1/* 2 * E-AC-3 encoder 3 * Copyright (c) 2011 Justin Ruggles <justin.ruggles@gmail.com> 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 * E-AC-3 encoder 25 */ 26 27#define CONFIG_AC3ENC_FLOAT 1 28 29#include "libavutil/attributes.h" 30#include "ac3enc.h" 31#include "eac3enc.h" 32#include "eac3_data.h" 33 34 35#define AC3ENC_TYPE AC3ENC_TYPE_EAC3 36#include "ac3enc_opts_template.c" 37 38static const AVClass eac3enc_class = { 39 .class_name = "E-AC-3 Encoder", 40 .item_name = av_default_item_name, 41 .option = ac3_options, 42 .version = LIBAVUTIL_VERSION_INT, 43}; 44 45/** 46 * LUT for finding a matching frame exponent strategy index from a set of 47 * exponent strategies for a single channel across all 6 blocks. 48 */ 49static int8_t eac3_frame_expstr_index_tab[3][4][4][4][4][4]; 50 51 52av_cold void ff_eac3_exponent_init(void) 53{ 54 int i; 55 56 memset(eac3_frame_expstr_index_tab, -1, sizeof(eac3_frame_expstr_index_tab)); 57 for (i = 0; i < 32; i++) { 58 eac3_frame_expstr_index_tab[ff_eac3_frm_expstr[i][0]-1] 59 [ff_eac3_frm_expstr[i][1]] 60 [ff_eac3_frm_expstr[i][2]] 61 [ff_eac3_frm_expstr[i][3]] 62 [ff_eac3_frm_expstr[i][4]] 63 [ff_eac3_frm_expstr[i][5]] = i; 64 } 65} 66 67 68void ff_eac3_get_frame_exp_strategy(AC3EncodeContext *s) 69{ 70 int ch; 71 72 if (s->num_blocks < 6) { 73 s->use_frame_exp_strategy = 0; 74 return; 75 } 76 77 s->use_frame_exp_strategy = 1; 78 for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) { 79 int expstr = eac3_frame_expstr_index_tab[s->exp_strategy[ch][0]-1] 80 [s->exp_strategy[ch][1]] 81 [s->exp_strategy[ch][2]] 82 [s->exp_strategy[ch][3]] 83 [s->exp_strategy[ch][4]] 84 [s->exp_strategy[ch][5]]; 85 if (expstr < 0) { 86 s->use_frame_exp_strategy = 0; 87 break; 88 } 89 s->frame_exp_strategy[ch] = expstr; 90 } 91} 92 93 94 95void ff_eac3_set_cpl_states(AC3EncodeContext *s) 96{ 97 int ch, blk; 98 int first_cpl_coords[AC3_MAX_CHANNELS]; 99 100 /* set first cpl coords */ 101 for (ch = 1; ch <= s->fbw_channels; ch++) 102 first_cpl_coords[ch] = 1; 103 for (blk = 0; blk < s->num_blocks; blk++) { 104 AC3Block *block = &s->blocks[blk]; 105 for (ch = 1; ch <= s->fbw_channels; ch++) { 106 if (block->channel_in_cpl[ch]) { 107 if (first_cpl_coords[ch]) { 108 block->new_cpl_coords[ch] = 2; 109 first_cpl_coords[ch] = 0; 110 } 111 } else { 112 first_cpl_coords[ch] = 1; 113 } 114 } 115 } 116 117 /* set first cpl leak */ 118 for (blk = 0; blk < s->num_blocks; blk++) { 119 AC3Block *block = &s->blocks[blk]; 120 if (block->cpl_in_use) { 121 block->new_cpl_leak = 2; 122 break; 123 } 124 } 125} 126 127 128void ff_eac3_output_frame_header(AC3EncodeContext *s) 129{ 130 int blk, ch; 131 AC3EncOptions *opt = &s->options; 132 133 put_bits(&s->pb, 16, 0x0b77); /* sync word */ 134 135 /* BSI header */ 136 put_bits(&s->pb, 2, 0); /* stream type = independent */ 137 put_bits(&s->pb, 3, 0); /* substream id = 0 */ 138 put_bits(&s->pb, 11, (s->frame_size / 2) - 1); /* frame size */ 139 if (s->bit_alloc.sr_shift) { 140 put_bits(&s->pb, 2, 0x3); /* fscod2 */ 141 put_bits(&s->pb, 2, s->bit_alloc.sr_code); /* sample rate code */ 142 } else { 143 put_bits(&s->pb, 2, s->bit_alloc.sr_code); /* sample rate code */ 144 put_bits(&s->pb, 2, s->num_blks_code); /* number of blocks */ 145 } 146 put_bits(&s->pb, 3, s->channel_mode); /* audio coding mode */ 147 put_bits(&s->pb, 1, s->lfe_on); /* LFE channel indicator */ 148 put_bits(&s->pb, 5, s->bitstream_id); /* bitstream id (EAC3=16) */ 149 put_bits(&s->pb, 5, -opt->dialogue_level); /* dialogue normalization level */ 150 put_bits(&s->pb, 1, 0); /* no compression gain */ 151 /* mixing metadata*/ 152 put_bits(&s->pb, 1, opt->eac3_mixing_metadata); 153 if (opt->eac3_mixing_metadata) { 154 if (s->channel_mode > AC3_CHMODE_STEREO) 155 put_bits(&s->pb, 2, opt->preferred_stereo_downmix); 156 if (s->has_center) { 157 put_bits(&s->pb, 3, s->ltrt_center_mix_level); 158 put_bits(&s->pb, 3, s->loro_center_mix_level); 159 } 160 if (s->has_surround) { 161 put_bits(&s->pb, 3, s->ltrt_surround_mix_level); 162 put_bits(&s->pb, 3, s->loro_surround_mix_level); 