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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 Libav.

  7.  *

  8.  * Libav 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.  * Libav 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 Libav; 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. 

  38. #include <stdint.h>

  39. #include <float.h>

  40. 

  41. #define ENVELOPE_ADJUSTMENT_OFFSET 2

  42. #define NOISE_FLOOR_OFFSET 6.0f

  43. 

  44. /**

  45.  * SBR VLC tables

  46.  */

  47. enum {

  48.     T_HUFFMAN_ENV_1_5DB,

  49.     F_HUFFMAN_ENV_1_5DB,

  50.     T_HUFFMAN_ENV_BAL_1_5DB,

  51.     F_HUFFMAN_ENV_BAL_1_5DB,

  52.     T_HUFFMAN_ENV_3_0DB,

  53.     F_HUFFMAN_ENV_3_0DB,

  54.     T_HUFFMAN_ENV_BAL_3_0DB,

  55.     F_HUFFMAN_ENV_BAL_3_0DB,

  56.     T_HUFFMAN_NOISE_3_0DB,

  57.     T_HUFFMAN_NOISE_BAL_3_0DB,

  58. };

  59. 

  60. /**

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

  62.  */

  63. enum {

  64.     FIXFIX,

  65.     FIXVAR,

  66.     VARFIX,

  67.     VARVAR,

  68. };

  69. 

  70. enum {

  71.     EXTENSION_ID_PS = 2,

  72. };

  73. 

  74. static VLC vlc_sbr[10];

  75. static const int8_t vlc_sbr_lav[10] =

  76.     { 60, 60, 24, 24, 31, 31, 12, 12, 31, 12 };

  77. 

  78. #define SBR_INIT_VLC_STATIC(num, size) \

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

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

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

  82.                     size)

  83. 

  84. #define SBR_VLC_ROW(name) \

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

  86. 

  87. av_cold void ff_aac_sbr_init(void)

  88. {

  89.     int n;

  90.     static const struct {

  91.         const void *sbr_codes, *sbr_bits;

  92.         const unsigned int table_size, elem_size;

  93.     } sbr_tmp[] = {

  94.         SBR_VLC_ROW(t_huffman_env_1_5dB),

  95.         SBR_VLC_ROW(f_huffman_env_1_5dB),

  96.         SBR_VLC_ROW(t_huffman_env_bal_1_5dB),

  97.         SBR_VLC_ROW(f_huffman_env_bal_1_5dB),

  98.         SBR_VLC_ROW(t_huffman_env_3_0dB),

  99.         SBR_VLC_ROW(f_huffman_env_3_0dB),

  100.         SBR_VLC_ROW(t_huffman_env_bal_3_0dB),

  101.         SBR_VLC_ROW(f_huffman_env_bal_3_0dB),

  102.         SBR_VLC_ROW(t_huffman_noise_3_0dB),

  103.         SBR_VLC_ROW(t_huffman_noise_bal_3_0dB),

  104.     };

  105. 

  106.     // SBR VLC table initialization

  107.     SBR_INIT_VLC_STATIC(0, 1098);

  108.     SBR_INIT_VLC_STATIC(1, 1092);

  109.     SBR_INIT_VLC_STATIC(2, 768);

  110.     SBR_INIT_VLC_STATIC(3, 1026);

  111.     SBR_INIT_VLC_STATIC(4, 1058);

  112.     SBR_INIT_VLC_STATIC(5, 1052);

  113.     SBR_INIT_VLC_STATIC(6, 544);

  114.     SBR_INIT_VLC_STATIC(7, 544);

  115.     SBR_INIT_VLC_STATIC(8, 592);

  116.     SBR_INIT_VLC_STATIC(9, 512);

  117. 

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

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

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

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

  122. 

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

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

  125. 

  126.     ff_ps_init();

  127. }

  128. 

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

  130. static void sbr_turnoff(SpectralBandReplication *sbr) {

  131.     sbr->start = 0;

  132.     // Init defults used in pure upsampling mode

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

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

  135.     // Reset values for first SBR header

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

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

  138. }

  139. 

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

  141. {

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

  143.     sbr_turnoff(sbr);

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

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

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

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

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

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

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

  151.     ff_ps_ctx_init(&sbr->ps);

  152.     ff_sbrdsp_init(&sbr->dsp);

  153. }

  154. 

  155. av_cold void ff_aac_sbr_ctx_close(SpectralBandReplication *sbr)

  156. {

  157.     ff_mdct_end(&sbr->mdct);

  158.     ff_mdct_end(&sbr->mdct_ana);

  159. }

  160. 

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

  162. {

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

  164. }

  165. 

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

  167. {

  168.     int i;

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

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

  171.             return 1;

  172.     return 0;

  173. }

  174. 

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

  176. static void sbr_make_f_tablelim(SpectralBandReplication *sbr)

  177. {

  178.     int k;

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

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

  181.                                                1.18509277094158210129f,   //2^(0.49/2)

  182.                                                1.11987160404675912501f }; //2^(0.49/3)

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

  184.         int16_t patch_borders[7];

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

  186. 

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

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

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

  190. 

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

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

  193.         if (sbr->num_patches > 1)

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

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

  196. 

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

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

  199.               qsort_comparison_function_int16);

  200. 

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

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

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

  204.                 *++out = *in++;

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

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

  207.                 in++;

  208.                 sbr->n_lim--;

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

  210.                 *out = *in++;

  211.                 sbr->n_lim--;

  212.             } else {

  213.                 *++out = *in++;

  214.             }

  215.         }

  216.     } else {

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

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

  219.         sbr->n_lim = 1;

  220.     }

  221. }

  222. 

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

  224. {

  225.     unsigned int cnt = get_bits_count(gb);

  226.     uint8_t bs_header_extra_1;

  227.     uint8_t bs_header_extra_2;

  228.     int old_bs_limiter_bands = sbr->bs_limiter_bands;

  229.     SpectrumParameters old_spectrum_params;

  230. 

  231.     sbr->start = 1;

  232. 

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

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

  235. 

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

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

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

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

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

  241. 

  242.     bs_header_extra_1 = get_bits1(gb);

  243.     bs_header_extra_2 = get_bits1(gb);

  244. 

  245.     if (bs_header_extra_1) {

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

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

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

  249.     } else {

  250.         sbr->spectrum_params.bs_freq_scale  = 2;

  251.         sbr->spectrum_params.bs_alter_scale = 1;

  252.         sbr->spectrum_params.bs_noise_bands = 2;

  253.     }

  254. 

  255.     // Check if spectrum parameters changed

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

  257.         sbr->reset = 1;

  258. 

  259.     if (bs_header_extra_2) {

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

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

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

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

  264.     } else {

  265.         sbr->bs_limiter_bands  = 2;

  266.         sbr->bs_limiter_gains  = 2;

  267.         sbr->bs_interpol_freq  = 1;

  268.         sbr->bs_smoothing_mode = 1;

  269.     }

  270. 

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

  272.         sbr_make_f_tablelim(sbr);

  273. 

