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); }