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FFmpeg/libavcodec/aacsbr.c

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  1. /*

  2.  * AAC Spectral Band Replication decoding functions

  3.  * Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )

  4.  * Copyright (c) 2009-2010 Alex Converse <alex.converse@gmail.com>

  5.  *

  6.  * This file is part of FFmpeg.

  7.  *

  8.  * FFmpeg is free software; you can redistribute it and/or

  9.  * modify it under the terms of the GNU Lesser General Public

  10.  * License as published by the Free Software Foundation; either

  11.  * version 2.1 of the License, or (at your option) any later version.

  12.  *

  13.  * FFmpeg is distributed in the hope that it will be useful,

  14.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  15.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  16.  * Lesser General Public License for more details.

  17.  *

  18.  * You should have received a copy of the GNU Lesser General Public

  19.  * License along with FFmpeg; if not, write to the Free Software

  20.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  21.  */

  22. 

  23. /**

  24.  * @file

  25.  * AAC Spectral Band Replication decoding functions

  26.  * @author Robert Swain ( rob opendot cl )

  27.  */

  28. 

  29. #include "aac.h"

  30. #include "sbr.h"

  31. #include "aacsbr.h"

  32. #include "aacsbrdata.h"

  33. #include "fft.h"

  34. #include "aacps.h"

  35. #include "sbrdsp.h"

  36. #include "libavutil/libm.h"

  37. #include "libavutil/avassert.h"

  38. 

  39. #include <stdint.h>

  40. #include <float.h>

  41. #include <math.h>

  42. 

  43. #define ENVELOPE_ADJUSTMENT_OFFSET 2

  44. #define NOISE_FLOOR_OFFSET 6.0f

  45. 

  46. /**

  47.  * SBR VLC tables

  48.  */

  49. enum {

  50.     T_HUFFMAN_ENV_1_5DB,

  51.     F_HUFFMAN_ENV_1_5DB,

  52.     T_HUFFMAN_ENV_BAL_1_5DB,

  53.     F_HUFFMAN_ENV_BAL_1_5DB,

  54.     T_HUFFMAN_ENV_3_0DB,

  55.     F_HUFFMAN_ENV_3_0DB,

  56.     T_HUFFMAN_ENV_BAL_3_0DB,

  57.     F_HUFFMAN_ENV_BAL_3_0DB,

  58.     T_HUFFMAN_NOISE_3_0DB,

  59.     T_HUFFMAN_NOISE_BAL_3_0DB,

  60. };

  61. 

  62. /**

  63.  * bs_frame_class - frame class of current SBR frame (14496-3 sp04 p98)

  64.  */

  65. enum {

  66.     FIXFIX,

  67.     FIXVAR,

  68.     VARFIX,

  69.     VARVAR,

  70. };

  71. 

  72. enum {

  73.     EXTENSION_ID_PS = 2,

  74. };

  75. 

  76. static VLC vlc_sbr[10];

  77. static const int8_t vlc_sbr_lav[10] =

  78.     { 60, 60, 24, 24, 31, 31, 12, 12, 31, 12 };

  79. 

  80. #define SBR_INIT_VLC_STATIC(num, size) \

  81.     INIT_VLC_STATIC(&vlc_sbr[num], 9, sbr_tmp[num].table_size / sbr_tmp[num].elem_size,     \

  82.                     sbr_tmp[num].sbr_bits ,                      1,                      1, \

  83.                     sbr_tmp[num].sbr_codes, sbr_tmp[num].elem_size, sbr_tmp[num].elem_size, \

  84.                     size)

  85. 

  86. #define SBR_VLC_ROW(name) \

  87.     { name ## _codes, name ## _bits, sizeof(name ## _codes), sizeof(name ## _codes[0]) }

  88. 

  89. av_cold void ff_aac_sbr_init(void)

  90. {

  91.     int n;

  92.     static const struct {

  93.         const void *sbr_codes, *sbr_bits;

  94.         const unsigned int table_size, elem_size;

  95.     } sbr_tmp[] = {

  96.         SBR_VLC_ROW(t_huffman_env_1_5dB),

  97.         SBR_VLC_ROW(f_huffman_env_1_5dB),

  98.         SBR_VLC_ROW(t_huffman_env_bal_1_5dB),

  99.         SBR_VLC_ROW(f_huffman_env_bal_1_5dB),

  100.         SBR_VLC_ROW(t_huffman_env_3_0dB),

  101.         SBR_VLC_ROW(f_huffman_env_3_0dB),

  102.         SBR_VLC_ROW(t_huffman_env_bal_3_0dB),

  103.         SBR_VLC_ROW(f_huffman_env_bal_3_0dB),

  104.         SBR_VLC_ROW(t_huffman_noise_3_0dB),

  105.         SBR_VLC_ROW(t_huffman_noise_bal_3_0dB),

  106.     };

  107. 

  108.     // SBR VLC table initialization

  109.     SBR_INIT_VLC_STATIC(0, 1098);

  110.     SBR_INIT_VLC_STATIC(1, 1092);

  111.     SBR_INIT_VLC_STATIC(2, 768);

  112.     SBR_INIT_VLC_STATIC(3, 1026);

  113.     SBR_INIT_VLC_STATIC(4, 1058);

  114.     SBR_INIT_VLC_STATIC(5, 1052);

  115.     SBR_INIT_VLC_STATIC(6, 544);

  116.     SBR_INIT_VLC_STATIC(7, 544);

  117.     SBR_INIT_VLC_STATIC(8, 592);

  118.     SBR_INIT_VLC_STATIC(9, 512);

  119. 

  120.     for (n = 1; n < 320; n++)

  121.         sbr_qmf_window_us[320 + n] = sbr_qmf_window_us[320 - n];

  122.     sbr_qmf_window_us[384] = -sbr_qmf_window_us[384];

  123.     sbr_qmf_window_us[512] = -sbr_qmf_window_us[512];

  124. 

  125.     for (n = 0; n < 320; n++)

  126.         sbr_qmf_window_ds[n] = sbr_qmf_window_us[2*n];

  127. 

  128.     ff_ps_init();

  129. }

  130. 

  131. /** Places SBR in pure upsampling mode. */

  132. static void sbr_turnoff(SpectralBandReplication *sbr) {

  133.     sbr->start = 0;

  134.     // Init defults used in pure upsampling mode

  135.     sbr->kx[1] = 32; //Typo in spec, kx' inits to 32

  136.     sbr->m[1] = 0;

  137.     // Reset values for first SBR header

  138.     sbr->data[0].e_a[1] = sbr->data[1].e_a[1] = -1;

  139.     memset(&sbr->spectrum_params, -1, sizeof(SpectrumParameters));

  140. }

  141. 

  142. av_cold void ff_aac_sbr_ctx_init(AACContext *ac, SpectralBandReplication *sbr)

  143. {

  144.     if(sbr->mdct.mdct_bits)

  145.         return;

  146.     sbr->kx[0] = sbr->kx[1];

  147.     sbr_turnoff(sbr);

  148.     sbr->data[0].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128);

  149.     sbr->data[1].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128);

  150.     /* SBR requires samples to be scaled to +/-32768.0 to work correctly.

  151.      * mdct scale factors are adjusted to scale up from +/-1.0 at analysis

  152.      * and scale back down at synthesis. */

  153.     ff_mdct_init(&sbr->mdct,     7, 1, 1.0 / (64 * 32768.0));

  154.     ff_mdct_init(&sbr->mdct_ana, 7, 1, -2.0 * 32768.0);

  155.     ff_ps_ctx_init(&sbr->ps);

  156.     ff_sbrdsp_init(&sbr->dsp);

  157. }

  158. 

  159. av_cold void ff_aac_sbr_ctx_close(SpectralBandReplication *sbr)

  160. {

  161.     ff_mdct_end(&sbr->mdct);

  162.     ff_mdct_end(&sbr->mdct_ana);

  163. }

  164. 

  165. static int qsort_comparison_function_int16(const void *a, const void *b)

  166. {

  167.     return *(const int16_t *)a - *(const int16_t *)b;

  168. }

  169. 

  170. static inline int in_table_int16(const int16_t *table, int last_el, int16_t needle)

  171. {

  172.     int i;

  173.     for (i = 0; i <= last_el; i++)

  174.         if (table[i] == needle)

  175.             return 1;

  176.     return 0;

  177. }

  178. 

  179. /// Limiter Frequency Band Table (14496-3 sp04 p198)

  180. static void sbr_make_f_tablelim(SpectralBandReplication *sbr)

  181. {

  182.     int k;

  183.     if (sbr->bs_limiter_bands > 0) {

  184.         static const float bands_warped[3] = { 1.32715174233856803909f,   //2^(0.49/1.2)

  185.                                                1.18509277094158210129f,   //2^(0.49/2)

  186.                                                1.11987160404675912501f }; //2^(0.49/3)

  187.         const float lim_bands_per_octave_warped = bands_warped[sbr->bs_limiter_bands - 1];

  188.         int16_t patch_borders[7];

  189.         uint16_t *in = sbr->f_tablelim + 1, *out = sbr->f_tablelim;

  190. 

  191.         patch_borders[0] = sbr->kx[1];

  192.         for (k = 1; k <= sbr->num_patches; k++)

  193.             patch_borders[k] = patch_borders[k-1] + sbr->patch_num_subbands[k-1];

  194. 

  195.         memcpy(sbr->f_tablelim, sbr->f_tablelow,

  196.                (sbr->n[0] + 1) * sizeof(sbr->f_tablelow[0]));

  197.         if (sbr->num_patches > 1)

  198.             memcpy(sbr->f_tablelim + sbr->n[0] + 1, patch_borders + 1,

  199.                    (sbr->num_patches - 1) * sizeof(patch_borders[0]));

  200. 

  201.         qsort(sbr->f_tablelim, sbr->num_patches + sbr->n[0],

  202.               sizeof(sbr->f_tablelim[0]),

  203.               qsort_comparison_function_int16);

  204. 

  205.         sbr->n_lim = sbr->n[0] + sbr->num_patches - 1;

  206.         while (out < sbr->f_tablelim + sbr->n_lim) {

  207.             if (*in >= *out * lim_bands_per_octave_warped) {

  208.                 *++out = *in++;

  209.             } else if (*in == *out ||

  210.                 !in_table_int16(patch_borders, sbr->num_patches, *in)) {

  211.                 in++;

  212.                 sbr->n_lim--;

  213.             } else if (!in_table_int16(patch_borders, sbr->num_patches, *out)) {

  214.                 *out = *in++;

  215.                 sbr->n_lim--;

  216.             } else {

  217.                 *++out = *in++;

  218.             }

  219.         }

  220.     } else {

  221.         sbr->f_tablelim[0] = sbr->f_tablelow[0];

  222.         sbr->f_tablelim[1] = sbr->f_tablelow[sbr->n[0]];

  223.         sbr->n_lim = 1;

  224.     }

  225. }

  226. 

