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     if(sbr->mdct.mdct_bits)
00135         return;
00136     sbr->kx[0] = sbr->kx[1] = 32; //Typo in spec, kx' inits to 32
00137     sbr->data[0].e_a[1] = sbr->data[1].e_a[1] = -1;
00138     sbr->data[0].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128);
00139     sbr->data[1].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128);
00140     /* SBR requires samples to be scaled to +/-32768.0 to work correctly.
00141      * mdct scale factors are adjusted to scale up from +/-1.0 at analysis
00142      * and scale back down at synthesis. */
00143     mdct_scale = ac->avctx->sample_fmt == AV_SAMPLE_FMT_FLT ? 32768.0f : 1.0f;
00144     ff_mdct_init(&sbr->mdct,     7, 1, 1.0 / (64 * mdct_scale));
00145     ff_mdct_init(&sbr->mdct_ana, 7, 1, -2.0 * mdct_scale);
00146     ff_ps_ctx_init(&sbr->ps);
00147 }
00148 
00149 av_cold void ff_aac_sbr_ctx_close(SpectralBandReplication *sbr)
00150 {
00151     ff_mdct_end(&sbr->mdct);
00152     ff_mdct_end(&sbr->mdct_ana);
00153 }
00154 
00155 static int qsort_comparison_function_int16(const void *a, const void *b)
00156 {
00157     return *(const int16_t *)a - *(const int16_t *)b;
00158 }
00159 
00160 static inline int in_table_int16(const int16_t *table, int last_el, int16_t needle)
00161 {
00162     int i;
00163     for (i = 0; i <= last_el; i++)
00164         if (table[i] == needle)
00165             return 1;
00166     return 0;
00167 }
00168 
00170 static void sbr_make_f_tablelim(SpectralBandReplication *sbr)
00171 {
00172     int k;
00173     if (sbr->bs_limiter_bands > 0) {
00174         static const float bands_warped[3] = { 1.32715174233856803909f,   //2^(0.49/1.2)
00175                                                1.18509277094158210129f,   //2^(0.49/2)
00176                                                1.11987160404675912501f }; //2^(0.49/3)
00177         const float lim_bands_per_octave_warped = bands_warped[sbr->bs_limiter_bands - 1];
00178         int16_t patch_borders[7];
00179         uint16_t *in = sbr->f_tablelim + 1, *out = sbr->f_tablelim;
00180 
00181         patch_borders[0] = sbr->kx[1];
00182         for (k = 1; k <= sbr->num_patches; k++)
00183             patch_borders[k] = patch_borders[k-1] + sbr->patch_num_subbands[k-1];
00184 
00185         memcpy(sbr->f_tablelim, sbr->f_tablelow,
00186                (sbr->n[0] + 1) * sizeof(sbr->f_tablelow[0]));
00187         if (sbr->num_patches > 1)
00188             memcpy(sbr->f_tablelim + sbr->n[0] + 1, patch_borders + 1,
00189                    (sbr->num_patches - 1) * sizeof(patch_borders[0]));
00190 
00191         qsort(sbr->f_tablelim, sbr->num_patches + sbr->n[0],
00192               sizeof(sbr->f_tablelim[0]),
00193               qsort_comparison_function_int16);
00194 
00195         sbr->n_lim = sbr->n[0] + sbr->num_patches - 1;
00196         while (out < sbr->f_tablelim + sbr->n_lim) {
00197             if (*in >= *out * lim_bands_per_octave_warped) {
00198                 *++out = *in++;
00199             } else if (*in == *out ||
00200                 !in_table_int16(patch_borders, sbr->num_patches, *in)) {
00201                 in++;
00202                 sbr->n_lim--;
00203             } else if (!in_table_int16(patch_borders, sbr->num_patches, *out)) {
00204                 *out = *in++;
00205                 sbr->n_lim--;
00206             } else {
00207                 *++out = *in++;
00208             }
00209         }
00210     } else {
00211         sbr->f_tablelim[0] = sbr->f_tablelow[0];
00212         sbr->f_tablelim[1] = sbr->f_tablelow[sbr->n[0]];
00213         sbr->n_lim = 1;
00214     }
00215 }
00216 
00217 static unsigned int read_sbr_header(SpectralBandReplication *sbr, GetBitContext *gb)
00218 {
00219     unsigned int cnt = get_bits_count(gb);
00220     uint8_t bs_header_extra_1;
00221     uint8_t bs_header_extra_2;
00222     int old_bs_limiter_bands = sbr->bs_limiter_bands;
00223     SpectrumParameters old_spectrum_params;
00224 
00225     sbr->start = 1;
00226 
00227     // Save last spectrum parameters variables to compare to new ones
00228     memcpy(&old_spectrum_params, &sbr->spectrum_params, sizeof(SpectrumParameters));
00229 
00230     sbr->bs_amp_res_header              = get_bits1(gb);
00231     sbr->spectrum_params.bs_start_freq  = get_bits(gb, 4);
00232     sbr->spectrum_params.bs_stop_freq   = get_bits(gb, 4);
00233     sbr->spectrum_params.bs_xover_band  = get_bits(gb, 3);
00234                                           skip_bits(gb, 2); // bs_reserved
00235 
00236     bs_header_extra_1 = get_bits1(gb);
00237     bs_header_extra_2 = get_bits1(gb);
00238 
00239     if (bs_header_extra_1) {
00240         sbr->spectrum_params.bs_freq_scale  = get_bits(gb, 2);
00241         sbr->spectrum_params.bs_alter_scale = get_bits1(gb);
00242         sbr->spectrum_params.bs_noise_bands = get_bits(gb, 2);
00243     } else {
00244         sbr->spectrum_params.bs_freq_scale  = 2;
00245         sbr->spectrum_params.bs_alter_scale = 1;
00246         sbr->spectrum_params.bs_noise_bands = 2;
00247     }
00248 
00249     // Check if spectrum parameters changed
00250     if (memcmp(&old_spectrum_params, &sbr->spectrum_params, sizeof(SpectrumParameters)))
00251         sbr->reset = 1;
00252 
00253     if (bs_header_extra_2) {
00254         sbr->bs_limiter_bands  = get_bits(gb, 2);
00255         sbr->bs_limiter_gains  = get_bits(gb, 2);
00256         sbr->bs_interpol_freq  = get_bits1(gb);
00257         sbr->bs_smoothing_mode = get_bits1(gb);
00258     } else {
00259         sbr->bs_limiter_bands  = 2;
00260         sbr->bs_limiter_gains  = 2;
00261         sbr->bs_interpol_freq  = 1;
00262         sbr->bs_smoothing_mode = 1;
00263     }
00264 
00265     if (sbr->bs_limiter_bands != old_bs_limiter_bands && !sbr->reset)
00266         sbr_make_f_tablelim(sbr);
00267 
00268     return get_bits_count(gb) - cnt;
00269 }
00270 
00271 static int array_min_int16(const int16_t *array, int nel)
00272 {
00273     int i, min = array[0];
00274     for (i = 1; i < nel; i++)
00275         min = FFMIN(array[i], min);
00276     return min;
00277 }
00278 
00279 static void make_bands(int16_t* bands, int start, int stop, int num_bands)
00280 {
00281     int k, previous, present;
00282     float base, prod;
00283 
00284     base = powf((float)stop / start, 1.0f / num_bands);
00285     prod = start;
00286     previous = start;
00287 
00288     for (k = 0; k < num_bands-1; k++) {
00289         prod *= base;
00290         present  = lrintf(prod);
00291         bands[k] = present - previous;
00292         previous = present;
00293     }
00294     bands[num_bands-1] = stop - previous;
00295 }
00296 
00297 static int check_n_master(AVCodecContext *avctx, int n_master, int bs_xover_band)
00298 {
00299     // Requirements (14496-3 sp04 p205)
00300     if (n_master <= 0) {
00301         av_log(avctx, AV_LOG_ERROR, "Invalid n_master: %d\n", n_master);
00302         return -1;
00303     }
00304     if (bs_xover_band >= n_master) {
00305         av_log(avctx, AV_LOG_ERROR,
00306                "Invalid bitstream, crossover band index beyond array bounds: %d\n",
00307                bs_xover_band);
00308         return -1;
00309     }
00310     return 0;
00311 }
00312 
00314 static int sbr_make_f_master(AACContext *ac, SpectralBandReplication *sbr,
00315                              SpectrumParameters *spectrum)
00316 {
00317     unsigned int temp, max_qmf_subbands;
00318     unsigned int start_min, stop_min;
00319     int k;
00320     const int8_t *sbr_offset_ptr;
00321     int16_t stop_dk[13];
00322 
00323     if (sbr->sample_rate < 32000) {
00324         temp = 3000;
00325     } else if (sbr->sample_rate < 64000) {
00326         temp = 4000;
00327     } else
