/* * E-AC-3 encoder * Copyright (c) 2011 Justin Ruggles * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * E-AC-3 encoder */ #define AC3ENC_FLOAT 1 #include "libavutil/attributes.h" #include "ac3enc.h" #include "codec_internal.h" #include "eac3enc.h" #include "eac3_data.h" static const AVClass eac3enc_class = { .class_name = "E-AC-3 Encoder", .option = &ff_ac3_enc_options[2], /* First two options are AC-3 only. */ .version = LIBAVUTIL_VERSION_INT, }; /** * LUT for finding a matching frame exponent strategy index from a set of * exponent strategies for a single channel across all 6 blocks. */ static int8_t eac3_frame_expstr_index_tab[3][4][4][4][4][4]; av_cold void ff_eac3_exponent_init(void) { int i; memset(eac3_frame_expstr_index_tab, -1, sizeof(eac3_frame_expstr_index_tab)); for (i = 0; i < 32; i++) { eac3_frame_expstr_index_tab[ff_eac3_frm_expstr[i][0]-1] [ff_eac3_frm_expstr[i][1]] [ff_eac3_frm_expstr[i][2]] [ff_eac3_frm_expstr[i][3]] [ff_eac3_frm_expstr[i][4]] [ff_eac3_frm_expstr[i][5]] = i; } } void ff_eac3_get_frame_exp_strategy(AC3EncodeContext *s) { int ch; if (s->num_blocks < 6) { s->use_frame_exp_strategy = 0; return; } s->use_frame_exp_strategy = 1; for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) { int expstr = eac3_frame_expstr_index_tab[s->exp_strategy[ch][0]-1] [s->exp_strategy[ch][1]] [s->exp_strategy[ch][2]] [s->exp_strategy[ch][3]] [s->exp_strategy[ch][4]] [s->exp_strategy[ch][5]]; if (expstr < 0) { s->use_frame_exp_strategy = 0; break; } s->frame_exp_strategy[ch] = expstr; } } void ff_eac3_set_cpl_states(AC3EncodeContext *s) { int ch, blk; int first_cpl_coords[AC3_MAX_CHANNELS]; /* set first cpl coords */ for (ch = 1; ch <= s->fbw_channels; ch++) first_cpl_coords[ch] = 1; for (blk = 0; blk < s->num_blocks; blk++) { AC3Block *block = &s->blocks[blk]; for (ch = 1; ch <= s->fbw_channels; ch++) { if (block->channel_in_cpl[ch]) { if (first_cpl_coords[ch]) { block->new_cpl_coords[ch] = 2; first_cpl_coords[ch] = 0; } } else { first_cpl_coords[ch] = 1; } } } /* set first cpl leak */ for (blk = 0; blk < s->num_blocks; blk++) { AC3Block *block = &s->blocks[blk]; if (block->cpl_in_use) { block->new_cpl_leak = 2; break; } } } void ff_eac3_output_frame_header(AC3EncodeContext *s) { int blk, ch; AC3EncOptions *opt = &s->options; put_bits(&s->pb, 16, 0x0b77); /* sync word */ /* BSI header */ put_bits(&s->pb, 2, 0); /* stream type = independent */ put_bits(&s->pb, 3, 0); /* substream id = 0 */ put_bits(&s->pb, 11, (s->frame_size / 2) - 1); /* frame size */ if (s->bit_alloc.sr_shift) { put_bits(&s->pb, 2, 0x3); /* fscod2 */ put_bits(&s->pb, 2, s->bit_alloc.sr_code); /* sample rate code */ } else { put_bits(&s->pb, 2, s->bit_alloc.sr_code); /* sample rate code */ put_bits(&s->pb, 2, s->num_blks_code); /* number of blocks */ } put_bits(&s->pb, 3, s->channel_mode); /* audio coding mode */ put_bits(&s->pb, 1, s->lfe_on); /* LFE channel indicator */ put_bits(&s->pb, 5, s->bitstream_id); /* bitstream id (EAC3=16) */ put_bits(&s->pb, 5, -opt->dialogue_level); /* dialogue normalization level */ put_bits(&s->pb, 1, 0); /* no compression gain */ /* mixing metadata*/ put_bits(&s->pb, 1, opt->eac3_mixing_metadata); if (opt->eac3_mixing_metadata) { if (s->channel_mode > AC3_CHMODE_STEREO) put_bits(&s->pb, 2, opt->preferred_stereo_downmix); if (s->has_center) { put_bits(&s->pb, 3, s->ltrt_center_mix_level); put_bits(&s->pb, 3, s->loro_center_mix_level); } if (s->has_surround) { put_bits(&s->pb, 3, s->ltrt_surround_mix_level); put_bits(&s->pb, 3, s->loro_surround_mix_level); } if (s->lfe_on) put_bits(&s->pb, 1, 0); put_bits(&s->pb, 1, 0); /* no program scale */ put_bits(&s->pb, 1, 0); /* no ext program