  227. static unsigned int read_sbr_header(SpectralBandReplication *sbr, GetBitContext *gb)

  228. {

  229.     unsigned int cnt = get_bits_count(gb);

  230.     uint8_t bs_header_extra_1;

  231.     uint8_t bs_header_extra_2;

  232.     int old_bs_limiter_bands = sbr->bs_limiter_bands;

  233.     SpectrumParameters old_spectrum_params;

  234. 

  235.     sbr->start = 1;

  236. 

  237.     // Save last spectrum parameters variables to compare to new ones

  238.     memcpy(&old_spectrum_params, &sbr->spectrum_params, sizeof(SpectrumParameters));

  239. 

  240.     sbr->bs_amp_res_header              = get_bits1(gb);

  241.     sbr->spectrum_params.bs_start_freq  = get_bits(gb, 4);

  242.     sbr->spectrum_params.bs_stop_freq   = get_bits(gb, 4);

  243.     sbr->spectrum_params.bs_xover_band  = get_bits(gb, 3);

  244.                                           skip_bits(gb, 2); // bs_reserved

  245. 

  246.     bs_header_extra_1 = get_bits1(gb);

  247.     bs_header_extra_2 = get_bits1(gb);

  248. 

  249.     if (bs_header_extra_1) {

  250.         sbr->spectrum_params.bs_freq_scale  = get_bits(gb, 2);

  251.         sbr->spectrum_params.bs_alter_scale = get_bits1(gb);

  252.         sbr->spectrum_params.bs_noise_bands = get_bits(gb, 2);

  253.     } else {

  254.         sbr->spectrum_params.bs_freq_scale  = 2;

  255.         sbr->spectrum_params.bs_alter_scale = 1;

  256.         sbr->spectrum_params.bs_noise_bands = 2;

  257.     }

  258. 

  259.     // Check if spectrum parameters changed

  260.     if (memcmp(&old_spectrum_params, &sbr->spectrum_params, sizeof(SpectrumParameters)))

  261.         sbr->reset = 1;

  262. 

  263.     if (bs_header_extra_2) {

  264.         sbr->bs_limiter_bands  = get_bits(gb, 2);

  265.         sbr->bs_limiter_gains  = get_bits(gb, 2);

  266.         sbr->bs_interpol_freq  = get_bits1(gb);

  267.         sbr->bs_smoothing_mode = get_bits1(gb);

  268.     } else {

  269.         sbr->bs_limiter_bands  = 2;

  270.         sbr->bs_limiter_gains  = 2;

  271.         sbr->bs_interpol_freq  = 1;

  272.         sbr->bs_smoothing_mode = 1;

  273.     }

  274. 

  275.     if (sbr->bs_limiter_bands != old_bs_limiter_bands && !sbr->reset)

  276.         sbr_make_f_tablelim(sbr);

  277. 

  278.     return get_bits_count(gb) - cnt;

  279. }

  280. 

  281. static int array_min_int16(const int16_t *array, int nel)

  282. {

  283.     int i, min = array[0];

  284.     for (i = 1; i < nel; i++)

  285.         min = FFMIN(array[i], min);

  286.     return min;

  287. }

  288. 

  289. static void make_bands(int16_t* bands, int start, int stop, int num_bands)

  290. {

  291.     int k, previous, present;

  292.     float base, prod;

  293. 

  294.     base = powf((float)stop / start, 1.0f / num_bands);

  295.     prod = start;

  296.     previous = start;

  297. 

  298.     for (k = 0; k < num_bands-1; k++) {

  299.         prod *= base;

  300.         present  = lrintf(prod);

  301.         bands[k] = present - previous;

  302.         previous = present;

  303.     }

  304.     bands[num_bands-1] = stop - previous;

  305. }

  306. 

  307. static int check_n_master(AVCodecContext *avctx, int n_master, int bs_xover_band)

  308. {

  309.     // Requirements (14496-3 sp04 p205)

  310.     if (n_master <= 0) {

  311.         av_log(avctx, AV_LOG_ERROR, "Invalid n_master: %d\n", n_master);

  312.         return -1;

  313.     }

  314.     if (bs_xover_band >= n_master) {

  315.         av_log(avctx, AV_LOG_ERROR,

  316.                "Invalid bitstream, crossover band index beyond array bounds: %d\n",

  317.                bs_xover_band);

  318.         return -1;

  319.     }

  320.     return 0;

  321. }

  322. 

  323. /// Master Frequency Band Table (14496-3 sp04 p194)

  324. static int sbr_make_f_master(AACContext *ac, SpectralBandReplication *sbr,

  325.                              SpectrumParameters *spectrum)

  326. {

  327.     unsigned int temp, max_qmf_subbands;

  328.     unsigned int start_min, stop_min;

  329.     int k;

  330.     const int8_t *sbr_offset_ptr;

  331.     int16_t stop_dk[13];

  332. 

  333.     if (sbr->sample_rate < 32000) {

  334.         temp = 3000;

  335.     } else if (sbr->sample_rate < 64000) {

  336.         temp = 4000;

  337.     } else

  338.         temp = 5000;

  339. 

  340.     switch (sbr->sample_rate) {

  341.     case 16000:

  342.         sbr_offset_ptr = sbr_offset[0];

  343.         break;

  344.     case 22050:

  345.         sbr_offset_ptr = sbr_offset[1];

  346.         break;

  347.     case 24000:

  348.         sbr_offset_ptr = sbr_offset[2];

  349.         break;

  350.     case 32000:

  351.         sbr_offset_ptr = sbr_offset[3];

  352.         break;

  353.     case 44100: case 48000: case 64000:

  354.         sbr_offset_ptr = sbr_offset[4];

  355.         break;

  356.     case 88200: case 96000: case 128000: case 176400: case 192000:

  357.         sbr_offset_ptr = sbr_offset[5];

  358.         break;

  359.     default:

  360.         av_log(ac->avctx, AV_LOG_ERROR,

  361.                "Unsupported sample rate for SBR: %d\n", sbr->sample_rate);

  362.         return -1;

  363.     }

  364. 

  365.     start_min = ((temp << 7) + (sbr->sample_rate >> 1)) / sbr->sample_rate;

  366.     stop_min  = ((temp << 8) + (sbr->sample_rate >> 1)) / sbr->sample_rate;

  367. 

  368.     sbr->k[0] = start_min + sbr_offset_ptr[spectrum->bs_start_freq];

  369. 

  370.     if (spectrum->bs_stop_freq < 14) {

  371.         sbr->k[2] = stop_min;

  372.         make_bands(stop_dk, stop_min, 64, 13);

  373.         qsort(stop_dk, 13, sizeof(stop_dk[0]), qsort_comparison_function_int16);

  374.         for (k = 0; k < spectrum->bs_stop_freq; k++)

  375.             sbr->k[2] += stop_dk[k];

  376.     } else if (spectrum->bs_stop_freq == 14) {

  377.         sbr->k[2] = 2*sbr->k[0];

  378.     } else if (spectrum->bs_stop_freq == 15) {

  379.         sbr->k[2] = 3*sbr->k[0];

  380.     } else {

  381.         av_log(ac->avctx, AV_LOG_ERROR,

  382.                "Invalid bs_stop_freq: %d\n", spectrum->bs_stop_freq);

  383.         return -1;

  384.     }

  385.     sbr->k[2] = FFMIN(64, sbr->k[2]);

  386. 

  387.     // Requirements (14496-3 sp04 p205)

  388.     if (sbr->sample_rate <= 32000) {

  389.         max_qmf_subbands = 48;

  390.     } else if (sbr->sample_rate == 44100) {

  391.         max_qmf_subbands = 35;

  392.     } else if (sbr->sample_rate >= 48000)

  393.         max_qmf_subbands = 32;

  394. 

  395.     if (sbr->k[2] - sbr->k[0] > max_qmf_subbands) {

  396.         av_log(ac->avctx, AV_LOG_ERROR,

  397.                "Invalid bitstream, too many QMF subbands: %d\n", sbr->k[2] - sbr->k[0]);

  398.         return -1;

  399.     }

  400. 

  401.     if (!spectrum->bs_freq_scale) {

  402.         int dk, k2diff;

  403. 

  404.         dk = spectrum->bs_alter_scale + 1;

  405.         sbr->n_master = ((sbr->k[2] - sbr->k[0] + (dk&2)) >> dk) << 1;

  406.         if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))

  407.             return -1;

  408. 

  409.         for (k = 1; k <= sbr->n_master; k++)

  410.             sbr->f_master[k] = dk;

  411. 

  412.         k2diff = sbr->k[2] - sbr->k[0] - sbr->n_master * dk;

  413.         if (k2diff < 0) {

  414.             sbr->f_master[1]--;

  415.             sbr->f_master[2]-= (k2diff < -1);

  416.         } else if (k2diff) {

  417.             sbr->f_master[sbr->n_master]++;

  418.         }

  419. 

  420.         sbr->f_master[0] = sbr->k[0];

  421.         for (k = 1; k <= sbr->n_master; k++)

  422.             sbr->f_master[k] += sbr->f_master[k - 1];

  423. 

  424.     } else {

  425.         int half_bands = 7 - spectrum->bs_freq_scale;      // bs_freq_scale  = {1,2,3}

  426.         int two_regions, num_bands_0;

  427.         int vdk0_max, vdk1_min;

  428.         int16_t vk0[49];

  429. 

  430.         if (49 * sbr->k[2] > 110 * sbr->k[0]) {

  431.             two_regions = 1;

  432.             sbr->k[1] = 2 * sbr->k[0];

  433.         } else {

  434.             two_regions = 0;

  435.             sbr->k[1] = sbr->k[2];

  436.         }

  437. 

  438.         num_bands_0 = lrintf(half_bands * log2f(sbr->k[1] / (float)sbr->k[0])) * 2;

  439. 

  440.         if (num_bands_0 <= 0) { // Requirements (14496-3 sp04 p205)

  441.             av_log(ac->avctx, AV_LOG_ERROR, "Invalid num_bands_0: %d\n", num_bands_0);

  442.             return -1;

  443.         }

  444. 

  445.         vk0[0] = 0;

  446. 

  447.         make_bands(vk0+1, sbr->k[0], sbr->k[1], num_bands_0);

  448. 

  449.         qsort(vk0 + 1, num_bands_0, sizeof(vk0[1]), qsort_comparison_function_int16);

  450.         vdk0_max = vk0[num_bands_0];

  451. 

