/* * AAC Spectral Band Replication decoding functions * Copyright (c) 2008-2009 Robert Swain ( rob opendot cl ) * Copyright (c) 2009-2010 Alex Converse <alex.converse@gmail.com> * * 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 * AAC Spectral Band Replication decoding functions * @author Robert Swain ( rob opendot cl ) */ #include "aac.h" #include "sbr.h" #include "aacsbr.h" #include "aacsbrdata.h" #include "fft.h" #include "aacps.h" #include "libavutil/libm.h" #include <stdint.h> #include <float.h> #include <math.h> #define ENVELOPE_ADJUSTMENT_OFFSET 2 #define NOISE_FLOOR_OFFSET 6.0f /** * SBR VLC tables */ enum { T_HUFFMAN_ENV_1_5DB, F_HUFFMAN_ENV_1_5DB, T_HUFFMAN_ENV_BAL_1_5DB, F_HUFFMAN_ENV_BAL_1_5DB, T_HUFFMAN_ENV_3_0DB, F_HUFFMAN_ENV_3_0DB, T_HUFFMAN_ENV_BAL_3_0DB, F_HUFFMAN_ENV_BAL_3_0DB, T_HUFFMAN_NOISE_3_0DB, T_HUFFMAN_NOISE_BAL_3_0DB, }; /** * bs_frame_class - frame class of current SBR frame (14496-3 sp04 p98) */ enum { FIXFIX, FIXVAR, VARFIX, VARVAR, }; enum { EXTENSION_ID_PS = 2, }; static VLC vlc_sbr[10]; static const int8_t vlc_sbr_lav[10] = { 60, 60, 24, 24, 31, 31, 12, 12, 31, 12 }; static const DECLARE_ALIGNED(16, float, zero64)[64]; #define SBR_INIT_VLC_STATIC(num, size) \ INIT_VLC_STATIC(&vlc_sbr[num], 9, sbr_tmp[num].table_size / sbr_tmp[num].elem_size, \ sbr_tmp[num].sbr_bits , 1, 1, \ sbr_tmp[num].sbr_codes, sbr_tmp[num].elem_size, sbr_tmp[num].elem_size, \ size) #define SBR_VLC_ROW(name) \ { name ## _codes, name ## _bits, sizeof(name ## _codes), sizeof(name ## _codes[0]) } av_cold void ff_aac_sbr_init(void) { int n; static const struct { const void *sbr_codes, *sbr_bits; const unsigned int table_size, elem_size; } sbr_tmp[] = { SBR_VLC_ROW(t_huffman_env_1_5dB), SBR_VLC_ROW(f_huffman_env_1_5dB), SBR_VLC_ROW(t_huffman_env_bal_1_5dB), SBR_VLC_ROW(f_huffman_env_bal_1_5dB), SBR_VLC_ROW(t_huffman_env_3_0dB), SBR_VLC_ROW(f_huffman_env_3_0dB), SBR_VLC_ROW(t_huffman_env_bal_3_0dB), SBR_VLC_ROW(f_huffman_env_bal_3_0dB), SBR_VLC_ROW(t_huffman_noise_3_0dB), SBR_VLC_ROW(t_huffman_noise_bal_3_0dB), }; // SBR VLC table initialization SBR_INIT_VLC_STATIC(0, 1098); SBR_INIT_VLC_STATIC(1, 1092); SBR_INIT_VLC_STATIC(2, 768); SBR_INIT_VLC_STATIC(3, 1026); SBR_INIT_VLC_STATIC(4, 1058); SBR_INIT_VLC_STATIC(5, 1052); SBR_INIT_VLC_STATIC(6, 544); SBR_INIT_VLC_STATIC(7, 544); SBR_INIT_VLC_STATIC(8, 592); SBR_INIT_VLC_STATIC(9, 512); for (n = 1; n < 320; n++) sbr_qmf_window_us[320 + n] = sbr_qmf_window_us[320 - n]; sbr_qmf_window_us[384] = -sbr_qmf_window_us[384]; sbr_qmf_window_us[512] = -sbr_qmf_window_us[512]; for (n = 0; n < 320; n++) sbr_qmf_window_ds[n] = sbr_qmf_window_us[2*n]; ff_ps_init(); } av_cold void ff_aac_sbr_ctx_init(AACContext *ac, SpectralBandReplication *sbr) { float mdct_scale; sbr->kx[0] = sbr->kx[1] = 32; //Typo in spec, kx' inits to 32 sbr->data[0].e_a[1] = sbr->data[1].e_a[1] = -1; sbr->data[0].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128); sbr->data[1].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128); /* SBR requires samples to be scaled to +/-32768.0 to work correctly. * mdct scale factors are adjusted to scale up from +/-1.0 at analysis * and scale back down at synthesis. */ mdct_scale = ac->avctx->sample_fmt == AV_SAMPLE_FMT_FLT ? 32768.0f : 1.0f; ff_mdct_init(&sbr->mdct, 7, 1, 1.0 / (64 * mdct_scale)); ff_mdct_init(&sbr->mdct_ana, 7, 1, -2.0 * mdct_scale); ff_ps_ctx_init(&sbr->ps); } av_cold void ff_aac_sbr_ctx_close(SpectralBandReplication *sbr) { ff_mdct_end(&sbr->mdct); ff_mdct_end(&sbr->mdct_ana); } static int qsort_comparison_function_int16(const void *a, const void *b) { return *(const int16_t *)a - *(const int16_t *)b; } static inline int in_table_int16(const int16_t *table, int last_el, int16_t needle) { int i; for (i = 0; i <= last_el; i++) if (table[i] == needle) return 1; return 0; } /// Limiter Frequency Band Table (14496-3 sp04 p198) static void sbr_make_f_tablelim(SpectralBandReplication *sbr) { int k; if (sbr->bs_limiter_bands > 0) { static const float bands_warped[3] = { 1.32715174233856803909f, //2^(0.49/1.2) 1.18509277094158210129f, //2^(0.49/2) 1.11987160404675912501f }; //2^(0.49/3) const float lim_bands_per_octave_warped = bands_warped[sbr->bs_limiter_bands - 1]; int16_t patch_borders[7]; uint16_t *in = sbr->f_tablelim + 1, *out = sbr->f_tablelim; patch_borders[0] = sbr->kx[1]; for (k = 1; k <= sbr->num_patches; k++) patch_borders[k] = patch_borders[k-1] + sbr->patch_num_subbands[k-1]; memcpy(sbr->f_tablelim, sbr->f_tablelow, (sbr->n[0] + 1) * sizeof(sbr->f_tablelow[0])); if (sbr->num_patches > 1) memcpy(sbr->f_tablelim + sbr->n[0] + 1, patch_borders + 1, (sbr->num_patches - 1) * sizeof(patch_borders[0])); qsort(sbr->f_tablelim, sbr->num_patches + sbr->n[0], sizeof(sbr->f_tablelim[0]), qsort_comparison_function_int16); sbr->n_lim = sbr->n[0] + sbr->num_patches - 1; while (out < sbr->f_tablelim + sbr->n_lim) { if (*in >= *out * lim_bands_per_octave_warped) { *++out = *in++; } else if (*in == *out || !in_table_int16(patch_borders, sbr->num_patches, *in)) { in++; sbr->n_lim--; } else if (!in_table_int16(patch_borders, sbr->num_patches, *out)) { *out = *in++; sbr->n_lim--; } else { *++out = *in++; } } } else { sbr->f_tablelim[0] = sbr->f_tablelow[0]; sbr->f_tablelim[1] = sbr->f_tablelow[sbr->n[0]]; sbr->n_lim = 1; } } static unsigned int read_sbr_header(SpectralBandReplication *sbr, GetBitContext *gb) { unsigned int cnt = get_bits_count(gb); uint8_t bs_header_extra_1; uint8_t bs_header_extra_2; int old_bs_limiter_bands = sbr->bs_limiter_bands; SpectrumParameters old_spectrum_params; sbr->start = 1; // Save last spectrum parameters variables to compare to new ones memcpy(&old_spectrum_params, &sbr->spectrum_params, sizeof(SpectrumParameters)); sbr->bs_amp_res_header = get_bits1(gb); sbr->spectrum_params.bs_start_freq = get_bits(gb, 4); sbr->spectrum_params.bs_stop_freq = get_bits(gb, 4); sbr->spectrum_params.bs_xover_band = get_bits(gb, 3); skip_bits(gb, 2); // bs_reserved bs_header_extra_1 = get_bits1(gb); bs_header_extra_2 = get_bits1(gb); if (bs_header_extra_1) { sbr->spectrum_params.bs_freq_scale = get_bits(gb, 2); sbr->spectrum_params.bs_alter_scale = get_bits1(gb); sbr->spectrum_params.bs_noise_bands = get_bits(gb, 2); } else { sbr->spectrum_params.bs_freq_scale = 2; sbr->spectrum_params.bs_alter_scale = 1; sbr->spectrum_params.bs_noise_bands = 2; } // Check if spectrum parameters changed if (memcmp(&old_spectrum_params, &sbr->spectrum_params, sizeof(SpectrumParameters))) sbr->reset = 1; if (bs_header_extra_2) { sbr->bs_limiter_bands = get_bits(gb, 2); sbr->bs_limiter_gains = get_bits(gb, 2); sbr->bs_interpol_freq = get_bits1(gb); sbr->bs_smoothing_mode = get_bits1(gb); } else { sbr->bs_limiter_bands = 2; sbr->bs_limiter_gains = 2; sbr->bs_interpol_freq = 1; sbr->bs_smoothing_mode = 1; } if (sbr->bs_limiter_bands != old_bs_limiter_bands && !sbr->reset) sbr_make_f_tablelim(sbr); return get_bits_count(gb) - cnt; } static int array_min_int16(const int16_t *array, int nel) { int i, min = array[0]; for (i = 1; i < nel; i++) min = FFMIN(array[i], min); return min; } static void make_bands(int16_t* bands, int start, int stop, int num_bands) { int k, previous, present; float base, prod; base = powf((float)stop / start, 1.0f / num_bands); prod = start; previous = start; for (k = 0; k < num_bands-1; k++) { prod *= base; present = lrintf(prod); bands[k] = present - previous; previous = present; } bands[num_bands-1] = stop - previous; } static int check_n_master(AVCodecContext *avctx, int n_master, int bs_xover_band) { // Requirements (14496-3 sp04 p205) if (n_master <= 0) { av_log(avctx, AV_LOG_ERROR, "Invalid n_master: %d\n", n_master); return -1; } if (bs_xover_band >= n_master) { av_log(avctx, AV_LOG_ERROR, "Invalid bitstream, crossover band index beyond array bounds: %d\n", bs_xover_band); return -1; } return 0; } /// Master Frequency Band Table (14496-3 sp04 p194) static int sbr_make_f_master(AACContext *ac, SpectralBandReplication *sbr, SpectrumParameters *spectrum) { unsigned int temp, max_qmf_subbands; unsigned int start_min, stop_min; int k; const int8_t *sbr_offset_ptr; int16_t stop_dk[13]; if (sbr->sample_rate < 32000) { temp = 3000; } else if (sbr->sample_rate < 64000) { temp = 4000; } else temp = 5000; start_min = ((temp << 7) + (sbr->sample_rate >> 1)) / sbr->sample_rate; stop_min = ((temp << 8) + (sbr->sample_rate >> 1)) / sbr->sample_rate; switch (sbr->sample_rate) { case 16000: sbr_offset_ptr = sbr_offset[0]; break; case 22050: sbr_offset_ptr = sbr_offset[1]; break; case 24000: sbr_offset_ptr = sbr_offset[2]; break; case 32000: sbr_offset_ptr = sbr_offset[3]; break; case 44100: case 48000: case 64000: sbr_offset_ptr = sbr_offset[4]; break; case 88200: case 96000: case 128000: case 176400: case 192000: sbr_offset_ptr = sbr_offset[5]; break; default: av_log(ac->avctx, AV_LOG_ERROR, "Unsupported sample rate for SBR: %d\n", sbr->sample_rate); return -1; } sbr->k[0] = start_min + sbr_offset_ptr[spectrum->bs_start_freq]; if (spectrum->bs_stop_freq < 14) { sbr->k[2] = stop_min; make_bands(stop_dk, stop_min, 64, 13); qsort(stop_dk, 13, sizeof(stop_dk[0]), qsort_comparison_function_int16); for (k = 0; k < spectrum->bs_stop_freq; k++) sbr->k[2] += stop_dk[k]; } else if (spectrum->bs_stop_freq == 14) { sbr->k[2] = 2*sbr->k[0]; } else if (spectrum->bs_stop_freq == 15) { sbr->k[2] = 3*sbr->k[0]; } else { av_log(ac->avctx, AV_LOG_ERROR, "Invalid bs_stop_freq: %d\n", spectrum->bs_stop_freq); return -1; } sbr->k[2] = FFMIN(64, sbr->k[2]); // Requirements (14496-3 sp04 p205) if (sbr->sample_rate <= 32000) { max_qmf_subbands = 48; } else if (sbr->sample_rate == 44100) { max_qmf_subbands = 35; } else if (sbr->sample_rate >= 48000) max_qmf_subbands = 32; if (sbr->k[2] - sbr->k[0] > max_qmf_subbands) { av_log(ac->avctx, AV_LOG_ERROR, "Invalid bitstream, too many QMF subbands: %d\n", sbr->k[2] - sbr->k[0]); return -1; } if (!spectrum->bs_freq_scale) { int dk, k2diff; dk = spectrum->bs_alter_scale + 1; sbr->n_master = ((sbr->k[2] - sbr->k[0] + (dk&2)) >> dk) << 1; if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band)) return -1; for (k = 1; k <= sbr->n_master; k++) sbr->f_master[k] = dk; k2diff = sbr->k[2] - sbr->k[0] - sbr->n_master * dk; if (k2diff < 0) { sbr->f_master[1]--; sbr->f_master[2]-= (k2diff < -1); } else if (k2diff) { sbr->f_master[sbr->n_master]++; } sbr->f_master[0] = sbr->k[0]; for (k = 1; k <= sbr->n_master; k++) sbr->f_master[k] += sbr->f_master[k - 1]; } else { int half_bands = 7 - spectrum->bs_freq_scale; // bs_freq_scale = {1,2,3} int two_regions, num_bands_0; int vdk0_max, vdk1_min; int16_t vk0[49]; if (49 * sbr->k[2] > 110 * sbr->k[0]) { two_regions = 1; sbr->k[1] = 2 * sbr->k[0]; } else { two_regions = 0; sbr->k[1] = sbr->k[2]; } num_bands_0 = lrintf(half_bands * log2f(sbr->k[1] / (float)sbr->k[0])) * 2; if (num_bands_0 <= 0) { // Requirements (14496-3 sp04 p205) av_log(ac->avctx, AV_LOG_ERROR, "Invalid num_bands_0: %d\n", num_bands_0); return -1; } vk0[0] = 0; make_bands(vk0+1, sbr->k[0], sbr->k[1], num_bands_0); qsort(vk0 + 1, num_bands_0, sizeof(vk0[1]), qsort_comparison_function_int16); vdk0_max = vk0[num_bands_0]; vk0[0] = sbr->k[0]; for (k = 1; k <= num_bands_0; k++) { if (vk0[k] <= 0) { // Requirements (14496-3 sp04 p205) av_log(ac->avctx, AV_LOG_ERROR, "Invalid vDk0[%d]: %d\n", k, vk0[k]); return -1; } vk0[k] += vk0[k-1]; } if (two_regions) { int16_t vk1[49]; float invwarp = spectrum->bs_alter_scale ? 0.76923076923076923077f : 1.0f; // bs_alter_scale = {0,1} int num_bands_1 = lrintf(half_bands * invwarp * log2f(sbr->k[2] / (float)sbr->k[1])) * 2; make_bands(vk1+1, sbr->k[1], sbr->k[2], num_bands_1); vdk1_min = array_min_int16(vk1 + 1, num_bands_1); if (vdk1_min < vdk0_max) { int change; qsort(vk1 + 1, num_bands_1, sizeof(vk1[1]), qsort_comparison_function_int16); change = FFMIN(vdk0_max - vk1[1], (vk1[num_bands_1] - vk1[1]) >> 1); vk1[1] += change; vk1[num_bands_1] -= change; } qsort(vk1 + 1, num_bands_1, sizeof(vk1[1]), qsort_comparison_function_int16); vk1[0] = sbr->k[1]; for (k = 1; k <= num_bands_1; k++) { if (vk1[k] <= 0) { // Requirements (14496-3 sp04 p205) av_log(ac->avctx, AV_LOG_ERROR, "Invalid vDk1[%d]: %d\n", k, vk1[k]); return -1; } vk1[k] += vk1[k-1]; } sbr->n_master = num_bands_0 + num_bands_1; if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band)) return -1; memcpy(&sbr->f_master[0], vk0, (num_bands_0 + 1) * sizeof(sbr->f_master[0])); memcpy(&sbr->f_master[num_bands_0 + 1], vk1 + 1, num_bands_1 * sizeof(sbr->f_master[0])); } else { sbr->n_master = num_bands_0; if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band)) return -1; memcpy(sbr->f_master, vk0, (num_bands_0 + 1) * sizeof(sbr->f_master[0])); } } return 0; } /// High Frequency Generation - Patch Construction (14496-3 sp04 p216 fig. 4.46) static int sbr_hf_calc_npatches(AACContext *ac, SpectralBandReplication *sbr) { int i, k, sb = 0; int msb = sbr->k[0]; int usb = sbr->kx[1]; int goal_sb = ((1000 << 11) + (sbr->sample_rate >> 1)) / sbr->sample_rate; sbr->num_patches = 0; if (goal_sb < sbr->kx[1] + sbr->m[1]) { for (k = 0; sbr->f_master[k] < goal_sb; k++) ; } else k = sbr->n_master; do { int odd = 0; for (i = k; i == k || sb > (sbr->k[0] - 1 + msb - odd); i--) { sb = sbr->f_master[i]; odd = (sb + sbr->k[0]) & 1; } // Requirements (14496-3 sp04 p205) sets the maximum number of patches to 5. // After this check the final number of patches can still be six which is // illegal however the Coding Technologies decoder check stream has a final // count of 6 patches if (sbr->num_patches > 5) { av_log(ac->avctx, AV_LOG_ERROR, "Too many patches: %d\n", sbr->num_patches); return -1; } sbr->patch_num_subbands[sbr->num_patches] = FFMAX(sb - usb, 0); sbr->patch_start_subband[sbr->num_patches] = sbr->k[0] - odd - sbr->patch_num_subbands[sbr->num_patches]; if (sbr->patch_num_subbands[sbr->num_patches] > 0) { usb = sb; msb = sb; sbr->num_patches++; } else msb = sbr->kx[1]; if (sbr->f_master[k] - sb < 3) k = sbr->n_master; } while (sb != sbr->kx[1] + sbr->m[1]); if (sbr->patch_num_subbands[sbr->num_patches-1] < 3 && sbr->num_patches > 1) sbr->num_patches--; return 0; } /// Derived Frequency Band Tables (14496-3 sp04 p197) static int sbr_make_f_derived(AACContext *ac, SpectralBandReplication *sbr) { int k, temp; sbr->n[1] = sbr->n_master - sbr->spectrum_params.bs_xover_band; sbr->n[0] = (sbr->n[1] + 1) >> 1; memcpy(sbr->f_tablehigh, &sbr->f_master[sbr->spectrum_params.bs_xover_band], (sbr->n[1] + 1) * sizeof(sbr->f_master[0])); sbr->m[1] = sbr->f_tablehigh[sbr->n[1]] - sbr->f_tablehigh[0]; sbr->kx[1] = sbr->f_tablehigh[0]; // Requirements (14496-3 sp04 p205) if (sbr->kx[1] + sbr->m[1] > 64) { av_log(ac->avctx, AV_LOG_ERROR, "Stop frequency border too high: %d\n", sbr->kx[1] + sbr->m[1]); return -1; } if (sbr->kx[1] > 32) { av_log(ac->avctx, AV_LOG_ERROR, "Start frequency border too high: %d\n", sbr->kx[1]); return -1; } sbr->f_tablelow[0] = sbr->f_tablehigh[0]; temp = sbr->n[1] & 1; for (k = 1; k <= sbr->n[0]; k++) sbr->f_tablelow[k] = sbr->f_tablehigh[2 * k - temp]; sbr->n_q = FFMAX(1, lrintf(sbr->spectrum_params.bs_noise_bands * log2f(sbr->k[2] / (float)sbr->kx[1]))); // 0 <= bs_noise_bands <= 3 if (sbr->n_q > 5) { av_log(ac->avctx, AV_LOG_ERROR, "Too many noise floor scale factors: %d\n", sbr->n_q); return -1; } sbr->f_tablenoise[0] = sbr->f_tablelow[0]; temp = 0; for (k = 1; k <= sbr->n_q; k++) { temp += (sbr->n[0] - temp) / (sbr->n_q + 1 - k); sbr->f_tablenoise[k] = sbr->f_tablelow[temp]; } if (sbr_hf_calc_npatches(ac, sbr) < 0) return -1; sbr_make_f_tablelim(sbr); sbr->data[0].f_indexnoise = 0; sbr->data[1].f_indexnoise = 0; return 0; } static av_always_inline void get_bits1_vector(GetBitContext *gb, uint8_t *vec, int elements) { int i; for (i = 0; i < elements; i++) { vec[i] = get_bits1(gb); } } /** ceil(log2(index+1)) */ static const int8_t ceil_log2[] = { 0, 1, 2, 2, 3, 3, }; static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr, GetBitContext *gb, SBRData *ch_data) { int i; unsigned bs_pointer = 0; // frameLengthFlag ? 15 : 16; 960 sample length frames unsupported; this value is numTimeSlots int abs_bord_trail = 16; int num_rel_lead, num_rel_trail; unsigned bs_num_env_old = ch_data->bs_num_env; ch_data->bs_freq_res[0] = ch_data->bs_freq_res[ch_data->bs_num_env]; ch_data->bs_amp_res = sbr->bs_amp_res_header; ch_data->t_env_num_env_old = ch_data->t_env[bs_num_env_old]; switch (ch_data->bs_frame_class = get_bits(gb, 2)) { case FIXFIX: ch_data->bs_num_env = 1 << get_bits(gb, 2); num_rel_lead = ch_data->bs_num_env - 1; if (ch_data->bs_num_env == 1) ch_data->bs_amp_res = 0; if (ch_data->bs_num_env > 4) { av_log(ac->avctx, AV_LOG_ERROR, "Invalid bitstream, too many SBR envelopes in FIXFIX type SBR frame: %d\n", ch_data->bs_num_env); return -1; } ch_data->t_env[0] = 0; ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail; abs_bord_trail = (abs_bord_trail + (ch_data->bs_num_env >> 1)) / ch_data->bs_num_env; for (i = 0; i < num_rel_lead; i++) ch_data->t_env[i + 1] = ch_data->t_env[i] + abs_bord_trail; ch_data->bs_freq_res[1] = get_bits1(gb); for (i = 1; i < ch_data->bs_num_env; i++) ch_data->bs_freq_res[i + 1] = ch_data->bs_freq_res[1]; break; case FIXVAR: abs_bord_trail += get_bits(gb, 2); num_rel_trail = get_bits(gb, 2); ch_data->bs_num_env = num_rel_trail + 1; ch_data->t_env[0] = 0; ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail; for (i = 0; i < num_rel_trail; i++) ch_data->t_env[ch_data->bs_num_env - 1 - i] = ch_data->t_env[ch_data->bs_num_env - i] - 2 * get_bits(gb, 2) - 2; bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]); for (i = 0; i < ch_data->bs_num_env; i++) ch_data->bs_freq_res[ch_data->bs_num_env - i] = get_bits1(gb); break; case VARFIX: ch_data->t_env[0] = get_bits(gb, 2); num_rel_lead = get_bits(gb, 2); ch_data->bs_num_env = num_rel_lead + 1; ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail; for (i = 0; i < num_rel_lead; i++) ch_data->t_env[i + 1] = ch_data->t_env[i] + 2 * get_bits(gb, 2) + 2; bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]); get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env); break; case VARVAR: ch_data->t_env[0] = get_bits(gb, 2); abs_bord_trail += get_bits(gb, 2); num_rel_lead = get_bits(gb, 2); num_rel_trail = get_bits(gb, 2); ch_data->bs_num_env = num_rel_lead + num_rel_trail + 1; if (ch_data->bs_num_env > 5) { av_log(ac->avctx, AV_LOG_ERROR, "Invalid bitstream, too many SBR envelopes in VARVAR type SBR frame: %d\n", ch_data->bs_num_env); return -1; } ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail; for (i = 0; i < num_rel_lead; i++) ch_data->t_env[i + 1] = ch_data->t_env[i] + 2 * get_bits(gb, 2) + 2; for (i = 0; i < num_rel_trail; i++) ch_data->t_env[ch_data->bs_num_env - 1 - i] = ch_data->t_env[ch_data->bs_num_env - i] - 2 * get_bits(gb, 2) - 2; bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]); get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env); break; } if (bs_pointer > ch_data->bs_num_env + 1) { av_log(ac->avctx, AV_LOG_ERROR, "Invalid bitstream, bs_pointer points to a middle noise border outside the time borders table: %d\n", bs_pointer); return -1; } for (i = 1; i <= ch_data->bs_num_env; i++) { if (ch_data->t_env[i-1] > ch_data->t_env[i]) { av_log(ac->avctx, AV_LOG_ERROR, "Non monotone time borders\n"); return -1; } } ch_data->bs_num_noise = (ch_data->bs_num_env > 1) + 1; ch_data->t_q[0] = ch_data->t_env[0]; ch_data->t_q[ch_data->bs_num_noise] = ch_data->t_env[ch_data->bs_num_env]; if (ch_data->bs_num_noise > 1) { unsigned int idx; if (ch_data->bs_frame_class == FIXFIX) { idx = ch_data->bs_num_env >> 1; } else if (ch_data->bs_frame_class & 1) { // FIXVAR or VARVAR idx = ch_data->bs_num_env - FFMAX(bs_pointer - 1, 1); } else { // VARFIX if (!bs_pointer) idx = 1; else if (bs_pointer == 1) idx = ch_data->bs_num_env - 1; else // bs_pointer > 1 idx = bs_pointer - 1; } ch_data->t_q[1] = ch_data->t_env[idx]; } ch_data->e_a[0] = -(ch_data->e_a[1] != bs_num_env_old); // l_APrev ch_data->e_a[1] = -1; if ((ch_data->bs_frame_class & 1) && bs_pointer) { // FIXVAR or VARVAR and bs_pointer != 0 ch_data->e_a[1] = ch_data->bs_num_env + 1 - bs_pointer; } else if ((ch_data->bs_frame_class == 2) && (bs_pointer > 1)) // VARFIX and bs_pointer > 1 ch_data->e_a[1] = bs_pointer - 1; return 0; } static void copy_sbr_grid(SBRData *dst, const SBRData *src) { //These variables are saved from the previous frame rather than copied dst->bs_freq_res[0] = dst->bs_freq_res[dst->bs_num_env]; dst->t_env_num_env_old = dst->t_env[dst->bs_num_env]; dst->e_a[0] = -(dst->e_a[1] != dst->bs_num_env); //These variables are read from the bitstream and therefore copied memcpy(dst->bs_freq_res+1, src->bs_freq_res+1, sizeof(dst->bs_freq_res)-sizeof(*dst->bs_freq_res)); memcpy(dst->t_env, src->t_env, sizeof(dst->t_env)); memcpy(dst->t_q, src->t_q, sizeof(dst->t_q)); dst->bs_num_env = src->bs_num_env; dst->bs_amp_res = src->bs_amp_res; dst->bs_num_noise = src->bs_num_noise; dst->bs_frame_class = src->bs_frame_class; dst->e_a[1] = src->e_a[1]; } /// Read how the envelope and noise floor data is delta coded static void read_sbr_dtdf(SpectralBandReplication *sbr, GetBitContext *gb, SBRData *ch_data) { get_bits1_vector(gb, ch_data->bs_df_env, ch_data->bs_num_env); get_bits1_vector(gb, ch_data->bs_df_noise, ch_data->bs_num_noise); } /// Read inverse filtering data static void read_sbr_invf(SpectralBandReplication *sbr, GetBitContext *gb, SBRData *ch_data) { int i; memcpy(ch_data->bs_invf_mode[1], ch_data->bs_invf_mode[0], 5 * sizeof(uint8_t)); for (i = 0; i < sbr->n_q; i++) ch_data->bs_invf_mode[0][i] = get_bits(gb, 2); } static void read_sbr_envelope(SpectralBandReplication *sbr, GetBitContext *gb, SBRData *ch_data, int ch) { int bits; int i, j, k; VLC_TYPE (*t_huff)[2], (*f_huff)[2]; int t_lav, f_lav; const int delta = (ch == 1 && sbr->bs_coupling == 1) + 1; const int odd = sbr->n[1] & 1; if (sbr->bs_coupling && ch) { if (ch_data->bs_amp_res) { bits = 5; t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_3_0DB].table; t_lav = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_3_0DB]; f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table; f_lav = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB]; } else { bits = 6; t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_1_5DB].table; t_lav = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_1_5DB]; f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_1_5DB].table; f_lav = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_1_5DB]; } } else { if (ch_data->bs_amp_res) { bits = 6; t_huff = vlc_sbr[T_HUFFMAN_ENV_3_0DB].table; t_lav = vlc_sbr_lav[T_HUFFMAN_ENV_3_0DB]; f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table; f_lav = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB]; } else { bits = 7; t_huff = vlc_sbr[T_HUFFMAN_ENV_1_5DB].table; t_lav = vlc_sbr_lav[T_HUFFMAN_ENV_1_5DB]; f_huff = vlc_sbr[F_HUFFMAN_ENV_1_5DB].table; f_lav = vlc_sbr_lav[F_HUFFMAN_ENV_1_5DB]; } } for (i = 0; i < ch_data->bs_num_env; i++) { if (ch_data->bs_df_env[i]) { // bs_freq_res[0] == bs_freq_res[bs_num_env] from prev frame if (ch_data->bs_freq_res[i + 1] == ch_data->bs_freq_res[i]) { for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][j] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav); } else if (ch_data->bs_freq_res[i + 1]) { for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) { k = (j + odd) >> 1; // find k such that f_tablelow[k] <= f_tablehigh[j] < f_tablelow[k + 1] ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][k] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav); } } else { for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) { k = j ? 2*j - odd : 0; // find k such that f_tablehigh[k] == f_tablelow[j] ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][k] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav); } } } else { ch_data->env_facs[i + 1][0] = delta * get_bits(gb, bits); // bs_env_start_value_balance for (j = 1; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) ch_data->env_facs[i + 1][j] = ch_data->env_facs[i + 1][j - 1] + delta * (get_vlc2(gb, f_huff, 9, 3) - f_lav); } } //assign 0th elements of env_facs from last elements memcpy(ch_data->env_facs[0], ch_data->env_facs[ch_data->bs_num_env], sizeof(ch_data->env_facs[0])); } static void read_sbr_noise(SpectralBandReplication *sbr, GetBitContext *gb, SBRData *ch_data, int ch) { int i, j; VLC_TYPE (*t_huff)[2], (*f_huff)[2]; int t_lav, f_lav; int delta = (ch == 1 && sbr->bs_coupling == 1) + 1; if (sbr->bs_coupling && ch) { t_huff = vlc_sbr[T_HUFFMAN_NOISE_BAL_3_0DB].table; t_lav = vlc_sbr_lav[T_HUFFMAN_NOISE_BAL_3_0DB]; f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table; f_lav = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB]; } else { t_huff = vlc_sbr[T_HUFFMAN_NOISE_3_0DB].table; t_lav = vlc_sbr_lav[T_HUFFMAN_NOISE_3_0DB]; f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table; f_lav = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB]; } for (i = 0; i < ch_data->bs_num_noise; i++) { if (ch_data->bs_df_noise[i]) { for (j = 0; j < sbr->n_q; j++) ch_data->noise_facs[i + 1][j] = ch_data->noise_facs[i][j] + delta * (get_vlc2(gb, t_huff, 9, 2) - t_lav); } else { ch_data->noise_facs[i + 1][0] = delta * get_bits(gb, 5); // bs_noise_start_value_balance or bs_noise_start_value_level for (j = 1; j < sbr->n_q; j++) ch_data->noise_facs[i + 1][j] = ch_data->noise_facs[i + 1][j - 1] + delta * (get_vlc2(gb, f_huff, 9, 3) - f_lav); } } //assign 0th elements of noise_facs from last elements memcpy(ch_data->noise_facs[0], ch_data->noise_facs[ch_data->bs_num_noise], sizeof(ch_data->noise_facs[0])); } static void read_sbr_extension(AACContext *ac, SpectralBandReplication *sbr, GetBitContext *gb, int bs_extension_id, int *num_bits_left) { switch (bs_extension_id) { case EXTENSION_ID_PS: if (!ac->m4ac.ps) { av_log(ac->avctx, AV_LOG_ERROR, "Parametric Stereo signaled to be not-present but was found in the bitstream.