00328         temp = 5000;
00329 
00330     start_min = ((temp << 7) + (sbr->sample_rate >> 1)) / sbr->sample_rate;
00331     stop_min  = ((temp << 8) + (sbr->sample_rate >> 1)) / sbr->sample_rate;
00332 
00333     switch (sbr->sample_rate) {
00334     case 16000:
00335         sbr_offset_ptr = sbr_offset[0];
00336         break;
00337     case 22050:
00338         sbr_offset_ptr = sbr_offset[1];
00339         break;
00340     case 24000:
00341         sbr_offset_ptr = sbr_offset[2];
00342         break;
00343     case 32000:
00344         sbr_offset_ptr = sbr_offset[3];
00345         break;
00346     case 44100: case 48000: case 64000:
00347         sbr_offset_ptr = sbr_offset[4];
00348         break;
00349     case 88200: case 96000: case 128000: case 176400: case 192000:
00350         sbr_offset_ptr = sbr_offset[5];
00351         break;
00352     default:
00353         av_log(ac->avctx, AV_LOG_ERROR,
00354                "Unsupported sample rate for SBR: %d\n", sbr->sample_rate);
00355         return -1;
00356     }
00357 
00358     sbr->k[0] = start_min + sbr_offset_ptr[spectrum->bs_start_freq];
00359 
00360     if (spectrum->bs_stop_freq < 14) {
00361         sbr->k[2] = stop_min;
00362         make_bands(stop_dk, stop_min, 64, 13);
00363         qsort(stop_dk, 13, sizeof(stop_dk[0]), qsort_comparison_function_int16);
00364         for (k = 0; k < spectrum->bs_stop_freq; k++)
00365             sbr->k[2] += stop_dk[k];
00366     } else if (spectrum->bs_stop_freq == 14) {
00367         sbr->k[2] = 2*sbr->k[0];
00368     } else if (spectrum->bs_stop_freq == 15) {
00369         sbr->k[2] = 3*sbr->k[0];
00370     } else {
00371         av_log(ac->avctx, AV_LOG_ERROR,
00372                "Invalid bs_stop_freq: %d\n", spectrum->bs_stop_freq);
00373         return -1;
00374     }
00375     sbr->k[2] = FFMIN(64, sbr->k[2]);
00376 
00377     // Requirements (14496-3 sp04 p205)
00378     if (sbr->sample_rate <= 32000) {
00379         max_qmf_subbands = 48;
00380     } else if (sbr->sample_rate == 44100) {
00381         max_qmf_subbands = 35;
00382     } else if (sbr->sample_rate >= 48000)
00383         max_qmf_subbands = 32;
00384 
00385     if (sbr->k[2] - sbr->k[0] > max_qmf_subbands) {
00386         av_log(ac->avctx, AV_LOG_ERROR,
00387                "Invalid bitstream, too many QMF subbands: %d\n", sbr->k[2] - sbr->k[0]);
00388         return -1;
00389     }
00390 
00391     if (!spectrum->bs_freq_scale) {
00392         int dk, k2diff;
00393 
00394         dk = spectrum->bs_alter_scale + 1;
00395         sbr->n_master = ((sbr->k[2] - sbr->k[0] + (dk&2)) >> dk) << 1;
00396         if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))
00397             return -1;
00398 
00399         for (k = 1; k <= sbr->n_master; k++)
00400             sbr->f_master[k] = dk;
00401 
00402         k2diff = sbr->k[2] - sbr->k[0] - sbr->n_master * dk;
00403         if (k2diff < 0) {
00404             sbr->f_master[1]--;
00405             sbr->f_master[2]-= (k2diff < -1);
00406         } else if (k2diff) {
00407             sbr->f_master[sbr->n_master]++;
00408         }
00409 
00410         sbr->f_master[0] = sbr->k[0];
00411         for (k = 1; k <= sbr->n_master; k++)
00412             sbr->f_master[k] += sbr->f_master[k - 1];
00413 
00414     } else {
00415         int half_bands = 7 - spectrum->bs_freq_scale;      // bs_freq_scale  = {1,2,3}
00416         int two_regions, num_bands_0;
00417         int vdk0_max, vdk1_min;
00418         int16_t vk0[49];
00419 
00420         if (49 * sbr->k[2] > 110 * sbr->k[0]) {
00421             two_regions = 1;
00422             sbr->k[1] = 2 * sbr->k[0];
00423         } else {
00424             two_regions = 0;
00425             sbr->k[1] = sbr->k[2];
00426         }
00427 
00428         num_bands_0 = lrintf(half_bands * log2f(sbr->k[1] / (float)sbr->k[0])) * 2;
00429 
00430         if (num_bands_0 <= 0) { // Requirements (14496-3 sp04 p205)
00431             av_log(ac->avctx, AV_LOG_ERROR, "Invalid num_bands_0: %d\n", num_bands_0);
00432             return -1;
00433         }
00434 
00435         vk0[0] = 0;
00436 
00437         make_bands(vk0+1, sbr->k[0], sbr->k[1], num_bands_0);
00438 
00439         qsort(vk0 + 1, num_bands_0, sizeof(vk0[1]), qsort_comparison_function_int16);
00440         vdk0_max = vk0[num_bands_0];
00441 
00442         vk0[0] = sbr->k[0];
00443         for (k = 1; k <= num_bands_0; k++) {
00444             if (vk0[k] <= 0) { // Requirements (14496-3 sp04 p205)
00445                 av_log(ac->avctx, AV_LOG_ERROR, "Invalid vDk0[%d]: %d\n", k, vk0[k]);
00446                 return -1;
00447             }
00448             vk0[k] += vk0[k-1];
00449         }
00450 
00451         if (two_regions) {
00452             int16_t vk1[49];
00453             float invwarp = spectrum->bs_alter_scale ? 0.76923076923076923077f
00454                                                      : 1.0f; // bs_alter_scale = {0,1}
00455             int num_bands_1 = lrintf(half_bands * invwarp *
00456                                      log2f(sbr->k[2] / (float)sbr->k[1])) * 2;
00457 
00458             make_bands(vk1+1, sbr->k[1], sbr->k[2], num_bands_1);
00459 
00460             vdk1_min = array_min_int16(vk1 + 1, num_bands_1);
00461 
00462             if (vdk1_min < vdk0_max) {
00463                 int change;
00464                 qsort(vk1 + 1, num_bands_1, sizeof(vk1[1]), qsort_comparison_function_int16);
00465                 change = FFMIN(vdk0_max - vk1[1], (vk1[num_bands_1] - vk1[1]) >> 1);
00466                 vk1[1]           += change;
00467                 vk1[num_bands_1] -= change;
00468             }
00469 
00470             qsort(vk1 + 1, num_bands_1, sizeof(vk1[1]), qsort_comparison_function_int16);
00471 
00472             vk1[0] = sbr->k[1];
00473             for (k = 1; k <= num_bands_1; k++) {
00474                 if (vk1[k] <= 0) { // Requirements (14496-3 sp04 p205)
00475                     av_log(ac->avctx, AV_LOG_ERROR, "Invalid vDk1[%d]: %d\n", k, vk1[k]);
00476                     return -1;
00477                 }
00478                 vk1[k] += vk1[k-1];
00479             }
00480 
00481             sbr->n_master = num_bands_0 + num_bands_1;
00482             if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))
00483                 return -1;
00484             memcpy(&sbr->f_master[0],               vk0,
00485                    (num_bands_0 + 1) * sizeof(sbr->f_master[0]));
00486             memcpy(&sbr->f_master[num_bands_0 + 1], vk1 + 1,
00487                     num_bands_1      * sizeof(sbr->f_master[0]));
00488 
00489         } else {
00490             sbr->n_master = num_bands_0;
00491             if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))
00492                 return -1;
00493             memcpy(sbr->f_master, vk0, (num_bands_0 + 1) * sizeof(sbr->f_master[0]));
00494         }
00495     }
00496 
00497     return 0;
00498 }
00499 
00501 static int sbr_hf_calc_npatches(AACContext *ac, SpectralBandReplication *sbr)
00502 {
00503     int i, k, sb = 0;
00504     int msb = sbr->k[0];
00505     int usb = sbr->kx[1];
00506     int goal_sb = ((1000 << 11) + (sbr->sample_rate >> 1)) / sbr->sample_rate;
00507 
00508     sbr->num_patches = 0;
00509 
00510     if (goal_sb < sbr->kx[1] + sbr->m[1]) {
00511         for (k = 0; sbr->f_master[k] < goal_sb; k++) ;
00512     } else
00513         k = sbr->n_master;
00514 
00515     do {
00516         int odd = 0;
00517         for (i = k; i == k || sb > (sbr->k[0] - 1 + msb - odd); i--) {
00518             sb = sbr->f_master[i];
00519             odd = (sb + sbr->k[0]) & 1;
00520         }
00521 
00522         // Requirements (14496-3 sp04 p205) sets the maximum number of patches to 5.