  274.     return get_bits_count(gb) - cnt;

  275. }

  276. 

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

  278. {

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

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

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

  282.     return min;

  283. }

  284. 

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

  286. {

  287.     int k, previous, present;

  288.     float base, prod;

  289. 

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

  291.     prod = start;

  292.     previous = start;

  293. 

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

  295.         prod *= base;

  296.         present  = lrintf(prod);

  297.         bands[k] = present - previous;

  298.         previous = present;

  299.     }

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

  301. }

  302. 

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

  304. {

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

  306.     if (n_master <= 0) {

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

  308.         return -1;

  309.     }

  310.     if (bs_xover_band >= n_master) {

  311.         av_log(avctx, AV_LOG_ERROR,

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

  313.                bs_xover_band);

  314.         return -1;

  315.     }

  316.     return 0;

  317. }

  318. 

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

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

  321.                              SpectrumParameters *spectrum)

  322. {

  323.     unsigned int temp, max_qmf_subbands;

  324.     unsigned int start_min, stop_min;

  325.     int k;

  326.     const int8_t *sbr_offset_ptr;

  327.     int16_t stop_dk[13];

  328. 

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

  330.         temp = 3000;

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

  332.         temp = 4000;

  333.     } else

  334.         temp = 5000;

  335. 

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

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

  338. 

  339.     switch (sbr->sample_rate) {

  340.     case 16000:

  341.         sbr_offset_ptr = sbr_offset[0];

  342.         break;

  343.     case 22050:

  344.         sbr_offset_ptr = sbr_offset[1];

  345.         break;

  346.     case 24000:

  347.         sbr_offset_ptr = sbr_offset[2];

  348.         break;

  349.     case 32000:

  350.         sbr_offset_ptr = sbr_offset[3];

  351.         break;

  352.     case 44100: case 48000: case 64000:

  353.         sbr_offset_ptr = sbr_offset[4];

  354.         break;

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

  356.         sbr_offset_ptr = sbr_offset[5];

  357.         break;

  358.     default:

  359.         av_log(ac->avctx, AV_LOG_ERROR,

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

  361.         return -1;

  362.     }

  363. 

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

  365. 

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

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

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

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

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

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

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

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

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

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

  376.     } else {

  377.         av_log(ac->avctx, AV_LOG_ERROR,

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

  379.         return -1;

  380.     }

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

  382. 

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

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

  385.         max_qmf_subbands = 48;

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

  387.         max_qmf_subbands = 35;

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

  389.         max_qmf_subbands = 32;

  390. 

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

  392.         av_log(ac->avctx, AV_LOG_ERROR,

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

  394.         return -1;

  395.     }

  396. 

  397.     if (!spectrum->bs_freq_scale) {

  398.         int dk, k2diff;

  399. 

  400.         dk = spectrum->bs_alter_scale + 1;

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

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

  403.             return -1;

  404. 

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

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

  407. 

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

  409.         if (k2diff < 0) {

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

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

  412.         } else if (k2diff) {

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

  414.         }

  415. 

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

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

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

  419. 

  420.     } else {

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

  422.         int two_regions, num_bands_0;

  423.         int vdk0_max, vdk1_min;

  424.         int16_t vk0[49];

  425. 

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

  427.             two_regions = 1;

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

  429.         } else {

  430.             two_regions = 0;

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

  432.         }

  433. 

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

  435. 

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

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

  438.             return -1;

  439.         }

  440. 

  441.         vk0[0] = 0;

  442. 

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

  444. 

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

  446.         vdk0_max = vk0[num_bands_0];

  447. 

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

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

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

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

  452.                 return -1;

  453.             }

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

  455.         }

  456. 

  457.         if (two_regions) {

  458.             int16_t vk1[49];

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

  460.                                                      : 1.0f; // bs_alter_scale = {0,1}

  461.             int num_bands_1 = lrintf(half_bands * invwarp *

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

  463. 

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

  465. 

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

  467. 

  468.             if (vdk1_min < vdk0_max) {

  469.                 int change;

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

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

  472.                 vk1[1]           += change;

  473.                 vk1[num_bands_1] -= change;

  474.             }

  475. 

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

  477. 

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

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

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

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

  482.                     return -1;

  483.                 }

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

  485.             }

  486. 

  487.             sbr->n_master = num_bands_0 + num_bands_1;

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

  489.                 return -1;

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

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

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

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

  494. 

  495.         } else {

  496.             sbr->n_master = num_bands_0;

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

  498.                 return -1;

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

  500.         }

  501.     }

  502. 

  503.     return 0;

  504. }

  505. 

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

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

  508. {

  509.     int i, k, sb = 0;

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

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

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

  513. 

  514.     sbr->num_patches = 0;

  515. 

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

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

  518.     } else

  519.         k = sbr->n_master;

  520. 

  521.     do {

  522.         int odd = 0;

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

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

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

  526.         }

  527. 

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

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

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

  531.         // count of 6 patches

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

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

  534.             return -1;

  535.         }

  536. 

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

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

  539. 

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

  541.             usb = sb;

  542.             msb = sb;

  543.             sbr->num_patches++;

  544.         } else

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

  546. 

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

  548.             k = sbr->n_master;

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

  550. 

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

  552.         sbr->num_patches--;

  553. 

  554.     return 0;

  555. }

  556. 

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

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

  559. {

  560.     int k, temp;

  561. 

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

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

  564. 

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

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

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

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

  569. 

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

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

  572.         av_log(ac->avctx, AV_LOG_ERROR,

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

  574.         return -1;

  575.     }

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

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

  578.         return -1;

  579.     }

  580. 

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

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

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

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

  585. 

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

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

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

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

  590.         return -1;

  591.     }

  592. 

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

  594.     temp = 0;

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

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

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

  598.     }

  599. 

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

  601.         return -1;

  602. 

  603.     sbr_make_f_tablelim(sbr);

  604. 

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

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

  607. 

  608.     return 0;

  609. }

  610. 

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

  612.                                               int elements)

  613. {

  614.     int i;

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

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

  617.     }

  618. }

  619. 

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

  621. static const int8_t ceil_log2[] = {

  622.     0, 1, 2, 2, 3, 3,

  623. };

  624. 

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

  626.                          GetBitContext *gb, SBRData *ch_data)

  627. {

  628.     int i;

  629.     unsigned bs_pointer = 0;

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

  631.     int abs_bord_trail = 16;

  632.     int num_rel_lead, num_rel_trail;

  633.     unsigned bs_num_env_old = ch_data->bs_num_env;

  634. 

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

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

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

  638. 

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

  640.     case FIXFIX:

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

  642.         num_rel_lead                        = ch_data->bs_num_env - 1;

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

  644.             ch_data->bs_amp_res = 0;

  645. 

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

  647.             av_log(ac->avctx, AV_LOG_ERROR,

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

  649.                    ch_data->bs_num_env);

  650.             return -1;

  651.         }

  652. 

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

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

  655. 