\n"); skip_bits_long(gb, *num_bits_left); // bs_fill_bits *num_bits_left = 0; } else { #if 1 *num_bits_left -= ff_ps_read_data(ac->avctx, gb, &sbr->ps, *num_bits_left); #else av_log_missing_feature(ac->avctx, "Parametric Stereo is", 0); skip_bits_long(gb, *num_bits_left); // bs_fill_bits *num_bits_left = 0; #endif } break; default: av_log_missing_feature(ac->avctx, "Reserved SBR extensions are", 1); skip_bits_long(gb, *num_bits_left); // bs_fill_bits *num_bits_left = 0; break; } } static int read_sbr_single_channel_element(AACContext *ac, SpectralBandReplication *sbr, GetBitContext *gb) { if (get_bits1(gb)) // bs_data_extra skip_bits(gb, 4); // bs_reserved if (read_sbr_grid(ac, sbr, gb, &sbr->data[0])) return -1; read_sbr_dtdf(sbr, gb, &sbr->data[0]); read_sbr_invf(sbr, gb, &sbr->data[0]); read_sbr_envelope(sbr, gb, &sbr->data[0], 0); read_sbr_noise(sbr, gb, &sbr->data[0], 0); if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb))) get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]); return 0; } static int read_sbr_channel_pair_element(AACContext *ac, SpectralBandReplication *sbr, GetBitContext *gb) { if (get_bits1(gb)) // bs_data_extra skip_bits(gb, 8); // bs_reserved if ((sbr->bs_coupling = get_bits1(gb))) { if (read_sbr_grid(ac, sbr, gb, &sbr->data[0])) return -1; copy_sbr_grid(&sbr->data[1], &sbr->data[0]); read_sbr_dtdf(sbr, gb, &sbr->data[0]); read_sbr_dtdf(sbr, gb, &sbr->data[1]); read_sbr_invf(sbr, gb, &sbr->data[0]); memcpy(sbr->data[1].bs_invf_mode[1], sbr->data[1].bs_invf_mode[0], sizeof(sbr->data[1].bs_invf_mode[0])); memcpy(sbr->data[1].bs_invf_mode[0], sbr->data[0].bs_invf_mode[0], sizeof(sbr->data[1].bs_invf_mode[0])); read_sbr_envelope(sbr, gb, &sbr->data[0], 0); read_sbr_noise(sbr, gb, &sbr->data[0], 0); read_sbr_envelope(sbr, gb, &sbr->data[1], 1); read_sbr_noise(sbr, gb, &sbr->data[1], 1); } else { if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]) || read_sbr_grid(ac, sbr, gb, &sbr->data[1])) return -1; read_sbr_dtdf(sbr, gb, &sbr->data[0]); read_sbr_dtdf(sbr, gb, &sbr->data[1]); read_sbr_invf(sbr, gb, &sbr->data[0]); read_sbr_invf(sbr, gb, &sbr->data[1]); read_sbr_envelope(sbr, gb, &sbr->data[0], 0); read_sbr_envelope(sbr, gb, &sbr->data[1], 1); read_sbr_noise(sbr, gb, &sbr->data[0], 0); read_sbr_noise(sbr, gb, &sbr->data[1], 1); } if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb))) get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]); if ((sbr->data[1].bs_add_harmonic_flag = get_bits1(gb))) get_bits1_vector(gb, sbr->data[1].bs_add_harmonic, sbr->n[1]); return 0; } static unsigned int read_sbr_data(AACContext *ac, SpectralBandReplication *sbr, GetBitContext *gb, int id_aac) { unsigned int cnt = get_bits_count(gb); if (id_aac == TYPE_SCE || id_aac == TYPE_CCE) { if (read_sbr_single_channel_element(ac, sbr, gb)) { sbr->start = 0; return get_bits_count(gb) - cnt; } } else if (id_aac == TYPE_CPE) { if (read_sbr_channel_pair_element(ac, sbr, gb)) { sbr->start = 0; return get_bits_count(gb) - cnt; } } else { av_log(ac->avctx, AV_LOG_ERROR, "Invalid bitstream - cannot apply SBR to element type %d\n", id_aac); sbr->start = 0; return get_bits_count(gb) - cnt; } if (get_bits1(gb)) { // bs_extended_data int num_bits_left = get_bits(gb, 4); // bs_extension_size if (num_bits_left == 15) num_bits_left += get_bits(gb, 8); // bs_esc_count num_bits_left <<= 3; while (num_bits_left > 7) { num_bits_left -= 2; read_sbr_extension(ac, sbr, gb, get_bits(gb, 2), &num_bits_left); // bs_extension_id } if (num_bits_left < 0) { av_log(ac->avctx, AV_LOG_ERROR, "SBR Extension over read.\n"); } if (num_bits_left > 0) skip_bits(gb, num_bits_left); } return get_bits_count(gb) - cnt; } static void sbr_reset(AACContext *ac, SpectralBandReplication *sbr) { int err; err = sbr_make_f_master(ac, sbr, &sbr->spectrum_params); if (err >= 0) err = sbr_make_f_derived(ac, sbr); if (err < 0) { av_log(ac->avctx, AV_LOG_ERROR, "SBR reset failed. Switching SBR to pure upsampling mode.\n"); sbr->start = 0; } } /** * Decode Spectral Band Replication extension data; reference: table 4.55. * * @param crc flag indicating the presence of CRC checksum * @param cnt length of TYPE_FIL syntactic element in bytes * * @return Returns number of bytes consumed from the TYPE_FIL element. */ int ff_decode_sbr_extension(AACContext *ac, SpectralBandReplication *sbr, GetBitContext *gb_host, int crc, int cnt, int id_aac) { unsigned int num_sbr_bits = 0, num_align_bits; unsigned bytes_read; GetBitContext gbc = *gb_host, *gb = &gbc; skip_bits_long(gb_host, cnt*8 - 4); sbr->reset = 0; if (!sbr->sample_rate) sbr->sample_rate = 2 * ac->m4ac.sample_rate; //TODO use the nominal sample rate for arbitrary sample rate support if (!ac->m4ac.ext_sample_rate) ac->m4ac.ext_sample_rate = 2 * ac->m4ac.sample_rate; if (crc) { skip_bits(gb, 10); // bs_sbr_crc_bits; TODO - implement CRC check num_sbr_bits += 10; } //Save some state from the previous frame. sbr->kx[0] = sbr->kx[1]; sbr->m[0] = sbr->m[1]; num_sbr_bits++; if (get_bits1(gb)) // bs_header_flag num_sbr_bits += read_sbr_header(sbr, gb); if (sbr->reset) sbr_reset(ac, sbr); if (sbr->start) num_sbr_bits += read_sbr_data(ac, sbr, gb, id_aac); num_align_bits = ((cnt << 3) - 4 - num_sbr_bits) & 7; bytes_read = ((num_sbr_bits + num_align_bits + 4) >> 3); if (bytes_read > cnt) { av_log(ac->avctx, AV_LOG_ERROR, "Expected to read %d SBR bytes actually read %d.\n", cnt, bytes_read); } return cnt; } /// Dequantization and stereo decoding (14496-3 sp04 p203) static void sbr_dequant(SpectralBandReplication *sbr, int id_aac) { int k, e; int ch; if (id_aac == TYPE_CPE && sbr->bs_coupling) { float alpha = sbr->data[0].bs_amp_res ? 1.0f : 0.5f; float pan_offset = sbr->data[0].bs_amp_res ? 12.0f : 24.0f; for (e = 1; e <= sbr->data[0].bs_num_env; e++) { for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) { float temp1 = exp2f(sbr->data[0].env_facs[e][k] * alpha + 7.0f); float temp2 = exp2f((pan_offset - sbr->data[1].env_facs[e][k]) * alpha); float fac = temp1 / (1.0f + temp2); sbr->data[0].env_facs[e][k] = fac; sbr->data[1].env_facs[e][k] = fac * temp2; } } for (e = 1; e <= sbr->data[0].bs_num_noise; e++) { for (k = 0; k < sbr->n_q; k++) { float temp1 = exp2f(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs[e][k] + 1); float temp2 = exp2f(12 - sbr->data[1].noise_facs[e][k]); float fac = temp1 / (1.0f + temp2); sbr->data[0].noise_facs[e][k] = fac; sbr->data[1].noise_facs[e][k] = fac * temp2; } } } else { // SCE or one non-coupled CPE for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) { float alpha = sbr->data[ch].bs_amp_res ? 