falkTX
/
FFmpeg
mirror of https://github.com/falkTX/FFmpeg.git
1
0
Fork 0
Code Issues 0 Releases 338 Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
43714 Commits
32 Branches
283MB
Tree: 6c180b35c4
Branches Tags
${ item.name }
Create branch ${ searchTerm }
from '6c180b35c4'
${ noResults }
FFmpeg/libavcodec/aacsbr.c

1722 lines
64KB
Raw Blame History 

  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. static const DECLARE_ALIGNED(16, float, zero64)[64];

  80. 

  81. #define SBR_INIT_VLC_STATIC(num, size) \

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

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

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

  85.                     size)

  86. 

  87. #define SBR_VLC_ROW(name) \

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

  89. 

  90. av_cold void ff_aac_sbr_init(void)

  91. {

  92.     int n;

  93.     static const struct {

  94.         const void *sbr_codes, *sbr_bits;

  95.         const unsigned int table_size, elem_size;

  96.     } sbr_tmp[] = {

  97.         SBR_VLC_ROW(t_huffman_env_1_5dB),

  98.         SBR_VLC_ROW(f_huffman_env_1_5dB),

  99.         SBR_VLC_ROW(t_huffman_env_bal_1_5dB),

  100.         SBR_VLC_ROW(f_huffman_env_bal_1_5dB),

  101.         SBR_VLC_ROW(t_huffman_env_3_0dB),

  102.         SBR_VLC_ROW(f_huffman_env_3_0dB),

  103.         SBR_VLC_ROW(t_huffman_env_bal_3_0dB),

  104.         SBR_VLC_ROW(f_huffman_env_bal_3_0dB),

  105.         SBR_VLC_ROW(t_huffman_noise_3_0dB),

  106.         SBR_VLC_ROW(t_huffman_noise_bal_3_0dB),

  107.     };

  108. 

  109.     // SBR VLC table initialization

  110.     SBR_INIT_VLC_STATIC(0, 1098);

  111.     SBR_INIT_VLC_STATIC(1, 1092);

  112.     SBR_INIT_VLC_STATIC(2, 768);

  113.     SBR_INIT_VLC_STATIC(3, 1026);

  114.     SBR_INIT_VLC_STATIC(4, 1058);

  115.     SBR_INIT_VLC_STATIC(5, 1052);

  116.     SBR_INIT_VLC_STATIC(6, 544);

  117.     SBR_INIT_VLC_STATIC(7, 544);

  118.     SBR_INIT_VLC_STATIC(8, 592);

  119.     SBR_INIT_VLC_STATIC(9, 512);

  120. 

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

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

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

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

  125. 

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

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

  128. 

  129.     ff_ps_init();

  130. }

  131. 

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

  133. static void sbr_turnoff(SpectralBandReplication *sbr) {

  134.     sbr->start = 0;

  135.     // Init defults used in pure upsampling mode

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

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

  138.     // Reset values for first SBR header

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

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

  141. }

  142. 

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

  144. {

  145.     float mdct_scale;

  146.     if(sbr->mdct.mdct_bits)

  147.         return;

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

  149.     sbr_turnoff(sbr);

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

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

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

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

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

  155.     mdct_scale = ac->avctx->sample_fmt == AV_SAMPLE_FMT_FLT ? 32768.0f : 1.0f;

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

  157.     ff_mdct_init(&sbr->mdct_ana, 7, 1, -2.0 * mdct_scale);

  158.     ff_ps_ctx_init(&sbr->ps);

  159.     ff_sbrdsp_init(&sbr->dsp);

  160. }

  161. 

  162. av_cold void ff_aac_sbr_ctx_close(SpectralBandReplication *sbr)

  163. {

  164.     ff_mdct_end(&sbr->mdct);

  165.     ff_mdct_end(&sbr->mdct_ana);

  166. }

  167. 

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

  169. {

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

  171. }

  172. 

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

  174. {

  175.     int i;

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

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

  178.             return 1;

  179.     return 0;

  180. }

  181. 

