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libavcodec/aacsbr.c

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00001 /*
00002  * AAC Spectral Band Replication decoding functions
00003  * Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
00004  * Copyright (c) 2009-2010 Alex Converse <alex.converse@gmail.com>
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * FFmpeg is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00029 #include "aac.h"
00030 #include "sbr.h"
00031 #include "aacsbr.h"
00032 #include "aacsbrdata.h"
00033 #include "fft.h"
00034 #include "aacps.h"
00035 #include "libavutil/libm.h"
00036 #include "libavutil/avassert.h"
00037 
00038 #include <stdint.h>
00039 #include <float.h>
00040 #include <math.h>
00041 
00042 #define ENVELOPE_ADJUSTMENT_OFFSET 2
00043 #define NOISE_FLOOR_OFFSET 6.0f
00044 
00048 enum {
00049     T_HUFFMAN_ENV_1_5DB,
00050     F_HUFFMAN_ENV_1_5DB,
00051     T_HUFFMAN_ENV_BAL_1_5DB,
00052     F_HUFFMAN_ENV_BAL_1_5DB,
00053     T_HUFFMAN_ENV_3_0DB,
00054     F_HUFFMAN_ENV_3_0DB,
00055     T_HUFFMAN_ENV_BAL_3_0DB,
00056     F_HUFFMAN_ENV_BAL_3_0DB,
00057     T_HUFFMAN_NOISE_3_0DB,
00058     T_HUFFMAN_NOISE_BAL_3_0DB,
00059 };
00060 
00064 enum {
00065     FIXFIX,
00066     FIXVAR,
00067     VARFIX,
00068     VARVAR,
00069 };
00070 
00071 enum {
00072     EXTENSION_ID_PS = 2,
00073 };
00074 
00075 static VLC vlc_sbr[10];
00076 static const int8_t vlc_sbr_lav[10] =
00077     { 60, 60, 24, 24, 31, 31, 12, 12, 31, 12 };
00078 static const DECLARE_ALIGNED(16, float, zero64)[64];
00079 
00080 #define SBR_INIT_VLC_STATIC(num, size) \
00081     INIT_VLC_STATIC(&vlc_sbr[num], 9, sbr_tmp[num].table_size / sbr_tmp[num].elem_size,     \
00082                     sbr_tmp[num].sbr_bits ,                      1,                      1, \
00083                     sbr_tmp[num].sbr_codes, sbr_tmp[num].elem_size, sbr_tmp[num].elem_size, \
00084                     size)
00085 
00086 #define SBR_VLC_ROW(name) \
00087     { name ## _codes, name ## _bits, sizeof(name ## _codes), sizeof(name ## _codes[0]) }
00088 
00089 av_cold void ff_aac_sbr_init(void)
00090 {
00091     int n;
00092     static const struct {
00093         const void *sbr_codes, *sbr_bits;
00094         const unsigned int table_size, elem_size;
00095     } sbr_tmp[] = {
00096         SBR_VLC_ROW(t_huffman_env_1_5dB),
00097         SBR_VLC_ROW(f_huffman_env_1_5dB),
00098         SBR_VLC_ROW(t_huffman_env_bal_1_5dB),
00099         SBR_VLC_ROW(f_huffman_env_bal_1_5dB),
00100         SBR_VLC_ROW(t_huffman_env_3_0dB),
00101         SBR_VLC_ROW(f_huffman_env_3_0dB),
00102         SBR_VLC_ROW(t_huffman_env_bal_3_0dB),
00103         SBR_VLC_ROW(f_huffman_env_bal_3_0dB),
00104         SBR_VLC_ROW(t_huffman_noise_3_0dB),
00105         SBR_VLC_ROW(t_huffman_noise_bal_3_0dB),
00106     };
00107 
00108     // SBR VLC table initialization
00109     SBR_INIT_VLC_STATIC(0, 1098);
00110     SBR_INIT_VLC_STATIC(1, 1092);
00111     SBR_INIT_VLC_STATIC(2, 768);
00112     SBR_INIT_VLC_STATIC(3, 1026);
00113     SBR_INIT_VLC_STATIC(4, 1058);
00114     SBR_INIT_VLC_STATIC(5, 1052);
00115     SBR_INIT_VLC_STATIC(6, 544);
00116     SBR_INIT_VLC_STATIC(7, 544);
00117     SBR_INIT_VLC_STATIC(8, 592);
00118     SBR_INIT_VLC_STATIC(9, 512);
00119 
00120     for (n = 1; n < 320; n++)
00121         sbr_qmf_window_us[320 + n] = sbr_qmf_window_us[320 - n];
00122     sbr_qmf_window_us[384] = -sbr_qmf_window_us[384];
00123     sbr_qmf_window_us[512] = -sbr_qmf_window_us[512];
00124 
00125     for (n = 0; n < 320; n++)
00126         sbr_qmf_window_ds[n] = sbr_qmf_window_us[2*n];
00127 
00128     ff_ps_init();
00129 }
00130 
00131 av_cold void ff_aac_sbr_ctx_init(AACContext *ac, SpectralBandReplication *sbr)
00132 {
00133     float mdct_scale;
00134     sbr->kx[0] = sbr->kx[1] = 32; //Typo in spec, kx' inits to 32
00135     sbr->data[0].e_a[1] = sbr->data[1].e_a[1] = -1;
00136     sbr->data[0].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128);
00137     sbr->data[1].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128);
00138     /* SBR requires samples to be scaled to +/-32768.0 to work correctly.
00139      * mdct scale factors are adjusted to scale up from +/-1.0 at analysis
00140      * and scale back down at synthesis. */
00141     mdct_scale = ac->avctx->sample_fmt == AV_SAMPLE_FMT_FLT ? 32768.0f : 1.0f;
00142     ff_mdct_init(&sbr->mdct,     7, 1, 1.0 / (64 * mdct_scale));
00143     ff_mdct_init(&sbr->mdct_ana, 7, 1, -2.0 * mdct_scale);
00144     ff_ps_ctx_init(&sbr->ps);
00145 }
00146 
00147 av_cold void ff_aac_sbr_ctx_close(SpectralBandReplication *sbr)
00148 {
00149     ff_mdct_end(&sbr->mdct);
00150     ff_mdct_end(&sbr->mdct_ana);
00151 }
00152 
00153 static int qsort_comparison_function_int16(const void *a, const void *b)
00154 {
00155     return *(const int16_t *)a - *(const int16_t *)b;
00156 }
00157 
00158 static inline int in_table_int16(const int16_t *table, int last_el, int16_t needle)
00159 {
00160     int i;
00161     for (i = 0; i <= last_el; i++)
00162         if (table[i] == needle)
00163             return 1;
00164     return 0;
00165 }
00166 
00168 static void sbr_make_f_tablelim(SpectralBandReplication *sbr)
00169 {
00170     int k;
00171     if (sbr->bs_limiter_bands > 0) {
00172         static const float bands_warped[3] = { 1.32715174233856803909f,   //2^(0.49/1.2)
00173                                                1.18509277094158210129f,   //2^(0.49/2)
00174                                                1.11987160404675912501f }; //2^(0.49/3)
00175         const float lim_bands_per_octave_warped = bands_warped[sbr->bs_limiter_bands - 1];
00176         int16_t patch_borders[7];
00177         uint16_t *in = sbr->f_tablelim + 1, *out = sbr->f_tablelim;
00178 
00179         patch_borders[0] = sbr->kx[1];
00180         for (k = 1; k <= sbr->num_patches; k++)
00181             patch_borders[k] = patch_borders[k-1] + sbr->patch_num_subbands[k-1];
00182 
00183         memcpy(sbr->f_tablelim, sbr->f_tablelow,
00184                (sbr->n[0] + 1) * sizeof(sbr->f_tablelow[0]));
00185         if (sbr->num_patches > 1)
00186             memcpy(sbr->f_tablelim + sbr->n[0] + 1, patch_borders + 1,
00187                    (sbr->num_patches - 1) * sizeof(patch_borders[0]));
00188 
00189         qsort(sbr->f_tablelim, sbr->num_patches + sbr->n[0],
00190               sizeof(sbr->f_tablelim[0]),
00191               qsort_comparison_function_int16);
00192 
00193         sbr->n_lim = sbr->n[0] + sbr->num_patches - 1;
00194         while (out < sbr->f_tablelim + sbr->n_lim) {
00195             if (*in >= *out * lim_bands_per_octave_warped) {
00196                 *++out = *in++;
00197             } else if (*in == *out ||
00198                 !in_table_int16(patch_borders, sbr->num_patches, *in)) {
00199                 in++;
00200                 sbr->n_lim--;
00201             } else if (!in_table_int16(patch_borders, sbr->num_patches, *out)) {
00202                 *out = *in++;
00203                 sbr->n_lim--;
00204             } else {
00205                 *++out = *in++;
00206             }
00207         }
00208     } else {
00209         sbr->f_tablelim[0] = sbr->f_tablelow[0];
00210         sbr->f_tablelim[1] = sbr->f_tablelow[sbr->n[0]];
00211         sbr->n_lim = 1;
00212     }
00213 }
00214 
00215 static unsigned int read_sbr_header(SpectralBandReplication *sbr, GetBitContext *gb)
00216 {
00217     unsigned int cnt = get_bits_count(gb);
00218     uint8_t bs_header_extra_1;
00219     uint8_t bs_header_extra_2;
00220     int old_bs_limiter_bands = sbr->bs_limiter_bands;
00221     SpectrumParameters old_spectrum_params;
00222 
00223     sbr->start = 1;
00224 
00225     // Save last spectrum parameters variables to compare to new ones
00226     memcpy(&old_spectrum_params, &sbr->spectrum_params, sizeof(SpectrumParameters));
00227 
00228     sbr->bs_amp_res_header              = get_bits1(gb);
00229     sbr->spectrum_params.bs_start_freq  = get_bits(gb, 4);
00230     sbr->spectrum_params.bs_stop_freq   = get_bits(gb, 4);
00231     sbr->spectrum_params.bs_xover_band  = get_bits(gb, 3);
00232                                           skip_bits(gb, 2); // bs_reserved
00233 
00234     bs_header_extra_1 = get_bits1(gb);
00235     bs_header_extra_2 = get_bits1(gb);
00236 
00237     if (bs_header_extra_1) {
00238         sbr->spectrum_params.bs_freq_scale  = get_bits(gb, 2);
00239         sbr->spectrum_params.bs_alter_scale = get_bits1(gb);
00240         sbr->spectrum_params.bs_noise_bands = get_bits(gb, 2);
00241     } else {
00242         sbr->spectrum_params.bs_freq_scale  = 2;
00243         sbr->spectrum_params.bs_alter_scale = 1;
00244         sbr->spectrum_params.bs_noise_bands = 2;
00245     }
00246 
00247     // Check if spectrum parameters changed
00248     if (memcmp(&old_spectrum_params, &sbr->spectrum_params, sizeof(SpectrumParameters)))
00249         sbr->reset = 1;
00250 
00251     if (bs_header_extra_2) {
00252         sbr->bs_limiter_bands  = get_bits(gb, 2);
00253         sbr->bs_limiter_gains  = get_bits(gb, 2);
00254         sbr->bs_interpol_freq  = get_bits1(gb);
00255         sbr->bs_smoothing_mode = get_bits1(gb);
00256     } else {
00257         sbr->bs_limiter_bands  = 2;
00258         sbr->bs_limiter_gains  = 2;
00259         sbr->bs_interpol_freq  = 1;
00260         sbr->bs_smoothing_mode = 1;
00261     }
00262 
00263     if (sbr->bs_limiter_bands != old_bs_limiter_bands && !sbr->reset)
00264         sbr_make_f_tablelim(sbr);
00265 
00266     return get_bits_count(gb) - cnt;
00267 }
00268 