scale */ put_bits(&s->pb, 2, 0); /* no mixing parameters */ if (s->channel_mode < AC3_CHMODE_STEREO) put_bits(&s->pb, 1, 0); /* no pan info */ put_bits(&s->pb, 1, 0); /* no frame mix config info */ } /* info metadata*/ put_bits(&s->pb, 1, opt->eac3_info_metadata); if (opt->eac3_info_metadata) { put_bits(&s->pb, 3, s->bitstream_mode); put_bits(&s->pb, 1, opt->copyright); put_bits(&s->pb, 1, opt->original); if (s->channel_mode == AC3_CHMODE_STEREO) { put_bits(&s->pb, 2, opt->dolby_surround_mode); put_bits(&s->pb, 2, opt->dolby_headphone_mode); } if (s->channel_mode >= AC3_CHMODE_2F2R) put_bits(&s->pb, 2, opt->dolby_surround_ex_mode); put_bits(&s->pb, 1, opt->audio_production_info); if (opt->audio_production_info) { put_bits(&s->pb, 5, opt->mixing_level - 80); put_bits(&s->pb, 2, opt->room_type); put_bits(&s->pb, 1, opt->ad_converter_type); } put_bits(&s->pb, 1, 0); } if (s->num_blocks != 6) put_bits(&s->pb, 1, !(s->avctx->frame_num % 6)); /* converter sync flag */ put_bits(&s->pb, 1, 0); /* no additional bit stream info */ /* frame header */ if (s->num_blocks == 6) { put_bits(&s->pb, 1, !s->use_frame_exp_strategy); /* exponent strategy syntax */ put_bits(&s->pb, 1, 0); /* aht enabled = no */ } put_bits(&s->pb, 2, 0); /* snr offset strategy = 1 */ put_bits(&s->pb, 1, 0); /* transient pre-noise processing enabled = no */ put_bits(&s->pb, 1, 0); /* block switch syntax enabled = no */ put_bits(&s->pb, 1, 0); /* dither flag syntax enabled = no */ put_bits(&s->pb, 1, 0); /* bit allocation model syntax enabled = no */ put_bits(&s->pb, 1, 0); /* fast gain codes enabled = no */ put_bits(&s->pb, 1, 0); /* dba syntax enabled = no */ put_bits(&s->pb, 1, 0); /* skip field syntax enabled = no */ put_bits(&s->pb, 1, 0); /* spx enabled = no */ /* coupling strategy use flags */ if (s->channel_mode > AC3_CHMODE_MONO) { put_bits(&s->pb, 1, s->blocks[0].cpl_in_use); for (blk = 1; blk < s->num_blocks; blk++) { AC3Block *block = &s->blocks[blk]; put_bits(&s->pb, 1, block->new_cpl_strategy); if (block->new_cpl_strategy) put_bits(&s->pb, 1, block->cpl_in_use); } } /* exponent strategy */ if (s->use_frame_exp_strategy) { for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) put_bits(&s->pb, 5, s->frame_exp_strategy[ch]); } else { for (blk = 0; blk < s->num_blocks; blk++) for (ch = !s->blocks[blk].cpl_in_use; ch <= s->fbw_channels; ch++) put_bits(&s->pb, 2, s->exp_strategy[ch][blk]); } if (s->lfe_on) { for (blk = 0; blk < s->num_blocks; blk++) put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]); } /* E-AC-3 to AC-3 converter exponent strategy (not optional when num blocks == 6) */ if (s->num_blocks != 6) { put_bits(&s->pb, 1, 0); } else { for (ch = 1; ch <= s->fbw_channels; ch++) { if (s->use_frame_exp_strategy) put_bits(&s->pb, 5, s->frame_exp_strategy[ch]); else put_bits(&s->pb, 5, 0); } } /* snr offsets */ put_bits(&s->pb, 6, s->coarse_snr_offset); put_bits(&s->pb, 4, s->fine_snr_offset[1]); /* block start info */ if (s->num_blocks > 1) put_bits(&s->pb, 1, 0); } const FFCodec ff_eac3_encoder = { .p.name = "eac3", CODEC_LONG_NAME("ATSC A/52 E-AC-3"), .p.type = AVMEDIA_TYPE_AUDIO, .p.id = AV_CODEC_ID_EAC3, .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE, .priv_data_size = sizeof(AC3EncodeContext), .init = ff_ac3_float_encode_init, FF_CODEC_ENCODE_CB(ff_ac3_float_encode_frame), .close = ff_ac3_encode_close, .p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE }, .p.priv_class = &eac3enc_class, .p.supported_samplerates = ff_ac3_sample_rate_tab, CODEC_OLD_CHANNEL_LAYOUTS_ARRAY(ff_ac3_channel_layouts) .p.ch_layouts = ff_ac3_ch_layouts, .defaults = ff_ac3_enc_defaults, .caps_internal = FF_CODEC_CAP_INIT_CLEANUP, };