  452.         vk0[0] = sbr->k[0];

  453.         for (k = 1; k <= num_bands_0; k++) {

  454.             if (vk0[k] <= 0) { // Requirements (14496-3 sp04 p205)

  455.                 av_log(ac->avctx, AV_LOG_ERROR, "Invalid vDk0[%d]: %d\n", k, vk0[k]);

  456.                 return -1;

  457.             }

  458.             vk0[k] += vk0[k-1];

  459.         }

  460. 

  461.         if (two_regions) {

  462.             int16_t vk1[49];

  463.             float invwarp = spectrum->bs_alter_scale ? 0.76923076923076923077f

  464.                                                      : 1.0f; // bs_alter_scale = {0,1}

  465.             int num_bands_1 = lrintf(half_bands * invwarp *

  466.                                      log2f(sbr->k[2] / (float)sbr->k[1])) * 2;

  467. 

  468.             make_bands(vk1+1, sbr->k[1], sbr->k[2], num_bands_1);

  469. 

  470.             vdk1_min = array_min_int16(vk1 + 1, num_bands_1);

  471. 

  472.             if (vdk1_min < vdk0_max) {

  473.                 int change;

  474.                 qsort(vk1 + 1, num_bands_1, sizeof(vk1[1]), qsort_comparison_function_int16);

  475.                 change = FFMIN(vdk0_max - vk1[1], (vk1[num_bands_1] - vk1[1]) >> 1);

  476.                 vk1[1]           += change;

  477.                 vk1[num_bands_1] -= change;

  478.             }

  479. 

  480.             qsort(vk1 + 1, num_bands_1, sizeof(vk1[1]), qsort_comparison_function_int16);

  481. 

  482.             vk1[0] = sbr->k[1];

  483.             for (k = 1; k <= num_bands_1; k++) {

  484.                 if (vk1[k] <= 0) { // Requirements (14496-3 sp04 p205)

  485.                     av_log(ac->avctx, AV_LOG_ERROR, "Invalid vDk1[%d]: %d\n", k, vk1[k]);

  486.                     return -1;

  487.                 }

  488.                 vk1[k] += vk1[k-1];

  489.             }

  490. 

  491.             sbr->n_master = num_bands_0 + num_bands_1;

  492.             if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))

  493.                 return -1;

  494.             memcpy(&sbr->f_master[0],               vk0,

  495.                    (num_bands_0 + 1) * sizeof(sbr->f_master[0]));

  496.             memcpy(&sbr->f_master[num_bands_0 + 1], vk1 + 1,

  497.                     num_bands_1      * sizeof(sbr->f_master[0]));

  498. 

  499.         } else {

  500.             sbr->n_master = num_bands_0;

  501.             if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))

  502.                 return -1;

  503.             memcpy(sbr->f_master, vk0, (num_bands_0 + 1) * sizeof(sbr->f_master[0]));

  504.         }

  505.     }

  506. 

  507.     return 0;

  508. }

  509. 

  510. /// High Frequency Generation - Patch Construction (14496-3 sp04 p216 fig. 4.46)

  511. static int sbr_hf_calc_npatches(AACContext *ac, SpectralBandReplication *sbr)

  512. {

  513.     int i, k, sb = 0;

  514.     int msb = sbr->k[0];

  515.     int usb = sbr->kx[1];

  516.     int goal_sb = ((1000 << 11) + (sbr->sample_rate >> 1)) / sbr->sample_rate;

  517. 

  518.     sbr->num_patches = 0;

  519. 

  520.     if (goal_sb < sbr->kx[1] + sbr->m[1]) {

  521.         for (k = 0; sbr->f_master[k] < goal_sb; k++) ;

  522.     } else

  523.         k = sbr->n_master;

  524. 

  525.     do {

  526.         int odd = 0;

  527.         for (i = k; i == k || sb > (sbr->k[0] - 1 + msb - odd); i--) {

  528.             sb = sbr->f_master[i];

  529.             odd = (sb + sbr->k[0]) & 1;

  530.         }

  531. 

  532.         // Requirements (14496-3 sp04 p205) sets the maximum number of patches to 5.

  533.         // After this check the final number of patches can still be six which is

  534.         // illegal however the Coding Technologies decoder check stream has a final

  535.         // count of 6 patches

  536.         if (sbr->num_patches > 5) {

  537.             av_log(ac->avctx, AV_LOG_ERROR, "Too many patches: %d\n", sbr->num_patches);

  538.             return -1;

  539.         }

  540. 

  541.         sbr->patch_num_subbands[sbr->num_patches]  = FFMAX(sb - usb, 0);

  542.         sbr->patch_start_subband[sbr->num_patches] = sbr->k[0] - odd - sbr->patch_num_subbands[sbr->num_patches];

  543. 

  544.         if (sbr->patch_num_subbands[sbr->num_patches] > 0) {

  545.             usb = sb;

  546.             msb = sb;

  547.             sbr->num_patches++;

  548.         } else

  549.             msb = sbr->kx[1];

  550. 

  551.         if (sbr->f_master[k] - sb < 3)

  552.             k = sbr->n_master;

  553.     } while (sb != sbr->kx[1] + sbr->m[1]);

  554. 

  555.     if (sbr->num_patches > 1 && sbr->patch_num_subbands[sbr->num_patches-1] < 3)

  556.         sbr->num_patches--;

  557. 

  558.     return 0;

  559. }

  560. 

  561. /// Derived Frequency Band Tables (14496-3 sp04 p197)

  562. static int sbr_make_f_derived(AACContext *ac, SpectralBandReplication *sbr)

  563. {

  564.     int k, temp;

  565. 

  566.     sbr->n[1] = sbr->n_master - sbr->spectrum_params.bs_xover_band;

  567.     sbr->n[0] = (sbr->n[1] + 1) >> 1;

  568. 

  569.     memcpy(sbr->f_tablehigh, &sbr->f_master[sbr->spectrum_params.bs_xover_band],

  570.            (sbr->n[1] + 1) * sizeof(sbr->f_master[0]));

  571.     sbr->m[1] = sbr->f_tablehigh[sbr->n[1]] - sbr->f_tablehigh[0];

  572.     sbr->kx[1] = sbr->f_tablehigh[0];

  573. 

  574.     // Requirements (14496-3 sp04 p205)

  575.     if (sbr->kx[1] + sbr->m[1] > 64) {

  576.         av_log(ac->avctx, AV_LOG_ERROR,

  577.                "Stop frequency border too high: %d\n", sbr->kx[1] + sbr->m[1]);

  578.         return -1;

  579.     }

  580.     if (sbr->kx[1] > 32) {

  581.         av_log(ac->avctx, AV_LOG_ERROR, "Start frequency border too high: %d\n", sbr->kx[1]);

  582.         return -1;

  583.     }

  584. 

  585.     sbr->f_tablelow[0] = sbr->f_tablehigh[0];

  586.     temp = sbr->n[1] & 1;

  587.     for (k = 1; k <= sbr->n[0]; k++)

  588.         sbr->f_tablelow[k] = sbr->f_tablehigh[2 * k - temp];

  589. 

  590.     sbr->n_q = FFMAX(1, lrintf(sbr->spectrum_params.bs_noise_bands *

  591.                                log2f(sbr->k[2] / (float)sbr->kx[1]))); // 0 <= bs_noise_bands <= 3

  592.     if (sbr->n_q > 5) {

  593.         av_log(ac->avctx, AV_LOG_ERROR, "Too many noise floor scale factors: %d\n", sbr->n_q);

  594.         return -1;

  595.     }

  596. 

  597.     sbr->f_tablenoise[0] = sbr->f_tablelow[0];

  598.     temp = 0;

  599.     for (k = 1; k <= sbr->n_q; k++) {

  600.         temp += (sbr->n[0] - temp) / (sbr->n_q + 1 - k);

  601.         sbr->f_tablenoise[k] = sbr->f_tablelow[temp];

  602.     }

  603. 

  604.     if (sbr_hf_calc_npatches(ac, sbr) < 0)

  605.         return -1;

  606. 

  607.     sbr_make_f_tablelim(sbr);

  608. 

  609.     sbr->data[0].f_indexnoise = 0;

  610.     sbr->data[1].f_indexnoise = 0;

  611. 

  612.     return 0;

  613. }

  614. 

  615. static av_always_inline void get_bits1_vector(GetBitContext *gb, uint8_t *vec,

  616.                                               int elements)

  617. {

  618.     int i;

  619.     for (i = 0; i < elements; i++) {

  620.         vec[i] = get_bits1(gb);

  621.     }

  622. }

  623. 

  624. /** ceil(log2(index+1)) */

  625. static const int8_t ceil_log2[] = {

  626.     0, 1, 2, 2, 3, 3,

  627. };

  628. 

  629. static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr,

  630.                          GetBitContext *gb, SBRData *ch_data)

  631. {

  632.     int i;

  633.     unsigned bs_pointer = 0;

  634.     // frameLengthFlag ? 15 : 16; 960 sample length frames unsupported; this value is numTimeSlots

  635.     int abs_bord_trail = 16;

  636.     int num_rel_lead, num_rel_trail;

  637.     unsigned bs_num_env_old = ch_data->bs_num_env;

  638. 

  639.     ch_data->bs_freq_res[0] = ch_data->bs_freq_res[ch_data->bs_num_env];

  640.     ch_data->bs_amp_res = sbr->bs_amp_res_header;

  641.     ch_data->t_env_num_env_old = ch_data->t_env[bs_num_env_old];

  642. 

  643.     switch (ch_data->bs_frame_class = get_bits(gb, 2)) {

  644.     case FIXFIX:

  645.         ch_data->bs_num_env                 = 1 << get_bits(gb, 2);

  646.         num_rel_lead                        = ch_data->bs_num_env - 1;

  647.         if (ch_data->bs_num_env == 1)

  648.             ch_data->bs_amp_res = 0;

  649. 

  650.         if (ch_data->bs_num_env > 4) {

  651.             av_log(ac->avctx, AV_LOG_ERROR,

  652.                    "Invalid bitstream, too many SBR envelopes in FIXFIX type SBR frame: %d\n",

  653.                    ch_data->bs_num_env);

  654.             return -1;

  655.         }

  656. 

  657.         ch_data->t_env[0]                   = 0;

  658.         ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;

  659. 

  660.         abs_bord_trail = (abs_bord_trail + (ch_data->bs_num_env >> 1)) /

  661.                    ch_data->bs_num_env;

  662.         for (i = 0; i < num_rel_lead; i++)

  663.             ch_data->t_env[i + 1] = ch_data->t_env[i] + abs_bord_trail;

  664. 