00523         // After this check the final number of patches can still be six which is
00524         // illegal however the Coding Technologies decoder check stream has a final
00525         // count of 6 patches
00526         if (sbr->num_patches > 5) {
00527             av_log(ac->avctx, AV_LOG_ERROR, "Too many patches: %d\n", sbr->num_patches);
00528             return -1;
00529         }
00530 
00531         sbr->patch_num_subbands[sbr->num_patches]  = FFMAX(sb - usb, 0);
00532         sbr->patch_start_subband[sbr->num_patches] = sbr->k[0] - odd - sbr->patch_num_subbands[sbr->num_patches];
00533 
00534         if (sbr->patch_num_subbands[sbr->num_patches] > 0) {
00535             usb = sb;
00536             msb = sb;
00537             sbr->num_patches++;
00538         } else
00539             msb = sbr->kx[1];
00540 
00541         if (sbr->f_master[k] - sb < 3)
00542             k = sbr->n_master;
00543     } while (sb != sbr->kx[1] + sbr->m[1]);
00544 
00545     if (sbr->patch_num_subbands[sbr->num_patches-1] < 3 && sbr->num_patches > 1)
00546         sbr->num_patches--;
00547 
00548     return 0;
00549 }
00550 
00552 static int sbr_make_f_derived(AACContext *ac, SpectralBandReplication *sbr)
00553 {
00554     int k, temp;
00555 
00556     sbr->n[1] = sbr->n_master - sbr->spectrum_params.bs_xover_band;
00557     sbr->n[0] = (sbr->n[1] + 1) >> 1;
00558 
00559     memcpy(sbr->f_tablehigh, &sbr->f_master[sbr->spectrum_params.bs_xover_band],
00560            (sbr->n[1] + 1) * sizeof(sbr->f_master[0]));
00561     sbr->m[1] = sbr->f_tablehigh[sbr->n[1]] - sbr->f_tablehigh[0];
00562     sbr->kx[1] = sbr->f_tablehigh[0];
00563 
00564     // Requirements (14496-3 sp04 p205)
00565     if (sbr->kx[1] + sbr->m[1] > 64) {
00566         av_log(ac->avctx, AV_LOG_ERROR,
00567                "Stop frequency border too high: %d\n", sbr->kx[1] + sbr->m[1]);
00568         return -1;
00569     }
00570     if (sbr->kx[1] > 32) {
00571         av_log(ac->avctx, AV_LOG_ERROR, "Start frequency border too high: %d\n", sbr->kx[1]);
00572         return -1;
00573     }
00574 
00575     sbr->f_tablelow[0] = sbr->f_tablehigh[0];
00576     temp = sbr->n[1] & 1;
00577     for (k = 1; k <= sbr->n[0]; k++)
00578         sbr->f_tablelow[k] = sbr->f_tablehigh[2 * k - temp];
00579 
00580     sbr->n_q = FFMAX(1, lrintf(sbr->spectrum_params.bs_noise_bands *
00581                                log2f(sbr->k[2] / (float)sbr->kx[1]))); // 0 <= bs_noise_bands <= 3
00582     if (sbr->n_q > 5) {
00583         av_log(ac->avctx, AV_LOG_ERROR, "Too many noise floor scale factors: %d\n", sbr->n_q);
00584         return -1;
00585     }
00586 
00587     sbr->f_tablenoise[0] = sbr->f_tablelow[0];
00588     temp = 0;
00589     for (k = 1; k <= sbr->n_q; k++) {
00590         temp += (sbr->n[0] - temp) / (sbr->n_q + 1 - k);
00591         sbr->f_tablenoise[k] = sbr->f_tablelow[temp];
00592     }
00593 
00594     if (sbr_hf_calc_npatches(ac, sbr) < 0)
00595         return -1;
00596 
00597     sbr_make_f_tablelim(sbr);
00598 
00599     sbr->data[0].f_indexnoise = 0;
00600     sbr->data[1].f_indexnoise = 0;
00601 
00602     return 0;
00603 }
00604 
00605 static av_always_inline void get_bits1_vector(GetBitContext *gb, uint8_t *vec,
00606                                               int elements)
00607 {
00608     int i;
00609     for (i = 0; i < elements; i++) {
00610         vec[i] = get_bits1(gb);
00611     }
00612 }
00613 
00615 static const int8_t ceil_log2[] = {
00616     0, 1, 2, 2, 3, 3,
00617 };
00618 
00619 static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr,
00620                          GetBitContext *gb, SBRData *ch_data)
00621 {
00622     int i;
00623     unsigned bs_pointer = 0;
00624     // frameLengthFlag ? 15 : 16; 960 sample length frames unsupported; this value is numTimeSlots
00625     int abs_bord_trail = 16;
00626     int num_rel_lead, num_rel_trail;
00627     unsigned bs_num_env_old = ch_data->bs_num_env;
00628 
00629     ch_data->bs_freq_res[0] = ch_data->bs_freq_res[ch_data->bs_num_env];
00630     ch_data->bs_amp_res = sbr->bs_amp_res_header;
00631     ch_data->t_env_num_env_old = ch_data->t_env[bs_num_env_old];
00632 
00633     switch (ch_data->bs_frame_class = get_bits(gb, 2)) {
00634     case FIXFIX:
00635         ch_data->bs_num_env                 = 1 << get_bits(gb, 2);
00636         num_rel_lead                        = ch_data->bs_num_env - 1;
00637         if (ch_data->bs_num_env == 1)
00638             ch_data->bs_amp_res = 0;
00639 
00640         if (ch_data->bs_num_env > 4) {
00641             av_log(ac->avctx, AV_LOG_ERROR,
00642                    "Invalid bitstream, too many SBR envelopes in FIXFIX type SBR frame: %d\n",
00643                    ch_data->bs_num_env);
00644             return -1;
00645         }
00646 
00647         ch_data->t_env[0]                   = 0;
00648         ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
00649 
00650         abs_bord_trail = (abs_bord_trail + (ch_data->bs_num_env >> 1)) /
00651                    ch_data->bs_num_env;
00652         for (i = 0; i < num_rel_lead; i++)
00653             ch_data->t_env[i + 1] = ch_data->t_env[i] + abs_bord_trail;
00654 
00655         ch_data->bs_freq_res[1] = get_bits1(gb);
00656         for (i = 1; i < ch_data->bs_num_env; i++)
00657             ch_data->bs_freq_res[i + 1] = ch_data->bs_freq_res[1];
00658         break;
00659     case FIXVAR:
00660         abs_bord_trail                     += get_bits(gb, 2);
00661         num_rel_trail                       = get_bits(gb, 2);
00662         ch_data->bs_num_env                 = num_rel_trail + 1;
00663         ch_data->t_env[0]                   = 0;
00664         ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
00665 
00666         for (i = 0; i < num_rel_trail; i++)
00667             ch_data->t_env[ch_data->bs_num_env - 1 - i] =
00668                 ch_data->t_env[ch_data->bs_num_env - i] - 2 * get_bits(gb, 2) - 2;
00669 
00670         bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);
00671 
00672         for (i = 0; i < ch_data->bs_num_env; i++)
00673             ch_data->bs_freq_res[ch_data->bs_num_env - i] = get_bits1(gb);
00674         break;
00675     case VARFIX:
00676         ch_data->t_env[0]                   = get_bits(gb, 2);
00677         num_rel_lead                        = get_bits(gb, 2);
00678         ch_data->bs_num_env                 = num_rel_lead + 1;
00679         ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
00680 
00681         for (i = 0; i < num_rel_lead; i++)
00682             ch_data->t_env[i + 1] = ch_data->t_env[i] + 2 * get_bits(gb, 2) + 2;
00683 
00684         bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);
00685 
00686         get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env);
00687         break;
00688     case VARVAR:
00689         ch_data->t_env[0]                   = get_bits(gb, 2);
00690         abs_bord_trail                     += get_bits(gb, 2);
00691         num_rel_lead                        = get_bits(gb, 2);
00692         num_rel_trail                       = get_bits(gb, 2);
00693         ch_data->bs_num_env                 = num_rel_lead + num_rel_trail + 1;
00694 
00695         if (ch_data->bs_num_env > 5) {
00696             av_log(ac->avctx, AV_LOG_ERROR,
00697                    "Invalid bitstream, too many SBR envelopes in VARVAR type SBR frame: %d\n",
00698                    ch_data->bs_num_env);
00699             return -1;
00700         }
00701 
00702         ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
00703 
00704         for (i = 0; i < num_rel_lead; i++)
00705             ch_data->t_env[i + 1] = ch_data->t_env[i] + 2 * get_bits(gb, 2) + 2;
00706         for (i = 0; i < num_rel_trail; i++)
00707             ch_data->t_env[ch_data->bs_num_env - 1 - i] =
00708                 ch_data->t_env[ch_data->bs_num_env - i] - 2 * get_bits(gb, 2) - 2;
00709 
00710         bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);
00711 
00712         get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env);
00713         break;
00714     }
00715 
00716     if (bs_pointer > ch_data->bs_num_env + 1) {
00717         av_log(ac->avctx, AV_LOG_ERROR,
00718                "Invalid bitstream, bs_pointer points to a middle noise border outside the time borders table: %d\n",
00719                bs_pointer);
00720         return -1;
00721     }
00722 
00723     for (i = 1; i <= ch_data->bs_num_env; i++) {
00724         if (ch_data->t_env[i-1] > ch_data->t_env[i]) {
00725             av_log(ac->avctx, AV_LOG_ERROR, "Non monotone time borders\n");
00726             return -1;
00727         }
00728     }
00729 
00730     ch_data->bs_num_noise = (ch_data->bs_num_env > 1) + 1;
00731 
00732     ch_data->t_q[0]                     = ch_data->t_env[0];
00733     ch_data->t_q[ch_data->bs_num_noise] = ch_data->t_env[ch_data->bs_num_env];
00734     if (ch_data->bs_num_noise > 1) {
00735         unsigned int idx;
00736         if (ch_data->bs_frame_class == FIXFIX) {
00737             idx = ch_data->bs_num_env >> 1;
00738         } else if (ch_data->bs_frame_class & 1) { // FIXVAR or VARVAR
00739             idx = ch_data->bs_num_env - FFMAX(bs_pointer - 1, 1);