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

  657.                    ch_data->bs_num_env;

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

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

  660. 

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

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

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

  664.         break;

  665.     case FIXVAR:

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

  667.         num_rel_trail                       = get_bits(gb, 2);

  668.         ch_data->bs_num_env                 = num_rel_trail + 1;

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

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

  671. 

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

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

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

  675. 

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

  677. 

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

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

  680.         break;

  681.     case VARFIX:

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

  683.         num_rel_lead                        = get_bits(gb, 2);

  684.         ch_data->bs_num_env                 = num_rel_lead + 1;

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

  686. 

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

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

  689. 

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

  691. 

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

  693.         break;

  694.     case VARVAR:

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

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

  697.         num_rel_lead                        = get_bits(gb, 2);

  698.         num_rel_trail                       = get_bits(gb, 2);

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

  700. 

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

  702.             av_log(ac->avctx, AV_LOG_ERROR,

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

  704.                    ch_data->bs_num_env);

  705.             return -1;

  706.         }

  707. 

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

  709. 

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

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

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

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

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

  715. 

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

  717. 

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

  719.         break;

  720.     }

  721. 

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

  723.         av_log(ac->avctx, AV_LOG_ERROR,

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

  725.                bs_pointer);

  726.         return -1;

  727.     }

  728. 

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

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

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

  732.             return -1;

  733.         }

  734.     }

  735. 

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

  737. 

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

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

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

  741.         unsigned int idx;

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

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

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

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

  746.         } else { // VARFIX

  747.             if (!bs_pointer)

  748.                 idx = 1;

  749.             else if (bs_pointer == 1)

  750.                 idx = ch_data->bs_num_env - 1;

  751.             else // bs_pointer > 1

  752.                 idx = bs_pointer - 1;

  753.         }

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

  755.     }

  756. 

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

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

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

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

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

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

  763. 

  764.     return 0;

  765. }

  766. 

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

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

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

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

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

  772. 

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

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

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

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

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

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

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

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

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

  782. }

  783. 

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

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

  786.                           SBRData *ch_data)

  787. {

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

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

  790. }

  791. 

  792. /// Read inverse filtering data

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

  794.                           SBRData *ch_data)

  795. {

  796.     int i;

  797. 

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

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

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

  801. }

  802. 

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

  804.                               SBRData *ch_data, int ch)

  805. {

  806.     int bits;

  807.     int i, j, k;

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

  809.     int t_lav, f_lav;

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

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

  812. 

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

  814.         if (ch_data->bs_amp_res) {

  815.             bits   = 5;

  816.             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_3_0DB].table;

  817.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_3_0DB];

  818.             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;

  819.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];

  820.         } else {

  821.             bits   = 6;

  822.             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_1_5DB].table;

  823.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_1_5DB];

  824.             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_1_5DB].table;

  825.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_1_5DB];

  826.         }

  827.     } else {

  828.         if (ch_data->bs_amp_res) {

  829.             bits   = 6;

  830.             t_huff = vlc_sbr[T_HUFFMAN_ENV_3_0DB].table;

  831.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_3_0DB];

  832.             f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;

  833.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];

  834.         } else {

  835.             bits   = 7;

  836.             t_huff = vlc_sbr[T_HUFFMAN_ENV_1_5DB].table;

  837.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_1_5DB];

  838.             f_huff = vlc_sbr[F_HUFFMAN_ENV_1_5DB].table;

  839.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_1_5DB];

  840.         }

  841.     }

  842. 

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

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

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

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

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

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

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

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

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

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

  853.                 }

  854.             } else {

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

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

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

  858.                 }

  859.             }

  860.         } else {

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

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

  863.                 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);

  864.         }

  865.     }

  866. 

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

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

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

  870. }

  871. 

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

  873.                            SBRData *ch_data, int ch)

  874. {

  875.     int i, j;

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

  877.     int t_lav, f_lav;

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

  879. 

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

  881.         t_huff = vlc_sbr[T_HUFFMAN_NOISE_BAL_3_0DB].table;

  882.         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_BAL_3_0DB];

  883.         f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;

  884.         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];

  885.     } else {

  886.         t_huff = vlc_sbr[T_HUFFMAN_NOISE_3_0DB].table;

  887.         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_3_0DB];

  888.         f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;

  889.         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];

  890.     }

  891. 

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

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

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

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

  896.         } else {

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

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

  899.                 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);

  900.         }

  901.     }

  902. 

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

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

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

  906. }

  907. 

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

  909.                                GetBitContext *gb,

  910.                                int bs_extension_id, int *num_bits_left)

  911. {

  912.     switch (bs_extension_id) {

  913.     case EXTENSION_ID_PS:

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

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

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

  917.             *num_bits_left = 0;

  918.         } else {

  919. #if 1

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

  921. #else

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

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

  924.             *num_bits_left = 0;

  925. #endif

  926.         }

  927.         break;

  928.     default:

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

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

  931.         *num_bits_left = 0;

  932.         break;

  933.     }

  934. }

  935. 

  936. static int read_sbr_single_channel_element(AACContext *ac,

  937.                                             SpectralBandReplication *sbr,

  938.                                             GetBitContext *gb)

  939. {

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

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

  942. 

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

  944.         return -1;

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

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

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

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

  949. 

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

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

  952. 

  953.     return 0;

  954. }

  955. 

  956. static int read_sbr_channel_pair_element(AACContext *ac,

  957.                                           SpectralBandReplication *sbr,

  958.                                           GetBitContext *gb)

  959. {

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

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

  962. 

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

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

  965.             return -1;

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

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

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

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

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

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

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

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

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

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

  976.     } else {

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

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

  979.             return -1;

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

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

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

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

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

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

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

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

  988.     }

  989. 

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

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

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

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

  994. 

  995.     return 0;

  996. }

  997. 

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

  999.                                   GetBitContext *gb, int id_aac)

  1000. {

  1001.     unsigned int cnt = get_bits_count(gb);

  1002. 

  1003.     if (id_aac == TYPE_SCE || id_aac == TYPE_CCE) {

  1004.         if (read_sbr_single_channel_element(ac, sbr, gb)) {

  1005.             sbr_turnoff(sbr);

  1006.             return get_bits_count(gb) - cnt;

  1007.         }

  1008.     } else if (id_aac == TYPE_CPE) {

  1009.         if (read_sbr_channel_pair_element(ac, sbr, gb)) {

  1010.             sbr_turnoff(sbr);

  1011.             return get_bits_count(gb) - cnt;

  1012.         }

  1013.     } else {

  1014.         av_log(ac->avctx, AV_LOG_ERROR,

  1015.             "Invalid bitstream - cannot apply SBR to element type %d\n", id_aac);

  1016.         sbr_turnoff(sbr);

  1017.         return get_bits_count(gb) - cnt;

  1018.     }

  1019.     if (get_bits1(gb)) { // bs_extended_data

  1020.         int num_bits_left = get_bits(gb, 4); // bs_extension_size

  1021.         if (num_bits_left == 15)

  1022.             num_bits_left += get_bits(gb, 8); // bs_esc_count

  1023. 