  665.         ch_data->bs_freq_res[1] = get_bits1(gb);

  666.         for (i = 1; i < ch_data->bs_num_env; i++)

  667.             ch_data->bs_freq_res[i + 1] = ch_data->bs_freq_res[1];

  668.         break;

  669.     case FIXVAR:

  670.         abs_bord_trail                     += get_bits(gb, 2);

  671.         num_rel_trail                       = get_bits(gb, 2);

  672.         ch_data->bs_num_env                 = num_rel_trail + 1;

  673.         ch_data->t_env[0]                   = 0;

  674.         ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;

  675. 

  676.         for (i = 0; i < num_rel_trail; i++)

  677.             ch_data->t_env[ch_data->bs_num_env - 1 - i] =

  678.                 ch_data->t_env[ch_data->bs_num_env - i] - 2 * get_bits(gb, 2) - 2;

  679. 

  680.         bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);

  681. 

  682.         for (i = 0; i < ch_data->bs_num_env; i++)

  683.             ch_data->bs_freq_res[ch_data->bs_num_env - i] = get_bits1(gb);

  684.         break;

  685.     case VARFIX:

  686.         ch_data->t_env[0]                   = get_bits(gb, 2);

  687.         num_rel_lead                        = get_bits(gb, 2);

  688.         ch_data->bs_num_env                 = num_rel_lead + 1;

  689.         ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;

  690. 

  691.         for (i = 0; i < num_rel_lead; i++)

  692.             ch_data->t_env[i + 1] = ch_data->t_env[i] + 2 * get_bits(gb, 2) + 2;

  693. 

  694.         bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);

  695. 

  696.         get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env);

  697.         break;

  698.     case VARVAR:

  699.         ch_data->t_env[0]                   = get_bits(gb, 2);

  700.         abs_bord_trail                     += get_bits(gb, 2);

  701.         num_rel_lead                        = get_bits(gb, 2);

  702.         num_rel_trail                       = get_bits(gb, 2);

  703.         ch_data->bs_num_env                 = num_rel_lead + num_rel_trail + 1;

  704. 

  705.         if (ch_data->bs_num_env > 5) {

  706.             av_log(ac->avctx, AV_LOG_ERROR,

  707.                    "Invalid bitstream, too many SBR envelopes in VARVAR type SBR frame: %d\n",

  708.                    ch_data->bs_num_env);

  709.             return -1;

  710.         }

  711. 

  712.         ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;

  713. 

  714.         for (i = 0; i < num_rel_lead; i++)

  715.             ch_data->t_env[i + 1] = ch_data->t_env[i] + 2 * get_bits(gb, 2) + 2;

  716.         for (i = 0; i < num_rel_trail; i++)

  717.             ch_data->t_env[ch_data->bs_num_env - 1 - i] =

  718.                 ch_data->t_env[ch_data->bs_num_env - i] - 2 * get_bits(gb, 2) - 2;

  719. 

  720.         bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);

  721. 

  722.         get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env);

  723.         break;

  724.     }

  725. 

  726.     if (bs_pointer > ch_data->bs_num_env + 1) {

  727.         av_log(ac->avctx, AV_LOG_ERROR,

  728.                "Invalid bitstream, bs_pointer points to a middle noise border outside the time borders table: %d\n",

  729.                bs_pointer);

  730.         return -1;

  731.     }

  732. 

  733.     for (i = 1; i <= ch_data->bs_num_env; i++) {

  734.         if (ch_data->t_env[i-1] > ch_data->t_env[i]) {

  735.             av_log(ac->avctx, AV_LOG_ERROR, "Non monotone time borders\n");

  736.             return -1;

  737.         }

  738.     }

  739. 

  740.     ch_data->bs_num_noise = (ch_data->bs_num_env > 1) + 1;

  741. 

  742.     ch_data->t_q[0]                     = ch_data->t_env[0];

  743.     ch_data->t_q[ch_data->bs_num_noise] = ch_data->t_env[ch_data->bs_num_env];

  744.     if (ch_data->bs_num_noise > 1) {

  745.         unsigned int idx;

  746.         if (ch_data->bs_frame_class == FIXFIX) {

  747.             idx = ch_data->bs_num_env >> 1;

  748.         } else if (ch_data->bs_frame_class & 1) { // FIXVAR or VARVAR

  749.             idx = ch_data->bs_num_env - FFMAX((int)bs_pointer - 1, 1);

  750.         } else { // VARFIX

  751.             if (!bs_pointer)

  752.                 idx = 1;

  753.             else if (bs_pointer == 1)

  754.                 idx = ch_data->bs_num_env - 1;

  755.             else // bs_pointer > 1

  756.                 idx = bs_pointer - 1;

  757.         }

  758.         ch_data->t_q[1] = ch_data->t_env[idx];

  759.     }

  760. 

  761.     ch_data->e_a[0] = -(ch_data->e_a[1] != bs_num_env_old); // l_APrev

  762.     ch_data->e_a[1] = -1;

  763.     if ((ch_data->bs_frame_class & 1) && bs_pointer) { // FIXVAR or VARVAR and bs_pointer != 0

  764.         ch_data->e_a[1] = ch_data->bs_num_env + 1 - bs_pointer;

  765.     } else if ((ch_data->bs_frame_class == 2) && (bs_pointer > 1)) // VARFIX and bs_pointer > 1

  766.         ch_data->e_a[1] = bs_pointer - 1;

  767. 

  768.     return 0;

  769. }

  770. 

  771. static void copy_sbr_grid(SBRData *dst, const SBRData *src) {

  772.     //These variables are saved from the previous frame rather than copied

  773.     dst->bs_freq_res[0]    = dst->bs_freq_res[dst->bs_num_env];

  774.     dst->t_env_num_env_old = dst->t_env[dst->bs_num_env];

  775.     dst->e_a[0]            = -(dst->e_a[1] != dst->bs_num_env);

  776. 

  777.     //These variables are read from the bitstream and therefore copied

  778.     memcpy(dst->bs_freq_res+1, src->bs_freq_res+1, sizeof(dst->bs_freq_res)-sizeof(*dst->bs_freq_res));

  779.     memcpy(dst->t_env,         src->t_env,         sizeof(dst->t_env));

  780.     memcpy(dst->t_q,           src->t_q,           sizeof(dst->t_q));

  781.     dst->bs_num_env        = src->bs_num_env;

  782.     dst->bs_amp_res        = src->bs_amp_res;

  783.     dst->bs_num_noise      = src->bs_num_noise;

  784.     dst->bs_frame_class    = src->bs_frame_class;

  785.     dst->e_a[1]            = src->e_a[1];

  786. }

  787. 

  788. /// Read how the envelope and noise floor data is delta coded

  789. static void read_sbr_dtdf(SpectralBandReplication *sbr, GetBitContext *gb,

  790.                           SBRData *ch_data)

  791. {

  792.     get_bits1_vector(gb, ch_data->bs_df_env,   ch_data->bs_num_env);

  793.     get_bits1_vector(gb, ch_data->bs_df_noise, ch_data->bs_num_noise);

  794. }

  795. 

  796. /// Read inverse filtering data

  797. static void read_sbr_invf(SpectralBandReplication *sbr, GetBitContext *gb,

  798.                           SBRData *ch_data)

  799. {

  800.     int i;

  801. 

  802.     memcpy(ch_data->bs_invf_mode[1], ch_data->bs_invf_mode[0], 5 * sizeof(uint8_t));

  803.     for (i = 0; i < sbr->n_q; i++)

  804.         ch_data->bs_invf_mode[0][i] = get_bits(gb, 2);

  805. }

  806. 

  807. static void read_sbr_envelope(SpectralBandReplication *sbr, GetBitContext *gb,

  808.                               SBRData *ch_data, int ch)

  809. {

  810.     int bits;

  811.     int i, j, k;

  812.     VLC_TYPE (*t_huff)[2], (*f_huff)[2];

  813.     int t_lav, f_lav;

  814.     const int delta = (ch == 1 && sbr->bs_coupling == 1) + 1;

  815.     const int odd = sbr->n[1] & 1;

  816. 

  817.     if (sbr->bs_coupling && ch) {

  818.         if (ch_data->bs_amp_res) {

  819.             bits   = 5;

  820.             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_3_0DB].table;

  821.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_3_0DB];

  822.             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;

  823.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];

  824.         } else {

  825.             bits   = 6;

  826.             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_1_5DB].table;

  827.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_1_5DB];

  828.             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_1_5DB].table;

  829.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_1_5DB];

  830.         }

  831.     } else {

  832.         if (ch_data->bs_amp_res) {

  833.             bits   = 6;

  834.             t_huff = vlc_sbr[T_HUFFMAN_ENV_3_0DB].table;

  835.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_3_0DB];

  836.             f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;

  837.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];

  838.         } else {

  839.             bits   = 7;

  840.             t_huff = vlc_sbr[T_HUFFMAN_ENV_1_5DB].table;

  841.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_1_5DB];

  842.             f_huff = vlc_sbr[F_HUFFMAN_ENV_1_5DB].table;

  843.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_1_5DB];

  844.         }

  845.     }

  846. 

  847.     for (i = 0; i < ch_data->bs_num_env; i++) {

  848.         if (ch_data->bs_df_env[i]) {

  849.             // bs_freq_res[0] == bs_freq_res[bs_num_env] from prev frame

  850.             if (ch_data->bs_freq_res[i + 1] == ch_data->bs_freq_res[i]) {

  851.                 for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++)

  852.                     ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][j] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);

  853.             } else if (ch_data->bs_freq_res[i + 1]) {

  854.                 for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) {

  855.                     k = (j + odd) >> 1; // find k such that f_tablelow[k] <= f_tablehigh[j] < f_tablelow[k + 1]

  856.                     ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][k] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);

  857.                 }

  858.             } else {

  859.                 for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) {

  860.                     k = j ? 2*j - odd : 0; // find k such that f_tablehigh[k] == f_tablelow[j]

  861.                     ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][k] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);

  862.                 }

  863.             }

  864.         } else {

  865.             ch_data->env_facs[i + 1][0] = delta * get_bits(gb, bits); // bs_env_start_value_balance

  866.             for (j = 1; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++)

  867.                 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);

  868.         }

  869.     }

  870. 

  871.     //assign 0th elements of env_facs from last elements

  872.     memcpy(ch_data->env_facs[0], ch_data->env_facs[ch_data->bs_num_env],

  873.            sizeof(ch_data->env_facs[0]));

  874. }

  875. 

  876. static void read_sbr_noise(SpectralBandReplication *sbr, GetBitContext *gb,

  877.                            SBRData *ch_data, int ch)

  878. {

  879.     int i, j;

  880.     VLC_TYPE (*t_huff)[2], (*f_huff)[2];

  881.     int t_lav, f_lav;

  882.     int delta = (ch == 1 && sbr->bs_coupling == 1) + 1;

  883. 