00740         } else { // VARFIX
00741             if (!bs_pointer)
00742                 idx = 1;
00743             else if (bs_pointer == 1)
00744                 idx = ch_data->bs_num_env - 1;
00745             else // bs_pointer > 1
00746                 idx = bs_pointer - 1;
00747         }
00748         ch_data->t_q[1] = ch_data->t_env[idx];
00749     }
00750 
00751     ch_data->e_a[0] = -(ch_data->e_a[1] != bs_num_env_old); // l_APrev
00752     ch_data->e_a[1] = -1;
00753     if ((ch_data->bs_frame_class & 1) && bs_pointer) { // FIXVAR or VARVAR and bs_pointer != 0
00754         ch_data->e_a[1] = ch_data->bs_num_env + 1 - bs_pointer;
00755     } else if ((ch_data->bs_frame_class == 2) && (bs_pointer > 1)) // VARFIX and bs_pointer > 1
00756         ch_data->e_a[1] = bs_pointer - 1;
00757 
00758     return 0;
00759 }
00760 
00761 static void copy_sbr_grid(SBRData *dst, const SBRData *src) {
00762     //These variables are saved from the previous frame rather than copied
00763     dst->bs_freq_res[0]    = dst->bs_freq_res[dst->bs_num_env];
00764     dst->t_env_num_env_old = dst->t_env[dst->bs_num_env];
00765     dst->e_a[0]            = -(dst->e_a[1] != dst->bs_num_env);
00766 
00767     //These variables are read from the bitstream and therefore copied
00768     memcpy(dst->bs_freq_res+1, src->bs_freq_res+1, sizeof(dst->bs_freq_res)-sizeof(*dst->bs_freq_res));
00769     memcpy(dst->t_env,         src->t_env,         sizeof(dst->t_env));
00770     memcpy(dst->t_q,           src->t_q,           sizeof(dst->t_q));
00771     dst->bs_num_env        = src->bs_num_env;
00772     dst->bs_amp_res        = src->bs_amp_res;
00773     dst->bs_num_noise      = src->bs_num_noise;
00774     dst->bs_frame_class    = src->bs_frame_class;
00775     dst->e_a[1]            = src->e_a[1];
00776 }
00777 
00779 static void read_sbr_dtdf(SpectralBandReplication *sbr, GetBitContext *gb,
00780                           SBRData *ch_data)
00781 {
00782     get_bits1_vector(gb, ch_data->bs_df_env,   ch_data->bs_num_env);
00783     get_bits1_vector(gb, ch_data->bs_df_noise, ch_data->bs_num_noise);
00784 }
00785 
00787 static void read_sbr_invf(SpectralBandReplication *sbr, GetBitContext *gb,
00788                           SBRData *ch_data)
00789 {
00790     int i;
00791 
00792     memcpy(ch_data->bs_invf_mode[1], ch_data->bs_invf_mode[0], 5 * sizeof(uint8_t));
00793     for (i = 0; i < sbr->n_q; i++)
00794         ch_data->bs_invf_mode[0][i] = get_bits(gb, 2);
00795 }
00796 
00797 static void read_sbr_envelope(SpectralBandReplication *sbr, GetBitContext *gb,
00798                               SBRData *ch_data, int ch)
00799 {
00800     int bits;
00801     int i, j, k;
00802     VLC_TYPE (*t_huff)[2], (*f_huff)[2];
00803     int t_lav, f_lav;
00804     const int delta = (ch == 1 && sbr->bs_coupling == 1) + 1;
00805     const int odd = sbr->n[1] & 1;
00806 
00807     if (sbr->bs_coupling && ch) {
00808         if (ch_data->bs_amp_res) {
00809             bits   = 5;
00810             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_3_0DB].table;
00811             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_3_0DB];
00812             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;
00813             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];
00814         } else {
00815             bits   = 6;
00816             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_1_5DB].table;
00817             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_1_5DB];
00818             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_1_5DB].table;
00819             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_1_5DB];
00820         }
00821     } else {
00822         if (ch_data->bs_amp_res) {
00823             bits   = 6;
00824             t_huff = vlc_sbr[T_HUFFMAN_ENV_3_0DB].table;
00825             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_3_0DB];
00826             f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;
00827             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];
00828         } else {
00829             bits   = 7;
00830             t_huff = vlc_sbr[T_HUFFMAN_ENV_1_5DB].table;
00831             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_1_5DB];
00832             f_huff = vlc_sbr[F_HUFFMAN_ENV_1_5DB].table;
00833             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_1_5DB];
00834         }
00835     }
00836 
00837     for (i = 0; i < ch_data->bs_num_env; i++) {
00838         if (ch_data->bs_df_env[i]) {
00839             // bs_freq_res[0] == bs_freq_res[bs_num_env] from prev frame
00840             if (ch_data->bs_freq_res[i + 1] == ch_data->bs_freq_res[i]) {
00841                 for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++)
00842                     ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][j] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);
00843             } else if (ch_data->bs_freq_res[i + 1]) {
00844                 for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) {
00845                     k = (j + odd) >> 1; // find k such that f_tablelow[k] <= f_tablehigh[j] < f_tablelow[k + 1]
00846                     ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][k] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);
00847                 }
00848             } else {
00849                 for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) {
00850                     k = j ? 2*j - odd : 0; // find k such that f_tablehigh[k] == f_tablelow[j]
00851                     ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][k] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);
00852                 }
00853             }
00854         } else {
00855             ch_data->env_facs[i + 1][0] = delta * get_bits(gb, bits); // bs_env_start_value_balance
00856             for (j = 1; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++)
00857                 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);
00858         }
00859     }
00860 
00861     //assign 0th elements of env_facs from last elements
00862     memcpy(ch_data->env_facs[0], ch_data->env_facs[ch_data->bs_num_env],
00863            sizeof(ch_data->env_facs[0]));
00864 }
00865 
00866 static void read_sbr_noise(SpectralBandReplication *sbr, GetBitContext *gb,
00867                            SBRData *ch_data, int ch)
00868 {
00869     int i, j;
00870     VLC_TYPE (*t_huff)[2], (*f_huff)[2];
00871     int t_lav, f_lav;
00872     int delta = (ch == 1 && sbr->bs_coupling == 1) + 1;
00873 
00874     if (sbr->bs_coupling && ch) {
00875         t_huff = vlc_sbr[T_HUFFMAN_NOISE_BAL_3_0DB].table;
00876         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_BAL_3_0DB];
00877         f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;
00878         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];
00879     } else {
00880         t_huff = vlc_sbr[T_HUFFMAN_NOISE_3_0DB].table;
00881         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_3_0DB];
00882         f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;
00883         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];
00884     }
00885 
00886     for (i = 0; i < ch_data->bs_num_noise; i++) {
00887         if (ch_data->bs_df_noise[i]) {
00888             for (j = 0; j < sbr->n_q; j++)
00889                 ch_data->noise_facs[i + 1][j] = ch_data->noise_facs[i][j] + delta * (get_vlc2(gb, t_huff, 9, 2) - t_lav);
00890         } else {
00891             ch_data->noise_facs[i + 1][0] = delta * get_bits(gb, 5); // bs_noise_start_value_balance or bs_noise_start_value_level
00892             for (j = 1; j < sbr->n_q; j++)
00893                 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);
00894         }
00895     }
00896 
00897     //assign 0th elements of noise_facs from last elements
00898     memcpy(ch_data->noise_facs[0], ch_data->noise_facs[ch_data->bs_num_noise],
00899            sizeof(ch_data->noise_facs[0]));
00900 }
00901 
00902 static void read_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,
00903                                GetBitContext *gb,
00904                                int bs_extension_id, int *num_bits_left)
00905 {
00906     switch (bs_extension_id) {
00907     case EXTENSION_ID_PS:
00908         if (!ac->m4ac.ps) {
00909             av_log(ac->avctx, AV_LOG_ERROR, "Parametric Stereo signaled to be not-present but was found in the bitstream.\n");
00910             skip_bits_long(gb, *num_bits_left); // bs_fill_bits
00911             *num_bits_left = 0;
00912         } else {
00913 #if 1
00914             *num_bits_left -= ff_ps_read_data(ac->avctx, gb, &sbr->ps, *num_bits_left);
00915 #else
00916             av_log_missing_feature(ac->avctx, "Parametric Stereo is", 0);
00917             skip_bits_long(gb, *num_bits_left); // bs_fill_bits
00918             *num_bits_left = 0;
00919 #endif
00920         }
00921         break;
00922     default:
00923         av_log_missing_feature(ac->avctx, "Reserved SBR extensions are", 1);
00924         skip_bits_long(gb, *num_bits_left); // bs_fill_bits
00925         *num_bits_left = 0;
00926         break;
00927     }
00928 }
00929 
