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