1/* 2 * E-AC-3 encoder 3 * Copyright (c) 2011 Justin Ruggles <justin.ruggles@gmail.com> 4 * 5 * This file is part of Libav. 6 * 7 * Libav 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 * Libav 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 Libav; 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#include "ac3enc.h" 29#include "eac3enc.h" 30#include "eac3_data.h" 31 32 33#define AC3ENC_TYPE AC3ENC_TYPE_EAC3 34#include "ac3enc_opts_template.c" 35static const AVClass eac3enc_class = { "E-AC-3 Encoder", av_default_item_name, 36 eac3_options, LIBAVUTIL_VERSION_INT }; 37 38 39/** 40 * LUT for finding a matching frame exponent strategy index from a set of 41 * exponent strategies for a single channel across all 6 blocks. 42 */ 43static int8_t eac3_frame_expstr_index_tab[3][4][4][4][4][4]; 44 45 46void ff_eac3_exponent_init(void) 47{ 48 int i; 49 50 memset(eac3_frame_expstr_index_tab, -1, sizeof(eac3_frame_expstr_index_tab)); 51 for (i = 0; i < 32; i++) { 52 eac3_frame_expstr_index_tab[ff_eac3_frm_expstr[i][0]-1] 53 [ff_eac3_frm_expstr[i][1]] 54 [ff_eac3_frm_expstr[i][2]] 55 [ff_eac3_frm_expstr[i][3]] 56 [ff_eac3_frm_expstr[i][4]] 57 [ff_eac3_frm_expstr[i][5]] = i; 58 } 59} 60 61 62void ff_eac3_get_frame_exp_strategy(AC3EncodeContext *s) 63{ 64 int ch; 65 66 if (s->num_blocks < 6) { 67 s->use_frame_exp_strategy = 0; 68 return; 69 } 70 71 s->use_frame_exp_strategy = 1; 72 for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) { 73 int expstr = eac3_frame_expstr_index_tab[s->exp_strategy[ch][0]-1] 74 [s->exp_strategy[ch][1]] 75 [s->exp_strategy[ch][2]] 76 [s->exp_strategy[ch][3]] 77 [s->exp_strategy[ch][4]] 78 [s->exp_strategy[ch][5]]; 79 if (expstr < 0) { 80 s->use_frame_exp_strategy = 0; 81 break; 82 } 83 s->frame_exp_strategy[ch] = expstr; 84 } 85} 86 87 88 89void ff_eac3_set_cpl_states(AC3EncodeContext *s) 90{ 91 int ch, blk; 92 int first_cpl_coords[AC3_MAX_CHANNELS]; 93 94 /* set first cpl coords */ 95 for (ch = 1; ch <= s->fbw_channels; ch++) 96 first_cpl_coords[ch] = 1; 97 for (blk = 0; blk < s->num_blocks; blk++) { 98 AC3Block *block = &s->blocks[blk]; 99 for (ch = 1; ch <= s->fbw_channels; ch++) { 100 if (block->channel_in_cpl[ch]) { 101 if (first_cpl_coords[ch]) { 102 block->new_cpl_coords[ch] = 2; 103 first_cpl_coords[ch] = 0; 104 } 105 } else { 106 first_cpl_coords[ch] = 1; 107 } 108 } 109 } 110 111 /* set first cpl leak */ 112 for (blk = 0; blk < s->num_blocks; blk++) { 113 AC3Block *block = &s->blocks[blk]; 114 if (block->cpl_in_use) { 115 block->new_cpl_leak = 2; 116 break; 117 } 118 } 119} 120 121 122void ff_eac3_output_frame_header(AC3EncodeContext *s) 123{ 124 int blk, ch; 125 AC3EncOptions *opt = &s->options; 126 127 put_bits(&s->pb, 16, 0x0b77); /* sync word */ 128 129 /* BSI header */ 130 put_bits(&s->pb, 2, 0); /* stream type = independent */ 131 put_bits(&s->pb, 3, 0); /* substream id = 0 */ 132 put_bits(&s->pb, 11, (s->frame_size / 2) - 1); /* frame size */ 133 if (s->bit_alloc.sr_shift) { 134 put_bits(&s->pb, 2, 0x3); /* fscod2 */ 135 put_bits(&s->pb, 2, s->bit_alloc.sr_code); /* sample rate code */ 136 } else { 137 put_bits(&s->pb, 2, s->bit_alloc.sr_code); /* sample rate code */ 138 put_bits(&s->pb, 2, s->num_blks_code); /* number of blocks */ 139 } 140 put_bits(&s->pb, 3, s->channel_mode); /* audio coding mode */ 141 put_bits(&s->pb, 1, s->lfe_on); /* LFE channel indicator */ 142 put_bits(&s->pb, 5, s->bitstream_id); /* bitstream id (EAC3=16) */ 143 put_bits(&s->pb, 5, -opt->dialogue_level); /* dialogue normalization level */ 144 put_bits(&s->pb, 1, 0); /* no compression gain */ 145 /* mixing metadata*/ 146 put_bits(&s->pb, 1, opt->eac3_mixing_metadata); 147 if (opt->eac3_mixing_metadata) { 148 if (s->channel_mode > AC3_CHMODE_STEREO) 149 put_bits(&s->pb, 2, opt->preferred_stereo_downmix); 150 if (s->has_center) { 151 put_bits(&s->pb, 3, s->ltrt_center_mix_level); 152 put_bits(&s->pb, 3, s->loro_center_mix_level); 153 } 154 if (s->has_surround) { 155 put_bits(&s->pb, 3, s->ltrt_surround_mix_level); 156 put_bits(&s->pb, 3, s->loro_surround_mix_level); 