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
14 #include "vp9/common/vp9_seg_common.h"
15
16 #include "vp9/encoder/vp9_segmentation.h"
17
18 static const double in_frame_q_adj_ratio[MAX_SEGMENTS] =
19 {1.0, 2.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0};
20
vp9_setup_in_frame_q_adj(VP9_COMP * cpi)21 void vp9_setup_in_frame_q_adj(VP9_COMP *cpi) {
22 VP9_COMMON *const cm = &cpi->common;
23 struct segmentation *const seg = &cm->seg;
24
25 // Make SURE use of floating point in this function is safe.
26 vp9_clear_system_state();
27
28 if (cm->frame_type == KEY_FRAME ||
29 cpi->refresh_alt_ref_frame ||
30 (cpi->refresh_golden_frame && !cpi->rc.is_src_frame_alt_ref)) {
31 int segment;
32
33 // Clear down the segment map.
34 vpx_memset(cpi->segmentation_map, 0, cm->mi_rows * cm->mi_cols);
35
36 // Clear down the complexity map used for rd.
37 vpx_memset(cpi->complexity_map, 0, cm->mi_rows * cm->mi_cols);
38
39 vp9_enable_segmentation(seg);
40 vp9_clearall_segfeatures(seg);
41
42 // Select delta coding method.
43 seg->abs_delta = SEGMENT_DELTADATA;
44
45 // Segment 0 "Q" feature is disabled so it defaults to the baseline Q.
46 vp9_disable_segfeature(seg, 0, SEG_LVL_ALT_Q);
47
48 // Use some of the segments for in frame Q adjustment.
49 for (segment = 1; segment < 2; segment++) {
50 const int qindex_delta =
51 vp9_compute_qdelta_by_rate(cpi,
52 cm->base_qindex,
53 in_frame_q_adj_ratio[segment]);
54 vp9_enable_segfeature(seg, segment, SEG_LVL_ALT_Q);
55 vp9_set_segdata(seg, segment, SEG_LVL_ALT_Q, qindex_delta);
56 }
57 }
58 }
59
60 // Select a segment for the current SB64
vp9_select_in_frame_q_segment(VP9_COMP * cpi,int mi_row,int mi_col,int output_enabled,int projected_rate)61 void vp9_select_in_frame_q_segment(VP9_COMP *cpi,
62 int mi_row, int mi_col,
63 int output_enabled, int projected_rate) {
64 VP9_COMMON *const cm = &cpi->common;
65
66 const int mi_offset = mi_row * cm->mi_cols + mi_col;
67 const int bw = num_8x8_blocks_wide_lookup[BLOCK_64X64];
68 const int bh = num_8x8_blocks_high_lookup[BLOCK_64X64];
69 const int xmis = MIN(cm->mi_cols - mi_col, bw);
70 const int ymis = MIN(cm->mi_rows - mi_row, bh);
71 int complexity_metric = 64;
72 int x, y;
73
74 unsigned char segment;
75
76 if (!output_enabled) {
77 segment = 0;
78 } else {
79 // Rate depends on fraction of a SB64 in frame (xmis * ymis / bw * bh).
80 // It is converted to bits * 256 units.
81 const int target_rate = (cpi->rc.sb64_target_rate * xmis * ymis * 256) /
82 (bw * bh);
83
84 if (projected_rate < (target_rate / 4)) {
85 segment = 1;
86 } else {
87 segment = 0;
88 }
89
90 if (target_rate > 0) {
91 complexity_metric =
92 clamp((int)((projected_rate * 64) / target_rate), 16, 255);
93 }
94 }
95
96 // Fill in the entires in the segment map corresponding to this SB64.
97 for (y = 0; y < ymis; y++) {
98 for (x = 0; x < xmis; x++) {
99 cpi->segmentation_map[mi_offset + y * cm->mi_cols + x] = segment;
100 cpi->complexity_map[mi_offset + y * cm->mi_cols + x] =
101 (unsigned char)complexity_metric;
102 }
103 }
104 }
105