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1/*
2 * AAC encoder trellis codebook selector
3 * Copyright (C) 2008-2009 Konstantin Shishkov
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * AAC encoder trellis codebook selector
25 * @author Konstantin Shishkov
26 */
27
28/**
29 * This file contains a template for the codebook_trellis_rate selector function.
30 * It needs to be provided, externally, as an already included declaration,
31 * the following functions from aacenc_quantization/util.h. They're not included
32 * explicitly here to make it possible to provide alternative implementations:
33 * - quantize_band_cost_bits
34 * - abs_pow34_v
35 */
36
37#ifndef AVCODEC_AACCODER_TRELLIS_H
38#define AVCODEC_AACCODER_TRELLIS_H
39
40#include <float.h>
41#include "libavutil/mathematics.h"
42#include "avcodec.h"
43#include "put_bits.h"
44#include "aac.h"
45#include "aacenc.h"
46#include "aactab.h"
47#include "aacenctab.h"
48
49/**
50 * structure used in optimal codebook search
51 */
52typedef struct TrellisBandCodingPath {
53 int prev_idx; ///< pointer to the previous path point
54 float cost; ///< path cost
55 int run;
56} TrellisBandCodingPath;
57
58
59static void codebook_trellis_rate(AACEncContext *s, SingleChannelElement *sce,
60 int win, int group_len, const float lambda)
61{
62 TrellisBandCodingPath path[120][CB_TOT_ALL];
63 int w, swb, cb, start, size;
64 int i, j;
65 const int max_sfb = sce->ics.max_sfb;
66 const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
67 const int run_esc = (1 << run_bits) - 1;
68 int idx, ppos, count;
69 int stackrun[120], stackcb[120], stack_len;
70 float next_minbits = INFINITY;
71 int next_mincb = 0;
72
73 s->abs_pow34(s->scoefs, sce->coeffs, 1024);
74 start = win*128;
75 for (cb = 0; cb < CB_TOT_ALL; cb++) {
76 path[0][cb].cost = run_bits+4;
77 path[0][cb].prev_idx = -1;
78 path[0][cb].run = 0;
79 }
80 for (swb = 0; swb < max_sfb; swb++) {
81 size = sce->ics.swb_sizes[swb];
82 if (sce->zeroes[win*16 + swb]) {
83 float cost_stay_here = path[swb][0].cost;
84 float cost_get_here = next_minbits + run_bits + 4;
85 if ( run_value_bits[sce->ics.num_windows == 8][path[swb][0].run]
86 != run_value_bits[sce->ics.num_windows == 8][path[swb][0].run+1])
87 cost_stay_here += run_bits;
88 if (cost_get_here < cost_stay_here) {
89 path[swb+1][0].prev_idx = next_mincb;
90 path[swb+1][0].cost = cost_get_here;
91 path[swb+1][0].run = 1;
92 } else {
93 path[swb+1][0].prev_idx = 0;
94 path[swb+1][0].cost = cost_stay_here;
95 path[swb+1][0].run = path[swb][0].run + 1;
96 }
97 next_minbits = path[swb+1][0].cost;
98 next_mincb = 0;
99 for (cb = 1; cb < CB_TOT_ALL; cb++) {
100 path[swb+1][cb].cost = 61450;
101 path[swb+1][cb].prev_idx = -1;
102 path[swb+1][cb].run = 0;
103 }
104 } else {
105 float minbits = next_minbits;
106 int mincb = next_mincb;
107 int startcb = sce->band_type[win*16+swb];
108 startcb = aac_cb_in_map[startcb];
109 next_minbits = INFINITY;
110 next_mincb = 0;
111 for (cb = 0; cb < startcb; cb++) {
112 path[swb+1][cb].cost = 61450;
113 path[swb+1][cb].prev_idx = -1;
114 path[swb+1][cb].run = 0;
115 }
116 for (cb = startcb; cb < CB_TOT_ALL; cb++) {
117 float cost_stay_here, cost_get_here;
118 float bits = 0.0f;
119 if (cb >= 12 && sce->band_type[win*16+swb] != aac_cb_out_map[cb]) {
120 path[swb+1][cb].cost = 61450;
121 path[swb+1][cb].prev_idx = -1;
122 path[swb+1][cb].run = 0;
123 continue;
124 }
125 for (w = 0; w < group_len; w++) {
126 bits += quantize_band_cost_bits(s, &sce->coeffs[start + w*128],
127 &s->scoefs[start + w*128], size,
128 sce->sf_idx[win*16+swb],
129 aac_cb_out_map[cb],
130 0, INFINITY, NULL, NULL, 0);
131 }
132 cost_stay_here = path[swb][cb].cost + bits;
133 cost_get_here = minbits + bits + run_bits + 4;
134 if ( run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run]
135 != run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run+1])
136 cost_stay_here += run_bits;
137 if (cost_get_here < cost_stay_here) {
138 path[swb+1][cb].prev_idx = mincb;
139 path[swb+1][cb].cost = cost_get_here;
140 path[swb+1][cb].run = 1;
141 } else {
142 path[swb+1][cb].prev_idx = cb;
143 path[swb+1][cb].cost = cost_stay_here;
144 path[swb+1][cb].run = path[swb][cb].run + 1;
145 }
146 if (path[swb+1][cb].cost < next_minbits) {
147 next_minbits = path[swb+1][cb].cost;
148 next_mincb = cb;
149 }
150 }
151 }
152 start += sce->ics.swb_sizes[swb];
153 }
154
155 //convert resulting path from backward-linked list
156 stack_len = 0;
157 idx = 0;
158 for (cb = 1; cb < CB_TOT_ALL; cb++)
159 if (path[max_sfb][cb].cost < path[max_sfb][idx].cost)
160 idx = cb;
161 ppos = max_sfb;
162 while (ppos > 0) {
163 av_assert1(idx >= 0);
164 cb = idx;
165 stackrun[stack_len] = path[ppos][cb].run;
166 stackcb [stack_len] = cb;
167 idx = path[ppos-path[ppos][cb].run+1][cb].prev_idx;
168 ppos -= path[ppos][cb].run;
169 stack_len++;
170 }
171 //perform actual band info encoding
172 start = 0;
173 for (i = stack_len - 1; i >= 0; i--) {
174 cb = aac_cb_out_map[stackcb[i]];
175 put_bits(&s->pb, 4, cb);
176 count = stackrun[i];
177 memset(sce->zeroes + win*16 + start, !cb, count);
178 //XXX: memset when band_type is also uint8_t
179 for (j = 0; j < count; j++) {
180 sce->band_type[win*16 + start] = cb;
181 start++;
182 }
183 while (count >= run_esc) {
184 put_bits(&s->pb, run_bits, run_esc);
185 count -= run_esc;
186 }
187 put_bits(&s->pb, run_bits, count);
188 }
189}
190
191
192#endif /* AVCODEC_AACCODER_TRELLIS_H */
193
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