00269 static int array_min_int16(const int16_t *array, int nel)
00270 {
00271     int i, min = array[0];
00272     for (i = 1; i < nel; i++)
00273         min = FFMIN(array[i], min);
00274     return min;
00275 }
00276 
00277 static void make_bands(int16_t* bands, int start, int stop, int num_bands)
00278 {
00279     int k, previous, present;
00280     float base, prod;
00281 
00282     base = powf((float)stop / start, 1.0f / num_bands);
00283     prod = start;
00284     previous = start;
00285 
00286     for (k = 0; k < num_bands-1; k++) {
00287         prod *= base;
00288         present  = lrintf(prod);
00289         bands[k] = present - previous;
00290         previous = present;
00291     }
00292     bands[num_bands-1] = stop - previous;
00293 }
00294 
00295 static int check_n_master(AVCodecContext *avctx, int n_master, int bs_xover_band)
00296 {
00297     // Requirements (14496-3 sp04 p205)
00298     if (n_master <= 0) {
00299         av_log(avctx, AV_LOG_ERROR, "Invalid n_master: %d\n", n_master);
00300         return -1;
00301     }
00302     if (bs_xover_band >= n_master) {
00303         av_log(avctx, AV_LOG_ERROR,
00304                "Invalid bitstream, crossover band index beyond array bounds: %d\n",
00305                bs_xover_band);
00306         return -1;
00307     }
00308     return 0;
00309 }
00310 
00312 static int sbr_make_f_master(AACContext *ac, SpectralBandReplication *sbr,
00313                              SpectrumParameters *spectrum)
00314 {
00315     unsigned int temp, max_qmf_subbands;
00316     unsigned int start_min, stop_min;
00317     int k;
00318     const int8_t *sbr_offset_ptr;
00319     int16_t stop_dk[13];
00320 
00321     if (sbr->sample_rate < 32000) {
00322         temp = 3000;
00323     } else if (sbr->sample_rate < 64000) {
00324         temp = 4000;
00325     } else
00326         temp = 5000;
00327 
00328     start_min = ((temp << 7) + (sbr->sample_rate >> 1)) / sbr->sample_rate;
00329     stop_min  = ((temp << 8) + (sbr->sample_rate >> 1)) / sbr->sample_rate;
00330 
00331     switch (sbr->sample_rate) {
00332     case 16000:
00333         sbr_offset_ptr = sbr_offset[0];
00334         break;
00335     case 22050:
00336         sbr_offset_ptr = sbr_offset[1];
00337         break;
00338     case 24000:
00339         sbr_offset_ptr = sbr_offset[2];
00340         break;
00341     case 32000:
00342         sbr_offset_ptr = sbr_offset[3];
00343         break;
00344     case 44100: case 48000: case 64000:
00345         sbr_offset_ptr = sbr_offset[4];
00346         break;
00347     case 88200: case 96000: case 128000: case 176400: case 192000:
00348         sbr_offset_ptr = sbr_offset[5];
00349         break;
00350     default:
00351         av_log(ac->avctx, AV_LOG_ERROR,
00352                "Unsupported sample rate for SBR: %d\n", sbr->sample_rate);
00353         return -1;
00354     }
00355 
00356     sbr->k[0] = start_min + sbr_offset_ptr[spectrum->bs_start_freq];
00357 
00358     if (spectrum->bs_stop_freq < 14) {
00359         sbr->k[2] = stop_min;
00360         make_bands(stop_dk, stop_min, 64, 13);
00361         qsort(stop_dk, 13, sizeof(stop_dk[0]), qsort_comparison_function_int16);
00362         for (k = 0; k < spectrum->bs_stop_freq; k++)
00363             sbr->k[2] += stop_dk[k];
00364     } else if (spectrum->bs_stop_freq == 14) {
00365         sbr->k[2] = 2*sbr->k[0];
00366     } else if (spectrum->bs_stop_freq == 15) {
00367         sbr->k[2] = 3*sbr->k[0];
00368     } else {
00369         av_log(ac->avctx, AV_LOG_ERROR,
00370                "Invalid bs_stop_freq: %d\n", spectrum->bs_stop_freq);
00371         return -1;
00372     }
00373     sbr->k[2] = FFMIN(64, sbr->k[2]);
00374 
00375     // Requirements (14496-3 sp04 p205)
00376     if (sbr->sample_rate <= 32000) {
00377         max_qmf_subbands = 48;
00378     } else if (sbr->sample_rate == 44100) {
00379         max_qmf_subbands = 35;
00380     } else if (sbr->sample_rate >= 48000)
00381         max_qmf_subbands = 32;
00382 
00383     if (sbr->k[2] - sbr->k[0] > max_qmf_subbands) {
00384         av_log(ac->avctx, AV_LOG_ERROR,
00385                "Invalid bitstream, too many QMF subbands: %d\n", sbr->k[2] - sbr->k[0]);
00386         return -1;
00387     }
00388 
00389     if (!spectrum->bs_freq_scale) {
00390         int dk, k2diff;
00391 
00392         dk = spectrum->bs_alter_scale + 1;
00393         sbr->n_master = ((sbr->k[2] - sbr->k[0] + (dk&2)) >> dk) << 1;
00394         if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))
00395             return -1;
00396 
00397         for (k = 1; k <= sbr->n_master; k++)
00398             sbr->f_master[k] = dk;
00399 
00400         k2diff = sbr->k[2] - sbr->k[0] - sbr->n_master * dk;
00401         if (k2diff < 0) {
00402             sbr->f_master[1]--;
00403             sbr->f_master[2]-= (k2diff < -1);
00404         } else if (k2diff) {
00405             sbr->f_master[sbr->n_master]++;
00406         }
00407 
00408         sbr->f_master[0] = sbr->k[0];
00409         for (k = 1; k <= sbr->n_master; k++)
00410             sbr->f_master[k] += sbr->f_master[k - 1];
00411 
00412     } else {
00413         int half_bands = 7 - spectrum->bs_freq_scale;      // bs_freq_scale  = {1,2,3}
00414         int two_regions, num_bands_0;
00415         int vdk0_max, vdk1_min;
00416         int16_t vk0[49];
00417 
00418         if (49 * sbr->k[2] > 110 * sbr->k[0]) {
00419             two_regions = 1;
00420             sbr->k[1] = 2 * sbr->k[0];
00421         } else {
00422             two_regions = 0;
00423             sbr->k[1] = sbr->k[2];
00424         }
00425 
00426         num_bands_0 = lrintf(half_bands * log2f(sbr->k[1] / (float)sbr->k[0])) * 2;
00427 
00428         if (num_bands_0 <= 0) { // Requirements (14496-3 sp04 p205)
00429             av_log(ac->avctx, AV_LOG_ERROR, "Invalid num_bands_0: %d\n", num_bands_0);
00430             return -1;
00431         }
00432 
00433         vk0[0] = 0;
00434 
00435         make_bands(vk0+1, sbr->k[0], sbr->k[1], num_bands_0);
00436 
00437         qsort(vk0 + 1, num_bands_0, sizeof(vk0[1]), qsort_comparison_function_int16);
00438         vdk0_max = vk0[num_bands_0];
00439 
00440         vk0[0] = sbr->k[0];
00441         for (k = 1; k <= num_bands_0; k++) {
00442             if (vk0[k] <= 0) { // Requirements (14496-3 sp04 p205)
00443                 av_log(ac->avctx, AV_LOG_ERROR, "Invalid vDk0[%d]: %d\n", k, vk0[k]);
00444                 return -1;
00445             }
00446             vk0[k] += vk0[k-1];
00447         }
00448 
00449         if (two_regions) {
00450             int16_t vk1[49];
00451             float invwarp = spectrum->bs_alter_scale ? 0.76923076923076923077f
00452                                                      : 1.0f; // bs_alter_scale = {0,1}
00453             int num_bands_1 = lrintf(half_bands * invwarp *
00454                                      log2f(sbr->k[2] / (float)sbr->k[1])) * 2;
00455 
00456             make_bands(vk1+1, sbr->k[1], sbr->k[2], num_bands_1);
00457 
00458             vdk1_min = array_min_int16(vk1 + 1, num_bands_1);
00459 
00460             if (vdk1_min < vdk0_max) {
00461                 int change;
00462                 qsort(vk1 + 1, num_bands_1, sizeof(vk1[1]), qsort_comparison_function_int16);
00463                 change = FFMIN(vdk0_max - vk1[1], (vk1[num_bands_1] - vk1[1]) >> 1);
00464                 vk1[1]           += change;
00465                 vk1[num_bands_1] -= change;
00466             }
00467 
00468             qsort(vk1 + 1, num_bands_1, sizeof(vk1[1]), qsort_comparison_function_int16);
00469 
00470             vk1[0] = sbr->k[1];
00471             for (k = 1; k <= num_bands_1; k++) {
00472                 if (vk1[k] <= 0) { // Requirements (14496-3 sp04 p205)
00473                     av_log(ac->avctx, AV_LOG_ERROR, "Invalid vDk1[%d]: %d\n", k, vk1[k]);
00474                     return -1;
00475                 }
00476                 vk1[k] += vk1[k-1];
00477             }
00478 
00479             sbr->n_master = num_bands_0 + num_bands_1;
00480             if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))
00481                 return -1;
00482             memcpy(&sbr->f_master[0],               vk0,
00483                    (num_bands_0 + 1) * sizeof(sbr->f_master[0]));
00484             memcpy(&sbr->f_master[num_bands_0 + 1], vk1 + 1,
00485                     num_bands_1      * sizeof(sbr->f_master[0]));
00486 
00487         } else {
00488             sbr->n_master = num_bands_0;
00489             if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))
00490                 return -1;
00491             memcpy(sbr->f_master, vk0, (num_bands_0 + 1) * sizeof(sbr->f_master[0]));
00492         }
00493     }
00494 
00495     return 0;
00496 }
00497 
00499 static int sbr_hf_calc_npatches(AACContext *ac, SpectralBandReplication *sbr)
00500 {
00501     int i, k, sb = 0;
00502     int msb = sbr->k[0];
00503     int usb = sbr->kx[1];
00504     int goal_sb = ((1000 << 11) + (sbr->sample_rate >> 1)) / sbr->sample_rate;
00505 
00506     sbr->num_patches = 0;
00507 
00508     if (goal_sb < sbr->kx[1] + sbr->m[1]) {
00509         for (k = 0; sbr->f_master[k] < goal_sb; k++) ;
00510     } else
00511         k = sbr->n_master;
00512 
00513     do {
00514         int odd = 0;
00515         for (i = k; i == k || sb > (sbr->k[0] - 1 + msb - odd); i--) {
00516             sb = sbr->f_master[i];
00517             odd = (sb + sbr->k[0]) & 1;
00518         }
00519 
00520         // Requirements (14496-3 sp04 p205) sets the maximum number of patches to 5.
