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 AC3ENC_FLOAT 1 28 29#include "libavutil/attributes.h" 30#include "ac3enc.h" 31#include "codec_internal.h" 32#include "eac3enc.h" 33#include "eac3_data.h" 34 35 36static const AVClass eac3enc_class = { 37 .class_name = "E-AC-3 Encoder", 38 .item_name = av_default_item_name, 39 .option = &ff_ac3_enc_options[2], /* First two options are AC-3 only. */ 40 .version = LIBAVUTIL_VERSION_INT, 41}; 42 43/** 44 * LUT for finding a matching frame exponent strategy index from a set of 45 * exponent strategies for a single channel across all 6 blocks. 46 */ 47static int8_t eac3_frame_expstr_index_tab[3][4][4][4][4][4]; 48 49 50av_cold void ff_eac3_exponent_init(void) 51{ 52 int i; 53 54 memset(eac3_frame_expstr_index_tab, -1, sizeof(eac3_frame_expstr_index_tab)); 55 for (i = 0; i < 32; i++) { 56 eac3_frame_expstr_index_tab[ff_eac3_frm_expstr[i][0]-1] 57 [ff_eac3_frm_expstr[i][1]] 58 [ff_eac3_frm_expstr[i][2]] 59 [ff_eac3_frm_expstr[i][3]] 60 [ff_eac3_frm_expstr[i][4]] 61 [ff_eac3_frm_expstr[i][5]] = i; 62 } 63} 64 65 66void ff_eac3_get_frame_exp_strategy(AC3EncodeContext *s) 67{ 68 int ch; 69 70 if (s->num_blocks < 6) { 71 s->use_frame_exp_strategy = 0; 72 return; 73 } 74 75 s->use_frame_exp_strategy = 1; 76 for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) { 77 int expstr = eac3_frame_expstr_index_tab[s->exp_strategy[ch][0]-1] 78 [s->exp_strategy[ch][1]] 79 [s->exp_strategy[ch][2]] 80 [s->exp_strategy[ch][3]] 81 [s->exp_strategy[ch][4]] 82 [s->exp_strategy[ch][5]]; 83 if (expstr < 0) { 84 s->use_frame_exp_strategy = 0; 85 break; 86 } 87 s->frame_exp_strategy[ch] = expstr; 88 } 89} 90 91 92 93void ff_eac3_set_cpl_states(AC3EncodeContext *s) 94{ 95 int ch, blk; 96 int first_cpl_coords[AC3_MAX_CHANNELS]; 97 98 /* set first cpl coords */ 99 for (ch = 1; ch <= s->fbw_channels; ch++) 100 first_cpl_coords[ch] = 1; 101 for (blk = 0; blk < s->num_blocks; blk++) { 102 AC3Block *block = &s->blocks[blk]; 103 for (ch = 1; ch <= s->fbw_channels; ch++) { 104 if (block->channel_in_cpl[ch]) { 105 if (first_cpl_coords[ch]) { 106 block->new_cpl_coords[ch] = 2; 107 first_cpl_coords[ch] = 0; 108 } 109 } else { 110 first_cpl_coords[ch] = 1; 111 } 112 } 113 } 114 115 /* set first cpl leak */ 116 for (blk = 0; blk < s->num_blocks; blk++) { 117 AC3Block *block = &s->blocks[blk]; 118 if (block->cpl_in_use) { 119 block->new_cpl_leak = 2; 120 break; 121 } 122 } 123} 124 125 126void ff_eac3_output_frame_header(AC3EncodeContext *s) 127{ 128 int blk, ch; 129 AC3EncOptions *opt = &s->options; 130 131 put_bits(&s->pb, 16, 0x0b77); /* sync word */ 132 133 /* BSI header */ 134 put_bits(&s->pb, 2, 0); /* stream type = independent */ 135 put_bits(&s->pb, 3, 0); /* substream id = 0 */ 136 put_bits(&s->pb, 