00930 static int read_sbr_single_channel_element(AACContext *ac,
00931                                             SpectralBandReplication *sbr,
00932                                             GetBitContext *gb)
00933 {
00934     if (get_bits1(gb)) // bs_data_extra
00935         skip_bits(gb, 4); // bs_reserved
00936 
00937     if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]))
00938         return -1;
00939     read_sbr_dtdf(sbr, gb, &sbr->data[0]);
00940     read_sbr_invf(sbr, gb, &sbr->data[0]);
00941     read_sbr_envelope(sbr, gb, &sbr->data[0], 0);
00942     read_sbr_noise(sbr, gb, &sbr->data[0], 0);
00943 
00944     if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb)))
00945         get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);
00946 
00947     return 0;
00948 }
00949 
00950 static int read_sbr_channel_pair_element(AACContext *ac,
00951                                           SpectralBandReplication *sbr,
00952                                           GetBitContext *gb)
00953 {
00954     if (get_bits1(gb))    // bs_data_extra
00955         skip_bits(gb, 8); // bs_reserved
00956 
00957     if ((sbr->bs_coupling = get_bits1(gb))) {
00958         if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]))
00959             return -1;
00960         copy_sbr_grid(&sbr->data[1], &sbr->data[0]);
00961         read_sbr_dtdf(sbr, gb, &sbr->data[0]);
00962         read_sbr_dtdf(sbr, gb, &sbr->data[1]);
00963         read_sbr_invf(sbr, gb, &sbr->data[0]);
00964         memcpy(sbr->data[1].bs_invf_mode[1], sbr->data[1].bs_invf_mode[0], sizeof(sbr->data[1].bs_invf_mode[0]));
00965         memcpy(sbr->data[1].bs_invf_mode[0], sbr->data[0].bs_invf_mode[0], sizeof(sbr->data[1].bs_invf_mode[0]));
00966         read_sbr_envelope(sbr, gb, &sbr->data[0], 0);
00967         read_sbr_noise(sbr, gb, &sbr->data[0], 0);
00968         read_sbr_envelope(sbr, gb, &sbr->data[1], 1);
00969         read_sbr_noise(sbr, gb, &sbr->data[1], 1);
00970     } else {
00971         if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]) ||
00972             read_sbr_grid(ac, sbr, gb, &sbr->data[1]))
00973             return -1;
00974         read_sbr_dtdf(sbr, gb, &sbr->data[0]);
00975         read_sbr_dtdf(sbr, gb, &sbr->data[1]);
00976         read_sbr_invf(sbr, gb, &sbr->data[0]);
00977         read_sbr_invf(sbr, gb, &sbr->data[1]);
00978         read_sbr_envelope(sbr, gb, &sbr->data[0], 0);
00979         read_sbr_envelope(sbr, gb, &sbr->data[1], 1);
00980         read_sbr_noise(sbr, gb, &sbr->data[0], 0);
00981         read_sbr_noise(sbr, gb, &sbr->data[1], 1);
00982     }
00983 
00984     if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb)))
00985         get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);
00986     if ((sbr->data[1].bs_add_harmonic_flag = get_bits1(gb)))
00987         get_bits1_vector(gb, sbr->data[1].bs_add_harmonic, sbr->n[1]);
00988 
00989     return 0;
00990 }
00991 
00992 static unsigned int read_sbr_data(AACContext *ac, SpectralBandReplication *sbr,
00993                                   GetBitContext *gb, int id_aac)
00994 {
00995     unsigned int cnt = get_bits_count(gb);
00996 
00997     if (id_aac == TYPE_SCE || id_aac == TYPE_CCE) {
00998         if (read_sbr_single_channel_element(ac, sbr, gb)) {
00999             sbr->start = 0;
01000             return get_bits_count(gb) - cnt;
01001         }
01002     } else if (id_aac == TYPE_CPE) {
01003         if (read_sbr_channel_pair_element(ac, sbr, gb)) {
01004             sbr->start = 0;
01005             return get_bits_count(gb) - cnt;
01006         }
01007     } else {
01008         av_log(ac->avctx, AV_LOG_ERROR,
01009             "Invalid bitstream - cannot apply SBR to element type %d\n", id_aac);
01010         sbr->start = 0;
01011         return get_bits_count(gb) - cnt;
01012     }
01013     if (get_bits1(gb)) { // bs_extended_data
01014         int num_bits_left = get_bits(gb, 4); // bs_extension_size
01015         if (num_bits_left == 15)
01016             num_bits_left += get_bits(gb, 8); // bs_esc_count
01017 
01018         num_bits_left <<= 3;
01019         while (num_bits_left > 7) {
01020             num_bits_left -= 2;
01021             read_sbr_extension(ac, sbr, gb, get_bits(gb, 2), &num_bits_left); // bs_extension_id
01022         }
01023         if (num_bits_left < 0) {
01024             av_log(ac->avctx, AV_LOG_ERROR, "SBR Extension over read.\n");
01025         }
01026         if (num_bits_left > 0)
01027             skip_bits(gb, num_bits_left);
01028     }
01029 
01030     return get_bits_count(gb) - cnt;
01031 }
01032 
01033 static void sbr_reset(AACContext *ac, SpectralBandReplication *sbr)
01034 {
01035     int err;
01036     err = sbr_make_f_master(ac, sbr, &sbr->spectrum_params);
01037     if (err >= 0)
01038         err = sbr_make_f_derived(ac, sbr);
01039     if (err < 0) {
01040         av_log(ac->avctx, AV_LOG_ERROR,
01041                "SBR reset failed. Switching SBR to pure upsampling mode.\n");
01042         sbr->start = 0;
01043     }
01044 }
01045 
01054 int ff_decode_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,
01055                             GetBitContext *gb_host, int crc, int cnt, int id_aac)
01056 {
01057     unsigned int num_sbr_bits = 0, num_align_bits;
01058     unsigned bytes_read;
01059     GetBitContext gbc = *gb_host, *gb = &gbc;
01060     skip_bits_long(gb_host, cnt*8 - 4);
01061 
01062     sbr->reset = 0;
01063 
01064     if (!sbr->sample_rate)
01065         sbr->sample_rate = 2 * ac->m4ac.sample_rate; //TODO use the nominal sample rate for arbitrary sample rate support
01066     if (!ac->m4ac.ext_sample_rate)
01067         ac->m4ac.ext_sample_rate = 2 * ac->m4ac.sample_rate;
01068 
01069     if (crc) {
01070         skip_bits(gb, 10); // bs_sbr_crc_bits; TODO - implement CRC check
01071         num_sbr_bits += 10;
01072     }
01073 
01074     //Save some state from the previous frame.
01075     sbr->kx[0] = sbr->kx[1];
01076     sbr->m[0] = sbr->m[1];
01077 
01078     num_sbr_bits++;
01079     if (get_bits1(gb)) // bs_header_flag
01080         num_sbr_bits += read_sbr_header(sbr, gb);
01081 
01082     if (sbr->reset)
01083         sbr_reset(ac, sbr);
01084 
01085     if (sbr->start)
01086         num_sbr_bits  += read_sbr_data(ac, sbr, gb, id_aac);
01087 
01088     num_align_bits = ((cnt << 3) - 4 - num_sbr_bits) & 7;
01089     bytes_read = ((num_sbr_bits + num_align_bits + 4) >> 3);
01090 
01091     if (bytes_read > cnt) {
01092         av_log(ac->avctx, AV_LOG_ERROR,
01093                "Expected to read %d SBR bytes actually read %d.\n", cnt, bytes_read);
01094     }
01095     return cnt;
01096 }
01097 
01099 static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)
01100 {
01101     int k, e;
01102     int ch;
01103 
01104     if (id_aac == TYPE_CPE && sbr->bs_coupling) {
01105         float alpha      = sbr->data[0].bs_amp_res ?  1.0f :  0.5f;
01106         float pan_offset = sbr->data[0].bs_amp_res ? 12.0f : 24.0f;
01107         for (e = 1; e <= sbr->data[0].bs_num_env; e++) {
01108             for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {
01109                 float temp1 = exp2f(sbr->data[0].env_facs[e][k] * alpha + 7.0f);
01110                 float temp2 = exp2f((pan_offset - sbr->data[1].env_facs[e][k]) * alpha);
01111                 float fac   = temp1 / (1.0f + temp2);
01112                 sbr->data[0].env_facs[e][k] = fac;
01113                 sbr->data[1].env_facs[e][k] = fac * temp2;
01114             }
01115         }
01116         for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {
01117             for (k = 0; k < sbr->n_q; k++) {
01118                 float temp1 = exp2f(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs[e][k] + 1);
01119                 float temp2 = exp2f(12 - sbr->data[1].noise_facs[e][k]);
01120                 float fac   = temp1 / (1.0f + temp2);
01121                 sbr->data[0].noise_facs[e][k] = fac;
01122                 sbr->data[1].noise_facs[e][k] = fac * temp2;
01123             }
01124         }
01125     } else { // SCE or one non-coupled CPE
01126         for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {
01127             float alpha = sbr->data[ch].bs_amp_res ? 1.0f : 0.5f;
01128             for (e = 1; e <= sbr->data[ch].bs_num_env; e++)
01129                 for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++)
01130                     sbr->data[ch].env_facs[e][k] =
01131                         exp2f(alpha * sbr->data[ch].env_facs[e][k] + 6.0f);
01132             for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)
01133                 for (k = 0; k < sbr->n_q; k++)
01134                     sbr->data[ch].noise_facs[e][k] =
01135                         exp2f(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs[e][k]);
01136         }
01137     }
01138 }
01139 
01146 static void sbr_qmf_analysis(DSPContext *dsp, FFTContext *mdct, const float *in, float *x,
01147                              float z[320], float W[2][32][32][2])
01148 {
01149     int i, k;
01150     memcpy(W[0], W[1], sizeof(W[0]));
01151     memcpy(x    , x+1024, (320-32)*sizeof(x[0]));
01152     memcpy(x+288, in,         1024*sizeof(x[0]));
