
119 : int x, y;
120 : int i;
121 : unsigned char segment;
122 :
123 : if (0) {
124 : segment = DEFAULT_AQ2_SEG;
125 : } else {
126 : // Rate depends on fraction of a SB64 in frame (xmis * ymis / bw * bh).
127 : // It is converted to bits * 256 units.
128 0 : const int target_rate =
129 0 : (cpi->rc.sb64_target_rate * xmis * ymis * 256) / (bw * bh);
130 : double logvar;
131 : double low_var_thresh;
132 0 : const int aq_strength = get_aq_c_strength(cm->base_qindex, cm->bit_depth);
133 :
134 0 : vpx_clear_system_state();
135 0 : low_var_thresh = (cpi->oxcf.pass == 2) ? VPXMAX(cpi->twopass.mb_av_energy,
136 : MIN_DEFAULT_LV_THRESH)
137 0 : : DEFAULT_LV_THRESH;
138 :
139 0 : vp9_setup_src_planes(mb, cpi->Source, mi_row, mi_col);
140 0 : logvar = vp9_log_block_var(cpi, mb, bs);
141 :
142 0 : segment = AQ_C_SEGMENTS - 1; // Just in case no break out below.
143 0 : for (i = 0; i < AQ_C_SEGMENTS; ++i) {
144 : // Test rate against a threshold value and variance against a threshold.
145 : // Increasing segment number (higher variance and complexity) = higher Q.
146 0 : if ((projected_rate < target_rate * aq_c_transitions[aq_strength][i]) &&
147 0 : (logvar < (low_var_thresh + aq_c_var_thresholds[aq_strength][i]))) {
148 0 : segment = i;
149 0 : break;
150 : }
151 : }
152 : }
153 :
154 : // Fill in the entires in the segment map corresponding to this SB64.
155 0 : for (y = 0; y < ymis; y++) {
156 0 : for (x = 0; x < xmis; x++) {
157 0 : cpi->segmentation_map[mi_offset + y * cm->mi_cols + x] = segment;
158 : }
159 : }
160 0 : }
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