  1024.         num_bits_left <<= 3;

  1025.         while (num_bits_left > 7) {

  1026.             num_bits_left -= 2;

  1027.             read_sbr_extension(ac, sbr, gb, get_bits(gb, 2), &num_bits_left); // bs_extension_id

  1028.         }

  1029.         if (num_bits_left < 0) {

  1030.             av_log(ac->avctx, AV_LOG_ERROR, "SBR Extension over read.\n");

  1031.         }

  1032.         if (num_bits_left > 0)

  1033.             skip_bits(gb, num_bits_left);

  1034.     }

  1035. 

  1036.     return get_bits_count(gb) - cnt;

  1037. }

  1038. 

  1039. static void sbr_reset(AACContext *ac, SpectralBandReplication *sbr)

  1040. {

  1041.     int err;

  1042.     err = sbr_make_f_master(ac, sbr, &sbr->spectrum_params);

  1043.     if (err >= 0)

  1044.         err = sbr_make_f_derived(ac, sbr);

  1045.     if (err < 0) {

  1046.         av_log(ac->avctx, AV_LOG_ERROR,

  1047.                "SBR reset failed. Switching SBR to pure upsampling mode.\n");

  1048.         sbr_turnoff(sbr);

  1049.     }

  1050. }

  1051. 

  1052. /**

  1053.  * Decode Spectral Band Replication extension data; reference: table 4.55.

  1054.  *

  1055.  * @param   crc flag indicating the presence of CRC checksum

  1056.  * @param   cnt length of TYPE_FIL syntactic element in bytes

  1057.  *

  1058.  * @return  Returns number of bytes consumed from the TYPE_FIL element.

  1059.  */

  1060. int ff_decode_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,

  1061.                             GetBitContext *gb_host, int crc, int cnt, int id_aac)

  1062. {

  1063.     unsigned int num_sbr_bits = 0, num_align_bits;

  1064.     unsigned bytes_read;

  1065.     GetBitContext gbc = *gb_host, *gb = &gbc;

  1066.     skip_bits_long(gb_host, cnt*8 - 4);

  1067. 

  1068.     sbr->reset = 0;

  1069. 

  1070.     if (!sbr->sample_rate)

  1071.         sbr->sample_rate = 2 * ac->oc[1].m4ac.sample_rate; //TODO use the nominal sample rate for arbitrary sample rate support

  1072.     if (!ac->oc[1].m4ac.ext_sample_rate)

  1073.         ac->oc[1].m4ac.ext_sample_rate = 2 * ac->oc[1].m4ac.sample_rate;

  1074. 

  1075.     if (crc) {

  1076.         skip_bits(gb, 10); // bs_sbr_crc_bits; TODO - implement CRC check

  1077.         num_sbr_bits += 10;

  1078.     }

  1079. 

  1080.     //Save some state from the previous frame.

  1081.     sbr->kx[0] = sbr->kx[1];

  1082.     sbr->m[0] = sbr->m[1];

  1083.     sbr->kx_and_m_pushed = 1;

  1084. 

  1085.     num_sbr_bits++;

  1086.     if (get_bits1(gb)) // bs_header_flag

  1087.         num_sbr_bits += read_sbr_header(sbr, gb);

  1088. 

  1089.     if (sbr->reset)

  1090.         sbr_reset(ac, sbr);

  1091. 

  1092.     if (sbr->start)

  1093.         num_sbr_bits  += read_sbr_data(ac, sbr, gb, id_aac);

  1094. 

  1095.     num_align_bits = ((cnt << 3) - 4 - num_sbr_bits) & 7;

  1096.     bytes_read = ((num_sbr_bits + num_align_bits + 4) >> 3);

  1097. 

  1098.     if (bytes_read > cnt) {

  1099.         av_log(ac->avctx, AV_LOG_ERROR,

  1100.                "Expected to read %d SBR bytes actually read %d.\n", cnt, bytes_read);

  1101.     }

  1102.     return cnt;

  1103. }

  1104. 

  1105. /// Dequantization and stereo decoding (14496-3 sp04 p203)

  1106. static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)

  1107. {

  1108.     int k, e;

  1109.     int ch;

  1110. 

  1111.     if (id_aac == TYPE_CPE && sbr->bs_coupling) {

  1112.         float alpha      = sbr->data[0].bs_amp_res ?  1.0f :  0.5f;

  1113.         float pan_offset = sbr->data[0].bs_amp_res ? 12.0f : 24.0f;

  1114.         for (e = 1; e <= sbr->data[0].bs_num_env; e++) {

  1115.             for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {

  1116.                 float temp1 = exp2f(sbr->data[0].env_facs[e][k] * alpha + 7.0f);

  1117.                 float temp2 = exp2f((pan_offset - sbr->data[1].env_facs[e][k]) * alpha);

  1118.                 float fac   = temp1 / (1.0f + temp2);

  1119.                 sbr->data[0].env_facs[e][k] = fac;

  1120.                 sbr->data[1].env_facs[e][k] = fac * temp2;

  1121.             }

  1122.         }

  1123.         for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {

  1124.             for (k = 0; k < sbr->n_q; k++) {

  1125.                 float temp1 = exp2f(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs[e][k] + 1);

  1126.                 float temp2 = exp2f(12 - sbr->data[1].noise_facs[e][k]);

  1127.                 float fac   = temp1 / (1.0f + temp2);

  1128.                 sbr->data[0].noise_facs[e][k] = fac;

  1129.                 sbr->data[1].noise_facs[e][k] = fac * temp2;

  1130.             }

  1131.         }

  1132.     } else { // SCE or one non-coupled CPE

  1133.         for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {

  1134.             float alpha = sbr->data[ch].bs_amp_res ? 1.0f : 0.5f;

  1135.             for (e = 1; e <= sbr->data[ch].bs_num_env; e++)

  1136.                 for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++)

  1137.                     sbr->data[ch].env_facs[e][k] =

  1138.                         exp2f(alpha * sbr->data[ch].env_facs[e][k] + 6.0f);

  1139.             for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)

  1140.                 for (k = 0; k < sbr->n_q; k++)

  1141.                     sbr->data[ch].noise_facs[e][k] =

  1142.                         exp2f(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs[e][k]);

  1143.         }

  1144.     }

  1145. }

  1146. 