  884.     if (sbr->bs_coupling && ch) {

  885.         t_huff = vlc_sbr[T_HUFFMAN_NOISE_BAL_3_0DB].table;

  886.         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_BAL_3_0DB];

  887.         f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;

  888.         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];

  889.     } else {

  890.         t_huff = vlc_sbr[T_HUFFMAN_NOISE_3_0DB].table;

  891.         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_3_0DB];

  892.         f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;

  893.         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];

  894.     }

  895. 

  896.     for (i = 0; i < ch_data->bs_num_noise; i++) {

  897.         if (ch_data->bs_df_noise[i]) {

  898.             for (j = 0; j < sbr->n_q; j++)

  899.                 ch_data->noise_facs[i + 1][j] = ch_data->noise_facs[i][j] + delta * (get_vlc2(gb, t_huff, 9, 2) - t_lav);

  900.         } else {

  901.             ch_data->noise_facs[i + 1][0] = delta * get_bits(gb, 5); // bs_noise_start_value_balance or bs_noise_start_value_level

  902.             for (j = 1; j < sbr->n_q; j++)

  903.                 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);

  904.         }

  905.     }

  906. 

  907.     //assign 0th elements of noise_facs from last elements

  908.     memcpy(ch_data->noise_facs[0], ch_data->noise_facs[ch_data->bs_num_noise],

  909.            sizeof(ch_data->noise_facs[0]));

  910. }

  911. 

  912. static void read_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,

  913.                                GetBitContext *gb,

  914.                                int bs_extension_id, int *num_bits_left)

  915. {

  916.     switch (bs_extension_id) {

  917.     case EXTENSION_ID_PS:

  918.         if (!ac->oc[1].m4ac.ps) {

  919.             av_log(ac->avctx, AV_LOG_ERROR, "Parametric Stereo signaled to be not-present but was found in the bitstream.\n");

  920.             skip_bits_long(gb, *num_bits_left); // bs_fill_bits

  921.             *num_bits_left = 0;

  922.         } else {

  923. #if 1

  924.             *num_bits_left -= ff_ps_read_data(ac->avctx, gb, &sbr->ps, *num_bits_left);

  925. #else

  926.             av_log_missing_feature(ac->avctx, "Parametric Stereo", 0);

  927.             skip_bits_long(gb, *num_bits_left); // bs_fill_bits

  928.             *num_bits_left = 0;

  929. #endif

  930.         }

  931.         break;

  932.     default:

  933.         // some files contain 0-padding

  934.         if (bs_extension_id || *num_bits_left > 16 || show_bits(gb, *num_bits_left))

  935.             av_log_missing_feature(ac->avctx, "Reserved SBR extensions", 1);

  936.         skip_bits_long(gb, *num_bits_left); // bs_fill_bits

  937.         *num_bits_left = 0;

  938.         break;

  939.     }

  940. }

  941. 

  942. static int read_sbr_single_channel_element(AACContext *ac,

  943.                                             SpectralBandReplication *sbr,

  944.                                             GetBitContext *gb)

  945. {

  946.     if (get_bits1(gb)) // bs_data_extra

  947.         skip_bits(gb, 4); // bs_reserved

  948. 

  949.     if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]))

  950.         return -1;

  951.     read_sbr_dtdf(sbr, gb, &sbr->data[0]);

  952.     read_sbr_invf(sbr, gb, &sbr->data[0]);

  953.     read_sbr_envelope(sbr, gb, &sbr->data[0], 0);

  954.     read_sbr_noise(sbr, gb, &sbr->data[0], 0);

  955. 

  956.     if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb)))

  957.         get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);

  958. 

  959.     return 0;

  960. }

  961. 

  962. static int read_sbr_channel_pair_element(AACContext *ac,

  963.                                           SpectralBandReplication *sbr,

  964.                                           GetBitContext *gb)

  965. {

  966.     if (get_bits1(gb))    // bs_data_extra

  967.         skip_bits(gb, 8); // bs_reserved

  968. 

  969.     if ((sbr->bs_coupling = get_bits1(gb))) {

  970.         if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]))

  971.             return -1;

  972.         copy_sbr_grid(&sbr->data[1], &sbr->data[0]);

  973.         read_sbr_dtdf(sbr, gb, &sbr->data[0]);

  974.         read_sbr_dtdf(sbr, gb, &sbr->data[1]);

  975.         read_sbr_invf(sbr, gb, &sbr->data[0]);

  976.         memcpy(sbr->data[1].bs_invf_mode[1], sbr->data[1].bs_invf_mode[0], sizeof(sbr->data[1].bs_invf_mode[0]));

  977.         memcpy(sbr->data[1].bs_invf_mode[0], sbr->data[0].bs_invf_mode[0], sizeof(sbr->data[1].bs_invf_mode[0]));

  978.         read_sbr_envelope(sbr, gb, &sbr->data[0], 0);

  979.         read_sbr_noise(sbr, gb, &sbr->data[0], 0);

  980.         read_sbr_envelope(sbr, gb, &sbr->data[1], 1);

  981.         read_sbr_noise(sbr, gb, &sbr->data[1], 1);

  982.     } else {

  983.         if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]) ||

  984.             read_sbr_grid(ac, sbr, gb, &sbr->data[1]))

  985.             return -1;

  986.         read_sbr_dtdf(sbr, gb, &sbr->data[0]);

  987.         read_sbr_dtdf(sbr, gb, &sbr->data[1]);

  988.         read_sbr_invf(sbr, gb, &sbr->data[0]);

  989.         read_sbr_invf(sbr, gb, &sbr->data[1]);

  990.         read_sbr_envelope(sbr, gb, &sbr->data[0], 0);

  991.         read_sbr_envelope(sbr, gb, &sbr->data[1], 1);

  992.         read_sbr_noise(sbr, gb, &sbr->data[0], 0);

  993.         read_sbr_noise(sbr, gb, &sbr->data[1], 1);

  994.     }

  995. 

  996.     if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb)))

  997.         get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);

  998.     if ((sbr->data[1].bs_add_harmonic_flag = get_bits1(gb)))

  999.         get_bits1_vector(gb, sbr->data[1].bs_add_harmonic, sbr->n[1]);

  1000. 

  1001.     return 0;

  1002. }

  1003. 

  1004. static unsigned int read_sbr_data(AACContext *ac, SpectralBandReplication *sbr,

  1005.                                   GetBitContext *gb, int id_aac)

  1006. {

  1007.     unsigned int cnt = get_bits_count(gb);

  1008. 

  1009.     if (id_aac == TYPE_SCE || id_aac == TYPE_CCE) {

  1010.         if (read_sbr_single_channel_element(ac, sbr, gb)) {

  1011.             sbr_turnoff(sbr);

  1012.             return get_bits_count(gb) - cnt;

  1013.         }

  1014.     } else if (id_aac == TYPE_CPE) {

  1015.         if (read_sbr_channel_pair_element(ac, sbr, gb)) {

  1016.             sbr_turnoff(sbr);

  1017.             return get_bits_count(gb) - cnt;

  1018.         }

  1019.     } else {

  1020.         av_log(ac->avctx, AV_LOG_ERROR,

  1021.             "Invalid bitstream - cannot apply SBR to element type %d\n", id_aac);

  1022.         sbr_turnoff(sbr);

  1023.         return get_bits_count(gb) - cnt;

  1024.     }

  1025.     if (get_bits1(gb)) { // bs_extended_data

  1026.         int num_bits_left = get_bits(gb, 4); // bs_extension_size

  1027.         if (num_bits_left == 15)

  1028.             num_bits_left += get_bits(gb, 8); // bs_esc_count

  1029. 

  1030.         num_bits_left <<= 3;

  1031.         while (num_bits_left > 7) {

  1032.             num_bits_left -= 2;

  1033.             read_sbr_extension(ac, sbr, gb, get_bits(gb, 2), &num_bits_left); // bs_extension_id

  1034.         }

  1035.         if (num_bits_left < 0) {

  1036.             av_log(ac->avctx, AV_LOG_ERROR, "SBR Extension over read.\n");

  1037.         }

  1038.         if (num_bits_left > 0)

  1039.             skip_bits(gb, num_bits_left);

  1040.     }

  1041. 

  1042.     return get_bits_count(gb) - cnt;

  1043. }

  1044. 

  1045. static void sbr_reset(AACContext *ac, SpectralBandReplication *sbr)

  1046. {

  1047.     int err;

  1048.     err = sbr_make_f_master(ac, sbr, &sbr->spectrum_params);

  1049.     if (err >= 0)

  1050.         err = sbr_make_f_derived(ac, sbr);

  1051.     if (err < 0) {

  1052.         av_log(ac->avctx, AV_LOG_ERROR,

  1053.                "SBR reset failed. Switching SBR to pure upsampling mode.\n");

  1054.         sbr_turnoff(sbr);

  1055.     }

  1056. }

  1057. 

  1058. /**

  1059.  * Decode Spectral Band Replication extension data; reference: table 4.55.

  1060.  *

  1061.  * @param   crc flag indicating the presence of CRC checksum

  1062.  * @param   cnt length of TYPE_FIL syntactic element in bytes

  1063.  *

  1064.  * @return  Returns number of bytes consumed from the TYPE_FIL element.

  1065.  */

  1066. int ff_decode_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,

  1067.                             GetBitContext *gb_host, int crc, int cnt, int id_aac)

  1068. {

  1069.     unsigned int num_sbr_bits = 0, num_align_bits;

  1070.     unsigned bytes_read;

  1071.     GetBitContext gbc = *gb_host, *gb = &gbc;

  1072.     skip_bits_long(gb_host, cnt*8 - 4);

  1073. 

  1074.     sbr->reset = 0;

  1075. 

  1076.     if (!sbr->sample_rate)

  1077.         sbr->sample_rate = 2 * ac->oc[1].m4ac.sample_rate; //TODO use the nominal sample rate for arbitrary sample rate support

  1078.     if (!ac->oc[1].m4ac.ext_sample_rate)

  1079.         ac->oc[1].m4ac.ext_sample_rate = 2 * ac->oc[1].m4ac.sample_rate;

  1080. 

  1081.     if (crc) {

  1082.         skip_bits(gb, 10); // bs_sbr_crc_bits; TODO - implement CRC check

  1083.         num_sbr_bits += 10;

  1084.     }

  1085. 

  1086.     //Save some state from the previous frame.

  1087.     sbr->kx[0] = sbr->kx[1];

  1088.     sbr->m[0] = sbr->m[1];

  1089.     sbr->kx_and_m_pushed = 1;

  1090. 