00521         // After this check the final number of patches can still be six which is
00522         // illegal however the Coding Technologies decoder check stream has a final
00523         // count of 6 patches
00524         if (sbr->num_patches > 5) {
00525             av_log(ac->avctx, AV_LOG_ERROR, "Too many patches: %d\n", sbr->num_patches);
00526             return -1;
00527         }
00528 
00529         sbr->patch_num_subbands[sbr->num_patches]  = FFMAX(sb - usb, 0);
00530         sbr->patch_start_subband[sbr->num_patches] = sbr->k[0] - odd - sbr->patch_num_subbands[sbr->num_patches];
00531 
00532         if (sbr->patch_num_subbands[sbr->num_patches] > 0) {
00533             usb = sb;
00534             msb = sb;
00535             sbr->num_patches++;
00536         } else
00537             msb = sbr->kx[1];
00538 
00539         if (sbr->f_master[k] - sb < 3)
00540             k = sbr->n_master;
00541     } while (sb != sbr->kx[1] + sbr->m[1]);
00542 
00543     if (sbr->patch_num_subbands[sbr->num_patches-1] < 3 && sbr->num_patches > 1)
00544         sbr->num_patches--;
00545 
00546     return 0;
00547 }
00548 
00550 static int sbr_make_f_derived(AACContext *ac, SpectralBandReplication *sbr)
00551 {
00552     int k, temp;
00553 
00554     sbr->n[1] = sbr->n_master - sbr->spectrum_params.bs_xover_band;
00555     sbr->n[0] = (sbr->n[1] + 1) >> 1;
00556 
00557     memcpy(sbr->f_tablehigh, &sbr->f_master[sbr->spectrum_params.bs_xover_band],
00558            (sbr->n[1] + 1) * sizeof(sbr->f_master[0]));
00559     sbr->m[1] = sbr->f_tablehigh[sbr->n[1]] - sbr->f_tablehigh[0];
00560     sbr->kx[1] = sbr->f_tablehigh[0];
00561 
00562     // Requirements (14496-3 sp04 p205)
00563     if (sbr->kx[1] + sbr->m[1] > 64) {
00564         av_log(ac->avctx, AV_LOG_ERROR,
00565                "Stop frequency border too high: %d\n", sbr->kx[1] + sbr->m[1]);
00566         return -1;
00567     }
00568     if (sbr->kx[1] > 32) {
00569         av_log(ac->avctx, AV_LOG_ERROR, "Start frequency border too high: %d\n", sbr->kx[1]);
00570         return -1;
00571     }
00572 
00573     sbr->f_tablelow[0] = sbr->f_tablehigh[0];
00574     temp = sbr->n[1] & 1;
00575     for (k = 1; k <= sbr->n[0]; k++)
00576         sbr->f_tablelow[k] = sbr->f_tablehigh[2 * k - temp];
00577 
00578     sbr->n_q = FFMAX(1, lrintf(sbr->spectrum_params.bs_noise_bands *
00579                                log2f(sbr->k[2] / (float)sbr->kx[1]))); // 0 <= bs_noise_bands <= 3
00580     if (sbr->n_q > 5) {
00581         av_log(ac->avctx, AV_LOG_ERROR, "Too many noise floor scale factors: %d\n", sbr->n_q);
00582         return -1;
00583     }
00584 
00585     sbr->f_tablenoise[0] = sbr->f_tablelow[0];
00586     temp = 0;
00587     for (k = 1; k <= sbr->n_q; k++) {
00588         temp += (sbr->n[0] - temp) / (sbr->n_q + 1 - k);
00589         sbr->f_tablenoise[k] = sbr->f_tablelow[temp];
00590     }
00591 
00592     if (sbr_hf_calc_npatches(ac, sbr) < 0)
00593         return -1;
00594 
00595     sbr_make_f_tablelim(sbr);
00596 
00597     sbr->data[0].f_indexnoise = 0;
00598     sbr->data[1].f_indexnoise = 0;
00599 
00600     return 0;
00601 }
00602 
00603 static av_always_inline void get_bits1_vector(GetBitContext *gb, uint8_t *vec,
00604                                               int elements)
00605 {
00606     int i;
00607     for (i = 0; i < elements; i++) {
00608         vec[i] = get_bits1(gb);
00609     }
00610 }
00611 
00613 static const int8_t ceil_log2[] = {
00614     0, 1, 2, 2, 3, 3,
00615 };
00616 
00617 static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr,
00618                          GetBitContext *gb, SBRData *ch_data)
00619 {
00620     int i;
00621     unsigned bs_pointer = 0;
00622     // frameLengthFlag ? 15 : 16; 960 sample length frames unsupported; this value is numTimeSlots
00623     int abs_bord_trail = 16;
00624     int num_rel_lead, num_rel_trail;
00625     unsigned bs_num_env_old = ch_data->bs_num_env;
00626 
00627     ch_data->bs_freq_res[0] = ch_data->bs_freq_res[ch_data->bs_num_env];
00628     ch_data->bs_amp_res = sbr->bs_amp_res_header;
00629     ch_data->t_env_num_env_old = ch_data->t_env[bs_num_env_old];
00630 
00631     switch (ch_data->bs_frame_class = get_bits(gb, 2)) {
00632     case FIXFIX:
00633         ch_data->bs_num_env                 = 1 << get_bits(gb, 2);
00634         num_rel_lead                        = ch_data->bs_num_env - 1;
00635         if (ch_data->bs_num_env == 1)
00636             ch_data->bs_amp_res = 0;
00637 
00638         if (ch_data->bs_num_env > 4) {
00639             av_log(ac->avctx, AV_LOG_ERROR,
00640                    "Invalid bitstream, too many SBR envelopes in FIXFIX type SBR frame: %d\n",
00641                    ch_data->bs_num_env);
00642             return -1;
00643         }
00644 
00645         ch_data->t_env[0]                   = 0;
00646         ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
00647 
00648         abs_bord_trail = (abs_bord_trail + (ch_data->bs_num_env >> 1)) /
00649                    ch_data->bs_num_env;
00650         for (i = 0; i < num_rel_lead; i++)
00651             ch_data->t_env[i + 1] = ch_data->t_env[i] + abs_bord_trail;
00652 
00653         ch_data->bs_freq_res[1] = get_bits1(gb);
00654         for (i = 1; i < ch_data->bs_num_env; i++)
00655             ch_data->bs_freq_res[i + 1] = ch_data->bs_freq_res[1];
00656         break;
00657     case FIXVAR:
00658         abs_bord_trail                     += get_bits(gb, 2);
00659         num_rel_trail                       = get_bits(gb, 2);
00660         ch_data->bs_num_env                 = num_rel_trail + 1;
00661         ch_data->t_env[0]                   = 0;
00662         ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
00663 
00664         for (i = 0; i < num_rel_trail; i++)
00665             ch_data->t_env[ch_data->bs_num_env - 1 - i] =
00666                 ch_data->t_env[ch_data->bs_num_env - i] - 2 * get_bits(gb, 2) - 2;
00667 
00668         bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);
00669 
00670         for (i = 0; i < ch_data->bs_num_env; i++)
00671             ch_data->bs_freq_res[ch_data->bs_num_env - i] = get_bits1(gb);
00672         break;
00673     case VARFIX:
00674         ch_data->t_env[0]                   = get_bits(gb, 2);
00675         num_rel_lead                        = get_bits(gb, 2);
00676         ch_data->bs_num_env                 = num_rel_lead + 1;
00677         ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
00678 
00679         for (i = 0; i < num_rel_lead; i++)
00680             ch_data->t_env[i + 1] = ch_data->t_env[i] + 2 * get_bits(gb, 2) + 2;
00681 
00682         bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);
00683 
00684         get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env);
00685         break;
00686     case VARVAR:
00687         ch_data->t_env[0]                   = get_bits(gb, 2);
00688         abs_bord_trail                     += get_bits(gb, 2);
00689         num_rel_lead                        = get_bits(gb, 2);
00690         num_rel_trail                       = get_bits(gb, 2);
00691         ch_data->bs_num_env                 = num_rel_lead + num_rel_trail + 1;
00692 
00693         if (ch_data->bs_num_env > 5) {
00694             av_log(ac->avctx, AV_LOG_ERROR,
00695                    "Invalid bitstream, too many SBR envelopes in VARVAR type SBR frame: %d\n",
00696                    ch_data->bs_num_env);
00697             return -1;
00698         }
00699 
00700         ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
00701 
00702         for (i = 0; i < num_rel_lead; i++)
00703             ch_data->t_env[i + 1] = ch_data->t_env[i] + 2 * get_bits(gb, 2) + 2;
00704         for (i = 0; i < num_rel_trail; i++)
00705             ch_data->t_env[ch_data->bs_num_env - 1 - i] =
00706                 ch_data->t_env[ch_data->bs_num_env - i] - 2 * get_bits(gb, 2) - 2;
00707 
00708         bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);
00709 
00710         get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env);
00711         break;
00712     }
00713 