  1147. /**

  1148.  * Analysis QMF Bank (14496-3 sp04 p206)

  1149.  *

  1150.  * @param   x       pointer to the beginning of the first sample window

  1151.  * @param   W       array of complex-valued samples split into subbands

  1152.  */

  1153. static void sbr_qmf_analysis(DSPContext *dsp, FFTContext *mdct,

  1154.                              SBRDSPContext *sbrdsp, const float *in, float *x,

  1155.                              float z[320], float W[2][32][32][2], int buf_idx)

  1156. {

  1157.     int i;

  1158.     memcpy(x    , x+1024, (320-32)*sizeof(x[0]));

  1159.     memcpy(x+288, in,         1024*sizeof(x[0]));

  1160.     for (i = 0; i < 32; i++) { // numTimeSlots*RATE = 16*2 as 960 sample frames

  1161.                                // are not supported

  1162.         dsp->vector_fmul_reverse(z, sbr_qmf_window_ds, x, 320);

  1163.         sbrdsp->sum64x5(z);

  1164.         sbrdsp->qmf_pre_shuffle(z);

  1165.         mdct->imdct_half(mdct, z, z+64);

  1166.         sbrdsp->qmf_post_shuffle(W[buf_idx][i], z);

  1167.         x += 32;

  1168.     }

  1169. }

  1170. 

  1171. /**

  1172.  * Synthesis QMF Bank (14496-3 sp04 p206) and Downsampled Synthesis QMF Bank

  1173.  * (14496-3 sp04 p206)

  1174.  */

  1175. static void sbr_qmf_synthesis(DSPContext *dsp, FFTContext *mdct,

  1176.                               SBRDSPContext *sbrdsp, AVFloatDSPContext *fdsp,

  1177.                               float *out, float X[2][38][64],

  1178.                               float mdct_buf[2][64],

  1179.                               float *v0, int *v_off, const unsigned int div)

  1180. {

  1181.     int i, n;

  1182.     const float *sbr_qmf_window = div ? sbr_qmf_window_ds : sbr_qmf_window_us;

  1183.     const int step = 128 >> div;

  1184.     float *v;

  1185.     for (i = 0; i < 32; i++) {

  1186.         if (*v_off < step) {

  1187.             int saved_samples = (1280 - 128) >> div;

  1188.             memcpy(&v0[SBR_SYNTHESIS_BUF_SIZE - saved_samples], v0, saved_samples * sizeof(float));

  1189.             *v_off = SBR_SYNTHESIS_BUF_SIZE - saved_samples - step;

  1190.         } else {

  1191.             *v_off -= step;

  1192.         }

  1193.         v = v0 + *v_off;

  1194.         if (div) {

  1195.             for (n = 0; n < 32; n++) {

  1196.                 X[0][i][   n] = -X[0][i][n];

  1197.                 X[0][i][32+n] =  X[1][i][31-n];

  1198.             }

  1199.             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);

  1200.             sbrdsp->qmf_deint_neg(v, mdct_buf[0]);

  1201.         } else {

  1202.             sbrdsp->neg_odd_64(X[1][i]);

  1203.             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);

  1204.             mdct->imdct_half(mdct, mdct_buf[1], X[1][i]);

  1205.             sbrdsp->qmf_deint_bfly(v, mdct_buf[1], mdct_buf[0]);

  1206.         }

  1207.         fdsp->vector_fmul   (out, v                , sbr_qmf_window                       , 64 >> div);

  1208.         dsp->vector_fmul_add(out, v + ( 192 >> div), sbr_qmf_window + ( 64 >> div), out   , 64 >> div);

  1209.         dsp->vector_fmul_add(out, v + ( 256 >> div), sbr_qmf_window + (128 >> div), out   , 64 >> div);

  1210.         dsp->vector_fmul_add(out, v + ( 448 >> div), sbr_qmf_window + (192 >> div), out   , 64 >> div);

  1211.         dsp->vector_fmul_add(out, v + ( 512 >> div), sbr_qmf_window + (256 >> div), out   , 64 >> div);

  1212.         dsp->vector_fmul_add(out, v + ( 704 >> div), sbr_qmf_window + (320 >> div), out   , 64 >> div);

  1213.         dsp->vector_fmul_add(out, v + ( 768 >> div), sbr_qmf_window + (384 >> div), out   , 64 >> div);

  1214.         dsp->vector_fmul_add(out, v + ( 960 >> div), sbr_qmf_window + (448 >> div), out   , 64 >> div);

  1215.         dsp->vector_fmul_add(out, v + (1024 >> div), sbr_qmf_window + (512 >> div), out   , 64 >> div);

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

  1217.         out += 64 >> div;

  1218.     }

  1219. }

  1220. 

  1221. /** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering

  1222.  * (14496-3 sp04 p214)

  1223.  * Warning: This routine does not seem numerically stable.

  1224.  */

  1225. static void sbr_hf_inverse_filter(SBRDSPContext *dsp,

  1226.                                   float (*alpha0)[2], float (*alpha1)[2],

  1227.                                   const float X_low[32][40][2], int k0)

  1228. {

  1229.     int k;

  1230.     for (k = 0; k < k0; k++) {

  1231.         LOCAL_ALIGNED_16(float, phi, [3], [2][2]);

  1232.         float dk;

  1233. 

  1234.         dsp->autocorrelate(X_low[k], phi);

  1235. 

  1236.         dk =  phi[2][1][0] * phi[1][0][0] -

  1237.              (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;

  1238. 

  1239.         if (!dk) {

  1240.             alpha1[k][0] = 0;

  1241.             alpha1[k][1] = 0;

  1242.         } else {

  1243.             float temp_real, temp_im;

  1244.             temp_real = phi[0][0][0] * phi[1][1][0] -

  1245.                         phi[0][0][1] * phi[1][1][1] -

  1246.                         phi[0][1][0] * phi[1][0][0];

  1247.             temp_im   = phi[0][0][0] * phi[1][1][1] +

  1248.                         phi[0][0][1] * phi[1][1][0] -

  1249.                         phi[0][1][1] * phi[1][0][0];

  1250. 

  1251.             alpha1[k][0] = temp_real / dk;

  1252.             alpha1[k][1] = temp_im   / dk;

  1253.         }

  1254. 

  1255.         if (!phi[1][0][0]) {

  1256.             alpha0[k][0] = 0;

  1257.             alpha0[k][1] = 0;

  1258.         } else {

  1259.             float temp_real, temp_im;

  1260.             temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +

  1261.                                        alpha1[k][1] * phi[1][1][1];

  1262.             temp_im   = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -

  1263.                                        alpha1[k][0] * phi[1][1][1];

  1264. 

  1265.             alpha0[k][0] = -temp_real / phi[1][0][0];

  1266.             alpha0[k][1] = -temp_im   / phi[1][0][0];

  1267.         }

  1268. 

  1269.         if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||

  1270.            alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {

  1271.             alpha1[k][0] = 0;

  1272.             alpha1[k][1] = 0;

  1273.             alpha0[k][0] = 0;

  1274.             alpha0[k][1] = 0;

  1275.         }

  1276.     }

  1277. }

  1278. 

  1279. /// Chirp Factors (14496-3 sp04 p214)

  1280. static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)

  1281. {

  1282.     int i;

  1283.     float new_bw;

  1284.     static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };

  1285. 

  1286.     for (i = 0; i < sbr->n_q; i++) {

  1287.         if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {

  1288.             new_bw = 0.6f;

  1289.         } else

  1290.             new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];

  1291. 