01153     for (i = 0; i < 32; i++) { // numTimeSlots*RATE = 16*2 as 960 sample frames
01154                                // are not supported
01155         dsp->vector_fmul_reverse(z, sbr_qmf_window_ds, x, 320);
01156         for (k = 0; k < 64; k++) {
01157             float f = z[k] + z[k + 64] + z[k + 128] + z[k + 192] + z[k + 256];
01158             z[k] = f;
01159         }
01160         //Shuffle to IMDCT
01161         z[64] = z[0];
01162         for (k = 1; k < 32; k++) {
01163             z[64+2*k-1] =  z[   k];
01164             z[64+2*k  ] = -z[64-k];
01165         }
01166         z[64+63] = z[32];
01167 
01168         mdct->imdct_half(mdct, z, z+64);
01169         for (k = 0; k < 32; k++) {
01170             W[1][i][k][0] = -z[63-k];
01171             W[1][i][k][1] = z[k];
01172         }
01173         x += 32;
01174     }
01175 }
01176 
01181 static void sbr_qmf_synthesis(DSPContext *dsp, FFTContext *mdct,
01182                               float *out, float X[2][38][64],
01183                               float mdct_buf[2][64],
01184                               float *v0, int *v_off, const unsigned int div)
01185 {
01186     int i, n;
01187     const float *sbr_qmf_window = div ? sbr_qmf_window_ds : sbr_qmf_window_us;
01188     const int step = 128 >> div;
01189     float *v;
01190     for (i = 0; i < 32; i++) {
01191         if (*v_off < step) {
01192             int saved_samples = (1280 - 128) >> div;
01193             memcpy(&v0[SBR_SYNTHESIS_BUF_SIZE - saved_samples], v0, saved_samples * sizeof(float));
01194             *v_off = SBR_SYNTHESIS_BUF_SIZE - saved_samples - step;
01195         } else {
01196             *v_off -= step;
01197         }
01198         v = v0 + *v_off;
01199         if (div) {
01200             for (n = 0; n < 32; n++) {
01201                 X[0][i][   n] = -X[0][i][n];
01202                 X[0][i][32+n] =  X[1][i][31-n];
01203             }
01204             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);
01205             for (n = 0; n < 32; n++) {
01206                 v[     n] =  mdct_buf[0][63 - 2*n];
01207                 v[63 - n] = -mdct_buf[0][62 - 2*n];
01208             }
01209         } else {
01210             for (n = 1; n < 64; n+=2) {
01211                 X[1][i][n] = -X[1][i][n];
01212             }
01213             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);
01214             mdct->imdct_half(mdct, mdct_buf[1], X[1][i]);
01215             for (n = 0; n < 64; n++) {
01216                 v[      n] = -mdct_buf[0][63 -   n] + mdct_buf[1][  n    ];
01217                 v[127 - n] =  mdct_buf[0][63 -   n] + mdct_buf[1][  n    ];
01218             }
01219         }
01220         dsp->vector_fmul_add(out, v                , sbr_qmf_window               , zero64, 64 >> div);
01221         dsp->vector_fmul_add(out, v + ( 192 >> div), sbr_qmf_window + ( 64 >> div), out   , 64 >> div);
01222         dsp->vector_fmul_add(out, v + ( 256 >> div), sbr_qmf_window + (128 >> div), out   , 64 >> div);
01223         dsp->vector_fmul_add(out, v + ( 448 >> div), sbr_qmf_window + (192 >> div), out   , 64 >> div);
01224         dsp->vector_fmul_add(out, v + ( 512 >> div), sbr_qmf_window + (256 >> div), out   , 64 >> div);
01225         dsp->vector_fmul_add(out, v + ( 704 >> div), sbr_qmf_window + (320 >> div), out   , 64 >> div);
01226         dsp->vector_fmul_add(out, v + ( 768 >> div), sbr_qmf_window + (384 >> div), out   , 64 >> div);
01227         dsp->vector_fmul_add(out, v + ( 960 >> div), sbr_qmf_window + (448 >> div), out   , 64 >> div);
01228         dsp->vector_fmul_add(out, v + (1024 >> div), sbr_qmf_window + (512 >> div), out   , 64 >> div);
01229         dsp->vector_fmul_add(out, v + (1216 >> div), sbr_qmf_window + (576 >> div), out   , 64 >> div);
01230         out += 64 >> div;
01231     }
01232 }
01233 
01234 static void autocorrelate(const float x[40][2], float phi[3][2][2], int lag)
01235 {
01236     int i;
01237     float real_sum = 0.0f;
01238     float imag_sum = 0.0f;
01239     if (lag) {
01240         for (i = 1; i < 38; i++) {
01241             real_sum += x[i][0] * x[i+lag][0] + x[i][1] * x[i+lag][1];
01242             imag_sum += x[i][0] * x[i+lag][1] - x[i][1] * x[i+lag][0];
01243         }
01244         phi[2-lag][1][0] = real_sum + x[ 0][0] * x[lag][0] + x[ 0][1] * x[lag][1];
01245         phi[2-lag][1][1] = imag_sum + x[ 0][0] * x[lag][1] - x[ 0][1] * x[lag][0];
01246         if (lag == 1) {
01247             phi[0][0][0] = real_sum + x[38][0] * x[39][0] + x[38][1] * x[39][1];
01248             phi[0][0][1] = imag_sum + x[38][0] * x[39][1] - x[38][1] * x[39][0];
01249         }
01250     } else {
01251         for (i = 1; i < 38; i++) {
01252             real_sum += x[i][0] * x[i][0] + x[i][1] * x[i][1];
01253         }
01254         phi[2][1][0] = real_sum + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1];
01255         phi[1][0][0] = real_sum + x[38][0] * x[38][0] + x[38][1] * x[38][1];
01256     }
01257 }
01258 
01263 static void sbr_hf_inverse_filter(float (*alpha0)[2], float (*alpha1)[2],
01264                                   const float X_low[32][40][2], int k0)
01265 {
01266     int k;
01267     for (k = 0; k < k0; k++) {
01268         float phi[3][2][2], dk;
01269 
01270         autocorrelate(X_low[k], phi, 0);
01271         autocorrelate(X_low[k], phi, 1);
01272         autocorrelate(X_low[k], phi, 2);
01273 
01274         dk =  phi[2][1][0] * phi[1][0][0] -
01275              (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;
01276 
01277         if (!dk) {
01278             alpha1[k][0] = 0;
01279             alpha1[k][1] = 0;
01280         } else {
01281             float temp_real, temp_im;
01282             temp_real = phi[0][0][0] * phi[1][1][0] -
01283                         phi[0][0][1] * phi[1][1][1] -
01284                         phi[0][1][0] * phi[1][0][0];
01285             temp_im   = phi[0][0][0] * phi[1][1][1] +
01286                         phi[0][0][1] * phi[1][1][0] -
01287                         phi[0][1][1] * phi[1][0][0];
01288 
01289             alpha1[k][0] = temp_real / dk;
01290             alpha1[k][1] = temp_im   / dk;
01291         }
01292 
01293         if (!phi[1][0][0]) {
01294             alpha0[k][0] = 0;
01295             alpha0[k][1] = 0;
01296         } else {
01297             float temp_real, temp_im;
01298             temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +
01299                                        alpha1[k][1] * phi[1][1][1];
01300             temp_im   = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -
01301                                        alpha1[k][0] * phi[1][1][1];
01302 
01303             alpha0[k][0] = -temp_real / phi[1][0][0];
01304             alpha0[k][1] = -temp_im   / phi[1][0][0];
01305         }
01306 
01307         if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||
01308            alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {
01309             alpha1[k][0] = 0;
01310             alpha1[k][1] = 0;
01311             alpha0[k][0] = 0;
01312             alpha0[k][1] = 0;
01313         }
01314     }
01315 }
01316 
01318 static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)
01319 {
01320     int i;
01321     float new_bw;
01322     static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };
01323 
01324     for (i = 0; i < sbr->n_q; i++) {
01325         if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {
01326             new_bw = 0.6f;
01327         } else
01328             new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];
01329 
01330         if (new_bw < ch_data->bw_array[i]) {
01331             new_bw = 0.75f    * new_bw + 0.25f    * ch_data->bw_array[i];
01332         } else
01333             new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];
01334         ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;
01335     }
01336 }
01337 
01339 static int sbr_lf_gen(AACContext *ac, SpectralBandReplication *sbr,
01340                       float X_low[32][40][2], const float W[2][32][32][2])
01341 {
01342     int i, k;
01343     const int t_HFGen = 8;
01344     const int i_f = 32;
01345     memset(X_low, 0, 32*sizeof(*X_low));
01346     for (k = 0; k < sbr->kx[1]; k++) {
01347         for (i = t_HFGen; i < i_f + t_HFGen; i++) {
01348             X_low[k][i][0] = W[1][i - t_HFGen][k][0];
01349             X_low[k][i][1] = W[1][i - t_HFGen][k][1];
01350         }
01351     }
01352     for (k = 0; k < sbr->kx[0]; k++) {
01353         for (i = 0; i < t_HFGen; i++) {
01354             X_low[k][i][0] = W[0][i + i_f - t_HFGen][k][0];
01355             X_low[k][i][1] = W[0][i + i_f - t_HFGen][k][1];
01356         }
01357     }
01358     return 0;
01359 }
01360 
01362 static int sbr_hf_gen(AACContext *ac, SpectralBandReplication *sbr,
01363                       float X_high[64][40][2], const float X_low[32][40][2],
01364                       const float (*alpha0)[2], const float (*alpha1)[2],
01365                       const float bw_array[5], const uint8_t *t_env,
01366                       int bs_num_env)
01367 {
01368     int i, j, x;
01369     int g = 0;
01370     int k = sbr->kx[1];
01371     for (j = 0; j < sbr->num_patches; j++) {