157 } 158 if (s->lfe_on) 159 put_bits(&s->pb, 1, 0); 160 put_bits(&s->pb, 1, 0); /* no program scale */ 161 put_bits(&s->pb, 1, 0); /* no ext program scale */ 162 put_bits(&s->pb, 2, 0); /* no mixing parameters */ 163 if (s->channel_mode < AC3_CHMODE_STEREO) 164 put_bits(&s->pb, 1, 0); /* no pan info */ 165 put_bits(&s->pb, 1, 0); /* no frame mix config info */ 166 } 167 /* info metadata*/ 168 put_bits(&s->pb, 1, opt->eac3_info_metadata); 169 if (opt->eac3_info_metadata) { 170 put_bits(&s->pb, 3, s->bitstream_mode); 171 put_bits(&s->pb, 1, opt->copyright); 172 put_bits(&s->pb, 1, opt->original); 173 if (s->channel_mode == AC3_CHMODE_STEREO) { 174 put_bits(&s->pb, 2, opt->dolby_surround_mode); 175 put_bits(&s->pb, 2, opt->dolby_headphone_mode); 176 } 177 if (s->channel_mode >= AC3_CHMODE_2F2R) 178 put_bits(&s->pb, 2, opt->dolby_surround_ex_mode); 179 put_bits(&s->pb, 1, opt->audio_production_info); 180 if (opt->audio_production_info) { 181 put_bits(&s->pb, 5, opt->mixing_level - 80); 182 put_bits(&s->pb, 2, opt->room_type); 183 put_bits(&s->pb, 1, opt->ad_converter_type); 184 } 185 put_bits(&s->pb, 1, 0); 186 } 187 if (s->num_blocks != 6) 188 put_bits(&s->pb, 1, !(s->avctx->frame_number % 6)); /* converter sync flag */ 189 put_bits(&s->pb, 1, 0); /* no additional bit stream info */ 190 191 /* frame header */ 192 if (s->num_blocks == 6) { 193 put_bits(&s->pb, 1, !s->use_frame_exp_strategy);/* exponent strategy syntax */ 194 put_bits(&s->pb, 1, 0); /* aht enabled = no */ 195 } 196 put_bits(&s->pb, 2, 0); /* snr offset strategy = 1 */ 197 put_bits(&s->pb, 1, 0); /* transient pre-noise processing enabled = no */ 198 put_bits(&s->pb, 1, 0); /* block switch syntax enabled = no */ 199 put_bits(&s->pb, 1, 0); /* dither flag syntax enabled = no */ 200 put_bits(&s->pb, 1, 0); /* bit allocation model syntax enabled = no */ 201 put_bits(&s->pb, 1, 0); /* fast gain codes enabled = no */ 202 put_bits(&s->pb, 1, 0); /* dba syntax enabled = no */ 203 put_bits(&s->pb, 1, 0); /* skip field syntax enabled = no */ 204 put_bits(&s->pb, 1, 0); /* spx enabled = no */ 205 /* coupling strategy use flags */ 206 if (s->channel_mode > AC3_CHMODE_MONO) { 207 put_bits(&s->pb, 1, s->blocks[0].cpl_in_use); 208 for (blk = 1; blk < s->num_blocks; blk++) { 209 AC3Block *block = &s->blocks[blk]; 210 put_bits(&s->pb, 1, block->new_cpl_strategy); 211 if (block->new_cpl_strategy) 212 put_bits(&s->pb, 1, block->cpl_in_use); 213 } 214 } 215 /* exponent strategy */ 216 if (s->use_frame_exp_strategy) { 217 for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) 218 put_bits(&s->pb, 5, s->frame_exp_strategy[ch]); 219 } else { 220 for (blk = 0; blk < s->num_blocks; blk++) 221 for (ch = !s->blocks[blk].cpl_in_use; ch <= s->fbw_channels; ch++) 222 put_bits(&s->pb, 2, s->exp_strategy[ch][blk]); 223 } 224 if (s->lfe_on) { 225 for (blk = 0; blk < s->num_blocks; blk++) 226 put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]); 227 } 228 /* E-AC-3 to AC-3 converter exponent strategy (not optional when num blocks == 6) */ 229 if (s->num_blocks != 6) { 230 put_bits(&s->pb, 1, 0); 231 } else { 232 for (ch = 1; ch <= s->fbw_channels; ch++) { 233 if (s->use_frame_exp_strategy) 234 put_bits(&s->pb, 5, s->frame_exp_strategy[ch]); 235 else 236 put_bits(&s->pb, 5, 0); 237 } 238 } 239 /* snr offsets */ 240 put_bits(&s->pb, 6, s->coarse_snr_offset); 241 put_bits(&s->pb, 4, s->fine_snr_offset[1]); 242 /* block start info */ 243 if (s->num_blocks > 1) 244 put_bits(&s->pb, 1, 0); 245} 246 247 248#if CONFIG_EAC3_ENCODER 249AVCodec ff_eac3_encoder = { 250 .name = "eac3", 251 .type = AVMEDIA_TYPE_AUDIO, 252 .id = CODEC_ID_EAC3, 253 .priv_data_size = sizeof(AC3EncodeContext), 254 .init = ff_ac3_encode_init, 255 .encode = ff_ac3_float_encode_frame, 256 .close = ff_ac3_encode_close, 257 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_FLT,AV_SAMPLE_FMT_NONE}, 258 .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52 E-AC-3"), 259 .priv_class = &eac3enc_class, 260 .channel_layouts = ff_ac3_channel_layouts, 261}; 262#endif 263