00714     if (bs_pointer > ch_data->bs_num_env + 1) {
00715         av_log(ac->avctx, AV_LOG_ERROR,
00716                "Invalid bitstream, bs_pointer points to a middle noise border outside the time borders table: %d\n",
00717                bs_pointer);
00718         return -1;
00719     }
00720 
00721     for (i = 1; i <= ch_data->bs_num_env; i++) {
00722         if (ch_data->t_env[i-1] > ch_data->t_env[i]) {
00723             av_log(ac->avctx, AV_LOG_ERROR, "Non monotone time borders\n");
00724             return -1;
00725         }
00726     }
00727 
00728     ch_data->bs_num_noise = (ch_data->bs_num_env > 1) + 1;
00729 
00730     ch_data->t_q[0]                     = ch_data->t_env[0];
00731     ch_data->t_q[ch_data->bs_num_noise] = ch_data->t_env[ch_data->bs_num_env];
00732     if (ch_data->bs_num_noise > 1) {
00733         unsigned int idx;
00734         if (ch_data->bs_frame_class == FIXFIX) {
00735             idx = ch_data->bs_num_env >> 1;
00736         } else if (ch_data->bs_frame_class & 1) { // FIXVAR or VARVAR
00737             idx = ch_data->bs_num_env - FFMAX(bs_pointer - 1, 1);
00738         } else { // VARFIX
00739             if (!bs_pointer)
00740                 idx = 1;
00741             else if (bs_pointer == 1)
00742                 idx = ch_data->bs_num_env - 1;
00743             else // bs_pointer > 1
00744                 idx = bs_pointer - 1;
00745         }
00746         ch_data->t_q[1] = ch_data->t_env[idx];
00747     }
00748 
00749     ch_data->e_a[0] = -(ch_data->e_a[1] != bs_num_env_old); // l_APrev
00750     ch_data->e_a[1] = -1;
00751     if ((ch_data->bs_frame_class & 1) && bs_pointer) { // FIXVAR or VARVAR and bs_pointer != 0
00752         ch_data->e_a[1] = ch_data->bs_num_env + 1 - bs_pointer;
00753     } else if ((ch_data->bs_frame_class == 2) && (bs_pointer > 1)) // VARFIX and bs_pointer > 1
00754         ch_data->e_a[1] = bs_pointer - 1;
00755 
00756     return 0;
00757 }
00758 
00759 static void copy_sbr_grid(SBRData *dst, const SBRData *src) {
00760     //These variables are saved from the previous frame rather than copied
00761     dst->bs_freq_res[0]    = dst->bs_freq_res[dst->bs_num_env];
00762     dst->t_env_num_env_old = dst->t_env[dst->bs_num_env];
00763     dst->e_a[0]            = -(dst->e_a[1] != dst->bs_num_env);
00764 
00765     //These variables are read from the bitstream and therefore copied
00766     memcpy(dst->bs_freq_res+1, src->bs_freq_res+1, sizeof(dst->bs_freq_res)-sizeof(*dst->bs_freq_res));
00767     memcpy(dst->t_env,         src->t_env,         sizeof(dst->t_env));
00768     memcpy(dst->t_q,           src->t_q,           sizeof(dst->t_q));
00769     dst->bs_num_env        = src->bs_num_env;
00770     dst->bs_amp_res        = src->bs_amp_res;
00771     dst->bs_num_noise      = src->bs_num_noise;
00772     dst->bs_frame_class    = src->bs_frame_class;
00773     dst->e_a[1]            = src->e_a[1];
00774 }
00775 
00777 static void read_sbr_dtdf(SpectralBandReplication *sbr, GetBitContext *gb,
00778                           SBRData *ch_data)
00779 {
00780     get_bits1_vector(gb, ch_data->bs_df_env,   ch_data->bs_num_env);
00781     get_bits1_vector(gb, ch_data->bs_df_noise, ch_data->bs_num_noise);
00782 }
00783 
00785 static void read_sbr_invf(SpectralBandReplication *sbr, GetBitContext *gb,
00786                           SBRData *ch_data)
00787 {
00788     int i;
00789 
00790     memcpy(ch_data->bs_invf_mode[1], ch_data->bs_invf_mode[0], 5 * sizeof(uint8_t));
00791     for (i = 0; i < sbr->n_q; i++)
00792         ch_data->bs_invf_mode[0][i] = get_bits(gb, 2);
00793 }
00794 
00795 static void read_sbr_envelope(SpectralBandReplication *sbr, GetBitContext *gb,
00796                               SBRData *ch_data, int ch)
00797 {
00798     int bits;
00799     int i, j, k;
00800     VLC_TYPE (*t_huff)[2], (*f_huff)[2];
00801     int t_lav, f_lav;
00802     const int delta = (ch == 1 && sbr->bs_coupling == 1) + 1;
00803     const int odd = sbr->n[1] & 1;
00804 
00805     if (sbr->bs_coupling && ch) {
00806         if (ch_data->bs_amp_res) {
00807             bits   = 5;
00808             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_3_0DB].table;
00809             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_3_0DB];
00810             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;
00811             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];
00812         } else {
00813             bits   = 6;
00814             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_1_5DB].table;
00815             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_1_5DB];
00816             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_1_5DB].table;
00817             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_1_5DB];
00818         }
00819     } else {
00820         if (ch_data->bs_amp_res) {
00821             bits   = 6;
00822             t_huff = vlc_sbr[T_HUFFMAN_ENV_3_0DB].table;
00823             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_3_0DB];
00824             f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;
00825             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];
00826         } else {
00827             bits   = 7;
00828             t_huff = vlc_sbr[T_HUFFMAN_ENV_1_5DB].table;
00829             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_1_5DB];
00830             f_huff = vlc_sbr[F_HUFFMAN_ENV_1_5DB].table;
00831             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_1_5DB];
00832         }
00833     }
00834 
00835     for (i = 0; i < ch_data->bs_num_env; i++) {
00836         if (ch_data->bs_df_env[i]) {
00837             // bs_freq_res[0] == bs_freq_res[bs_num_env] from prev frame
00838             if (ch_data->bs_freq_res[i + 1] == ch_data->bs_freq_res[i]) {
00839                 for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++)
00840                     ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][j] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);
00841             } else if (ch_data->bs_freq_res[i + 1]) {
00842                 for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) {
00843                     k = (j + odd) >> 1; // find k such that f_tablelow[k] <= f_tablehigh[j] < f_tablelow[k + 1]
00844                     ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][k] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);
00845                 }
00846             } else {
00847                 for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) {
00848                     k = j ? 2*j - odd : 0; // find k such that f_tablehigh[k] == f_tablelow[j]
00849                     ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][k] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);
00850                 }
00851             }
00852         } else {
00853             ch_data->env_facs[i + 1][0] = delta * get_bits(gb, bits); // bs_env_start_value_balance
00854             for (j = 1; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++)
00855                 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);
00856         }
00857     }
00858 
00859     //assign 0th elements of env_facs from last elements
00860     memcpy(ch_data->env_facs[0], ch_data->env_facs[ch_data->bs_num_env],
00861            sizeof(ch_data->env_facs[0]));
00862 }
00863 
00864 static void read_sbr_noise(SpectralBandReplication *sbr, GetBitContext *gb,
00865                            SBRData *ch_data, int ch)
00866 {
00867     int i, j;
00868     VLC_TYPE (*t_huff)[2], (*f_huff)[2];
00869     int t_lav, f_lav;
00870     int delta = (ch == 1 && sbr->bs_coupling == 1) + 1;
00871 
00872     if (sbr->bs_coupling && ch) {
00873         t_huff = vlc_sbr[T_HUFFMAN_NOISE_BAL_3_0DB].table;
00874         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_BAL_3_0DB];
00875         f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;
00876         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];
00877     } else {
00878         t_huff = vlc_sbr[T_HUFFMAN_NOISE_3_0DB].table;
00879         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_3_0DB];