  1091.     num_sbr_bits++;

  1092.     if (get_bits1(gb)) // bs_header_flag

  1093.         num_sbr_bits += read_sbr_header(sbr, gb);

  1094. 

  1095.     if (sbr->reset)

  1096.         sbr_reset(ac, sbr);

  1097. 

  1098.     if (sbr->start)

  1099.         num_sbr_bits  += read_sbr_data(ac, sbr, gb, id_aac);

  1100. 

  1101.     num_align_bits = ((cnt << 3) - 4 - num_sbr_bits) & 7;

  1102.     bytes_read = ((num_sbr_bits + num_align_bits + 4) >> 3);

  1103. 

  1104.     if (bytes_read > cnt) {

  1105.         av_log(ac->avctx, AV_LOG_ERROR,

  1106.                "Expected to read %d SBR bytes actually read %d.\n", cnt, bytes_read);

  1107.     }

  1108.     return cnt;

  1109. }

  1110. 

  1111. /// Dequantization and stereo decoding (14496-3 sp04 p203)

  1112. static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)

  1113. {

  1114.     int k, e;

  1115.     int ch;

  1116. 

  1117.     if (id_aac == TYPE_CPE && sbr->bs_coupling) {

  1118.         float alpha      = sbr->data[0].bs_amp_res ?  1.0f :  0.5f;

  1119.         float pan_offset = sbr->data[0].bs_amp_res ? 12.0f : 24.0f;

  1120.         for (e = 1; e <= sbr->data[0].bs_num_env; e++) {

  1121.             for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {

  1122.                 float temp1 = exp2f(sbr->data[0].env_facs[e][k] * alpha + 7.0f);

  1123.                 float temp2 = exp2f((pan_offset - sbr->data[1].env_facs[e][k]) * alpha);

  1124.                 float fac   = temp1 / (1.0f + temp2);

  1125.                 sbr->data[0].env_facs[e][k] = fac;

  1126.                 sbr->data[1].env_facs[e][k] = fac * temp2;

  1127.             }

  1128.         }

  1129.         for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {

  1130.             for (k = 0; k < sbr->n_q; k++) {

  1131.                 float temp1 = exp2f(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs[e][k] + 1);

  1132.                 float temp2 = exp2f(12 - sbr->data[1].noise_facs[e][k]);

  1133.                 float fac   = temp1 / (1.0f + temp2);

  1134.                 sbr->data[0].noise_facs[e][k] = fac;

  1135.                 sbr->data[1].noise_facs[e][k] = fac * temp2;

  1136.             }

  1137.         }

  1138.     } else { // SCE or one non-coupled CPE

  1139.         for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {

  1140.             float alpha = sbr->data[ch].bs_amp_res ? 1.0f : 0.5f;

  1141.             for (e = 1; e <= sbr->data[ch].bs_num_env; e++)

  1142.                 for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++)

  1143.                     sbr->data[ch].env_facs[e][k] =

  1144.                         exp2f(alpha * sbr->data[ch].env_facs[e][k] + 6.0f);

  1145.             for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)

  1146.                 for (k = 0; k < sbr->n_q; k++)

  1147.                     sbr->data[ch].noise_facs[e][k] =

  1148.                         exp2f(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs[e][k]);

  1149.         }

  1150.     }

  1151. }

  1152. 

  1153. /**

  1154.  * Analysis QMF Bank (14496-3 sp04 p206)

  1155.  *

  1156.  * @param   x       pointer to the beginning of the first sample window

  1157.  * @param   W       array of complex-valued samples split into subbands

  1158.  */

  1159. static void sbr_qmf_analysis(AVFloatDSPContext *dsp, FFTContext *mdct,

  1160.                              SBRDSPContext *sbrdsp, const float *in, float *x,

  1161.                              float z[320], float W[2][32][32][2], int buf_idx)

  1162. {

  1163.     int i;

  1164.     memcpy(x    , x+1024, (320-32)*sizeof(x[0]));

  1165.     memcpy(x+288, in,         1024*sizeof(x[0]));

  1166.     for (i = 0; i < 32; i++) { // numTimeSlots*RATE = 16*2 as 960 sample frames

  1167.                                // are not supported

  1168.         dsp->vector_fmul_reverse(z, sbr_qmf_window_ds, x, 320);

  1169.         sbrdsp->sum64x5(z);

  1170.         sbrdsp->qmf_pre_shuffle(z);

  1171.         mdct->imdct_half(mdct, z, z+64);

  1172.         sbrdsp->qmf_post_shuffle(W[buf_idx][i], z);

  1173.         x += 32;

  1174.     }

  1175. }

  1176. 

  1177. /**

  1178.  * Synthesis QMF Bank (14496-3 sp04 p206) and Downsampled Synthesis QMF Bank

  1179.  * (14496-3 sp04 p206)

  1180.  */

  1181. static void sbr_qmf_synthesis(FFTContext *mdct,

  1182.                               SBRDSPContext *sbrdsp, AVFloatDSPContext *dsp,

  1183.                               float *out, float X[2][38][64],

  1184.                               float mdct_buf[2][64],

  1185.                               float *v0, int *v_off, const unsigned int div)

  1186. {

  1187.     int i, n;

  1188.     const float *sbr_qmf_window = div ? sbr_qmf_window_ds : sbr_qmf_window_us;

  1189.     const int step = 128 >> div;

  1190.     float *v;

  1191.     for (i = 0; i < 32; i++) {

  1192.         if (*v_off < step) {

  1193.             int saved_samples = (1280 - 128) >> div;

  1194.             memcpy(&v0[SBR_SYNTHESIS_BUF_SIZE - saved_samples], v0, saved_samples * sizeof(float));

  1195.             *v_off = SBR_SYNTHESIS_BUF_SIZE - saved_samples - step;

  1196.         } else {

  1197.             *v_off -= step;

  1198.         }

  1199.         v = v0 + *v_off;

  1200.         if (div) {

  1201.             for (n = 0; n < 32; n++) {

  1202.                 X[0][i][   n] = -X[0][i][n];

  1203.                 X[0][i][32+n] =  X[1][i][31-n];

  1204.             }

  1205.             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);

  1206.             sbrdsp->qmf_deint_neg(v, mdct_buf[0]);

  1207.         } else {

  1208.             sbrdsp->neg_odd_64(X[1][i]);

  1209.             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);

  1210.             mdct->imdct_half(mdct, mdct_buf[1], X[1][i]);

  1211.             sbrdsp->qmf_deint_bfly(v, mdct_buf[1], mdct_buf[0]);

  1212.         }

  1213.         dsp->vector_fmul    (out, v                , sbr_qmf_window                       , 64 >> div);

  1214.         dsp->vector_fmul_add(out, v + ( 192 >> div), sbr_qmf_window + ( 64 >> div), out   , 64 >> div);

  1215.         dsp->vector_fmul_add(out, v + ( 256 >> div), sbr_qmf_window + (128 >> div), out   , 64 >> div);

  1216.         dsp->vector_fmul_add(out, v + ( 448 >> div), sbr_qmf_window + (192 >> div), out   , 64 >> div);

  1217.         dsp->vector_fmul_add(out, v + ( 512 >> div), sbr_qmf_window + (256 >> div), out   , 64 >> div);

  1218.         dsp->vector_fmul_add(out, v + ( 704 >> div), sbr_qmf_window + (320 >> div), out   , 64 >> div);

  1219.         dsp->vector_fmul_add(out, v + ( 768 >> div), sbr_qmf_window + (384 >> div), out   , 64 >> div);

  1220.         dsp->vector_fmul_add(out, v + ( 960 >> div), sbr_qmf_window + (448 >> div), out   , 64 >> div);

  1221.         dsp->vector_fmul_add(out, v + (1024 >> div), sbr_qmf_window + (512 >> div), out   , 64 >> div);

  1222.         dsp->vector_fmul_add(out, v + (1216 >> div), sbr_qmf_window + (576 >> div), out   , 64 >> div);

  1223.         out += 64 >> div;

  1224.     }

  1225. }

  1226. 

  1227. /** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering

  1228.  * (14496-3 sp04 p214)

  1229.  * Warning: This routine does not seem numerically stable.

  1230.  */

  1231. static void sbr_hf_inverse_filter(SBRDSPContext *dsp,

  1232.                                   float (*alpha0)[2], float (*alpha1)[2],

  1233.                                   const float X_low[32][40][2], int k0)

  1234. {

  1235.     int k;

  1236.     for (k = 0; k < k0; k++) {

  1237.         LOCAL_ALIGNED_16(float, phi, [3], [2][2]);

  1238.         float dk;

  1239. 

  1240.         dsp->autocorrelate(X_low[k], phi);

  1241. 

  1242.         dk =  phi[2][1][0] * phi[1][0][0] -

  1243.              (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;

  1244. 

  1245.         if (!dk) {

  1246.             alpha1[k][0] = 0;

  1247.             alpha1[k][1] = 0;

  1248.         } else {

  1249.             float temp_real, temp_im;

  1250.             temp_real = phi[0][0][0] * phi[1][1][0] -

  1251.                         phi[0][0][1] * phi[1][1][1] -

  1252.                         phi[0][1][0] * phi[1][0][0];

  1253.             temp_im   = phi[0][0][0] * phi[1][1][1] +

  1254.                         phi[0][0][1] * phi[1][1][0] -

  1255.                         phi[0][1][1] * phi[1][0][0];

  1256. 

  1257.             alpha1[k][0] = temp_real / dk;

  1258.             alpha1[k][1] = temp_im   / dk;

  1259.         }

  1260. 

  1261.         if (!phi[1][0][0]) {

  1262.             alpha0[k][0] = 0;

  1263.             alpha0[k][1] = 0;

  1264.         } else {

  1265.             float temp_real, temp_im;

  1266.             temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +

  1267.                                        alpha1[k][1] * phi[1][1][1];

  1268.             temp_im   = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -

  1269.                                        alpha1[k][0] * phi[1][1][1];

  1270. 

  1271.             alpha0[k][0] = -temp_real / phi[1][0][0];

  1272.             alpha0[k][1] = -temp_im   / phi[1][0][0];

  1273.         }

  1274. 

  1275.         if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||

  1276.            alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {

  1277.             alpha1[k][0] = 0;

  1278.             alpha1[k][1] = 0;

  1279.             alpha0[k][0] = 0;

  1280.             alpha0[k][1] = 0;

  1281.         }

  1282.     }

  1283. }

  1284. 

  1285. /// Chirp Factors (14496-3 sp04 p214)

  1286. static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)

  1287. {

  1288.     int i;

  1289.     float new_bw;

  1290.     static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };

  1291. 