11, (s->frame_size / 2) - 1); /* frame size */ 137 if (s->bit_alloc.sr_shift) { 138 put_bits(&s->pb, 2, 0x3); /* fscod2 */ 139 put_bits(&s->pb, 2, s->bit_alloc.sr_code); /* sample rate code */ 140 } else { 141 put_bits(&s->pb, 2, s->bit_alloc.sr_code); /* sample rate code */ 142 put_bits(&s->pb, 2, s->num_blks_code); /* number of blocks */ 143 } 144 put_bits(&s->pb, 3, s->channel_mode); /* audio coding mode */ 145 put_bits(&s->pb, 1, s->lfe_on); /* LFE channel indicator */ 146 put_bits(&s->pb, 5, s->bitstream_id); /* bitstream id (EAC3=16) */ 147 put_bits(&s->pb, 5, -opt->dialogue_level); /* dialogue normalization level */ 148 put_bits(&s->pb, 1, 0); /* no compression gain */ 149 /* mixing metadata*/ 150 put_bits(&s->pb, 1, opt->eac3_mixing_metadata); 151 if (opt->eac3_mixing_metadata) { 152 if (s->channel_mode > AC3_CHMODE_STEREO) 153 put_bits(&s->pb, 2, opt->preferred_stereo_downmix); 154 if (s->has_center) { 155 put_bits(&s->pb, 3, s->ltrt_center_mix_level); 156 put_bits(&s->pb, 3, s->loro_center_mix_level); 157 } 158 if (s->has_surround) { 159 put_bits(&s->pb, 3, s->ltrt_surround_mix_level); 160 put_bits(&s->pb, 3, s->loro_surround_mix_level); 161 } 162 if (s->lfe_on) 163 put_bits(&s->pb, 1, 0); 164 put_bits(&s->pb, 1, 0); /* no program scale */ 165 put_bits(&s->pb, 1, 0); /* no ext program scale */ 166 put_bits(&s->pb, 2, 0); /* no mixing parameters */ 167 if (s->channel_mode < AC3_CHMODE_STEREO) 168 put_bits(&s->pb, 1, 0); /* no pan info */ 169 put_bits(&s->pb, 1, 0); /* no frame mix config info */ 170 } 171 /* info metadata*/ 172 put_bits(&s->pb, 1, opt->eac3_info_metadata); 173 if (opt->eac3_info_metadata) { 174 put_bits(&s->pb, 3, s->bitstream_mode); 175 put_bits(&s->pb, 1, opt->copyright); 176 put_bits(&s->pb, 1, opt->original); 177 if (s->channel_mode == AC3_CHMODE_STEREO) { 178 put_bits(&s->pb, 2, opt->dolby_surround_mode); 179 put_bits(&s->pb, 2, opt->dolby_headphone_mode); 180 } 181 if (s->channel_mode >= AC3_CHMODE_2F2R) 182 put_bits(&s->pb, 2, opt->dolby_surround_ex_mode); 183 put_bits(&s->pb, 1, opt->audio_production_info); 184 if (opt->audio_production_info) { 185 put_bits(&s->pb, 5, opt->mixing_level - 80); 186 put_bits(&s->pb, 2, opt->room_type); 187 put_bits(&s->pb, 1, opt->ad_converter_type); 188 } 189 put_bits(&s->pb, 1, 0); 190 } 191 if (s->num_blocks != 6) 192 put_bits(&s->pb, 1, !(s->avctx->frame_number % 6)); /* converter sync flag */ 193 put_bits(&s->pb, 1, 0); /* no additional bit stream info */ 194 195 /* frame header */ 196 if (s->num_blocks == 6) { 197 put_bits(&s->pb, 1, !s->use_frame_exp_strategy); /* exponent strategy syntax */ 198 put_bits(&s->pb, 1, 0); /* aht enabled = no */ 199 } 200 put_bits(&s->pb, 2, 0); /* snr offset strategy = 1 */ 201 put_bits(&s->pb, 1, 0); /* transient pre-noise