00880         f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;
00881         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];
00882     }
00883 
00884     for (i = 0; i < ch_data->bs_num_noise; i++) {
00885         if (ch_data->bs_df_noise[i]) {
00886             for (j = 0; j < sbr->n_q; j++)
00887                 ch_data->noise_facs[i + 1][j] = ch_data->noise_facs[i][j] + delta * (get_vlc2(gb, t_huff, 9, 2) - t_lav);
00888         } else {
00889             ch_data->noise_facs[i + 1][0] = delta * get_bits(gb, 5); // bs_noise_start_value_balance or bs_noise_start_value_level
00890             for (j = 1; j < sbr->n_q; j++)
00891                 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);
00892         }
00893     }
00894 
00895     //assign 0th elements of noise_facs from last elements
00896     memcpy(ch_data->noise_facs[0], ch_data->noise_facs[ch_data->bs_num_noise],
00897            sizeof(ch_data->noise_facs[0]));
00898 }
00899 
00900 static void read_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,
00901                                GetBitContext *gb,
00902                                int bs_extension_id, int *num_bits_left)
00903 {
00904     switch (bs_extension_id) {
00905     case EXTENSION_ID_PS:
00906         if (!ac->m4ac.ps) {
00907             av_log(ac->avctx, AV_LOG_ERROR, "Parametric Stereo signaled to be not-present but was found in the bitstream.\n");
00908             skip_bits_long(gb, *num_bits_left); // bs_fill_bits
00909             *num_bits_left = 0;
00910         } else {
00911 #if 1
00912             *num_bits_left -= ff_ps_read_data(ac->avctx, gb, &sbr->ps, *num_bits_left);
00913 #else
00914             av_log_missing_feature(ac->avctx, "Parametric Stereo is", 0);
00915             skip_bits_long(gb, *num_bits_left); // bs_fill_bits
00916             *num_bits_left = 0;
00917 #endif
00918         }
00919         break;
00920     default:
00921         av_log_missing_feature(ac->avctx, "Reserved SBR extensions are", 1);
00922         skip_bits_long(gb, *num_bits_left); // bs_fill_bits
00923         *num_bits_left = 0;
00924         break;
00925     }
00926 }
00927 
00928 static int read_sbr_single_channel_element(AACContext *ac,
00929                                             SpectralBandReplication *sbr,
00930                                             GetBitContext *gb)
00931 {
00932     if (get_bits1(gb)) // bs_data_extra
00933         skip_bits(gb, 4); // bs_reserved
00934 
00935     if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]))
00936         return -1;
00937     read_sbr_dtdf(sbr, gb, &sbr->data[0]);
00938     read_sbr_invf(sbr, gb, &sbr->data[0]);
00939     read_sbr_envelope(sbr, gb, &sbr->data[0], 0);
00940     read_sbr_noise(sbr, gb, &sbr->data[0], 0);
00941 
00942     if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb)))
00943         get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);
00944 
00945     return 0;
00946 }
00947 
00948 static int read_sbr_channel_pair_element(AACContext *ac,
00949                                           SpectralBandReplication *sbr,
00950                                           GetBitContext *gb)
00951 {
00952     if (get_bits1(gb))    // bs_data_extra
00953         skip_bits(gb, 8); // bs_reserved
00954 
00955     if ((sbr->bs_coupling = get_bits1(gb))) {
00956         if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]))
00957             return -1;
00958         copy_sbr_grid(&sbr->data[1], &sbr->data[0]);
00959         read_sbr_dtdf(sbr, gb, &sbr->data[0]);
00960         read_sbr_dtdf(sbr, gb, &sbr->data[1]);
00961         read_sbr_invf(sbr, gb, &sbr->data[0]);
00962         memcpy(sbr->data[1].bs_invf_mode[1], sbr->data[1].bs_invf_mode[0], sizeof(sbr->data[1].bs_invf_mode[0]));
00963         memcpy(sbr->data[1].bs_invf_mode[0], sbr->data[0].bs_invf_mode[0], sizeof(sbr->data[1].bs_invf_mode[0]));
00964         read_sbr_envelope(sbr, gb, &sbr->data[0], 0);
00965         read_sbr_noise(sbr, gb, &sbr->data[0], 0);
00966         read_sbr_envelope(sbr, gb, &sbr->data[1], 1);
00967         read_sbr_noise(sbr, gb, &sbr->data[1], 1);
00968     } else {
00969         if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]) ||
00970             read_sbr_grid(ac, sbr, gb, &sbr->data[1]))
00971             return -1;
00972         read_sbr_dtdf(sbr, gb, &sbr->data[0]);
00973         read_sbr_dtdf(sbr, gb, &sbr->data[1]);
00974         read_sbr_invf(sbr, gb, &sbr->data[0]);
00975         read_sbr_invf(sbr, gb, &sbr->data[1]);
00976         read_sbr_envelope(sbr, gb, &sbr->data[0], 0);
00977         read_sbr_envelope(sbr, gb, &sbr->data[1], 1);
00978         read_sbr_noise(sbr, gb, &sbr->data[0], 0);
00979         read_sbr_noise(sbr, gb, &sbr->data[1], 1);
00980     }
00981 
00982     if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb)))
00983         get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);
00984     if ((sbr->data[1].bs_add_harmonic_flag = get_bits1(gb)))
00985         get_bits1_vector(gb, sbr->data[1].bs_add_harmonic, sbr->n[1]);
00986 
00987     return 0;
00988 }
00989 
00990 static unsigned int read_sbr_data(AACContext *ac, SpectralBandReplication *sbr,
00991                                   GetBitContext *gb, int id_aac)
00992 {
00993     unsigned int cnt = get_bits_count(gb);
00994 
00995     if (id_aac == TYPE_SCE || id_aac == TYPE_CCE) {
00996         if (read_sbr_single_channel_element(ac, sbr, gb)) {
00997             sbr->start = 0;
00998             return get_bits_count(gb) - cnt;
00999         }
01000     } else if (id_aac == TYPE_CPE) {
01001         if (read_sbr_channel_pair_element(ac, sbr, gb)) {
01002             sbr->start = 0;
01003             return get_bits_count(gb) - cnt;
01004         }
01005     } else {
01006         av_log(ac->avctx, AV_LOG_ERROR,
01007             "Invalid bitstream - cannot apply SBR to element type %d\n", id_aac);
01008         sbr->start = 0;
01009         return get_bits_count(gb) - cnt;
01010     }
01011     if (get_bits1(gb)) { // bs_extended_data
01012         int num_bits_left = get_bits(gb, 4); // bs_extension_size
01013         if (num_bits_left == 15)
01014             num_bits_left += get_bits(gb, 8); // bs_esc_count
01015 
01016         num_bits_left <<= 3;
01017         while (num_bits_left > 7) {
01018             num_bits_left -= 2;
01019             read_sbr_extension(ac, sbr, gb, get_bits(gb, 2), &num_bits_left); // bs_extension_id
01020         }
01021         if (num_bits_left < 0) {
01022             av_log(ac->avctx, AV_LOG_ERROR, "SBR Extension over read.\n");
01023         }
01024         if (num_bits_left > 0)
01025             skip_bits(gb, num_bits_left);
01026     }
01027 
01028     return get_bits_count(gb) - cnt;
01029 }
01030 
01031 static void sbr_reset(AACContext *ac, SpectralBandReplication *sbr)
01032 {
01033     int err;
01034     err = sbr_make_f_master(ac, sbr, &sbr->spectrum_params);
01035     if (err >= 0)
01036         err = sbr_make_f_derived(ac, sbr);
01037     if (err < 0) {
01038         av_log(ac->avctx, AV_LOG_ERROR,
01039                "SBR reset failed. Switching SBR to pure upsampling mode.\n");
01040         sbr->start = 0;
01041     }
01042 }
01043 
01052 int ff_decode_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,
01053                             GetBitContext *gb_host, int crc, int cnt, int id_aac)
01054 {
01055     unsigned int num_sbr_bits = 0, num_align_bits;
01056     unsigned bytes_read;
01057     GetBitContext gbc = *gb_host, *gb = &gbc;
01058     skip_bits_long(gb_host, cnt*8 - 4);
01059 
01060     sbr->reset = 0;
01061 
01062     if (!sbr->sample_rate)
01063         sbr->sample_rate = 2 * ac->m4ac.sample_rate; //TODO use the nominal sample rate for arbitrary sample rate support
01064     if (!ac->m4ac.ext_sample_rate)
01065         ac->m4ac.ext_sample_rate = 2 * ac->m4ac.sample_rate;
01066 
01067     if (crc) {
01068         skip_bits(gb, 10); // bs_sbr_crc_bits; TODO - implement CRC check
01069         num_sbr_bits += 10;
01070     }
01071 
01072     //Save some state from the previous frame.
