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Diffstat (limited to 'src/libfaad/sbr_syntax.c')
| -rw-r--r-- | src/libfaad/sbr_syntax.c | 609 |
1 files changed, 609 insertions, 0 deletions
diff --git a/src/libfaad/sbr_syntax.c b/src/libfaad/sbr_syntax.c new file mode 100644 index 000000000..4d8b8f0ff --- /dev/null +++ b/src/libfaad/sbr_syntax.c @@ -0,0 +1,609 @@ +/* +** FAAD - Freeware Advanced Audio Decoder +** Copyright (C) 2002 M. Bakker +** +** This program is free software; you can redistribute it and/or modify +** it under the terms of the GNU General Public License as published by +** the Free Software Foundation; either version 2 of the License, or +** (at your option) any later version. +** +** This program 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 General Public License for more details. +** +** You should have received a copy of the GNU General Public License +** along with this program; if not, write to the Free Software +** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. +** +** $Id: sbr_syntax.c,v 1.1 2002/07/14 23:43:01 miguelfreitas Exp $ +**/ + +/* + This is the initial support for MPEG-4 AAC+SBR + + All data is taken from the Working Draft Text for Backward Compatible + Bandwidth Extension for General Audio Coding (N4611) +*/ + +/* + Mind the sbr_extension() function, it is not defined in the text + obviously it just reads some bytes. + */ + + +#include "common.h" + +#ifdef SBR + +#include "sbr_syntax.h" +#include "syntax.h" +#include "sbr_huff.h" +#include "bits.h" +#include "analysis.h" + +/* table 2 */ +uint8_t sbr_bitstream(bitfile *ld, sbr_info *sbr, uint8_t id_aac, + uint8_t bs_extension_type) +{ + sbr->bs_crc_flag = faad_get1bit(ld + DEBUGVAR(1,200,"sbr_bitstream(): bs_crc_flag")); + if (sbr->bs_crc_flag) + { + sbr->bs_sbr_crc_bits = faad_getbits(ld, 7 + DEBUGVAR(1,201,"sbr_bitstream(): bs_sbr_crc_bits")); + } + + if (bs_extension_type == SBR_HDR) + { + sbr_header(ld, sbr, id_aac); + sbr_data(ld, sbr, id_aac); + } else if (bs_extension_type == SBR_STD) { + sbr_data(ld, sbr, id_aac); + } +} + +/* table 3 */ +static void sbr_header(bitfile *ld, sbr_info *sbr, uint8_t id_aac) +{ + uint8_t bs_header_extra_1, bs_header_extra_2; + + sbr->bs_protocol_version = faad_getbits(ld, 2 + DEBUGVAR(1,202,"sbr_header(): bs_protocol_version")); + sbr->bs_amp_res = faad_get1bit(ld + DEBUGVAR(1,203,"sbr_header(): bs_amp_res")); + sbr->bs_start_freq = faad_getbits(ld, 4 + DEBUGVAR(1,204,"sbr_header(): bs_start_freq")); + sbr->bs_stop_freq = faad_getbits(ld, 4 + DEBUGVAR(1,205,"sbr_header(): bs_stop_freq")); + sbr->bs_xover_band = faad_getbits(ld, 3 + DEBUGVAR(1,206,"sbr_header(): bs_xover_band")); + faad_getbits(ld, 3 + DEBUGVAR(1,207,"sbr_header(): bs_reserved")); + bs_header_extra_1 = faad_get1bit(ld + DEBUGVAR(1,208,"sbr_header(): bs_header_extra_1")); + bs_header_extra_2 = faad_get1bit(ld + DEBUGVAR(1,209,"sbr_header(): bs_header_extra_2")); + + if (id_aac == ID_SCE) + { + faad_getbits(ld, 2 + DEBUGVAR(1,210,"sbr_header(): bs_reserved")); + } + + if (bs_header_extra_1) + { + sbr->bs_freq_scale = faad_getbits(ld, 2 + DEBUGVAR(1,211,"sbr_header(): bs_freq_scale")); + sbr->bs_alter_scale = faad_get1bit(ld + DEBUGVAR(1,212,"sbr_header(): bs_alter_scale")); + sbr->bs_noise_bands = faad_getbits(ld, 2 + DEBUGVAR(1,213,"sbr_header(): bs_noise_bands")); + } + if (bs_header_extra_2) + { + sbr->bs_limiter_bands = faad_getbits(ld, 2 + DEBUGVAR(1,214,"sbr_header(): bs_limiter_bands")); + sbr->bs_limiter_gains = faad_getbits(ld, 2 + DEBUGVAR(1,215,"sbr_header(): bs_limiter_gains")); + sbr->bs_interpol_freq = faad_get1bit(ld + DEBUGVAR(1,216,"sbr_header(): bs_interpol_freq")); + sbr->bs_smoothing_mode = faad_get1bit(ld + DEBUGVAR(1,217,"sbr_header(): bs_smoothing_mode")); + faad_get1bit(ld + DEBUGVAR(1,218,"sbr_header(): bs_reserved")); + } +} + +/* table 4 */ +static void sbr_data(bitfile *ld, sbr_info *sbr, uint8_t id_aac) +{ + sbr->bs_samplerate_mode = faad_get1bit(ld + DEBUGVAR(1,219,"sbr_data(): bs_samplerate_mode")); + + switch (id_aac) + { + case ID_SCE: + sbr_single_channel_element(ld, sbr); + break; + case ID_CPE: + sbr_channel_pair_element(ld, sbr); + break; + } +} + +/* table 5 */ +static void sbr_single_channel_element(bitfile *ld, sbr_info *sbr) +{ + faad_get1bit(ld + DEBUGVAR(1,220,"sbr_single_channel_element(): bs_reserved")); + + sbr_grid(ld, sbr, 0); + sbr_dtdf(ld, sbr, 0); + invf_mode(ld, sbr, 0); + + faad_getbits(ld, 2 + DEBUGVAR(1,221,"sbr_single_channel_element(): bs_reserved")); + + sbr_envelope(ld, sbr, 0); + sbr_noise(ld, sbr, 0); + + faad_get1bit(ld + DEBUGVAR(1,222,"sbr_single_channel_element(): bs_reserved")); + + faad_get1bit(ld + DEBUGVAR(1,222,"sbr_single_channel_element(): bs_reserved")); + + sbr->bs_add_harmonic_flag[0] = faad_get1bit(ld + DEBUGVAR(1,223,"sbr_single_channel_element(): bs_add_harmonic_flag[0]")); + if (sbr->bs_add_harmonic_flag[0]) + sinusoidal_coding(ld, sbr, 0); + + sbr->bs_extended_data[0] = faad_get1bit(ld + DEBUGVAR(1,224,"sbr_single_channel_element(): bs_extended_data[0]")); + if (sbr->bs_extended_data[0]) + { + uint16_t nr_bits_left; + uint16_t cnt = faad_getbits(ld, 4 + DEBUGVAR(1,225,"sbr_single_channel_element(): bs_extension_size")); + if (cnt == 15) + { + cnt += faad_getbits(ld, 8 + DEBUGVAR(1,226,"sbr_single_channel_element(): bs_esc_count")); + } + + nr_bits_left = 8 * cnt; + while (nr_bits_left > 7) + { + sbr->bs_extension_id = faad_getbits(ld, 2 + DEBUGVAR(1,227,"sbr_single_channel_element(): bs_extension_id")); + nr_bits_left -= 2; + /* sbr_extension(ld, sbr, 0, nr_bits_left); */ + faad_getbits(ld, 6 + DEBUGVAR(1,279,"sbr_single_channel_element(): bs_extension_data")); + } + } +} + +/* table 