| /* |
| * E-AC-3 encoder |
| * Copyright (c) 2011 Justin Ruggles <justin.ruggles@gmail.com> |
| * |
| * This file is part of Libav. |
| * |
| * Libav 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. |
| * |
| * Libav 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 Libav; 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 CONFIG_AC3ENC_FLOAT 1 |
| #include "ac3enc.h" |
| #include "eac3enc.h" |
| |
| |
| #define AC3ENC_TYPE AC3ENC_TYPE_EAC3 |
| #include "ac3enc_opts_template.c" |
| static AVClass eac3enc_class = { "E-AC-3 Encoder", av_default_item_name, |
| eac3_options, LIBAVUTIL_VERSION_INT }; |
| |
| |
| 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 < AC3_MAX_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 = 2; |
| first_cpl_coords[ch] = 0; |
| } |
| } else { |
| first_cpl_coords[ch] = 1; |
| } |
| } |
| } |
| |
| /* set first cpl leak */ |
| for (blk = 0; blk < AC3_MAX_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, 0x3); /* number of blocks = 6 */ |
| } |
| 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 */ |
| put_bits(&s->pb, 1, 0); /* no mixing metadata */ |
| /* TODO: mixing metadata */ |
| put_bits(&s->pb, 1, 0); /* no info metadata */ |
| /* TODO: info metadata */ |
| put_bits(&s->pb, 1, 0); /* no additional bit stream info */ |
| |
| /* frame header */ |
| put_bits(&s->pb, 1, 1); /* exponent strategy syntax = each block */ |
| 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 < AC3_MAX_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 */ |
| for (blk = 0; blk < AC3_MAX_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 < AC3_MAX_BLOCKS; blk++) |
| put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]); |
| } |
| /* E-AC-3 to AC-3 converter exponent strategy (unfortunately not optional...) */ |
| for (ch = 1; ch <= s->fbw_channels; ch++) |
| 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 */ |
| put_bits(&s->pb, 1, 0); |
| } |
| |
| |
| #if CONFIG_EAC3_ENCODER |
| AVCodec ff_eac3_encoder = { |
| .name = "eac3", |
| .type = AVMEDIA_TYPE_AUDIO, |
| .id = CODEC_ID_EAC3, |
| .priv_data_size = sizeof(AC3EncodeContext), |
| .init = ff_ac3_encode_init, |
| .encode = ff_ac3_encode_frame, |
| .close = ff_ac3_encode_close, |
| .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_FLT,AV_SAMPLE_FMT_NONE}, |
| .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52 E-AC-3"), |
| .priv_class = &eac3enc_class, |
| .channel_layouts = ff_ac3_channel_layouts, |
| }; |
| #endif |