01372         for (x = 0; x < sbr->patch_num_subbands[j]; x++, k++) {
01373             float alpha[4];
01374             const int p = sbr->patch_start_subband[j] + x;
01375             while (g <= sbr->n_q && k >= sbr->f_tablenoise[g])
01376                 g++;
01377             g--;
01378 
01379             if (g < 0) {
01380                 av_log(ac->avctx, AV_LOG_ERROR,
01381                        "ERROR : no subband found for frequency %d\n", k);
01382                 return -1;
01383             }
01384 
01385             alpha[0] = alpha1[p][0] * bw_array[g] * bw_array[g];
01386             alpha[1] = alpha1[p][1] * bw_array[g] * bw_array[g];
01387             alpha[2] = alpha0[p][0] * bw_array[g];
01388             alpha[3] = alpha0[p][1] * bw_array[g];
01389 
01390             for (i = 2 * t_env[0]; i < 2 * t_env[bs_num_env]; i++) {
01391                 const int idx = i + ENVELOPE_ADJUSTMENT_OFFSET;
01392                 X_high[k][idx][0] =
01393                     X_low[p][idx - 2][0] * alpha[0] -
01394                     X_low[p][idx - 2][1] * alpha[1] +
01395                     X_low[p][idx - 1][0] * alpha[2] -
01396                     X_low[p][idx - 1][1] * alpha[3] +
01397                     X_low[p][idx][0];
01398                 X_high[k][idx][1] =
01399                     X_low[p][idx - 2][1] * alpha[0] +
01400                     X_low[p][idx - 2][0] * alpha[1] +
01401                     X_low[p][idx - 1][1] * alpha[2] +
01402                     X_low[p][idx - 1][0] * alpha[3] +
01403                     X_low[p][idx][1];
01404             }
01405         }
01406     }
01407     if (k < sbr->m[1] + sbr->kx[1])
01408         memset(X_high + k, 0, (sbr->m[1] + sbr->kx[1] - k) * sizeof(*X_high));
01409 
01410     return 0;
01411 }
01412 
01414 static int sbr_x_gen(SpectralBandReplication *sbr, float X[2][38][64],
01415                      const float X_low[32][40][2], const float Y[2][38][64][2],
01416                      int ch)
01417 {
01418     int k, i;
01419     const int i_f = 32;
01420     const int i_Temp = FFMAX(2*sbr->data[ch].t_env_num_env_old - i_f, 0);
01421     memset(X, 0, 2*sizeof(*X));
01422     for (k = 0; k < sbr->kx[0]; k++) {
01423         for (i = 0; i < i_Temp; i++) {
01424             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];
01425             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];
01426         }
01427     }
01428     for (; k < sbr->kx[0] + sbr->m[0]; k++) {
01429         for (i = 0; i < i_Temp; i++) {
01430             X[0][i][k] = Y[0][i + i_f][k][0];
01431             X[1][i][k] = Y[0][i + i_f][k][1];
01432         }
01433     }
01434 
01435     for (k = 0; k < sbr->kx[1]; k++) {
01436         for (i = i_Temp; i < 38; i++) {
01437             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];
01438             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];
01439         }
01440     }
01441     for (; k < sbr->kx[1] + sbr->m[1]; k++) {
01442         for (i = i_Temp; i < i_f; i++) {
01443             X[0][i][k] = Y[1][i][k][0];
01444             X[1][i][k] = Y[1][i][k][1];
01445         }
01446     }
01447     return 0;
01448 }
01449 
01453 static void sbr_mapping(AACContext *ac, SpectralBandReplication *sbr,
01454                         SBRData *ch_data, int e_a[2])
01455 {
01456     int e, i, m;
01457 
01458     memset(ch_data->s_indexmapped[1], 0, 7*sizeof(ch_data->s_indexmapped[1]));
01459     for (e = 0; e < ch_data->bs_num_env; e++) {
01460         const unsigned int ilim = sbr->n[ch_data->bs_freq_res[e + 1]];
01461         uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;
01462         int k;
01463 
01464         av_assert0(sbr->kx[1] <= table[0]);
01465         for (i = 0; i < ilim; i++)
01466             for (m = table[i]; m < table[i + 1]; m++)
01467                 sbr->e_origmapped[e][m - sbr->kx[1]] = ch_data->env_facs[e+1][i];
01468 
01469         // ch_data->bs_num_noise > 1 => 2 noise floors
01470         k = (ch_data->bs_num_noise > 1) && (ch_data->t_env[e] >= ch_data->t_q[1]);
01471         for (i = 0; i < sbr->n_q; i++)
01472             for (m = sbr->f_tablenoise[i]; m < sbr->f_tablenoise[i + 1]; m++)
01473                 sbr->q_mapped[e][m - sbr->kx[1]] = ch_data->noise_facs[k+1][i];
01474 
01475         for (i = 0; i < sbr->n[1]; i++) {
01476             if (ch_data->bs_add_harmonic_flag) {
01477                 const unsigned int m_midpoint =
01478                     (sbr->f_tablehigh[i] + sbr->f_tablehigh[i + 1]) >> 1;
01479 
01480                 ch_data->s_indexmapped[e + 1][m_midpoint - sbr->kx[1]] = ch_data->bs_add_harmonic[i] *
01481                     (e >= e_a[1] || (ch_data->s_indexmapped[0][m_midpoint - sbr->kx[1]] == 1));
01482             }
01483         }
01484 
01485         for (i = 0; i < ilim; i++) {
01486             int additional_sinusoid_present = 0;
01487             for (m = table[i]; m < table[i + 1]; m++) {
01488                 if (ch_data->s_indexmapped[e + 1][m - sbr->kx[1]]) {
01489                     additional_sinusoid_present = 1;
01490                     break;
01491                 }
01492             }
01493             memset(&sbr->s_mapped[e][table[i] - sbr->kx[1]], additional_sinusoid_present,
01494                    (table[i + 1] - table[i]) * sizeof(sbr->s_mapped[e][0]));
01495         }
01496     }
01497 
01498     memcpy(ch_data->s_indexmapped[0], ch_data->s_indexmapped[ch_data->bs_num_env], sizeof(ch_data->s_indexmapped[0]));
01499 }
01500 
01502 static void sbr_env_estimate(float (*e_curr)[48], float X_high[64][40][2],
01503                              SpectralBandReplication *sbr, SBRData *ch_data)
01504 {
01505     int e, i, m;
01506 
01507     if (sbr->bs_interpol_freq) {
01508         for (e = 0; e < ch_data->bs_num_env; e++) {
01509             const float recip_env_size = 0.5f / (ch_data->t_env[e + 1] - ch_data->t_env[e]);
01510             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
01511             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
01512 
01513             for (m = 0; m < sbr->m[1]; m++) {
01514                 float sum = 0.0f;
01515 
01516                 for (i = ilb; i < iub; i++) {
01517                     sum += X_high[m + sbr->kx[1]][i][0] * X_high[m + sbr->kx[1]][i][0] +
01518                            X_high[m + sbr->kx[1]][i][1] * X_high[m + sbr->kx[1]][i][1];
01519                 }
01520                 e_curr[e][m] = sum * recip_env_size;
01521             }
01522         }
01523     } else {
01524         int k, p;
01525 
01526         for (e = 0; e < ch_data->bs_num_env; e++) {
01527             const int env_size = 2 * (ch_data->t_env[e + 1] - ch_data->t_env[e]);
01528             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
01529             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
01530             const uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;
01531 
01532             for (p = 0; p < sbr->n[ch_data->bs_freq_res[e + 1]]; p++) {
01533                 float sum = 0.0f;
01534                 const int den = env_size * (table[p + 1] - table[p]);
01535 
01536                 for (k = table[p]; k < table[p + 1]; k++) {
01537                     for (i = ilb; i < iub; i++) {
01538                         sum += X_high[k][i][0] * X_high[k][i][0] +
01539                                X_high[k][i][1] * X_high[k][i][1];
01540                     }
01541                 }
01542                 sum /= den;
01543                 for (k = table[p]; k < table[p + 1]; k++) {
01544                     e_curr[e][k - sbr->kx[1]] = sum;
01545                 }
01546             }
01547         }
01548     }
01549 }
01550 
01555 static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,
01556                           SBRData *ch_data, const int e_a[2])
01557 {
01558     int e, k, m;
01559     // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)
01560     static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };
01561 
01562     for (e = 0; e < ch_data->bs_num_env; e++) {
01563         int delta = !((e == e_a[1]) || (e == e_a[0]));
01564         for (k = 0; k < sbr->n_lim; k++) {
01565             float gain_boost, gain_max;
01566             float sum[2] = { 0.0f, 0.0f };
01567             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
01568                 const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);
01569                 sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);
01570                 sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);
01571                 if (!sbr->s_mapped[e][m]) {
01572                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /
01573                                             ((1.0f + sbr->e_curr[e][m]) *
01574                                              (1.0f + sbr->q_mapped[e][m] * delta)));
01575                 } else {
01576                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /
01577                                             ((1.0f + sbr->e_curr[e][m]) *
01578                                              (1.0f + sbr->q_mapped[e][m])));
01579                 }
01580             }