  1292.     for (i = 0; i < sbr->n_q; i++) {

  1293.         if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {

  1294.             new_bw = 0.6f;

  1295.         } else

  1296.             new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];

  1297. 

  1298.         if (new_bw < ch_data->bw_array[i]) {

  1299.             new_bw = 0.75f    * new_bw + 0.25f    * ch_data->bw_array[i];

  1300.         } else

  1301.             new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];

  1302.         ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;

  1303.     }

  1304. }

  1305. 

  1306. /// Generate the subband filtered lowband

  1307. static int sbr_lf_gen(AACContext *ac, SpectralBandReplication *sbr,

  1308.                       float X_low[32][40][2], const float W[2][32][32][2],

  1309.                       int buf_idx)

  1310. {

  1311.     int i, k;

  1312.     const int t_HFGen = 8;

  1313.     const int i_f = 32;

  1314.     memset(X_low, 0, 32*sizeof(*X_low));

  1315.     for (k = 0; k < sbr->kx[1]; k++) {

  1316.         for (i = t_HFGen; i < i_f + t_HFGen; i++) {

  1317.             X_low[k][i][0] = W[buf_idx][i - t_HFGen][k][0];

  1318.             X_low[k][i][1] = W[buf_idx][i - t_HFGen][k][1];

  1319.         }

  1320.     }

  1321.     buf_idx = 1-buf_idx;

  1322.     for (k = 0; k < sbr->kx[0]; k++) {

  1323.         for (i = 0; i < t_HFGen; i++) {

  1324.             X_low[k][i][0] = W[buf_idx][i + i_f - t_HFGen][k][0];

  1325.             X_low[k][i][1] = W[buf_idx][i + i_f - t_HFGen][k][1];

  1326.         }

  1327.     }

  1328.     return 0;

  1329. }

  1330. 

  1331. /// High Frequency Generator (14496-3 sp04 p215)

  1332. static int sbr_hf_gen(AACContext *ac, SpectralBandReplication *sbr,

  1333.                       float X_high[64][40][2], const float X_low[32][40][2],

  1334.                       const float (*alpha0)[2], const float (*alpha1)[2],

  1335.                       const float bw_array[5], const uint8_t *t_env,

  1336.                       int bs_num_env)

  1337. {

  1338.     int j, x;

  1339.     int g = 0;

  1340.     int k = sbr->kx[1];

  1341.     for (j = 0; j < sbr->num_patches; j++) {

  1342.         for (x = 0; x < sbr->patch_num_subbands[j]; x++, k++) {

  1343.             const int p = sbr->patch_start_subband[j] + x;

  1344.             while (g <= sbr->n_q && k >= sbr->f_tablenoise[g])

  1345.                 g++;

  1346.             g--;

  1347. 

  1348.             if (g < 0) {

  1349.                 av_log(ac->avctx, AV_LOG_ERROR,

  1350.                        "ERROR : no subband found for frequency %d\n", k);

  1351.                 return -1;

  1352.             }

  1353. 

  1354.             sbr->dsp.hf_gen(X_high[k] + ENVELOPE_ADJUSTMENT_OFFSET,

  1355.                             X_low[p]  + ENVELOPE_ADJUSTMENT_OFFSET,

  1356.                             alpha0[p], alpha1[p], bw_array[g],

  1357.                             2 * t_env[0], 2 * t_env[bs_num_env]);

  1358.         }

  1359.     }

  1360.     if (k < sbr->m[1] + sbr->kx[1])

  1361.         memset(X_high + k, 0, (sbr->m[1] + sbr->kx[1] - k) * sizeof(*X_high));

  1362. 

  1363.     return 0;

  1364. }

  1365. 

  1366. /// Generate the subband filtered lowband

  1367. static int sbr_x_gen(SpectralBandReplication *sbr, float X[2][38][64],

  1368.                      const float Y0[38][64][2], const float Y1[38][64][2],

  1369.                      const float X_low[32][40][2], int ch)

  1370. {

  1371.     int k, i;

  1372.     const int i_f = 32;

  1373.     const int i_Temp = FFMAX(2*sbr->data[ch].t_env_num_env_old - i_f, 0);

  1374.     memset(X, 0, 2*sizeof(*X));

  1375.     for (k = 0; k < sbr->kx[0]; k++) {

  1376.         for (i = 0; i < i_Temp; i++) {

  1377.             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];

  1378.             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];

  1379.         }

  1380.     }

  1381.     for (; k < sbr->kx[0] + sbr->m[0]; k++) {

  1382.         for (i = 0; i < i_Temp; i++) {

  1383.             X[0][i][k] = Y0[i + i_f][k][0];

  1384.             X[1][i][k] = Y0[i + i_f][k][1];

  1385.         }

  1386.     }

  1387. 

  1388.     for (k = 0; k < sbr->kx[1]; k++) {

  1389.         for (i = i_Temp; i < 38; i++) {

  1390.             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];

  1391.             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];

  1392.         }

  1393.     }

  1394.     for (; k < sbr->kx[1] + sbr->m[1]; k++) {

  1395.         for (i = i_Temp; i < i_f; i++) {

  1396.             X[0][i][k] = Y1[i][k][0];

  1397.             X[1][i][k] = Y1[i][k][1];

  1398.         }

  1399.     }

  1400.     return 0;

  1401. }

  1402. 

  1403. /** High Frequency Adjustment (14496-3 sp04 p217) and Mapping

  1404.  * (14496-3 sp04 p217)

  1405.  */

  1406. static int sbr_mapping(AACContext *ac, SpectralBandReplication *sbr,

  1407.                         SBRData *ch_data, int e_a[2])

  1408. {

  1409.     int e, i, m;

  1410. 

  1411.     memset(ch_data->s_indexmapped[1], 0, 7*sizeof(ch_data->s_indexmapped[1]));

  1412.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1413.         const unsigned int ilim = sbr->n[ch_data->bs_freq_res[e + 1]];

  1414.         uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

  1415.         int k;

  1416. 

  1417.         if (sbr->kx[1] != table[0]) {

  1418.             av_log(ac->avctx, AV_LOG_ERROR, "kx != f_table{high,low}[0]. "

  1419.                    "Derived frequency tables were not regenerated.\n");

  1420.             sbr_turnoff(sbr);

  1421.             return AVERROR_BUG;

  1422.         }

  1423.         for (i = 0; i < ilim; i++)

  1424.             for (m = table[i]; m < table[i + 1]; m++)

  1425.                 sbr->e_origmapped[e][m - sbr->kx[1]] = ch_data->env_facs[e+1][i];

  1426. 

  1427.         // ch_data->bs_num_noise > 1 => 2 noise floors

  1428.         k = (ch_data->bs_num_noise > 1) && (ch_data->t_env[e] >= ch_data->t_q[1]);

  1429.         for (i = 0; i < sbr->n_q; i++)

  1430.             for (m = sbr->f_tablenoise[i]; m < sbr->f_tablenoise[i + 1]; m++)

  1431.                 sbr->q_mapped[e][m - sbr->kx[1]] = ch_data->noise_facs[k+1][i];

  1432. 

  1433.         for (i = 0; i < sbr->n[1]; i++) {

  1434.             if (ch_data->bs_add_harmonic_flag) {

  1435.                 const unsigned int m_midpoint =

  1436.                     (sbr->f_tablehigh[i] + sbr->f_tablehigh[i + 1]) >> 1;

  1437. 

  1438.                 ch_data->s_indexmapped[e + 1][m_midpoint - sbr->kx[1]] = ch_data->bs_add_harmonic[i] *

  1439.                     (e >= e_a[1] || (ch_data->s_indexmapped[0][m_midpoint - sbr->kx[1]] == 1));

  1440.             }

  1441.         }

  1442. 

  1443.         for (i = 0; i < ilim; i++) {

  1444.             int additional_sinusoid_present = 0;

  1445.             for (m = table[i]; m < table[i + 1]; m++) {

  1446.                 if (ch_data->s_indexmapped[e + 1][m - sbr->kx[1]]) {

  1447.                     additional_sinusoid_present = 1;

  1448.                     break;

  1449.                 }

  1450.             }

  1451.             memset(&sbr->s_mapped[e][table[i] - sbr->kx[1]], additional_sinusoid_present,

  1452.                    (table[i + 1] - table[i]) * sizeof(sbr->s_mapped[e][0]));

  1453.         }

  1454.     }

  1455. 

  1456.     memcpy(ch_data->s_indexmapped[0], ch_data->s_indexmapped[ch_data->bs_num_env], sizeof(ch_data->s_indexmapped[0]));

  1457.     return 0;

  1458. }

  1459. 

  1460. /// Estimation of current envelope (14496-3 sp04 p218)

  1461. static void sbr_env_estimate(float (*e_curr)[48], float X_high[64][40][2],

  1462.                              SpectralBandReplication *sbr, SBRData *ch_data)

  1463. {

  1464.     int e, m;

  1465.     int kx1 = sbr->kx[1];

  1466. 

  1467.     if (sbr->bs_interpol_freq) {

  1468.         for (e = 0; e < ch_data->bs_num_env; e++) {

  1469.             const float recip_env_size = 0.5f / (ch_data->t_env[e + 1] - ch_data->t_env[e]);

  1470.             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1471.             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1472. 

  1473.             for (m = 0; m < sbr->m[1]; m++) {

  1474.                 float sum = sbr->dsp.sum_square(X_high[m+kx1] + ilb, iub - ilb);

  1475.                 e_curr[e][m] = sum * recip_env_size;

  1476.             }

  1477.         }

  1478.     } else {

  1479.         int k, p;

  1480. 

  1481.         for (e = 0; e < ch_data->bs_num_env; e++) {

  1482.             const int env_size = 2 * (ch_data->t_env[e + 1] - ch_data->t_env[e]);

  1483.             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1484.             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1485.             const uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

  1486. 

  1487.             for (p = 0; p < sbr->n[ch_data->bs_freq_res[e + 1]]; p++) {

  1488.                 float sum = 0.0f;

  1489.                 const int den = env_size * (table[p + 1] - table[p]);

  1490. 

  1491.                 for (k = table[p]; k < table[p + 1]; k++) {

  1492.                     sum += sbr->dsp.sum_square(X_high[k] + ilb, iub - ilb);

  1493.                 }

  1494.                 sum /= den;

  1495.                 for (k = table[p]; k < table[p + 1]; k++) {

  1496.                     e_curr[e][k - kx1] = sum;

  1497.                 }

  1498.             }

  1499.         }

  1500.     }

  1501. }

  1502. 