6 */ +static void sbr_channel_pair_element(bitfile *ld, sbr_info *sbr) +{ + sbr->bs_coupling = faad_get1bit(ld + DEBUGVAR(1,228,"sbr_channel_pair_element(): bs_coupling")); + + if (sbr->bs_coupling) + { + sbr_grid(ld, sbr, 0); + sbr_dtdf(ld, sbr, 0); + sbr_dtdf(ld, sbr, 1); + invf_mode(ld, sbr, 0); + + faad_getbits(ld, 2 + DEBUGVAR(1,229,"sbr_channel_pair_element(): bs_reserved")); + + sbr_envelope(ld, sbr, 0); + sbr_noise(ld, sbr, 0); + sbr_envelope(ld, sbr, 1); + sbr_noise(ld, sbr, 1); + + faad_getbits(ld, 2 + DEBUGVAR(1,230,"sbr_channel_pair_element(): bs_reserved")); + + sbr->bs_add_harmonic_flag[0] = faad_get1bit(ld + DEBUGVAR(1,231,"sbr_channel_pair_element(): bs_add_harmonic_flag[0]")); + if (sbr->bs_add_harmonic_flag[0]) + sinusoidal_coding(ld, sbr, 0); + + sbr->bs_add_harmonic_flag[1] = faad_get1bit(ld + DEBUGVAR(1,232,"sbr_channel_pair_element(): bs_add_harmonic_flag[1]")); + if (sbr->bs_add_harmonic_flag[1]) + sinusoidal_coding(ld, sbr, 1); + + sbr->bs_extended_data[0] = faad_get1bit(ld + DEBUGVAR(1,233,"sbr_channel_pair_element(): bs_extended_data[0]")); + if (sbr->bs_extended_data[0]) + { + uint16_t nr_bits_left; + uint16_t cnt = faad_getbits(ld, 4 + DEBUGVAR(1,234,"sbr_channel_pair_element(): bs_extension_size")); + if (cnt == 15) + { + cnt += faad_getbits(ld, 8 + DEBUGVAR(1,235,"sbr_channel_pair_element(): bs_esc_count")); + } + + nr_bits_left = 8 * cnt; + while (nr_bits_left > 7) + { + sbr->bs_extension_id = faad_getbits(ld, 2 + DEBUGVAR(1,236,"sbr_channel_pair_element(): bs_extension_id")); + nr_bits_left -= 2; + /* sbr_extension(ld, sbr, 0, nr_bits_left); */ + faad_getbits(ld, 6 + DEBUGVAR(1,280,"sbr_single_channel_element(): bs_extension_data")); + } + } + } else { + sbr_grid(ld, sbr, 0); + sbr_grid(ld, sbr, 1); + sbr_dtdf(ld, sbr, 0); + sbr_dtdf(ld, sbr, 1); + invf_mode(ld, sbr, 0); + invf_mode(ld, sbr, 1); + + faad_getbits(ld, 4 + DEBUGVAR(1,237,"sbr_channel_pair_element(): bs_reserved")); + + sbr_envelope(ld, sbr, 0); + sbr_envelope(ld, sbr, 1); + sbr_noise(ld, sbr, 0); + sbr_noise(ld, sbr, 1); + + faad_getbits(ld, 2 + DEBUGVAR(1,238,"sbr_channel_pair_element(): bs_reserved")); + + sbr->bs_add_harmonic_flag[0] = faad_get1bit(ld + DEBUGVAR(1,239,"sbr_channel_pair_element(): bs_add_harmonic_flag[0]")); + if (sbr->bs_add_harmonic_flag[0]) + sinusoidal_coding(ld, sbr, 0); + + sbr->bs_add_harmonic_flag[1] = faad_get1bit(ld + DEBUGVAR(1,240,"sbr_channel_pair_element(): bs_add_harmonic_flag[1]")); + if (sbr->bs_add_harmonic_flag[1]) + sinusoidal_coding(ld, sbr, 1); + + sbr->bs_extended_data[0] = faad_get1bit(ld + DEBUGVAR(1,241,"sbr_channel_pair_element(): bs_extended_data[0]")); + if (sbr->bs_extended_data[0]) + { + uint16_t nr_bits_left; + uint16_t cnt = faad_getbits(ld, 4 + DEBUGVAR(1,242,"sbr_channel_pair_element(): bs_extension_size")); + if (cnt == 15) + { + cnt += faad_getbits(ld, 8 + DEBUGVAR(1,243,"sbr_channel_pair_element(): bs_esc_count")); + } + + nr_bits_left = 8 * cnt; + while (nr_bits_left > 7) + { + sbr->bs_extension_id = faad_getbits(ld, 2 + DEBUGVAR(1,244,"sbr_channel_pair_element(): bs_extension_id")); + nr_bits_left -= 2; + /* sbr_extension(ld, sbr, 0, nr_bits_left); */ + faad_getbits(ld, 6 + DEBUGVAR(1,281,"sbr_single_channel_element(): bs_extension_data")); + } + } + + sbr->bs_extended_data[1] = faad_get1bit(ld + DEBUGVAR(1,245,"sbr_channel_pair_element(): bs_extended_data[1]")); + if (sbr->bs_extended_data[1]) + { + uint16_t nr_bits_left; + uint16_t cnt = faad_getbits(ld, 4 + DEBUGVAR(1,246,"sbr_channel_pair_element(): bs_extension_size")); + if (cnt == 15) + { + cnt += faad_getbits(ld, 8 + DEBUGVAR(1,247,"sbr_channel_pair_element(): bs_esc_count")); + } + + nr_bits_left = 8 * cnt; + while (nr_bits_left > 7) + { + sbr->bs_extension_id = faad_getbits(ld, 2 + DEBUGVAR(1,248,"sbr_channel_pair_element(): bs_extension_id")); + nr_bits_left -= 2; + /* sbr_extension(ld, sbr, 0, nr_bits_left); */ + faad_getbits(ld, 6 + DEBUGVAR(1,282,"sbr_single_channel_element(): bs_extension_data")); + } + } + } +} + +/* table 7 */ +static void sbr_grid(bitfile *ld, sbr_info *sbr, uint8_t ch) +{ + uint8_t i, env, rel; + uint8_t bs_abs_bord, bs_abs_bord_1; + + sbr->bs_frame_class = faad_getbits(ld, 2 + DEBUGVAR(1,248,"sbr_grid(): bs_frame_class")); + + switch (sbr->bs_frame_class) + { + case FIXFIX: + i = faad_getbits(ld, 2 + DEBUGVAR(1,249,"sbr_grid(): bs_num_env_raw")); + + sbr->bs_num_env[ch] = min(1 << i, 5); + if (sbr->bs_num_env[ch] == 1) + sbr->bs_amp_res = 0; + + i = faad_get1bit(ld + DEBUGVAR(1,250,"sbr_grid(): bs_freq_res_flag")); + for (env = 0; env < sbr->bs_num_env[ch]; env++) + sbr->bs_freq_res[ch][env] = i; + + sbr->abs_bord_lead[ch] = 0; + sbr->abs_bord_trail[ch] = NO_TIME_SLOTS; + break; + + case FIXVAR: + bs_abs_bord = faad_getbits(ld, 3 + DEBUGVAR(1,251,"sbr_grid(): bs_abs_bord")) + NO_TIME_SLOTS; + sbr->bs_num_env[ch] = faad_getbits(ld, 2 + DEBUGVAR(1,252,"sbr_grid(): bs_num_env")) + 1; + + for (rel = 0; rel < sbr->bs_num_env[ch]-1; rel++) + { + sbr->bs_rel_bord[ch][rel] = 2 * faad_getbits(ld, 2 + DEBUGVAR(1,253,"sbr_grid(): bs_rel_bord")) + 2; + } + i = int_log2((uint32_t)(sbr->bs_num_env[ch] + 1)); + sbr->bs_pointer[ch] = faad_getbits(ld, i + DEBUGVAR(1,254,"sbr_grid(): bs_pointer")); + + for (env = 0; env < sbr->bs_num_env[ch]; env++) + { + sbr->bs_freq_res[ch][sbr->bs_num_env[ch] - env - 1] = faad_get1bit(ld + DEBUGVAR(1,255,"sbr_grid(): bs_freq_res")); + } + + sbr->abs_bord_lead[ch] = 0; + sbr->abs_bord_trail[ch] = bs_abs_bord; + break; + + case VARFIX: + bs_abs_bord = faad_getbits(ld, 3 + DEBUGVAR(1,256,"sbr_grid(): bs_abs_bord")); + sbr->bs_num_env[ch] = faad_getbits(ld, 2 + DEBUGVAR(1,257,"sbr_grid(): bs_num_env")) + 1; + + for (rel = 0; rel < sbr->bs_num_env[ch]-1; rel++) + { + sbr->bs_rel_bord[ch][rel] = 2 * faad_getbits(ld, 2 + DEBUGVAR(1,258,"sbr_grid(): bs_rel_bord")) + 2; + } + i = int_log2((uint32_t)(sbr->bs_num_env[ch] + 1)); + sbr->bs_pointer[ch] = faad_getbits(ld, i + DEBUGVAR(1,259,"sbr_grid(): bs_pointer")); + + for (env = 0; env < sbr->bs_num_env[ch]; env++) + { + sbr->bs_freq_res[ch][env] = faad_get1bit(ld + DEBUGVAR(1,260,"sbr_grid(): bs_freq_res")); + } + + sbr->abs_bord_lead[ch] = bs_abs_bord; + sbr->abs_bord_trail[ch] = NO_TIME_SLOTS; + break; + + case VARVAR: + bs_abs_bord = faad_getbits(ld, 3 + DEBUGVAR(1,261,"sbr_grid(): bs_abs_bord_0")); + bs_abs_bord_1 = faad_getbits(ld, 3 + DEBUGVAR(1,262,"sbr_grid(): bs_abs_bord_1")) + NO_TIME_SLOTS; + sbr->bs_num_rel_0[ch] = faad_getbits(ld, 2 + DEBUGVAR(1,263,"sbr_grid(): bs_num_rel_0")); + sbr->bs_num_rel_1[ch] = faad_getbits(ld, 2 + DEBUGVAR(1,264,"sbr_grid(): bs_num_rel_1")); + sbr->bs_num_env[ch] = sbr->bs_num_rel_0[ch] + sbr->bs_num_rel_1[ch] + 1; + + for (rel = 0; rel < sbr->bs_num_rel_0[ch]; rel++) + { + sbr->bs_rel_bord_0[ch][rel] = 2 * faad_getbits(ld, 2 + DEBUGVAR(1,265,"sbr_grid(): bs_rel_bord")) + 2; + } + for(rel = 0; rel < sbr->bs_num_rel_1[ch]; rel++) + { + sbr->bs_rel_bord_1[ch][rel] = 2 * faad_getbits(ld, 2 + DEBUGVAR(1,266,"sbr_grid(): bs_rel_bord")) + 2; + } + i = int_log2((uint32_t)(sbr->bs_num_rel_0[ch] + sbr->bs_num_rel_1[ch] + 2)); + sbr->bs_pointer[ch] = faad_getbits(ld, i + DEBUGVAR(1,267,"sbr_grid(): bs_pointer")); + + for (env = 0; env < sbr->bs_num_env[ch]; env++) + { + sbr->bs_freq_res[ch][env] = faad_get1bit(ld + DEBUGVAR(1,268,"sbr_grid(): bs_freq_res")); + } + + sbr->abs_bord_lead[ch] = bs_abs_bord; + sbr->abs_bord_trail[ch] = bs_abs_bord_1; + break; + } + + if (sbr->bs_num_env[ch] > 1) + sbr->bs_num_noise[ch] = 2; + else + sbr->bs_num_noise[ch] = 1; +} + +/* table 8 */ +static void sbr_dtdf(bitfile *ld, sbr_info *sbr, uint8_t ch) +{ + uint8_t i; + + for (i = 0; i < sbr->bs_num_env[ch]; i++) + { + sbr->bs_df_env[ch][i] = faad_get1bit(ld + DEBUGVAR(1,269,"sbr_dtdf(): bs_df_env")); + } + + for (i = 0; i < sbr->bs_num_noise[ch]; i++) + { + sbr->bs_df_noise[ch][i] = faad_get1bit(ld + DEBUGVAR(1,270,"sbr_dtdf(): bs_df_noise")); + } +} + +/* table 9 */ +static void invf_mode(bitfile *ld, sbr_info *sbr, uint8_t ch) +{ + uint8_t n; + + for (n = 0; n < sbr->num_noise_bands[ch]; n++) + { + sbr->bs_invf_mode_vec[ch][n] = faad_getbits(ld, 2 + DEBUGVAR(1,271,"invf_mode(): bs_invf_mode_vec")); + } +} + +/* table 10 */ +static void sbr_envelope(bitfile *ld, sbr_info *sbr, uint8_t ch) +{ + uint8_t env, band; + sbr_huff_tab *t_huff, *f_huff; + + if (sbr->bs_coupling) + { + if (ch) + { + if (sbr->bs_amp_res) + { + t_huff = t_huffman_env_bal_3_0dB; + f_huff = f_huffman_env_bal_3_0dB; + } else { + t_huff = t_huffman_env_bal_1_5dB; + f_huff = f_huffman_env_bal_1_5dB; + } + } else { + if (sbr->bs_amp_res) + { + t_huff = t_huffman_env_3_0dB; + f_huff = f_huffman_env_3_0dB; + } else { + t_huff = t_huffman_env_1_5dB; + f_huff = f_huffman_env_1_5dB; + } + } + } else { + if (sbr->bs_amp_res) + { + t_huff = t_huffman_env_3_0dB; + f_huff = f_huffman_env_3_0dB; + } else { + t_huff = t_huffman_env_1_5dB; + f_huff = f_huffman_env_1_5dB; + } + } + + for (env = 0; env < sbr->bs_num_env[ch]; env++) + { + if (sbr->bs_df_env[ch][env] == 0) + { + if (sbr->bs_coupling && ch) + { + if (sbr->bs_amp_res) + { + sbr->bs_data_env[ch][env][0] = faad_getbits(ld, 5 + DEBUGVAR(1,272,"sbr_envelope(): bs_data_env")); + } else { + sbr->bs_data_env[ch][env][0] = faad_getbits(ld, 6 + DEBUGVAR(1,273,"sbr_envelope(): bs_data_env")); + } + } else { + if (sbr->bs_amp_res) + { + sbr->bs_data_env[ch][env][0] = faad_getbits(ld, 6 + DEBUGVAR(1,274,"sbr_envelope(): bs_data_env")); + } else { + sbr->bs_data_env[ch][env][0] = faad_getbits(ld, 7 + DEBUGVAR(1,275,"sbr_envelope(): bs_data_env")); + } + for (band = 1; band < sbr->num_env_bands[sbr->bs_freq_res[ch][env]]; band++) + { + sbr->bs_data_env[ch][env][band] = sbr_huff_dec(ld, f_huff); + } + } + } else { + for (band = 0; band < sbr->num_env_bands[sbr->bs_freq_res[ch][env]]; band++) + sbr->bs_data_env[ch][env][band] = sbr_huff_dec(ld, t_huff); + } + } +} + +/* table 11 */ +static void sbr_noise(bitfile *ld, sbr_info *sbr, uint8_t ch) +{ + uint8_t noise, band; + sbr_huff_tab *t_huff, *f_huff; + + if (sbr->bs_coupling) + { + if (ch) { + t_huff = t_huffman_noise_bal_3_0dB; + f_huff = f_huffman_noise_bal_3_0dB; + } else { + t_huff = t_huffman_noise_3_0dB; + f_huff = f_huffman_noise_3_0dB; + } + } else { + t_huff = t_huffman_noise_3_0dB; + f_huff = f_huffman_noise_3_0dB; + } + + for(noise = 0; noise < sbr->bs_num_noise[ch]; noise++) + { + if(sbr->bs_df_noise[ch][noise] == 0) + { + if (sbr->bs_coupling && ch) + { + sbr->bs_data_noise[ch][noise][0] = faad_getbits(ld, 5 + DEBUGVAR(1,276,"sbr_noise(): bs_data_noise")); + } else { + sbr->bs_data_noise[ch][noise][0] = faad_getbits(ld, 5 + DEBUGVAR(1,277,"sbr_noise(): bs_data_noise")); + } + for (band = 1; band < sbr->num_noise_bands[ch]; band++) + { + sbr->bs_data_noise[ch][noise][band] = sbr_huff_dec(ld, f_huff); + } + } else { + for (band = 0; band < sbr->num_noise_bands[ch]; band++) + { + sbr->bs_data_noise[ch][noise][band] = sbr_huff_dec(ld, t_huff); + } + } + } +} + +/* table 12 */ +static void sinusoidal_coding(bitfile *ld, sbr_info *sbr, uint8_t ch) +{ + uint8_t n; + + for (n = 0; n < sbr->num_high_res[ch]; n++) + { + sbr->bs_add_harmonic[ch][n] = faad_get1bit(ld + DEBUGVAR(1,278,"sinusoidal_coding(): bs_add_harmonic")); + } +} + + +#endif /* SBR */
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