01581             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
01582                 sum[0] += sbr->e_origmapped[e][m];
01583                 sum[1] += sbr->e_curr[e][m];
01584             }
01585             gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
01586             gain_max = FFMIN(100000.f, gain_max);
01587             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
01588                 float q_m_max   = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];
01589                 sbr->q_m[e][m]  = FFMIN(sbr->q_m[e][m], q_m_max);
01590                 sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);
01591             }
01592             sum[0] = sum[1] = 0.0f;
01593             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
01594                 sum[0] += sbr->e_origmapped[e][m];
01595                 sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]
01596                           + sbr->s_m[e][m] * sbr->s_m[e][m]
01597                           + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];
01598             }
01599             gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
01600             gain_boost = FFMIN(1.584893192f, gain_boost);
01601             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
01602                 sbr->gain[e][m] *= gain_boost;
01603                 sbr->q_m[e][m]  *= gain_boost;
01604                 sbr->s_m[e][m]  *= gain_boost;
01605             }
01606         }
01607     }
01608 }
01609 
01611 static void sbr_hf_assemble(float Y[2][38][64][2], const float X_high[64][40][2],
01612                             SpectralBandReplication *sbr, SBRData *ch_data,
01613                             const int e_a[2])
01614 {
01615     int e, i, j, m;
01616     const int h_SL = 4 * !sbr->bs_smoothing_mode;
01617     const int kx = sbr->kx[1];
01618     const int m_max = sbr->m[1];
01619     static const float h_smooth[5] = {
01620         0.33333333333333,
01621         0.30150283239582,
01622         0.21816949906249,
01623         0.11516383427084,
01624         0.03183050093751,
01625     };
01626     static const int8_t phi[2][4] = {
01627         {  1,  0, -1,  0}, // real
01628         {  0,  1,  0, -1}, // imaginary
01629     };
01630     float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;
01631     int indexnoise = ch_data->f_indexnoise;
01632     int indexsine  = ch_data->f_indexsine;
01633     memcpy(Y[0], Y[1], sizeof(Y[0]));
01634 
01635     if (sbr->reset) {
01636         for (i = 0; i < h_SL; i++) {
01637             memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));
01638             memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0],  m_max * sizeof(sbr->q_m[0][0]));
01639         }
01640     } else if (h_SL) {
01641         memcpy(g_temp[2*ch_data->t_env[0]], g_temp[2*ch_data->t_env_num_env_old], 4*sizeof(g_temp[0]));
01642         memcpy(q_temp[2*ch_data->t_env[0]], q_temp[2*ch_data->t_env_num_env_old], 4*sizeof(q_temp[0]));
01643     }
01644 
01645     for (e = 0; e < ch_data->bs_num_env; e++) {
01646         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
01647             memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));
01648             memcpy(q_temp[h_SL + i], sbr->q_m[e],  m_max * sizeof(sbr->q_m[0][0]));
01649         }
01650     }
01651 
01652     for (e = 0; e < ch_data->bs_num_env; e++) {
01653         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
01654             int phi_sign = (1 - 2*(kx & 1));
01655 
01656             if (h_SL && e != e_a[0] && e != e_a[1]) {
01657                 for (m = 0; m < m_max; m++) {
01658                     const int idx1 = i + h_SL;
01659                     float g_filt = 0.0f;
01660                     for (j = 0; j <= h_SL; j++)
01661                         g_filt += g_temp[idx1 - j][m] * h_smooth[j];
01662                     Y[1][i][m + kx][0] =
01663                         X_high[m + kx][i + ENVELOPE_ADJUSTMENT_OFFSET][0] * g_filt;
01664                     Y[1][i][m + kx][1] =
01665                         X_high[m + kx][i + ENVELOPE_ADJUSTMENT_OFFSET][1] * g_filt;
01666                 }
01667             } else {
01668                 for (m = 0; m < m_max; m++) {
01669                     const float g_filt = g_temp[i + h_SL][m];
01670                     Y[1][i][m + kx][0] =
01671                         X_high[m + kx][i + ENVELOPE_ADJUSTMENT_OFFSET][0] * g_filt;
01672                     Y[1][i][m + kx][1] =
01673                         X_high[m + kx][i + ENVELOPE_ADJUSTMENT_OFFSET][1] * g_filt;
01674                 }
01675             }
01676 
01677             if (e != e_a[0] && e != e_a[1]) {
01678                 for (m = 0; m < m_max; m++) {
01679                     indexnoise = (indexnoise + 1) & 0x1ff;
01680                     if (sbr->s_m[e][m]) {
01681                         Y[1][i][m + kx][0] +=
01682                             sbr->s_m[e][m] * phi[0][indexsine];
01683                         Y[1][i][m + kx][1] +=
01684                             sbr->s_m[e][m] * (phi[1][indexsine] * phi_sign);
01685                     } else {
01686                         float q_filt;
01687                         if (h_SL) {
01688                             const int idx1 = i + h_SL;
01689                             q_filt = 0.0f;
01690                             for (j = 0; j <= h_SL; j++)
01691                                 q_filt += q_temp[idx1 - j][m] * h_smooth[j];
01692                         } else {
01693                             q_filt = q_temp[i][m];
01694                         }
01695                         Y[1][i][m + kx][0] +=
01696                             q_filt * sbr_noise_table[indexnoise][0];
01697                         Y[1][i][m + kx][1] +=
01698                             q_filt * sbr_noise_table[indexnoise][1];
01699                     }
01700                     phi_sign = -phi_sign;
01701                 }
01702             } else {
01703                 indexnoise = (indexnoise + m_max) & 0x1ff;
01704                 for (m = 0; m < m_max; m++) {
01705                     Y[1][i][m + kx][0] +=
01706                         sbr->s_m[e][m] * phi[0][indexsine];
01707                     Y[1][i][m + kx][1] +=
01708                         sbr->s_m[e][m] * (phi[1][indexsine] * phi_sign);
01709                     phi_sign = -phi_sign;
01710                 }
01711             }
01712             indexsine = (indexsine + 1) & 3;
01713         }
01714     }
01715     ch_data->f_indexnoise = indexnoise;
01716     ch_data->f_indexsine  = indexsine;
01717 }
01718 
01719 void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,
01720                   float* L, float* R)
01721 {
01722     int downsampled = ac->m4ac.ext_sample_rate < sbr->sample_rate;
01723     int ch;
01724     int nch = (id_aac == TYPE_CPE) ? 2 : 1;
01725 
01726     if (sbr->start) {
01727         sbr_dequant(sbr, id_aac);
01728     }
01729     for (ch = 0; ch < nch; ch++) {
01730         /* decode channel */
01731         sbr_qmf_analysis(&ac->dsp, &sbr->mdct_ana, ch ? R : L, sbr->data[ch].analysis_filterbank_samples,
01732                          (float*)sbr->qmf_filter_scratch,
01733                          sbr->data[ch].W);
01734         sbr_lf_gen(ac, sbr, sbr->X_low, sbr->data[ch].W);
01735         if (sbr->start) {
01736             sbr_hf_inverse_filter(sbr->alpha0, sbr->alpha1, sbr->X_low, sbr->k[0]);
01737             sbr_chirp(sbr, &sbr->data[ch]);
01738             sbr_hf_gen(ac, sbr, sbr->X_high, sbr->X_low, sbr->alpha0, sbr->alpha1,
01739                        sbr->data[ch].bw_array, sbr->data[ch].t_env,
01740                        sbr->data[ch].bs_num_env);
01741 
01742             // hf_adj
01743             sbr_mapping(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);
01744             sbr_env_estimate(sbr->e_curr, sbr->X_high, sbr, &sbr->data[ch]);
01745             sbr_gain_calc(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);
01746             sbr_hf_assemble(sbr->data[ch].Y, sbr->X_high, sbr, &sbr->data[ch],
01747                             sbr->data[ch].e_a);
01748         }
01749 
01750         /* synthesis */
01751         sbr_x_gen(sbr, sbr->X[ch], sbr->X_low, sbr->data[ch].Y, ch);
01752     }
01753 
01754     if (ac->m4ac.ps == 1) {
01755         if (sbr->ps.start) {
01756             ff_ps_apply(ac->avctx, &sbr->ps, sbr->X[0], sbr->X[1], sbr->kx[1] + sbr->m[1]);
01757         } else {
01758             memcpy(sbr->X[1], sbr->X[0], sizeof(sbr->X[0]));
01759         }
01760         nch = 2;
01761     }
01762 
01763     sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, L, sbr->X[0], sbr->qmf_filter_scratch,
01764                       sbr->data[0].synthesis_filterbank_samples,
01765                       &sbr->data[0].synthesis_filterbank_samples_offset,
01766                       downsampled);
01767     if (nch == 2)
01768         sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, R, sbr->X[1], sbr->qmf_filter_scratch,
01769                           sbr->data[1].synthesis_filterbank_samples,
01770                           &sbr->data[1].synthesis_filterbank_samples_offset,
01771                           downsampled);
01772 }