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155 lines
6.1 KiB
155 lines
6.1 KiB
/* |
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* E-AC-3 encoder |
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* Copyright (c) 2011 Justin Ruggles <justin.ruggles@gmail.com> |
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* |
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* This file is part of Libav. |
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* |
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* Libav is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* Libav is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with Libav; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/** |
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* @file |
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* E-AC-3 encoder |
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*/ |
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#define CONFIG_AC3ENC_FLOAT 1 |
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#include "ac3enc.h" |
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#include "eac3enc.h" |
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#define AC3ENC_TYPE AC3ENC_TYPE_EAC3 |
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#include "ac3enc_opts_template.c" |
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static AVClass eac3enc_class = { "E-AC-3 Encoder", av_default_item_name, |
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eac3_options, LIBAVUTIL_VERSION_INT }; |
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void ff_eac3_set_cpl_states(AC3EncodeContext *s) |
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{ |
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int ch, blk; |
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int first_cpl_coords[AC3_MAX_CHANNELS]; |
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/* set first cpl coords */ |
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for (ch = 1; ch <= s->fbw_channels; ch++) |
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first_cpl_coords[ch] = 1; |
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for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { |
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AC3Block *block = &s->blocks[blk]; |
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for (ch = 1; ch <= s->fbw_channels; ch++) { |
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if (block->channel_in_cpl[ch]) { |
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if (first_cpl_coords[ch]) { |
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block->new_cpl_coords = 2; |
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first_cpl_coords[ch] = 0; |
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} |
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} else { |
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first_cpl_coords[ch] = 1; |
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} |
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} |
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} |
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/* set first cpl leak */ |
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for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { |
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AC3Block *block = &s->blocks[blk]; |
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if (block->cpl_in_use) { |
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block->new_cpl_leak = 2; |
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break; |
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} |
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} |
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} |
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void ff_eac3_output_frame_header(AC3EncodeContext *s) |
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{ |
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int blk, ch; |
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AC3EncOptions *opt = &s->options; |
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put_bits(&s->pb, 16, 0x0b77); /* sync word */ |
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/* BSI header */ |
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put_bits(&s->pb, 2, 0); /* stream type = independent */ |
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put_bits(&s->pb, 3, 0); /* substream id = 0 */ |
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put_bits(&s->pb, 11, (s->frame_size / 2) - 1); /* frame size */ |
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if (s->bit_alloc.sr_shift) { |
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put_bits(&s->pb, 2, 0x3); /* fscod2 */ |
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put_bits(&s->pb, 2, s->bit_alloc.sr_code); /* sample rate code */ |
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} else { |
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put_bits(&s->pb, 2, s->bit_alloc.sr_code); /* sample rate code */ |
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put_bits(&s->pb, 2, 0x3); /* number of blocks = 6 */ |
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} |
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put_bits(&s->pb, 3, s->channel_mode); /* audio coding mode */ |
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put_bits(&s->pb, 1, s->lfe_on); /* LFE channel indicator */ |
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put_bits(&s->pb, 5, s->bitstream_id); /* bitstream id (EAC3=16) */ |
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put_bits(&s->pb, 5, -opt->dialogue_level); /* dialogue normalization level */ |
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put_bits(&s->pb, 1, 0); /* no compression gain */ |
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put_bits(&s->pb, 1, 0); /* no mixing metadata */ |
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/* TODO: mixing metadata */ |
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put_bits(&s->pb, 1, 0); /* no info metadata */ |
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/* TODO: info metadata */ |
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put_bits(&s->pb, 1, 0); /* no additional bit stream info */ |
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/* frame header */ |
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put_bits(&s->pb, 1, 1); /* exponent strategy syntax = each block */ |
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put_bits(&s->pb, 1, 0); /* aht enabled = no */ |
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put_bits(&s->pb, 2, 0); /* snr offset strategy = 1 */ |
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put_bits(&s->pb, 1, 0); /* transient pre-noise processing enabled = no */ |
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put_bits(&s->pb, 1, 0); /* block switch syntax enabled = no */ |
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put_bits(&s->pb, 1, 0); /* dither flag syntax enabled = no */ |
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put_bits(&s->pb, 1, 0); /* bit allocation model syntax enabled = no */ |
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put_bits(&s->pb, 1, 0); /* fast gain codes enabled = no */ |
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put_bits(&s->pb, 1, 0); /* dba syntax enabled = no */ |
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put_bits(&s->pb, 1, 0); /* skip field syntax enabled = no */ |
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put_bits(&s->pb, 1, 0); /* spx enabled = no */ |
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/* coupling strategy use flags */ |
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if (s->channel_mode > AC3_CHMODE_MONO) { |
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put_bits(&s->pb, 1, s->blocks[0].cpl_in_use); |
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for (blk = 1; blk < AC3_MAX_BLOCKS; blk++) { |
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AC3Block *block = &s->blocks[blk]; |
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put_bits(&s->pb, 1, block->new_cpl_strategy); |
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if (block->new_cpl_strategy) |
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put_bits(&s->pb, 1, block->cpl_in_use); |
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} |
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} |
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/* exponent strategy */ |
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for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) |
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for (ch = !s->blocks[blk].cpl_in_use; ch <= s->fbw_channels; ch++) |
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put_bits(&s->pb, 2, s->exp_strategy[ch][blk]); |
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if (s->lfe_on) { |
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for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) |
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put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]); |
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} |
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/* E-AC-3 to AC-3 converter exponent strategy (unfortunately not optional...) */ |
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for (ch = 1; ch <= s->fbw_channels; ch++) |
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put_bits(&s->pb, 5, 0); |
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/* snr offsets */ |
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put_bits(&s->pb, 6, s->coarse_snr_offset); |
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put_bits(&s->pb, 4, s->fine_snr_offset[1]); |
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/* block start info */ |
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put_bits(&s->pb, 1, 0); |
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} |
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#if CONFIG_EAC3_ENCODER |
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AVCodec ff_eac3_encoder = { |
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.name = "eac3", |
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.type = AVMEDIA_TYPE_AUDIO, |
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.id = CODEC_ID_EAC3, |
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.priv_data_size = sizeof(AC3EncodeContext), |
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.init = ff_ac3_encode_init, |
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.encode = ff_ac3_encode_frame, |
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.close = ff_ac3_encode_close, |
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.sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_FLT,AV_SAMPLE_FMT_NONE}, |
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.long_name = NULL_IF_CONFIG_SMALL("ATSC A/52 E-AC-3"), |
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.priv_class = &eac3enc_class, |
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.channel_layouts = ff_ac3_channel_layouts, |
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}; |
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#endif
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