01073     sbr->kx[0] = sbr->kx[1];
01074     sbr->m[0] = sbr->m[1];
01075 
01076     num_sbr_bits++;
01077     if (get_bits1(gb)) // bs_header_flag
01078         num_sbr_bits += read_sbr_header(sbr, gb);
01079 
01080     if (sbr->reset)
01081         sbr_reset(ac, sbr);
01082 
01083     if (sbr->start)
01084         num_sbr_bits  += read_sbr_data(ac, sbr, gb, id_aac);
01085 
01086     num_align_bits = ((cnt << 3) - 4 - num_sbr_bits) & 7;
01087     bytes_read = ((num_sbr_bits + num_align_bits + 4) >> 3);
01088 
01089     if (bytes_read > cnt) {
01090         av_log(ac->avctx, AV_LOG_ERROR,
01091                "Expected to read %d SBR bytes actually read %d.\n", cnt, bytes_read);
01092     }
01093     return cnt;
01094 }
01095 
01097 static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)
01098 {
01099     int k, e;
01100     int ch;
01101 
01102     if (id_aac == TYPE_CPE && sbr->bs_coupling) {
01103         float alpha      = sbr->data[0].bs_amp_res ?  1.0f :  0.5f;
01104         float pan_offset = sbr->data[0].bs_amp_res ? 12.0f : 24.0f;
01105         for (e = 1; e <= sbr->data[0].bs_num_env; e++) {
01106             for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {
01107                 float temp1 = exp2f(sbr->data[0].env_facs[e][k] * alpha + 7.0f);
01108                 float temp2 = exp2f((pan_offset - sbr->data[1].env_facs[e][k]) * alpha);
01109                 float fac   = temp1 / (1.0f + temp2);
01110                 sbr->data[0].env_facs[e][k] = fac;
01111                 sbr->data[1].env_facs[e][k] = fac * temp2;
01112             }
01113         }
01114         for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {
01115             for (k = 0; k < sbr->n_q; k++) {
01116                 float temp1 = exp2f(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs[e][k] + 1);
01117                 float temp2 = exp2f(12 - sbr->data[1].noise_facs[e][k]);
01118                 float fac   = temp1 / (1.0f + temp2);
01119                 sbr->data[0].noise_facs[e][k] = fac;
01120                 sbr->data[1].noise_facs[e][k] = fac * temp2;
01121             }
01122         }
01123     } else { // SCE or one non-coupled CPE
01124         for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {
01125             float alpha = sbr->data[ch].bs_amp_res ? 1.0f : 0.5f;
01126             for (e = 1; e <= sbr->data[ch].bs_num_env; e++)
01127                 for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++)
01128                     sbr->data[ch].env_facs[e][k] =
01129                         exp2f(alpha * sbr->data[ch].env_facs[e][k] + 6.0f);
01130             for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)
01131                 for (k = 0; k < sbr->n_q; k++)
01132                     sbr->data[ch].noise_facs[e][k] =
01133                         exp2f(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs[e][k]);
01134         }
01135     }
01136 }
01137 
01144 static void sbr_qmf_analysis(DSPContext *dsp, FFTContext *mdct, const float *in, float *x,
01145                              float z[320], float W[2][32][32][2])
01146 {
01147     int i, k;
01148     memcpy(W[0], W[1], sizeof(W[0]));
01149     memcpy(x    , x+1024, (320-32)*sizeof(x[0]));
01150     memcpy(x+288, in,         1024*sizeof(x[0]));
01151     for (i = 0; i < 32; i++) { // numTimeSlots*RATE = 16*2 as 960 sample frames
01152                                // are not supported
01153         dsp->vector_fmul_reverse(z, sbr_qmf_window_ds, x, 320);
01154         for (k = 0; k < 64; k++) {
01155             float f = z[k] + z[k + 64] + z[k + 128] + z[k + 192] + z[k + 256];
01156             z[k] = f;
01157         }
01158         //Shuffle to IMDCT
01159         z[64] = z[0];
01160         for (k = 1; k < 32; k++) {
01161             z[64+2*k-1] =  z[   k];
01162             z[64+2*k  ] = -z[64-k];
01163         }
01164         z[64+63] = z[32];
01165 
01166         mdct->imdct_half(mdct, z, z+64);
01167         for (k = 0; k < 32; k++) {
01168             W[1][i][k][0] = -z[63-k];
01169             W[1][i][k][1] = z[k];
01170         }
01171         x += 32;
01172     }
01173 }
01174 
01179 static void sbr_qmf_synthesis(DSPContext *dsp, FFTContext *mdct,
01180                               float *out, float X[2][38][64],
01181                               float mdct_buf[2][64],
01182                               float *v0, int *v_off, const unsigned int div)
01183 {
01184     int i, n;
01185     const float *sbr_qmf_window = div ? sbr_qmf_window_ds : sbr_qmf_window_us;
01186     const int step = 128 >> div;
01187     float *v;
01188     for (i = 0; i < 32; i++) {
01189         if (*v_off < step) {
01190             int saved_samples = (1280 - 128) >> div;
01191             memcpy(&v0[SBR_SYNTHESIS_BUF_SIZE - saved_samples], v0, saved_samples * sizeof(float));
01192             *v_off = SBR_SYNTHESIS_BUF_SIZE - saved_samples - step;
01193         } else {
01194             *v_off -= step;
01195         }
01196         v = v0 + *v_off;
01197         if (div) {
01198             for (n = 0; n < 32; n++) {
01199                 X[0][i][   n] = -X[0][i][n];
01200                 X[0][i][32+n] =  X[1][i][31-n];
01201             }
01202             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);
01203             for (n = 0; n < 32; n++) {
01204                 v[     n] =  mdct_buf[0][63 - 2*n];
01205                 v[63 - n] = -mdct_buf[0][62 - 2*n];
01206             }
01207         } else {
01208             for (n = 1; n < 64; n+=2) {
01209                 X[1][i][n] = -X[1][i][n];
01210             }
01211             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);
01212             mdct->imdct_half(mdct, mdct_buf[1], X[1][i]);
01213             for (n = 0; n < 64; n++) {
01214                 v[      n] = -mdct_buf[0][63 -   n] + mdct_buf[1][  n    ];
01215                 v[127 - n] =  mdct_buf[0][63 -   n] + mdct_buf[1][  n    ];
01216             }
01217         }
01218         dsp->vector_fmul_add(out, v                , sbr_qmf_window               , zero64, 64 >> div);
01219         dsp->vector_fmul_add(out, v + ( 192 >> div), sbr_qmf_window + ( 64 >> div), out   , 64 >> div);
01220         dsp->vector_fmul_add(out, v + ( 256 >> div), sbr_qmf_window + (128 >> div), out   , 64 >> div);
01221         dsp->vector_fmul_add(out, v + ( 448 >> div), sbr_qmf_window + (192 >> div), out   , 64 >> div);
01222         dsp->vector_fmul_add(out, v + ( 512 >> div), sbr_qmf_window + (256 >> div), out   , 64 >> div);
01223         dsp->vector_fmul_add(out, v + ( 704 >> div), sbr_qmf_window + (320 >> div), out   , 64 >> div);
01224         dsp->vector_fmul_add(out, v + ( 768 >> div), sbr_qmf_window + (384 >> div), out   , 64 >> div);
01225         dsp->vector_fmul_add(out, v + ( 960 >> div), sbr_qmf_window + (448 >> div), out   , 64 >> div);
01226         dsp->vector_fmul_add(out, v + (1024 >> div), sbr_qmf_window + (512 >> div), out   , 64 >> div);
01227         dsp->vector_fmul_add(out, v + (1216 >> div), sbr_qmf_window + (576 >> div), out   , 64 >> div);
01228         out += 64 >> div;
01229     }
01230 }
01231 
01232 static void autocorrelate(const float x[40][2], float phi[3][2][2], int lag)
01233 {
01234     int i;
01235     float real_sum = 0.0f;
01236     float imag_sum = 0.0f;
01237     if (lag) {
01238         for (i = 1; i < 38; i++) {
01239             real_sum += x[i][0] * x[i+lag][0] + x[i][1] * x[i+lag][1];
01240             imag_sum += x[i][0] * x[i+lag][1] - x[i][1] * x[i+lag][0];
01241         }
01242         phi[2-lag][1][0] = real_sum + x[ 0][0] * x[lag][0] + x[ 0][1] * x[lag][1];
01243         phi[2-lag][1][1] = imag_sum + x[ 0][0] * x[lag][1] - x[ 0][1] * x[lag][0];
01244         if (lag == 1) {
01245             phi[0][0][0] = real_sum + x[38][0] * x[39][0] + x[38][1] * x[39][1];
01246             phi[0][0][1] = imag_sum + x[38][0] * x[39][1] - x[38][1] * x[39][0];
01247         }
01248     } else {
01249         for (i = 1; i < 38; i++) {
01250             real_sum += x[i][0] * x[i][0] + x[i][1] * x[i][1];
01251         }
01252         phi[2][1][0] = real_sum + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1];
01253         phi[1][0][0] = real_sum + x[38][0] * x[38][0] + x[38][1] * x[38][1];
01254     }
01255 }
01256 
01261 static void sbr_hf_inverse_filter(float (*alpha0)[2], float (*alpha1)[2],
01262                                   const float X_low[32][40][2], int k0)
01263 {
01264     int k;
01265     for (k = 0; k < k0; k++) {
01266         float phi[3][2][2], dk;
01267 
01268         autocorrelate(X_low[k], phi, 0);
01269         autocorrelate(X_low[k], phi, 1);
01270         autocorrelate(X_low[k], phi, 2);
01271 
01272         dk =  phi[2][1][0] * phi[1][0][0] -
01273              (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;
01274 
01275         if (!dk) {
01276             alpha1[k][0] = 0;
01277             alpha1[k][1] = 0;
01278         } else {
01279             float temp_real, temp_im;
01280             temp_real = phi[0][0][0] * phi[1][1][0] -
01281                         phi[0][0][1] * phi[1][1][1] -
01282                         phi[0][1][0] * phi[1][0][0];
01283             temp_im   = phi[0][0][0] * phi[1][1][1] +
01284                         phi[0][0][1] * phi[1][1][0] -
01285                         phi[0][1][1] * phi[1][0][0];
01286 
01287             alpha1[k][0] = temp_real / dk;
01288             alpha1[k][1] = temp_im   / dk;
01289         }
01290 
01291         if (!phi[1][0][0]) {
01292             alpha0[k][0] = 0;
01293             alpha0[k][1] = 0;
01294         } else {
01295             float temp_real, temp_im;
01296             temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +
01297                                        alpha1[k][1] * phi[1][1][1];
01298             temp_im   = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -
01299                                        alpha1[k][0] * phi[1][1][1];
01300 
01301             alpha0[k][0] = -temp_real / phi[1][0][0];
01302             alpha0[k][1] = -temp_im   / phi[1][0][0];
01303         }
01304 
01305         if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||
01306            alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {
01307             alpha1[k][0] = 0;
01308             alpha1[k][1] = 0;