  1292.         if (new_bw < ch_data->bw_array[i]) {

  1293.             new_bw = 0.75f    * new_bw + 0.25f    * ch_data->bw_array[i];

  1294.         } else

  1295.             new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];

  1296.         ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;

  1297.     }

  1298. }

  1299. 

  1300. /// Generate the subband filtered lowband

  1301. static int sbr_lf_gen(AACContext *ac, SpectralBandReplication *sbr,

  1302.                       float X_low[32][40][2], const float W[2][32][32][2],

  1303.                       int buf_idx)

  1304. {

  1305.     int i, k;

  1306.     const int t_HFGen = 8;

  1307.     const int i_f = 32;

  1308.     memset(X_low, 0, 32*sizeof(*X_low));

  1309.     for (k = 0; k < sbr->kx[1]; k++) {

  1310.         for (i = t_HFGen; i < i_f + t_HFGen; i++) {

  1311.             X_low[k][i][0] = W[buf_idx][i - t_HFGen][k][0];

  1312.             X_low[k][i][1] = W[buf_idx][i - t_HFGen][k][1];

  1313.         }

  1314.     }

  1315.     buf_idx = 1-buf_idx;

  1316.     for (k = 0; k < sbr->kx[0]; k++) {

  1317.         for (i = 0; i < t_HFGen; i++) {

  1318.             X_low[k][i][0] = W[buf_idx][i + i_f - t_HFGen][k][0];

  1319.             X_low[k][i][1] = W[buf_idx][i + i_f - t_HFGen][k][1];

  1320.         }

  1321.     }

  1322.     return 0;

  1323. }

  1324. 

  1325. /// High Frequency Generator (14496-3 sp04 p215)

  1326. static int sbr_hf_gen(AACContext *ac, SpectralBandReplication *sbr,

  1327.                       float X_high[64][40][2], const float X_low[32][40][2],

  1328.                       const float (*alpha0)[2], const float (*alpha1)[2],

  1329.                       const float bw_array[5], const uint8_t *t_env,

  1330.                       int bs_num_env)

  1331. {

  1332.     int j, x;

  1333.     int g = 0;

  1334.     int k = sbr->kx[1];

  1335.     for (j = 0; j < sbr->num_patches; j++) {

  1336.         for (x = 0; x < sbr->patch_num_subbands[j]; x++, k++) {

  1337.             const int p = sbr->patch_start_subband[j] + x;

  1338.             while (g <= sbr->n_q && k >= sbr->f_tablenoise[g])

  1339.                 g++;

  1340.             g--;

  1341. 

  1342.             if (g < 0) {

  1343.                 av_log(ac->avctx, AV_LOG_ERROR,

  1344.                        "ERROR : no subband found for frequency %d\n", k);

  1345.                 return -1;

  1346.             }

  1347. 

  1348.             sbr->dsp.hf_gen(X_high[k] + ENVELOPE_ADJUSTMENT_OFFSET,

  1349.                             X_low[p]  + ENVELOPE_ADJUSTMENT_OFFSET,

  1350.                             alpha0[p], alpha1[p], bw_array[g],

  1351.                             2 * t_env[0], 2 * t_env[bs_num_env]);

  1352.         }

  1353.     }

  1354.     if (k < sbr->m[1] + sbr->kx[1])

  1355.         memset(X_high + k, 0, (sbr->m[1] + sbr->kx[1] - k) * sizeof(*X_high));

  1356. 

  1357.     return 0;

  1358. }

  1359. 

  1360. /// Generate the subband filtered lowband

  1361. static int sbr_x_gen(SpectralBandReplication *sbr, float X[2][38][64],

  1362.                      const float Y0[38][64][2], const float Y1[38][64][2],

  1363.                      const float X_low[32][40][2], int ch)

  1364. {

  1365.     int k, i;

  1366.     const int i_f = 32;

  1367.     const int i_Temp = FFMAX(2*sbr->data[ch].t_env_num_env_old - i_f, 0);

  1368.     memset(X, 0, 2*sizeof(*X));

  1369.     for (k = 0; k < sbr->kx[0]; k++) {

  1370.         for (i = 0; i < i_Temp; i++) {

  1371.             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];

  1372.             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];

  1373.         }

  1374.     }

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

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

  1377.             X[0][i][k] = Y0[i + i_f][k][0];

  1378.             X[1][i][k] = Y0[i + i_f][k][1];

  1379.         }

  1380.     }

  1381. 

  1382.     for (k = 0; k < sbr->kx[1]; k++) {

  1383.         for (i = i_Temp; i < 38; i++) {

  1384.             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];

  1385.             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];

  1386.         }

  1387.     }

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

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

  1390.             X[0][i][k] = Y1[i][k][0];

  1391.             X[1][i][k] = Y1[i][k][1];

  1392.         }

  1393.     }

  1394.     return 0;

  1395. }

  1396. 

  1397. /** High Frequency Adjustment (14496-3 sp04 p217) and Mapping

  1398.  * (14496-3 sp04 p217)

  1399.  */

  1400. static int sbr_mapping(AACContext *ac, SpectralBandReplication *sbr,

  1401.                         SBRData *ch_data, int e_a[2])

  1402. {

  1403.     int e, i, m;

  1404. 

  1405.     memset(ch_data->s_indexmapped[1], 0, 7*sizeof(ch_data->s_indexmapped[1]));

  1406.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1407.         const unsigned int ilim = sbr->n[ch_data->bs_freq_res[e + 1]];

  1408.         uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

  1409.         int k;

  1410. 

  1411.         if (sbr->kx[1] != table[0]) {

  1412.             av_log(ac->avctx, AV_LOG_ERROR, "kx != f_table{high,low}[0]. "

  1413.                    "Derived frequency tables were not regenerated.\n");

  1414.             sbr_turnoff(sbr);

  1415.             return AVERROR_BUG;

  1416.         }

  1417.         for (i = 0; i < ilim; i++)

  1418.             for (m = table[i]; m < table[i + 1]; m++)

  1419.                 sbr->e_origmapped[e][m - sbr->kx[1]] = ch_data->env_facs[e+1][i];

  1420. 

  1421.         // ch_data->bs_num_noise > 1 => 2 noise floors

  1422.         k = (ch_data->bs_num_noise > 1) && (ch_data->t_env[e] >= ch_data->t_q[1]);

  1423.         for (i = 0; i < sbr->n_q; i++)

  1424.             for (m = sbr->f_tablenoise[i]; m < sbr->f_tablenoise[i + 1]; m++)

  1425.                 sbr->q_mapped[e][m - sbr->kx[1]] = ch_data->noise_facs[k+1][i];

  1426. 

  1427.         for (i = 0; i < sbr->n[1]; i++) {

  1428.             if (ch_data->bs_add_harmonic_flag) {

  1429.                 const unsigned int m_midpoint =

  1430.                     (sbr->f_tablehigh[i] + sbr->f_tablehigh[i + 1]) >> 1;

  1431. 