1.0f : 0.5f; for (e = 1; e <= sbr->data[ch].bs_num_env; e++) for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++) sbr->data[ch].env_facs[e][k] = exp2f(alpha * sbr->data[ch].env_facs[e][k] + 6.0f); for (e = 1; e <= sbr->data[ch].bs_num_noise; e++) for (k = 0; k < sbr->n_q; k++) sbr->data[ch].noise_facs[e][k] = exp2f(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs[e][k]); } } } /** * Analysis QMF Bank (14496-3 sp04 p206) * * @param x pointer to the beginning of the first sample window * @param W array of complex-valued samples split into subbands */ static void sbr_qmf_analysis(DSPContext *dsp, FFTContext *mdct, const float *in, float *x, float z[320], float W[2][32][32][2]) { int i, k; memcpy(W[0], W[1], sizeof(W[0])); memcpy(x , x+1024, (320-32)*sizeof(x[0])); memcpy(x+288, in, 1024*sizeof(x[0])); for (i = 0; i < 32; i++) { // numTimeSlots*RATE = 16*2 as 960 sample frames // are not supported dsp->vector_fmul_reverse(z, sbr_qmf_window_ds, x, 320); for (k = 0; k < 64; k++) { float f = z[k] + z[k + 64] + z[k + 128] + z[k + 192] + z[k + 256]; z[k] = f; } //Shuffle to IMDCT z[64] = z[0]; for (k = 1; k < 32; k++) { z[64+2*k-1] = z[ k]; z[64+2*k ] = -z[64-k]; } z[64+63] = z[32]; mdct->imdct_half(mdct, z, z+64); for (k = 0; k < 32; k++) { W[1][i][k][0] = -z[63-k]; W[1][i][k][1] = z[k]; } x += 32; } } /** * Synthesis QMF Bank (14496-3 sp04 p206) and Downsampled Synthesis QMF Bank * (14496-3 sp04 p206) */ static void sbr_qmf_synthesis(DSPContext *dsp, FFTContext *mdct, float *out, float X[2][38][64], float mdct_buf[2][64], float *v0, int *v_off, const unsigned int div) { int i, n; const float *sbr_qmf_window = div ? sbr_qmf_window_ds : sbr_qmf_window_us; float *v; for (i = 0; i < 32; i++) { if (*v_off == 0) { int saved_samples = (1280 - 128) >> div; memcpy(&v0[SBR_SYNTHESIS_BUF_SIZE - saved_samples], v0, saved_samples * sizeof(float)); *v_off = SBR_SYNTHESIS_BUF_SIZE - saved_samples - (128 >> div); } else { *v_off -= 128 >> div; } v = v0 + *v_off; if (div) { for (n = 0; n < 32; n++) { X[0][i][ n] = -X[0][i][n]; X[0][i][32+n] = X[1][i][31-n]; } mdct->imdct_half(mdct, mdct_buf[0], X[0][i]); for (n = 0; n < 32; n++) { v[ n] = mdct_buf[0][63 - 2*n]; v[63 - n] = -mdct_buf[0][62 - 2*n]; } } else { for (n = 1; n < 64; n+=2) { X[1][i][n] = -X[1][i][n]; } mdct->imdct_half(mdct, mdct_buf[0], X[0][i]); mdct->imdct_half(mdct, mdct_buf[1], X[1][i]); for (n = 0; n < 64; n++) { v[ n] = -mdct_buf[0][63 - n] + mdct_buf[1][ n ]; v[127 - n] = mdct_buf[0][63 - n] + mdct_buf[1][ n ]; } } dsp->vector_fmul_add(out, v , sbr_qmf_window , zero64, 64 >> div); dsp->vector_fmul_add(out, v + ( 192 >> div), sbr_qmf_window + ( 64 >> div), out , 64 >> div); dsp->vector_fmul_add(out, v + ( 256 >> div), sbr_qmf_window + (128 >> div), out , 64 >> div); dsp->vector_fmul_add(out, v + ( 448 >> div), sbr_qmf_window + (192 >> div), out , 64 >> div); dsp->vector_fmul_add(out, v + ( 512 >> div), sbr_qmf_window + (256 >> div), out , 64 >> div); dsp->vector_fmul_add(out, v + ( 704 >> div), sbr_qmf_window + (320 >> div), out , 64 >> div); dsp->vector_fmul_add(out, v + ( 768 >> div), sbr_qmf_window + (384 >> div), out , 64 >> div); dsp->vector_fmul_add(out, v + ( 960 >> div), sbr_qmf_window + (448 >> div), out , 64 >> div); dsp->vector_fmul_add(out, v + (1024 >> div), sbr_qmf_window + (512 >> div), out , 64 >> div); dsp->vector_fmul_add(out, v + (1216 >> div), sbr_qmf_window + (576 >> div), out , 64 >> div); out += 64 >> div; } } static void autocorrelate(const float x[40][2], float phi[3][2][2], int lag) { int i; float real_sum = 0.0f; float imag_sum = 0.0f; if (lag) { for (i = 1; i < 38; i++) { real_sum += x[i][0] * x[i+lag][0] + x[i][1] * x[i+lag][1]; imag_sum += x[i][0] * x[i+lag][1] - x[i][1] * x[i+lag][0]; } phi[2-lag][1][0] = real_sum + x[ 0][0] * x[lag][0] + x[ 0][1] * x[lag][1]; phi[2-lag][1][1] = imag_sum + x[ 0][0] * x[lag][1] - x[ 0][1] * x[lag][0]; if (lag == 1) { phi[0][0][0] = real_sum + x[38][0] * x[39][0] + x[38][1] * x[39][1]; phi[0][0][1] = imag_sum + x[38][0] * x[39][1] - x[38][1] * x[39][0]; } } else { for (i = 1; i < 38; i++) { real_sum += x[i][0] * x[i][0] + x[i][1] * x[i][1]; } phi[2][1][0] = real_sum + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1]; phi[1][0][0] = real_sum + x[38][0] * x[38][0] + x[38][1] * x[38][1]; } } /** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering * (14496-3 sp04 p214) * Warning: This routine does not seem numerically stable. */ static void sbr_hf_inverse_filter(float (*alpha0)[2], float (*alpha1)[2], const float X_low[32][40][2], int k0) { int k; for (k = 0; k < k0; k++) { float phi[3][2][2], dk; autocorrelate(X_low[k], phi, 0); autocorrelate(X_low[k], phi, 1); autocorrelate(X_low[k], phi, 2); dk = phi[2][1][0] * phi[1][0][0] - (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f; if (!dk) { alpha1[k][0] = 0; alpha1[k][1] = 0; } else { float temp_real, temp_im; temp_real = phi[0][0][0] * phi[1][1][0] - phi[0][0][1] * phi[1][1][1] - phi[0][1][0] * phi[1][0][0]; temp_im = phi[0][0][0] * phi[1][1][1] + phi[0][0][1] * phi[1][1][0] - phi[0][1][1] * phi[1][0][0]; alpha1[k][0] = temp_real / dk; alpha1[k][1] = temp_im / dk; } if (!phi[1][0][0]) { alpha0[k][0] = 0; alpha0[k][1] = 0; } else { float temp_real, temp_im; temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] + alpha1[k][1] * phi[1][1][1]; temp_im = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] - alpha1[k][0] * phi[1][1][1]; alpha0[k][0] = -temp_real / phi[1][0][0]; alpha0[k][1] = -temp_im / phi[1][0][0]; } if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f || alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) { alpha1[k][0] = 0; alpha1[k][1] = 0; alpha0[k][0] = 0; alpha0[k][1] = 0; } } } /// Chirp Factors (14496-3 sp04 p214) static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data) { int i; float new_bw; static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f }; for (i = 0; i < sbr->n_q; i++) { if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) { new_bw = 0.6f; } else new_bw = bw_tab[ch_data->bs_invf_mode[0][i]]; if (new_bw < ch_data->bw_array[i]) { new_bw = 0.75f * new_bw + 0.25f * ch_data->bw_array[i]; } else new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i]; ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw; } } /// Generate the