| 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 | |
| 38 | static 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 | */ |
| 49 | static int8_t eac3_frame_expstr_index_tab[3][4][4][4][4][4]; |
| 50 | |
| 51 | |
| 52 | av_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 | |
| 68 | void 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 | |
| 95 | void 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 | |
| 128 | void 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 | |
| 254 | AVCodec 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 | }; |