  1432.                 ch_data->s_indexmapped[e + 1][m_midpoint - sbr->kx[1]] = ch_data->bs_add_harmonic[i] *

  1433.                     (e >= e_a[1] || (ch_data->s_indexmapped[0][m_midpoint - sbr->kx[1]] == 1));

  1434.             }

  1435.         }

  1436. 

  1437.         for (i = 0; i < ilim; i++) {

  1438.             int additional_sinusoid_present = 0;

  1439.             for (m = table[i]; m < table[i + 1]; m++) {

  1440.                 if (ch_data->s_indexmapped[e + 1][m - sbr->kx[1]]) {

  1441.                     additional_sinusoid_present = 1;

  1442.                     break;

  1443.                 }

  1444.             }

  1445.             memset(&sbr->s_mapped[e][table[i] - sbr->kx[1]], additional_sinusoid_present,

  1446.                    (table[i + 1] - table[i]) * sizeof(sbr->s_mapped[e][0]));

  1447.         }

  1448.     }

  1449. 

  1450.     memcpy(ch_data->s_indexmapped[0], ch_data->s_indexmapped[ch_data->bs_num_env], sizeof(ch_data->s_indexmapped[0]));

  1451.     return 0;

  1452. }

  1453. 

  1454. /// Estimation of current envelope (14496-3 sp04 p218)

  1455. static void sbr_env_estimate(float (*e_curr)[48], float X_high[64][40][2],

  1456.                              SpectralBandReplication *sbr, SBRData *ch_data)

  1457. {

  1458.     int e, m;

  1459.     int kx1 = sbr->kx[1];

  1460. 

  1461.     if (sbr->bs_interpol_freq) {

  1462.         for (e = 0; e < ch_data->bs_num_env; e++) {

  1463.             const float recip_env_size = 0.5f / (ch_data->t_env[e + 1] - ch_data->t_env[e]);

  1464.             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1465.             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1466. 

  1467.             for (m = 0; m < sbr->m[1]; m++) {

  1468.                 float sum = sbr->dsp.sum_square(X_high[m+kx1] + ilb, iub - ilb);

  1469.                 e_curr[e][m] = sum * recip_env_size;

  1470.             }

  1471.         }

  1472.     } else {

  1473.         int k, p;

  1474. 

  1475.         for (e = 0; e < ch_data->bs_num_env; e++) {

  1476.             const int env_size = 2 * (ch_data->t_env[e + 1] - ch_data->t_env[e]);

  1477.             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1478.             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1479.             const uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

  1480. 

  1481.             for (p = 0; p < sbr->n[ch_data->bs_freq_res[e + 1]]; p++) {

  1482.                 float sum = 0.0f;

  1483.                 const int den = env_size * (table[p + 1] - table[p]);

  1484. 

  1485.                 for (k = table[p]; k < table[p + 1]; k++) {

  1486.                     sum += sbr->dsp.sum_square(X_high[k] + ilb, iub - ilb);

  1487.                 }

  1488.                 sum /= den;

  1489.                 for (k = table[p]; k < table[p + 1]; k++) {

  1490.                     e_curr[e][k - kx1] = sum;

  1491.                 }

  1492.             }

  1493.         }

  1494.     }

  1495. }

  1496. 

  1497. /**

  1498.  * Calculation of levels of additional HF signal components (14496-3 sp04 p219)

  1499.  * and Calculation of gain (14496-3 sp04 p219)

  1500.  */

  1501. static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,

  1502.                           SBRData *ch_data, const int e_a[2])

  1503. {

  1504.     int e, k, m;

  1505.     // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)

  1506.     static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };

  1507. 

  1508.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1509.         int delta = !((e == e_a[1]) || (e == e_a[0]));

  1510.         for (k = 0; k < sbr->n_lim; k++) {

  1511.             float gain_boost, gain_max;

  1512.             float sum[2] = { 0.0f, 0.0f };

  1513.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1514.                 const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);

  1515.                 sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);

  1516.                 sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);

  1517.                 if (!sbr->s_mapped[e][m]) {

  1518.                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /

  1519.                                             ((1.0f + sbr->e_curr[e][m]) *

  1520.                                              (1.0f + sbr->q_mapped[e][m] * delta)));

  1521.                 } else {

  1522.                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /

  1523.                                             ((1.0f + sbr->e_curr[e][m]) *

  1524.                                              (1.0f + sbr->q_mapped[e][m])));

  1525.                 }

  1526.             }

  1527.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1528.                 sum[0] += sbr->e_origmapped[e][m];

  1529.                 sum[1] += sbr->e_curr[e][m];

  1530.             }

  1531.             gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));

  1532.             gain_max = FFMIN(100000.f, gain_max);

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

  1534.                 float q_m_max   = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];

  1535.                 sbr->q_m[e][m]  = FFMIN(sbr->q_m[e][m], q_m_max);

  1536.                 sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);

  1537.             }

  1538.             sum[0] = sum[1] = 0.0f;

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

  1540.                 sum[0] += sbr->e_origmapped[e][m];

  1541.                 sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]

  1542.                           + sbr->s_m[e][m] * sbr->s_m[e][m]

  1543.                           + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];

  1544.             }

  1545.             gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));

  1546.             gain_boost = FFMIN(1.584893192f, gain_boost);

  1547.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1548.                 sbr->gain[e][m] *= gain_boost;

  1549.                 sbr->q_m[e][m]  *= gain_boost;

  1550.                 sbr->s_m[e][m]  *= gain_boost;

  1551.             }

  1552.         }

  1553.     }

  1554. }

  1555. 

  1556. /// Assembling HF Signals (14496-3 sp04 p220)

  1557. static void sbr_hf_assemble(float Y1[38][64][2],

  1558.                             const float X_high[64][40][2],

  1559.                             SpectralBandReplication *sbr, SBRData *ch_data,

  1560.                             const int e_a[2])

  1561. {

  1562.     int e, i, j, m;

  1563.     const int h_SL = 4 * !sbr->bs_smoothing_mode;

  1564.     const int kx = sbr->kx[1];

  1565.     const int m_max = sbr->m[1];

  1566.     static const float h_smooth[5] = {

  1567.         0.33333333333333,

  1568.         0.30150283239582,

  1569.         0.21816949906249,

  1570.         0.11516383427084,

  1571.         0.03183050093751,

  1572.     };

  1573.     static const int8_t phi[2][4] = {

  1574.         {  1,  0, -1,  0}, // real

  1575.         {  0,  1,  0, -1}, // imaginary

  1576.     };

  1577.     float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;

  1578.     int indexnoise = ch_data->f_indexnoise;

  1579.     int indexsine  = ch_data->f_indexsine;

  1580. 

  1581.     if (sbr->reset) {

  1582.         for (i = 0; i < h_SL; i++) {

  1583.             memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));

  1584.             memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0],  m_max * sizeof(sbr->q_m[0][0]));

  1585.         }

  1586.     } else if (h_SL) {

  1587.         memcpy(g_temp[2*ch_data->t_env[0]], g_temp[2*ch_data->t_env_num_env_old], 4*sizeof(g_temp[0]));

  1588.         memcpy(q_temp[2*ch_data->t_env[0]], q_temp[2*ch_data->t_env_num_env_old], 4*sizeof(q_temp[0]));

  1589.     }

  1590. 