subband filtered lowband static int sbr_lf_gen(AACContext *ac, SpectralBandReplication *sbr, float X_low[32][40][2], const float W[2][32][32][2]) { int i, k; const int t_HFGen = 8; const int i_f = 32; memset(X_low, 0, 32*sizeof(*X_low)); for (k = 0; k < sbr->kx[1]; k++) { for (i = t_HFGen; i < i_f + t_HFGen; i++) { X_low[k][i][0] = W[1][i - t_HFGen][k][0]; X_low[k][i][1] = W[1][i - t_HFGen][k][1]; } } for (k = 0; k < sbr->kx[0]; k++) { for (i = 0; i < t_HFGen; i++) { X_low[k][i][0] = W[0][i + i_f - t_HFGen][k][0]; X_low[k][i][1] = W[0][i + i_f - t_HFGen][k][1]; } } return 0; } /// High Frequency Generator (14496-3 sp04 p215) static int sbr_hf_gen(AACContext *ac, SpectralBandReplication *sbr, float X_high[64][40][2], const float X_low[32][40][2], const float (*alpha0)[2], const float (*alpha1)[2], const float bw_array[5], const uint8_t *t_env, int bs_num_env) { int i, j, x; int g = 0; int k = sbr->kx[1]; for (j = 0; j < sbr->num_patches; j++) { for (x = 0; x < sbr->patch_num_subbands[j]; x++, k++) { float alpha[4]; const int p = sbr->patch_start_subband[j] + x; while (g <= sbr->n_q && k >= sbr->f_tablenoise[g]) g++; g--; if (g < 0) { av_log(ac->avctx, AV_LOG_ERROR, "ERROR : no subband found for frequency %d\n", k); return -1; } alpha[0] = alpha1[p][0] * bw_array[g] * bw_array[g]; alpha[1] = alpha1[p][1] * bw_array[g] * bw_array[g]; alpha[2] = alpha0[p][0] * bw_array[g]; alpha[3] = alpha0[p][1] * bw_array[g]; for (i = 2 * t_env[0]; i < 2 * t_env[bs_num_env]; i++) { const int idx = i + ENVELOPE_ADJUSTMENT_OFFSET; X_high[k][idx][0] = X_low[p][idx - 2][0] * alpha[0] - X_low[p][idx - 2][1] * alpha[1] + X_low[p][idx - 1][0] * alpha[2] - X_low[p][idx - 1][1] * alpha[3] + X_low[p][idx][0]; X_high[k][idx][1] = X_low[p][idx - 2][1] * alpha[0] + X_low[p][idx - 2][0] * alpha[1] + X_low[p][idx - 1][1] * alpha[2] + X_low[p][idx - 1][0] * alpha[3] + X_low[p][idx][1]; } } } if (k < sbr->m[1] + sbr->kx[1]) memset(X_high + k, 0, (sbr->m[1] + sbr->kx[1] - k) * sizeof(*X_high)); return 0; } /// Generate the subband filtered lowband static int sbr_x_gen(SpectralBandReplication *sbr, float X[2][38][64], const float X_low[32][40][2], const float Y[2][38][64][2], int ch) { int k, i; const int i_f = 32; const int i_Temp = FFMAX(2*sbr->data[ch].t_env_num_env_old - i_f, 0); memset(X, 0, 2*sizeof(*X)); for (k = 0; k < sbr->kx[0]; k++) { for (i = 0; i < i_Temp; i++) { X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0]; X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1]; } } for (; k < sbr->kx[0] + sbr->m[0]; k++) { for (i = 0; i < i_Temp; i++) { X[0][i][k] = Y[0][i + i_f][k][0]; X[1][i][k] = Y[0][i + i_f][k][1]; } } for (k = 0; k < sbr->kx[1]; k++) { for (i = i_Temp; i < 38; i++) { X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0]; X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1]; } } for (; k < sbr->kx[1] + sbr->m[1]; k++) { for (i = i_Temp; i < i_f; i++) { X[0][i][k] = Y[1][i][k][0]; X[1][i][k] = Y[1][i][k][1]; } } return 0; } /** High Frequency Adjustment (14496-3 sp04 p217) and Mapping * (14496-3 sp04 p217) */ static void sbr_mapping(AACContext *ac, SpectralBandReplication *sbr, SBRData *ch_data, int e_a[2]) { int e, i, m; memset(ch_data->s_indexmapped[1], 0, 7*sizeof(ch_data->s_indexmapped[1])); for (e = 0; e < ch_data->bs_num_env; e++) { const unsigned int ilim = sbr->n[ch_data->bs_freq_res[e + 1]]; uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow; int k; for (i = 0; i < ilim; i++) for (m = table[i]; m < table[i + 1]; m++) sbr->e_origmapped[e][m - sbr->kx[1]] = ch_data->env_facs[e+1][i]; // ch_data->bs_num_noise > 1 => 2 noise floors k = (ch_data->bs_num_noise > 1) && (ch_data->t_env[e] >= ch_data->t_q[1]); for (i = 0; i < sbr->n_q; i++) for (m = sbr->f_tablenoise[i]; m < sbr->f_tablenoise[i + 1]; m++) sbr->q_mapped[e][m - sbr->kx[1]] = ch_data->noise_facs[k+1][i]; for (i = 0; i < sbr->n[1]; i++) { if (ch_data->bs_add_harmonic_flag) { const unsigned int m_midpoint = (sbr->f_tablehigh[i] + sbr->f_tablehigh[i + 1]) >> 1; ch_data->s_indexmapped[e + 1][m_midpoint - sbr->kx[1]] = ch_data->bs_add_harmonic[i] * (e >= e_a[1] || (ch_data->s_indexmapped[0][m_midpoint - sbr->kx[1]] == 1)); } } for (i = 0; i < ilim; i++) { int additional_sinusoid_present = 0; for (m = table[i]; m < table[i + 1]; m++) { if (ch_data->s_indexmapped[e + 1][m - sbr->kx[1]]) { additional_sinusoid_present = 1; break; } } memset(&sbr->s_mapped[e][table[i] - sbr->kx[1]], additional_sinusoid_present, (table[i + 1] - table[i]) * sizeof(sbr->s_mapped[e][0])); } } memcpy(ch_data->s_indexmapped[0], ch_data->s_indexmapped[ch_data->bs_num_env], sizeof(ch_data->s_indexmapped[0])); } /// Estimation of current envelope (14496-3 sp04 p218) static void sbr_env_estimate(float (*e_curr)[48], float X_high[64][40][2], SpectralBandReplication *sbr, SBRData *ch_data) { int e, i, m; if (sbr->bs_interpol_freq) { for (e = 0; e < ch_data->bs_num_env; e++) { const float recip_env_size = 0.5f / (ch_data->t_env[e + 1] - ch_data->t_env[e]); int ilb = ch_data->t_env[e] * 2 + ENVELOPE_ADJUSTMENT_OFFSET; int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET; for (m = 0; m < sbr->m[1]; m++) { float sum = 0.0f; for (i = ilb; i < iub; i++) { sum += X_high[m + sbr->kx[1]][i][0] * X_high[m + sbr->kx[1]][i][0] + X_high[m + sbr->kx[1]][i][1] * X_high[m + sbr->kx[1]][i][1]; } e_curr[e][m] = sum * recip_env_size; } } } else { int k, p; for (e = 0; e < ch_data->bs_num_env; e++) { const int env_size = 2 * (ch_data->t_env[e + 1] - ch_data->t_env[e]); int ilb = ch_data->t_env[e] * 2 + ENVELOPE_ADJUSTMENT_OFFSET; int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET; const uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow; for (p = 0; p < sbr->n[ch_data->bs_freq_res[e + 1]]; p++) { float sum = 0.0f; const int den = env_size * (table[p + 1] - table[p]); for (k = table[p]; k < table[p + 1]; k++) { for (i = ilb; i < iub; i++) { sum += X_high[k][i][0] * X_high[k][i][0] + X_high[k][i][1] * X_high[k][i][1]; } } sum /= den; for (k = table[p]; k < table[p + 1]; k++) { e_curr[e][k - sbr->kx[1]] = sum; } } } } } /** * Calculation of levels of additional HF signal components (14496-3 sp04 p219) * and Calculation of gain (14496-3 sp04 p219) */ static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr, SBRData *ch_data, const int e_a[2]) { int e, k, m; // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off) static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 }; for (e = 0; e < ch_data->bs_num_env; e++) { int delta = !