01309             alpha0[k][0] = 0;
01310             alpha0[k][1] = 0;
01311         }
01312     }
01313 }
01314 
01316 static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)
01317 {
01318     int i;
01319     float new_bw;
01320     static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };
01321 
01322     for (i = 0; i < sbr->n_q; i++) {
01323         if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {
01324             new_bw = 0.6f;
01325         } else
01326             new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];
01327 
01328         if (new_bw < ch_data->bw_array[i]) {
01329             new_bw = 0.75f    * new_bw + 0.25f    * ch_data->bw_array[i];
01330         } else
01331             new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];
01332         ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;
01333     }
01334 }
01335 
01337 static int sbr_lf_gen(AACContext *ac, SpectralBandReplication *sbr,
01338                       float X_low[32][40][2], const float W[2][32][32][2])
01339 {
01340     int i, k;
01341     const int t_HFGen = 8;
01342     const int i_f = 32;
01343     memset(X_low, 0, 32*sizeof(*X_low));
01344     for (k = 0; k < sbr->kx[1]; k++) {
01345         for (i = t_HFGen; i < i_f + t_HFGen; i++) {
01346             X_low[k][i][0] = W[1][i - t_HFGen][k][0];
01347             X_low[k][i][1] = W[1][i - t_HFGen][k][1];
01348         }
01349     }
01350     for (k = 0; k < sbr->kx[0]; k++) {
01351         for (i = 0; i < t_HFGen; i++) {
01352             X_low[k][i][0] = W[0][i + i_f - t_HFGen][k][0];
01353             X_low[k][i][1] = W[0][i + i_f - t_HFGen][k][1];
01354         }
01355     }
01356     return 0;
01357 }
01358 
01360 static int sbr_hf_gen(AACContext *ac, SpectralBandReplication *sbr,
01361                       float X_high[64][40][2], const float X_low[32][40][2],
01362                       const float (*alpha0)[2], const float (*alpha1)[2],
01363                       const float bw_array[5], const uint8_t *t_env,
01364                       int bs_num_env)
01365 {
01366     int i, j, x;
01367     int g = 0;
01368     int k = sbr->kx[1];
01369     for (j = 0; j < sbr->num_patches; j++) {
01370         for (x = 0; x < sbr->patch_num_subbands[j]; x++, k++) {
01371             float alpha[4];
01372             const int p = sbr->patch_start_subband[j] + x;
01373             while (g <= sbr->n_q && k >= sbr->f_tablenoise[g])
01374                 g++;
01375             g--;
01376 
01377             if (g < 0) {
01378                 av_log(ac->avctx, AV_LOG_ERROR,
01379                        "ERROR : no subband found for frequency %d\n", k);
01380                 return -1;
01381             }
01382 
01383             alpha[0] = alpha1[p][0] * bw_array[g] * bw_array[g];
01384             alpha[1] = alpha1[p][1] * bw_array[g] * bw_array[g];
01385             alpha[2] = alpha0[p][0] * bw_array[g];
01386             alpha[3] = alpha0[p][1] * bw_array[g];
01387 
01388             for (i = 2 * t_env[0]; i < 2 * t_env[bs_num_env]; i++) {
01389                 const int idx = i + ENVELOPE_ADJUSTMENT_OFFSET;
01390                 X_high[k][idx][0] =
01391                     X_low[p][idx - 2][0] * alpha[0] -
01392                     X_low[p][idx - 2][1] * alpha[1] +
01393                     X_low[p][idx - 1][0] * alpha[2] -
01394                     X_low[p][idx - 1][1] * alpha[3] +
01395                     X_low[p][idx][0];
01396                 X_high[k][idx][1] =
01397                     X_low[p][idx - 2][1] * alpha[0] +
01398                     X_low[p][idx - 2][0] * alpha[1] +
01399                     X_low[p][idx - 1][1] * alpha[2] +
01400                     X_low[p][idx - 1][0] * alpha[3] +
01401                     X_low[p][idx][1];
01402             }
01403         }
01404     }
01405     if (k < sbr->m[1] + sbr->kx[1])
01406         memset(X_high + k, 0, (sbr->m[1] + sbr->kx[1] - k) * sizeof(*X_high));
01407 
01408     return 0;
01409 }
01410 
01412 static int sbr_x_gen(SpectralBandReplication *sbr, float X[2][38][64],
01413                      const float X_low[32][40][2], const float Y[2][38][64][2],
01414                      int ch)
01415 {
01416     int k, i;
01417     const int i_f = 32;
01418     const int i_Temp = FFMAX(2*sbr->data[ch].t_env_num_env_old - i_f, 0);
01419     memset(X, 0, 2*sizeof(*X));
01420     for (k = 0; k < sbr->kx[0]; k++) {
01421         for (i = 0; i < i_Temp; i++) {
01422             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];
01423             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];
01424         }
01425     }
01426     for (; k < sbr->kx[0] + sbr->m[0]; k++) {
01427         for (i = 0; i < i_Temp; i++) {
01428             X[0][i][k] = Y[0][i + i_f][k][0];
01429             X[1][i][k] = Y[0][i + i_f][k][1];
01430         }
01431     }
01432 
01433     for (k = 0; k < sbr->kx[1]; k++) {
01434         for (i = i_Temp; i < 38; i++) {
01435             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];
01436             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];
01437         }
01438     }
01439     for (; k < sbr->kx[1] + sbr->m[1]; k++) {
01440         for (i = i_Temp; i < i_f; i++) {
01441             X[0][i][k] = Y[1][i][k][0];
01442             X[1][i][k] = Y[1][i][k][1];
01443         }
01444     }
01445     return 0;
01446 }
01447 
01451 static void sbr_mapping(AACContext *ac, SpectralBandReplication *sbr,
01452                         SBRData *ch_data, int e_a[2])
01453 {
01454     int e, i, m;
01455 
01456     memset(ch_data->s_indexmapped[1], 0, 7*sizeof(ch_data->s_indexmapped[1]));
01457     for (e = 0; e < ch_data->bs_num_env; e++) {
01458         const unsigned int ilim = sbr->n[ch_data->bs_freq_res[e + 1]];
01459         uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;
01460         int k;
01461 
01462         av_assert0(sbr->kx[1] <= table[0]);
01463         for (i = 0; i < ilim; i++)
01464             for (m = table[i]; m < table[i + 1]; m++)
01465                 sbr->e_origmapped[e][m - sbr->kx[1]] = ch_data->env_facs[e+1][i];
01466 
01467         // ch_data->bs_num_noise > 1 => 2 noise floors
01468         k = (ch_data->bs_num_noise > 1) && (ch_data->t_env[e] >= ch_data->t_q[1]);
01469         for (i = 0; i < sbr->n_q; i++)
01470             for (m = sbr->f_tablenoise[i]; m < sbr->f_tablenoise[i + 1]; m++)
01471                 sbr->q_mapped[e][m - sbr->kx[1]] = ch_data->noise_facs[k+1][i];
01472 
01473         for (i = 0; i < sbr->n[1]; i++) {
01474             if (ch_data->bs_add_harmonic_flag) {
01475                 const unsigned int m_midpoint =
01476                     (sbr->f_tablehigh[i] + sbr->f_tablehigh[i + 1]) >> 1;
01477 
01478                 ch_data->s_indexmapped[e + 1][m_midpoint - sbr->kx[1]] = ch_data->bs_add_harmonic[i] *
01479                     (e >= e_a[1] || (ch_data->s_indexmapped[0][m_midpoint - sbr->kx[1]] == 1));
01480             }
01481         }
01482 
01483         for (i = 0; i < ilim; i++) {
01484             int additional_sinusoid_present = 0;
01485             for (m = table[i]; m < table[i + 1]; m++) {
01486                 if (ch_data->s_indexmapped[e + 1][m - sbr->kx[1]]) {
01487                     additional_sinusoid_present = 1;
01488                     break;
01489                 }
01490             }
01491             memset(&sbr->s_mapped[e][table[i] - sbr->kx[1]], additional_sinusoid_present,
01492                    (table[i + 1] - table[i]) * sizeof(sbr->s_mapped[e][0]));
01493         }
01494     }
01495 
01496     memcpy(ch_data->s_indexmapped[0], ch_data->s_indexmapped[ch_data->bs_num_env], sizeof(ch_data->s_indexmapped[0]));
01497 }
01498 
01500 static void sbr_env_estimate(float (*e_curr)[48], float X_high[64][40][2],
01501                              SpectralBandReplication *sbr, SBRData *ch_data)
01502 {
01503     int e, i, m;
01504 
01505     if (sbr->bs_interpol_freq) {
01506         for (e = 0; e < ch_data->bs_num_env; e++) {
01507             const float recip_env_size = 0.5f / (ch_data->t_env[e + 1] - ch_data->t_env[e]);
01508             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
01509             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
01510 
01511             for (m = 0; m < sbr->m[1]; m++) {
01512                 float sum = 0.0f;
01513 
01514                 for (i = ilb; i < iub; i++) {
01515                     sum += X_high[m + sbr->kx[1]][i][0] * X_high[m + sbr->kx[1]][i][0] +
01516                            X_high[m + sbr->kx[1]][i][1] * X_high[m + sbr->kx[1]][i][1];
01517                 }
01518                 e_curr[e][m] = sum * recip_env_size;
01519             }
01520         }
01521     } else {
01522         int k, p;
01523 
01524         for (e = 0; e < ch_data->bs_num_env; e++) {
01525             const int env_size = 2 * (ch_data->t_env[e + 1] - ch_data->t_env[e]);
01526             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
01527             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
01528             const uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;
01529 
01530             for (p = 0; p < sbr->n[ch_data->bs_freq_res[e + 1]]; p++) {
01531                 float sum = 0.0f;
01532                 const int den = env_size * (table[p + 1] - table[p]);
01533 
01534                 for (k = table[p]; k < table[p + 1]; k++) {
01535                     for (i = ilb; i < iub; i++) {
01536                         sum += X_high[k][i][0] * X_high[k][i][0] +
01537                                X_high[k][i][1] * X_high[k][i][1];
01538                     }
01539                 }
01540                 sum /= den;
01541                 for (k = table[p]; k < table[p + 1]; k++) {
01542                     e_curr[e][k - sbr->kx[1]] = sum;
01543                 }
01544             }
01545         }
01546     }
01547 }
01548 
01553 static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,
01554                           SBRData *ch_data, const int e_a[2])
01555 {
01556     int e, k, m;
01557     // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)
01558     static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };
01559 
01560     for (e = 0; e < ch_data->bs_num_env; e++) {
01561         int delta = !((e == e_a[1]) || (e == e_a[0]));
01562         for (k = 0; k < sbr->n_lim; k++) {