  1591.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1592.         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {

  1593.             memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));

  1594.             memcpy(q_temp[h_SL + i], sbr->q_m[e],  m_max * sizeof(sbr->q_m[0][0]));

  1595.         }

  1596.     }

  1597. 

  1598.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1599.         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {

  1600.             int phi_sign = (1 - 2*(kx & 1));

  1601.             LOCAL_ALIGNED_16(float, g_filt_tab, [48]);

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

  1603.             float *g_filt, *q_filt;

  1604. 

  1605.             if (h_SL && e != e_a[0] && e != e_a[1]) {

  1606.                 g_filt = g_filt_tab;

  1607.                 q_filt = q_filt_tab;

  1608.                 for (m = 0; m < m_max; m++) {

  1609.                     const int idx1 = i + h_SL;

  1610.                     g_filt[m] = 0.0f;

  1611.                     q_filt[m] = 0.0f;

  1612.                     for (j = 0; j <= h_SL; j++) {

  1613.                         g_filt[m] += g_temp[idx1 - j][m] * h_smooth[j];

  1614.                         q_filt[m] += q_temp[idx1 - j][m] * h_smooth[j];

  1615.                     }

  1616.                 }

  1617.             } else {

  1618.                 g_filt = g_temp[i + h_SL];

  1619.                 q_filt = q_temp[i];

  1620.             }

  1621. 

  1622.             sbr->dsp.hf_g_filt(Y1[i] + kx, X_high + kx, g_filt, m_max,

  1623.                                i + ENVELOPE_ADJUSTMENT_OFFSET);

  1624. 

  1625.             if (e != e_a[0] && e != e_a[1]) {

  1626.                 sbr->dsp.hf_apply_noise[indexsine](Y1[i] + kx, sbr->s_m[e],

  1627.                                                    q_filt, indexnoise,

  1628.                                                    kx, m_max);

  1629.             } else {

  1630.                 for (m = 0; m < m_max; m++) {

  1631.                     Y1[i][m + kx][0] +=

  1632.                         sbr->s_m[e][m] * phi[0][indexsine];

  1633.                     Y1[i][m + kx][1] +=

  1634.                         sbr->s_m[e][m] * (phi[1][indexsine] * phi_sign);

  1635.                     phi_sign = -phi_sign;

  1636.                 }

  1637.             }

  1638.             indexnoise = (indexnoise + m_max) & 0x1ff;

  1639.             indexsine = (indexsine + 1) & 3;

  1640.         }

  1641.     }

  1642.     ch_data->f_indexnoise = indexnoise;

  1643.     ch_data->f_indexsine  = indexsine;

  1644. }

  1645. 

  1646. void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,

  1647.                   float* L, float* R)

  1648. {

  1649.     int downsampled = ac->oc[1].m4ac.ext_sample_rate < sbr->sample_rate;

  1650.     int ch;

  1651.     int nch = (id_aac == TYPE_CPE) ? 2 : 1;

  1652.     int err;

  1653. 

  1654.     if (!sbr->kx_and_m_pushed) {

  1655.         sbr->kx[0] = sbr->kx[1];

  1656.         sbr->m[0] = sbr->m[1];

  1657.     } else {

  1658.         sbr->kx_and_m_pushed = 0;

  1659.     }

  1660. 

  1661.     if (sbr->start) {

  1662.         sbr_dequant(sbr, id_aac);

  1663.     }

  1664.     for (ch = 0; ch < nch; ch++) {

  1665.         /* decode channel */

  1666.         sbr_qmf_analysis(&ac->dsp, &sbr->mdct_ana, &sbr->dsp, ch ? R : L, sbr->data[ch].analysis_filterbank_samples,

  1667.                          (float*)sbr->qmf_filter_scratch,

  1668.                          sbr->data[ch].W, sbr->data[ch].Ypos);

  1669.         sbr_lf_gen(ac, sbr, sbr->X_low, sbr->data[ch].W, sbr->data[ch].Ypos);

  1670.         sbr->data[ch].Ypos ^= 1;

  1671.         if (sbr->start) {

  1672.             sbr_hf_inverse_filter(&sbr->dsp, sbr->alpha0, sbr->alpha1, sbr->X_low, sbr->k[0]);

  1673.             sbr_chirp(sbr, &sbr->data[ch]);

  1674.             sbr_hf_gen(ac, sbr, sbr->X_high, sbr->X_low, sbr->alpha0, sbr->alpha1,

  1675.                        sbr->data[ch].bw_array, sbr->data[ch].t_env,

  1676.                        sbr->data[ch].bs_num_env);

  1677. 

  1678.             // hf_adj

  1679.             err = sbr_mapping(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);

  1680.             if (!err) {

  1681.                 sbr_env_estimate(sbr->e_curr, sbr->X_high, sbr, &sbr->data[ch]);

  1682.                 sbr_gain_calc(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);

  1683.                 sbr_hf_assemble(sbr->data[ch].Y[sbr->data[ch].Ypos],

  1684.                                 sbr->X_high, sbr, &sbr->data[ch],

  1685.                                 sbr->data[ch].e_a);

  1686.             }

  1687.         }

  1688. 

  1689.         /* synthesis */

  1690.         sbr_x_gen(sbr, sbr->X[ch],

  1691.                   sbr->data[ch].Y[1-sbr->data[ch].Ypos],

  1692.                   sbr->data[ch].Y[  sbr->data[ch].Ypos],

  1693.                   sbr->X_low, ch);

  1694.     }

  1695. 

  1696.     if (ac->oc[1].m4ac.ps == 1) {

  1697.         if (sbr->ps.start) {

  1698.             ff_ps_apply(ac->avctx, &sbr->ps, sbr->X[0], sbr->X[1], sbr->kx[1] + sbr->m[1]);

  1699.         } else {

  1700.             memcpy(sbr->X[1], sbr->X[0], sizeof(sbr->X[0]));

  1701.         }

  1702.         nch = 2;

  1703.     }

  1704. 

  1705.     sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, &sbr->dsp, &ac->fdsp,

  1706.                       L, sbr->X[0], sbr->qmf_filter_scratch,

  1707.                       sbr->data[0].synthesis_filterbank_samples,

  1708.                       &sbr->data[0].synthesis_filterbank_samples_offset,

  1709.                       downsampled);

  1710.     if (nch == 2)

  1711.         sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, &sbr->dsp, &ac->fdsp,

  1712.                           R, sbr->X[1], sbr->qmf_filter_scratch,

  1713.                           sbr->data[1].synthesis_filterbank_samples,

  1714.                           &sbr->data[1].synthesis_filterbank_samples_offset,

  1715.                           downsampled);

  1716. }