((e == e_a[1]) || (e == e_a[0])); for (k = 0; k < sbr->n_lim; k++) { float gain_boost, gain_max; float sum[2] = { 0.0f, 0.0f }; for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) { const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]); sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]); sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]); if (!sbr->s_mapped[e][m]) { sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] / ((1.0f + sbr->e_curr[e][m]) * (1.0f + sbr->q_mapped[e][m] * delta))); } else { sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] / ((1.0f + sbr->e_curr[e][m]) * (1.0f + sbr->q_mapped[e][m]))); } } for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) { sum[0] += sbr->e_origmapped[e][m]; sum[1] += sbr->e_curr[e][m]; } gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1])); gain_max = FFMIN(100000.f, gain_max); for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) { float q_m_max = sbr->q_m[e][m] * gain_max / sbr->gain[e][m]; sbr->q_m[e][m] = FFMIN(sbr->q_m[e][m], q_m_max); sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max); } sum[0] = sum[1] = 0.0f; for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) { sum[0] += sbr->e_origmapped[e][m]; sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m] + sbr->s_m[e][m] * sbr->s_m[e][m] + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m]; } gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1])); gain_boost = FFMIN(1.584893192f, gain_boost); for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) { sbr->gain[e][m] *= gain_boost; sbr->q_m[e][m] *= gain_boost; sbr->s_m[e][m] *= gain_boost; } } } } /// Assembling HF Signals (14496-3 sp04 p220) static void sbr_hf_assemble(float Y[2][38][64][2], const float X_high[64][40][2], SpectralBandReplication *sbr, SBRData *ch_data, const int e_a[2]) { int e, i, j, m; const int h_SL = 4 * !sbr->bs_smoothing_mode; const int kx = sbr->kx[1]; const int m_max = sbr->m[1]; static const float h_smooth[5] = { 0.33333333333333, 0.30150283239582, 0.21816949906249, 0.11516383427084, 0.03183050093751, }; static const int8_t phi[2][4] = { { 1, 0, -1, 0}, // real { 0, 1, 0, -1}, // imaginary }; float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp; int indexnoise = ch_data->f_indexnoise; int indexsine = ch_data->f_indexsine; memcpy(Y[0], Y[1], sizeof(Y[0])); if (sbr->reset) { for (i = 0; i < h_SL; i++) { memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0])); memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0], m_max * sizeof(sbr->q_m[0][0])); } } else if (h_SL) { memcpy(g_temp[2*ch_data->t_env[0]], g_temp[2*ch_data->t_env_num_env_old], 4*sizeof(g_temp[0])); memcpy(q_temp[2*ch_data->t_env[0]], q_temp[2*ch_data->t_env_num_env_old], 4*sizeof(q_temp[0])); } for (e = 0; e < ch_data->bs_num_env; e++) { for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) { memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0])); memcpy(q_temp[h_SL + i], sbr->q_m[e], m_max * sizeof(sbr->q_m[0][0])); } } for (e = 0; e < ch_data->bs_num_env; e++) { for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) { int phi_sign = (1 - 2*(kx & 1)); if (h_SL && e != e_a[0] && e != e_a[1]) { for (m = 0; m < m_max; m++) { const int idx1 = i + h_SL; float g_filt = 0.0f; for (j = 0; j <= h_SL; j++) g_filt += g_temp[idx1 - j][m] * h_smooth[j]; Y[1][i][m + kx][0] = X_high[m + kx][i + ENVELOPE_ADJUSTMENT_OFFSET][0] * g_filt; Y[1][i][m + kx][1] = X_high[m + kx][i + ENVELOPE_ADJUSTMENT_OFFSET][1] * g_filt; } } else { for (m = 0; m < m_max; m++) { const float g_filt = g_temp[i + h_SL][m]; Y[1][i][m + kx][0] = X_high[m + kx][i + ENVELOPE_ADJUSTMENT_OFFSET][0] * g_filt; Y[1][i][m + kx][1] = X_high[m + kx][i + ENVELOPE_ADJUSTMENT_OFFSET][1] * g_filt; } } if (e != e_a[0] && e != e_a[1]) { for (m = 0; m < m_max; m++) { indexnoise = (indexnoise + 1) & 0x1ff; if (sbr->s_m[e][m]) { Y[1][i][m + kx][0] += sbr->s_m[e][m] * phi[0][indexsine]; Y[1][i][m + kx][1] += sbr->s_m[e][m] * (phi[1][indexsine] * phi_sign); } else { float q_filt; if (h_SL) { const int idx1 = i + h_SL; q_filt = 0.0f; for (j = 0; j <= h_SL; j++) q_filt += q_temp[idx1 - j][m] * h_smooth[j]; } else { q_filt = q_temp[i][m]; } Y[1][i][m + kx][0] += q_filt * sbr_noise_table[indexnoise][0]; Y[1][i][m + kx][1] += q_filt * sbr_noise_table[indexnoise][1]; } phi_sign = -phi_sign; } } else { indexnoise = (indexnoise + m_max) & 0x1ff; for (m = 0; m < m_max; m++) { Y[1][i][m + kx][0] += sbr->s_m[e][m] * phi[0][indexsine]; Y[1][i][m + kx][1] += sbr->s_m[e][m] * (phi[1][indexsine] * phi_sign); phi_sign = -phi_sign; } } indexsine = (indexsine + 1) & 3; } } ch_data->f_indexnoise = indexnoise; ch_data->f_indexsine = indexsine; } void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac, float* L, float* R) { int downsampled = ac->m4ac.ext_sample_rate < sbr->sample_rate; int ch; int nch = (id_aac == TYPE_CPE) ? 2 : 1; if (sbr->start) { sbr_dequant(sbr, id_aac); } for (ch = 0; ch < nch; ch++) { /* decode channel */ sbr_qmf_analysis(&ac->dsp, &sbr->mdct_ana, ch ? R : L, sbr->data[ch].analysis_filterbank_samples, (float*)sbr->qmf_filter_scratch, sbr->data[ch].W); sbr_lf_gen(ac, sbr, sbr->X_low, sbr->data[ch].W); if (sbr->start) { sbr_hf_inverse_filter(sbr->alpha0, sbr->alpha1, sbr->X_low, sbr->k[0]); sbr_chirp(sbr, &sbr->data[ch]); sbr_hf_gen(ac, sbr, sbr->X_high, sbr->X_low, sbr->alpha0, sbr->alpha1, sbr->data[ch].bw_array, sbr->data[ch].t_env, sbr->data[ch].bs_num_env); // hf_adj sbr_mapping(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a); sbr_env_estimate(sbr->e_curr, sbr->X_high, sbr, &sbr->data[ch]); sbr_gain_calc(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a); sbr_hf_assemble(sbr->data[ch].Y, sbr->X_high, sbr, &sbr->data[ch], sbr->data[ch].e_a); } /* synthesis */ sbr_x_gen(sbr, sbr->X[ch], sbr->X_low, sbr->data[ch].Y, ch); } if (ac->m4ac.ps == 1) { if (sbr->ps.start) { ff_ps_apply(ac->avctx, &sbr->ps, sbr->X[0], sbr->X[1], sbr->kx[1] + sbr->m[1]); } else { memcpy(sbr->X[1], sbr->X[0], sizeof(sbr->X[0])); } nch = 2; } sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, L, sbr->X[0], sbr->qmf_filter_scratch, sbr->data[0].synthesis_filterbank_samples, &sbr->data[0].synthesis_filterbank_samples_offset, downsampled); if (nch == 2) sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, R, sbr->X[1], sbr->qmf_filter_scratch, sbr->data[1].synthesis_filterbank_samples, &sbr->data[1].synthesis_filterbank_samples_offset, downsampled); }