01563             float gain_boost, gain_max;
01564             float sum[2] = { 0.0f, 0.0f };
01565             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
01566                 const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);
01567                 sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);
01568                 sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);
01569                 if (!sbr->s_mapped[e][m]) {
01570                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /
01571                                             ((1.0f + sbr->e_curr[e][m]) *
01572                                              (1.0f + sbr->q_mapped[e][m] * delta)));
01573                 } else {
01574                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /
01575                                             ((1.0f + sbr->e_curr[e][m]) *
01576                                              (1.0f + sbr->q_mapped[e][m])));
01577                 }
01578             }
01579             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
01580                 sum[0] += sbr->e_origmapped[e][m];
01581                 sum[1] += sbr->e_curr[e][m];
01582             }
01583             gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
01584             gain_max = FFMIN(100000.f, gain_max);
01585             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
01586                 float q_m_max   = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];
01587                 sbr->q_m[e][m]  = FFMIN(sbr->q_m[e][m], q_m_max);
01588                 sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);
01589             }
01590             sum[0] = sum[1] = 0.0f;
01591             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
01592                 sum[0] += sbr->e_origmapped[e][m];
01593                 sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]
01594                           + sbr->s_m[e][m] * sbr->s_m[e][m]
01595                           + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];
01596             }
01597             gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
01598             gain_boost = FFMIN(1.584893192f, gain_boost);
01599             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
01600                 sbr->gain[e][m] *= gain_boost;
01601                 sbr->q_m[e][m]  *= gain_boost;
01602                 sbr->s_m[e][m]  *= gain_boost;
01603             }
01604         }
01605     }
01606 }
01607 
01609 static void sbr_hf_assemble(float Y[2][38][64][2], const float X_high[64][40][2],
01610                             SpectralBandReplication *sbr, SBRData *ch_data,
01611                             const int e_a[2])
01612 {
01613     int e, i, j, m;
01614     const int h_SL = 4 * !sbr->bs_smoothing_mode;
01615     const int kx = sbr->kx[1];
01616     const int m_max = sbr->m[1];
01617     static const float h_smooth[5] = {
01618         0.33333333333333,
01619         0.30150283239582,
01620         0.21816949906249,
01621         0.11516383427084,
01622         0.03183050093751,
01623     };
01624     static const int8_t phi[2][4] = {
01625         {  1,  0, -1,  0}, // real
01626         {  0,  1,  0, -1}, // imaginary
01627     };
01628     float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;
01629     int indexnoise = ch_data->f_indexnoise;
01630     int indexsine  = ch_data->f_indexsine;
01631     memcpy(Y[0], Y[1], sizeof(Y[0]));
01632 
01633     if (sbr->reset) {
01634         for (i = 0; i < h_SL; i++) {
01635             memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));
01636             memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0],  m_max * sizeof(sbr->q_m[0][0]));
01637         }
01638     } else if (h_SL) {
01639         memcpy(g_temp[2*ch_data->t_env[0]], g_temp[2*ch_data->t_env_num_env_old], 4*sizeof(g_temp[0]));
01640         memcpy(q_temp[2*ch_data->t_env[0]], q_temp[2*ch_data->t_env_num_env_old], 4*sizeof(q_temp[0]));
01641     }
01642 
01643     for (e = 0; e < ch_data->bs_num_env; e++) {
01644         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
01645             memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));
01646             memcpy(q_temp[h_SL + i], sbr->q_m[e],  m_max * sizeof(sbr->q_m[0][0]));
01647         }
01648     }
01649 
01650     for (e = 0; e < ch_data->bs_num_env; e++) {
01651         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
01652             int phi_sign = (1 - 2*(kx & 1));
01653 
01654             if (h_SL && e != e_a[0] && e != e_a[1]) {
01655                 for (m = 0; m < m_max; m++) {
01656                     const int idx1 = i + h_SL;
01657                     float g_filt = 0.0f;
01658                     for (j = 0; j <= h_SL; j++)
01659                         g_filt += g_temp[idx1 - j][m] * h_smooth[j];
01660                     Y[1][i][m + kx][0] =
01661                         X_high[m + kx][i + ENVELOPE_ADJUSTMENT_OFFSET][0] * g_filt;
01662                     Y[1][i][m + kx][1] =
01663                         X_high[m + kx][i + ENVELOPE_ADJUSTMENT_OFFSET][1] * g_filt;
01664                 }
01665             } else {
01666                 for (m = 0; m < m_max; m++) {
01667                     const float g_filt = g_temp[i + h_SL][m];
01668                     Y[1][i][m + kx][0] =
01669                         X_high[m + kx][i + ENVELOPE_ADJUSTMENT_OFFSET][0] * g_filt;
01670                     Y[1][i][m + kx][1] =
01671                         X_high[m + kx][i + ENVELOPE_ADJUSTMENT_OFFSET][1] * g_filt;
01672                 }
01673             }
01674 
01675             if (e != e_a[0] && e != e_a[1]) {
01676                 for (m = 0; m < m_max; m++) {
01677                     indexnoise = (indexnoise + 1) & 0x1ff;
01678                     if (sbr->s_m[e][m]) {
01679                         Y[1][i][m + kx][0] +=
01680                             sbr->s_m[e][m] * phi[0][indexsine];
01681                         Y[1][i][m + kx][1] +=
01682                             sbr->s_m[e][m] * (phi[1][indexsine] * phi_sign);
01683                     } else {
01684                         float q_filt;
01685                         if (h_SL) {
01686                             const int idx1 = i + h_SL;
01687                             q_filt = 0.0f;
01688                             for (j = 0; j <= h_SL; j++)
01689                                 q_filt += q_temp[idx1 - j][m] * h_smooth[j];
01690                         } else {
01691                             q_filt = q_temp[i][m];
01692                         }
01693                         Y[1][i][m + kx][0] +=
01694                             q_filt * sbr_noise_table[indexnoise][0];
01695                         Y[1][i][m + kx][1] +=
01696                             q_filt * sbr_noise_table[indexnoise][1];
01697                     }
01698                     phi_sign = -phi_sign;
01699                 }
01700             } else {
01701                 indexnoise = (indexnoise + m_max) & 0x1ff;
01702                 for (m = 0; m < m_max; m++) {
01703                     Y[1][i][m + kx][0] +=
01704                         sbr->s_m[e][m] * phi[0][indexsine];
01705                     Y[1][i][m + kx][1] +=
01706                         sbr->s_m[e][m] * (phi[1][indexsine] * phi_sign);
01707                     phi_sign = -phi_sign;
01708                 }
01709             }
01710             indexsine = (indexsine + 1) & 3;
01711         }
01712     }
01713     ch_data->f_indexnoise = indexnoise;
01714     ch_data->f_indexsine  = indexsine;
01715 }
01716 
01717 void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,
01718                   float* L, float* R)
01719 {
01720     int downsampled = ac->m4ac.ext_sample_rate < sbr->sample_rate;
01721     int ch;
01722     int nch = (id_aac == TYPE_CPE) ? 2 : 1;
01723 
01724     if (sbr->start) {
01725         sbr_dequant(sbr, id_aac);
01726     }
01727     for (ch = 0; ch < nch; ch++) {
01728         /* decode channel */
01729         sbr_qmf_analysis(&ac->dsp, &sbr->mdct_ana, ch ? R : L, sbr->data[ch].analysis_filterbank_samples,
01730                          (float*)sbr->qmf_filter_scratch,
01731                          sbr->data[ch].W);
01732         sbr_lf_gen(ac, sbr, sbr->X_low, sbr->data[ch].W);
01733         if (sbr->start) {
01734             sbr_hf_inverse_filter(sbr->alpha0, sbr->alpha1, sbr->X_low, sbr->k[0]);
01735             sbr_chirp(sbr, &sbr->data[ch]);
01736             sbr_hf_gen(ac, sbr, sbr->X_high, sbr->X_low, sbr->alpha0, sbr->alpha1,
01737                        sbr->data[ch].bw_array, sbr->data[ch].t_env,
01738                        sbr->data[ch].bs_num_env);
01739 
01740             // hf_adj
01741             sbr_mapping(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);
01742             sbr_env_estimate(sbr->e_curr, sbr->X_high, sbr, &sbr->data[ch]);
01743             sbr_gain_calc(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);
01744             sbr_hf_assemble(sbr->data[ch].Y, sbr->X_high, sbr, &sbr->data[ch],
01745                             sbr->data[ch].e_a);
01746         }
01747 
01748         /* synthesis */
01749         sbr_x_gen(sbr, sbr->X[ch], sbr->X_low, sbr->data[ch].Y, ch);
01750     }
01751 
01752     if (ac->m4ac.ps == 1) {
01753         if (sbr->ps.start) {
01754             ff_ps_apply(ac->avctx, &sbr->ps, sbr->X[0], sbr->X[1], sbr->kx[1] + sbr->m[1]);
01755         } else {
01756             memcpy(sbr->X[1], sbr->X[0], sizeof(sbr->X[0]));
01757         }
01758         nch = 2;
01759     }
01760 
01761     sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, L, sbr->X[0], sbr->qmf_filter_scratch,
01762                       sbr->data[0].synthesis_filterbank_samples,
01763                       &sbr->data[0].synthesis_filterbank_samples_offset,
01764                       downsampled);
01765     if (nch == 2)
01766         sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, R, sbr->X[1], sbr->qmf_filter_scratch,
01767                           sbr->data[1].synthesis_filterbank_samples,
01768                           &sbr->data[1].synthesis_filterbank_samples_offset,
01769                           downsampled);
01770 }

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