processing enabled = no */ 202 put_bits(&s->pb, 1, 0); /* block switch syntax enabled = no */ 203 put_bits(&s->pb, 1, 0); /* dither flag syntax enabled = no */ 204 put_bits(&s->pb, 1, 0); /* bit allocation model syntax enabled = no */ 205 put_bits(&s->pb, 1, 0); /* fast gain codes enabled = no */ 206 put_bits(&s->pb, 1, 0); /* dba syntax enabled = no */ 207 put_bits(&s->pb, 1, 0); /* skip field syntax enabled = no */ 208 put_bits(&s->pb, 1, 0); /* spx enabled = no */ 209 /* coupling strategy use flags */ 210 if (s->channel_mode > AC3_CHMODE_MONO) { 211 put_bits(&s->pb, 1, s->blocks[0].cpl_in_use); 212 for (blk = 1; blk < s->num_blocks; blk++) { 213 AC3Block *block = &s->blocks[blk]; 214 put_bits(&s->pb, 1, block->new_cpl_strategy); 215 if (block->new_cpl_strategy) 216 put_bits(&s->pb, 1, block->cpl_in_use); 217 } 218 } 219 /* exponent strategy */ 220 if (s->use_frame_exp_strategy) { 221 for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) 222 put_bits(&s->pb, 5, s->frame_exp_strategy[ch]); 223 } else { 224 for (blk = 0; blk < s->num_blocks; blk++) 225 for (ch = !s->blocks[blk].cpl_in_use; ch <= s->fbw_channels; ch++) 226 put_bits(&s->pb, 2, s->exp_strategy[ch][blk]); 227 } 228 if (s->lfe_on) { 229 for (blk = 0; blk < s->num_blocks; blk++) 230 put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]); 231 } 232 /* E-AC-3 to AC-3 converter exponent strategy (not optional when num blocks == 6) */ 233 if (s->num_blocks != 6) { 234 put_bits(&s->pb, 1, 0); 235 } else { 236 for (ch = 1; ch <= s->fbw_channels; ch++) { 237 if (s->use_frame_exp_strategy) 238 put_bits(&s->pb, 5, s->frame_exp_strategy[ch]); 239 else 240 put_bits(&s->pb, 5, 0); 241 } 242 } 243 /* snr offsets */ 244 put_bits(&s->pb, 6, s->coarse_snr_offset); 245 put_bits(&s->pb, 4, s->fine_snr_offset[1]); 246 /* block start info */ 247 if (s->num_blocks > 1) 248 put_bits(&s->pb, 1, 0); 249} 250 251 252FF_DISABLE_DEPRECATION_WARNINGS 253const FFCodec ff_eac3_encoder = { 254 .p.name = "eac3", 255 .p.long_name = NULL_IF_CONFIG_SMALL("ATSC A/52 E-AC-3"), 256 .p.type = AVMEDIA_TYPE_AUDIO, 257 .p.id = AV_CODEC_ID_EAC3, 258 .p.capabilities = AV_CODEC_CAP_DR1, 259 .priv_data_size = sizeof(AC3EncodeContext), 260 .init = ff_ac3_float_encode_init, 261 FF_CODEC_ENCODE_CB(ff_ac3_float_encode_frame), 262 .close = ff_ac3_encode_close, 263 .p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP, 264 AV_SAMPLE_FMT_NONE }, 265 .p.priv_class = &eac3enc_class, 266 .p.supported_samplerates = ff_ac3_sample_rate_tab, 267#if FF_API_OLD_CHANNEL_LAYOUT 268 .p.channel_layouts = ff_ac3_channel_layouts, 269#endif 270 .p.ch_layouts = ff_ac3_ch_layouts, 271 .defaults = ff_ac3_enc_defaults, 272 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP, 273}; 274FF_ENABLE_DEPRECATION_WARNINGS 275