163 } 164 if (s->lfe_on) 165 put_bits(&s->pb, 1, 0); 166 put_bits(&s->pb, 1, 0); /* no program scale */ 167 put_bits(&s->pb, 1, 0); /* no ext program scale */ 168 put_bits(&s->pb, 2, 0); /* no mixing parameters */ 169 if (s->channel_mode < AC3_CHMODE_STEREO) 170 put_bits(&s->pb, 1, 0); /* no pan info */ 171 put_bits(&s->pb, 1, 0); /* no frame mix config info */ 172 } 173 /* info metadata*/ 174 put_bits(&s->pb, 1, opt->eac3_info_metadata); 175 if (opt->eac3_info_metadata) { 176 put_bits(&s->pb, 3, s->bitstream_mode); 177 put_bits(&s->pb, 1, opt->copyright); 178 put_bits(&s->pb, 1, opt->original); 179 if (s->channel_mode == AC3_CHMODE_STEREO) { 180 put_bits(&s->pb, 2, opt->dolby_surround_mode); 181 put_bits(&s->pb, 2, opt->dolby_headphone_mode); 182 } 183 if (s->channel_mode >= AC3_CHMODE_2F2R) 184 put_bits(&s->pb, 2, opt->dolby_surround_ex_mode); 185 put_bits(&s->pb, 1, opt->audio_production_info); 186 if (opt->audio_production_info) { 187 put_bits(&s->pb, 5, opt->mixing_level - 80); 188 put_bits(&s->pb, 2, opt->room_type); 189 put_bits(&s->pb, 1, opt->ad_converter_type); 190 } 191 put_bits(&s->pb, 1, 0); 192 } 193 if (s->num_blocks != 6) 194 put_bits(&s->pb, 1, !(s->avctx->frame_number % 6)); /* converter sync flag */ 195 put_bits(&s->pb, 1, 0); /* no additional bit stream info */ 196 197 /* frame header */ 198 if (s->num_blocks == 6) { 199 put_bits(&s->pb, 1, !s->use_frame_exp_strategy);/* exponent strategy syntax */ 200 put_bits(&s->pb, 1, 0); /* aht enabled = no */ 201 } 202 put_bits(&s->pb, 2, 0); /* snr offset strategy = 1 */ 203 put_bits(&s->pb, 1, 0); /* transient pre-noise processing enabled = no */ 204 put_bits(&s->pb, 1, 0); /* block switch syntax enabled = no */ 205 put_bits(&s->pb, 1, 0); /* dither flag syntax enabled = no */ 206 put_bits(&s->pb, 1, 0); /* bit allocation model syntax enabled = no */ 207 put_bits(&s->pb, 1, 0); /* fast gain codes enabled = no */ 208 put_bits(&s->pb, 1, 0); /* dba syntax enabled = no */ 209 put_bits(&s->pb, 1, 0); /* skip field syntax enabled = no */ 210 put_bits(&s->pb, 1, 0); /* spx enabled = no */ 211 /* coupling strategy use flags */ 212 if (s->channel_mode > AC3_CHMODE_MONO) { 213 put_bits(&s->pb, 1, s->blocks[0].cpl_in_use); 214 for (blk = 1; blk < s->num_blocks; blk++) { 215 AC3Block *block = &s->blocks[blk]; 216 put_bits(&s->pb, 1, block->new_cpl_strategy); 217 if (block->new_cpl_strategy) 218 put_bits(&s->pb, 1, block->cpl_in_use); 219 } 220 } 221 /* exponent strategy */ 222 if (s->use_frame_exp_strategy) { 223 for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) 224 put_bits(&s->pb, 5, s->frame_exp_strategy[ch]); 225 } else { 226 for (blk = 0; blk < s->num_blocks; blk++) 227 for (ch = !s->blocks[blk].cpl_in_use; ch <= s->fbw_channels; ch++) 228 put_bits(&s->pb, 2, s->exp_strategy[ch][blk]); 229 } 230 if (s->lfe_on) { 231 for (blk = 0; blk < s->num_blocks; blk++) 232 put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]); 233 } 234 /* E-AC-3 to AC-3 converter exponent strategy (not optional when num blocks == 6) */ 235 if (s->num_blocks != 6) { 236 put_bits(&s->pb, 1, 0); 237 } else { 238 for (ch = 1; ch <= s->fbw_channels; ch++) { 239 if (s->use_frame_exp_strategy) 240 put_bits(&s->pb, 5, s->frame_exp_strategy[ch]); 241 else 242 put_bits(&s->pb, 5, 0); 243 } 244 } 245 /* snr offsets */ 246 put_bits(&s->pb, 6, s->coarse_snr_offset); 247 put_bits(&s->pb, 4, s->fine_snr_offset[1]); 248 /* block start info */ 249 if (s->num_blocks > 1) 250 put_bits(&s->pb, 1, 0); 251} 252 253 254AVCodec ff_eac3_encoder = { 255 .name = "eac3", 256 .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52 E-AC-3"), 257 .type = AVMEDIA_TYPE_AUDIO, 258 .id = AV_CODEC_ID_EAC3, 259 .priv_data_size = sizeof(AC3EncodeContext), 260 .init = ff_ac3_float_encode_init, 261 .encode2 = ff_ac3_float_encode_frame, 262 .close = ff_ac3_encode_close, 263 .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP, 264 AV_SAMPLE_FMT_NONE }, 265 .priv_class = &eac3enc_class, 266 .channel_layouts = ff_ac3_channel_layouts, 267 .defaults = ac3_defaults, 268}; 269