  1503. /**

  1504.  * Calculation of levels of additional HF signal components (14496-3 sp04 p219)

  1505.  * and Calculation of gain (14496-3 sp04 p219)

  1506.  */

  1507. static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,

  1508.                           SBRData *ch_data, const int e_a[2])

  1509. {

  1510.     int e, k, m;

  1511.     // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)

  1512.     static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };

  1513. 

  1514.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1515.         int delta = !((e == e_a[1]) || (e == e_a[0]));

  1516.         for (k = 0; k < sbr->n_lim; k++) {

  1517.             float gain_boost, gain_max;

  1518.             float sum[2] = { 0.0f, 0.0f };

  1519.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1520.                 const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);

  1521.                 sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);

  1522.                 sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);

  1523.                 if (!sbr->s_mapped[e][m]) {

  1524.                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /

  1525.                                             ((1.0f + sbr->e_curr[e][m]) *

  1526.                                              (1.0f + sbr->q_mapped[e][m] * delta)));

  1527.                 } else {

  1528.                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /

  1529.                                             ((1.0f + sbr->e_curr[e][m]) *

  1530.                                              (1.0f + sbr->q_mapped[e][m])));

  1531.                 }

  1532.             }

  1533.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1534.                 sum[0] += sbr->e_origmapped[e][m];

  1535.                 sum[1] += sbr->e_curr[e][m];

  1536.             }

  1537.             gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));

  1538.             gain_max = FFMIN(100000.f, gain_max);

  1539.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1540.                 float q_m_max   = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];

  1541.                 sbr->q_m[e][m]  = FFMIN(sbr->q_m[e][m], q_m_max);

  1542.                 sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);

  1543.             }

  1544.             sum[0] = sum[1] = 0.0f;

  1545.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1546.                 sum[0] += sbr->e_origmapped[e][m];

  1547.                 sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]

  1548.                           + sbr->s_m[e][m] * sbr->s_m[e][m]

  1549.                           + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];

  1550.             }

  1551.             gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));

  1552.             gain_boost = FFMIN(1.584893192f, gain_boost);

  1553.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1554.                 sbr->gain[e][m] *= gain_boost;

  1555.                 sbr->q_m[e][m]  *= gain_boost;

  1556.                 sbr->s_m[e][m]  *= gain_boost;

  1557.             }

  1558.         }

  1559.     }

  1560. }

  1561. 

  1562. /// Assembling HF Signals (14496-3 sp04 p220)

  1563. static void sbr_hf_assemble(float Y1[38][64][2],

  1564.                             const float X_high[64][40][2],

  1565.                             SpectralBandReplication *sbr, SBRData *ch_data,

  1566.                             const int e_a[2])

  1567. {

  1568.     int e, i, j, m;

  1569.     const int h_SL = 4 * !sbr->bs_smoothing_mode;

  1570.     const int kx = sbr->kx[1];

  1571.     const int m_max = sbr->m[1];

  1572.     static const float h_smooth[5] = {

  1573.         0.33333333333333,

  1574.         0.30150283239582,

  1575.         0.21816949906249,

  1576.         0.11516383427084,

  1577.         0.03183050093751,

  1578.     };

  1579.     float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;

  1580.     int indexnoise = ch_data->f_indexnoise;

  1581.     int indexsine  = ch_data->f_indexsine;

  1582. 

  1583.     if (sbr->reset) {

  1584.         for (i = 0; i < h_SL; i++) {

  1585.             memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));

  1586.             memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0],  m_max * sizeof(sbr->q_m[0][0]));

  1587.         }

  1588.     } else if (h_SL) {

  1589.         memcpy(g_temp[2*ch_data->t_env[0]], g_temp[2*ch_data->t_env_num_env_old], 4*sizeof(g_temp[0]));

  1590.         memcpy(q_temp[2*ch_data->t_env[0]], q_temp[2*ch_data->t_env_num_env_old], 4*sizeof(q_temp[0]));

  1591.     }

  1592. 

  1593.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1594.         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {

  1595.             memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));

  1596.             memcpy(q_temp[h_SL + i], sbr->q_m[e],  m_max * sizeof(sbr->q_m[0][0]));

  1597.         }

  1598.     }

  1599. 

  1600.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1601.         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {

  1602.             LOCAL_ALIGNED_16(float, g_filt_tab, [48]);

  1603.             LOCAL_ALIGNED_16(float, q_filt_tab, [48]);

  1604.             float *g_filt, *q_filt;

  1605. 

  1606.             if (h_SL && e != e_a[0] && e != e_a[1]) {

  1607.                 g_filt = g_filt_tab;

  1608.                 q_filt = q_filt_tab;

  1609.                 for (m = 0; m < m_max; m++) {

  1610.                     const int idx1 = i + h_SL;

  1611.                     g_filt[m] = 0.0f;

  1612.                     q_filt[m] = 0.0f;

  1613.                     for (j = 0; j <= h_SL; j++) {

  1614.                         g_filt[m] += g_temp[idx1 - j][m] * h_smooth[j];

  1615.                         q_filt[m] += q_temp[idx1 - j][m] * h_smooth[j];

  1616.                     }

  1617.                 }

  1618.             } else {

  1619.                 g_filt = g_temp[i + h_SL];

  1620.                 q_filt = q_temp[i];

  1621.             }

  1622. 

  1623.             sbr->dsp.hf_g_filt(Y1[i] + kx, X_high + kx, g_filt, m_max,

  1624.                                i + ENVELOPE_ADJUSTMENT_OFFSET);

  1625. 

  1626.             if (e != e_a[0] && e != e_a[1]) {

  1627.                 sbr->dsp.hf_apply_noise[indexsine](Y1[i] + kx, sbr->s_m[e],

  1628.                                                    q_filt, indexnoise,

  1629.                                                    kx, m_max);

  1630.             } else {

  1631.                 int idx = indexsine&1;

  1632.                 int A = (1-((indexsine+(kx & 1))&2));

  1633.                 int B = (A^(-idx)) + idx;

  1634.                 float *out = &Y1[i][kx][idx];

  1635.                 float *in  = sbr->s_m[e];

  1636.                 for (m = 0; m+1 < m_max; m+=2) {

  1637.                     out[2*m  ] += in[m  ] * A;

  1638.                     out[2*m+2] += in[m+1] * B;

  1639.                 }

  1640.                 if(m_max&1)

  1641.                     out[2*m  ] += in[m  ] * A;

  1642.             }

  1643.             indexnoise = (indexnoise + m_max) & 0x1ff;

  1644.             indexsine = (indexsine + 1) & 3;

  1645.         }

  1646.     }

  1647.     ch_data->f_indexnoise = indexnoise;

  1648.     ch_data->f_indexsine  = indexsine;

  1649. }

  1650. 

  1651. void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,

  1652.                   float* L, float* R)

  1653. {

  1654.     int downsampled = ac->oc[1].m4ac.ext_sample_rate < sbr->sample_rate;

  1655.     int ch;

  1656.     int nch = (id_aac == TYPE_CPE) ? 2 : 1;

  1657.     int err;

  1658. 

  1659.     if (!sbr->kx_and_m_pushed) {

  1660.         sbr->kx[0] = sbr->kx[1];

  1661.         sbr->m[0] = sbr->m[1];

  1662.     } else {

  1663.         sbr->kx_and_m_pushed = 0;

  1664.     }

  1665. 

  1666.     if (sbr->start) {

  1667.         sbr_dequant(sbr, id_aac);

  1668.     }

  1669.     for (ch = 0; ch < nch; ch++) {

  1670.         /* decode channel */

  1671.         sbr_qmf_analysis(&ac->fdsp, &sbr->mdct_ana, &sbr->dsp, ch ? R : L, sbr->data[ch].analysis_filterbank_samples,

  1672.                          (float*)sbr->qmf_filter_scratch,

  1673.                          sbr->data[ch].W, sbr->data[ch].Ypos);

  1674.         sbr_lf_gen(ac, sbr, sbr->X_low, sbr->data[ch].W, sbr->data[ch].Ypos);

  1675.         sbr->data[ch].Ypos ^= 1;

  1676.         if (sbr->start) {

  1677.             sbr_hf_inverse_filter(&sbr->dsp, sbr->alpha0, sbr->alpha1, sbr->X_low, sbr->k[0]);

  1678.             sbr_chirp(sbr, &sbr->data[ch]);

  1679.             sbr_hf_gen(ac, sbr, sbr->X_high, sbr->X_low, sbr->alpha0, sbr->alpha1,

  1680.                        sbr->data[ch].bw_array, sbr->data[ch].t_env,

  1681.                        sbr->data[ch].bs_num_env);

  1682. 

  1683.             // hf_adj

  1684.             err = sbr_mapping(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);

  1685.             if (!err) {

  1686.                 sbr_env_estimate(sbr->e_curr, sbr->X_high, sbr, &sbr->data[ch]);

  1687.                 sbr_gain_calc(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);

  1688.                 sbr_hf_assemble(sbr->data[ch].Y[sbr->data[ch].Ypos],

  1689.                                 sbr->X_high, sbr, &sbr->data[ch],

  1690.                                 sbr->data[ch].e_a);

  1691.             }

  1692.         }

  1693. 

  1694.         /* synthesis */

  1695.         sbr_x_gen(sbr, sbr->X[ch],

  1696.                   sbr->data[ch].Y[1-sbr->data[ch].Ypos],

  1697.                   sbr->data[ch].Y[  sbr->data[ch].Ypos],

  1698.                   sbr->X_low, ch);

  1699.     }

  1700. 

  1701.     if (ac->oc[1].m4ac.ps == 1) {

  1702.         if (sbr->ps.start) {

  1703.             ff_ps_apply(ac->avctx, &sbr->ps, sbr->X[0], sbr->X[1], sbr->kx[1] + sbr->m[1]);

  1704.         } else {

  1705.             memcpy(sbr->X[1], sbr->X[0], sizeof(sbr->X[0]));

  1706.         }

  1707.         nch = 2;

  1708.     }

  1709. 

  1710.     sbr_qmf_synthesis(&sbr->mdct, &sbr->dsp, &ac->fdsp,

  1711.                       L, sbr->X[0], sbr->qmf_filter_scratch,

  1712.                       sbr->data[0].synthesis_filterbank_samples,

  1713.                       &sbr->data[0].synthesis_filterbank_samples_offset,

  1714.                       downsampled);

  1715.     if (nch == 2)

  1716.         sbr_qmf_synthesis(&sbr->mdct, &sbr->dsp, &ac->fdsp,

  1717.                           R, sbr->X[1], sbr->qmf_filter_scratch,

  1718.                           sbr->data[1].synthesis_filterbank_samples,

  1719.                           &sbr->data[1].synthesis_filterbank_samples_offset,

  1720.                           downsampled);

  1721. }