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

  183. static void sbr_make_f_tablelim(SpectralBandReplication *sbr)

  184. {

  185.     int k;

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

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

  188.                                                1.18509277094158210129f,   //2^(0.49/2)

  189.                                                1.11987160404675912501f }; //2^(0.49/3)

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

  191.         int16_t patch_borders[7];

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

  193. 

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

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

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

  197. 

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

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

  200.         if (sbr->num_patches > 1)

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

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

  203. 

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

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

  206.               qsort_comparison_function_int16);

  207. 

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

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

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

  211.                 *++out = *in++;

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

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

  214.                 in++;

  215.                 sbr->n_lim--;

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

  217.                 *out = *in++;

  218.                 sbr->n_lim--;

  219.             } else {

  220.                 *++out = *in++;

  221.             }

  222.         }

  223.     } else {

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

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

  226.         sbr->n_lim = 1;

  227.     }

  228. }

  229. 

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

  231. {

  232.     unsigned int cnt = get_bits_count(gb);

  233.     uint8_t bs_header_extra_1;

  234.     uint8_t bs_header_extra_2;

  235.     int old_bs_limiter_bands = sbr->bs_limiter_bands;

  236.     SpectrumParameters old_spectrum_params;

  237. 

  238.     sbr->start = 1;

  239. 

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

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

  242. 

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

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

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

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

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

  248. 

  249.     bs_header_extra_1 = get_bits1(gb);

  250.     bs_header_extra_2 = get_bits1(gb);

  251. 

  252.     if (bs_header_extra_1) {

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

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

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

  256.     } else {

  257.         sbr->spectrum_params.bs_freq_scale  = 2;

  258.         sbr->spectrum_params.bs_alter_scale = 1;

  259.         sbr->spectrum_params.bs_noise_bands = 2;

  260.     }

  261. 

  262.     // Check if spectrum parameters changed

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

  264.         sbr->reset = 1;

  265. 

  266.     if (bs_header_extra_2) {

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

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

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

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

  271.     } else {

  272.         sbr->bs_limiter_bands  = 2;

  273.         sbr->bs_limiter_gains  = 2;

  274.         sbr->bs_interpol_freq  = 1;

  275.         sbr->bs_smoothing_mode = 1;

  276.     }

  277. 

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

  279.         sbr_make_f_tablelim(sbr);

  280. 

  281.     return get_bits_count(gb) - cnt;

  282. }

  283. 

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

  285. {

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

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

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

  289.     return min;

  290. }

  291. 

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

  293. {

  294.     int k, previous, present;

  295.     float base, prod;

  296. 

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

  298.     prod = start;

  299.     previous = start;

  300. 

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

  302.         prod *= base;

  303.         present  = lrintf(prod);

  304.         bands[k] = present - previous;

  305.         previous = present;

  306.     }

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

  308. }

  309. 

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

  311. {

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

  313.     if (n_master <= 0) {

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

  315.         return -1;

  316.     }

  317.     if (bs_xover_band >= n_master) {

  318.         av_log(avctx, AV_LOG_ERROR,

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

  320.                bs_xover_band);

  321.         return -1;

  322.     }

  323.     return 0;

  324. }

  325. 

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

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

  328.                              SpectrumParameters *spectrum)

  329. {

  330.     unsigned int temp, max_qmf_subbands;

  331.     unsigned int start_min, stop_min;

  332.     int k;

  333.     const int8_t *sbr_offset_ptr;

  334.     int16_t stop_dk[13];

  335. 

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

  337.         temp = 3000;

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

  339.         temp = 4000;

  340.     } else

  341.         temp = 5000;

  342. 

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

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

  345. 

  346.     switch (sbr->sample_rate) {

  347.     case 16000:

  348.         sbr_offset_ptr = sbr_offset[0];

  349.         break;

  350.     case 22050:

  351.         sbr_offset_ptr = sbr_offset[1];

  352.         break;

  353.     case 24000:

  354.         sbr_offset_ptr = sbr_offset[2];

  355.         break;

  356.     case 32000:

  357.         sbr_offset_ptr = sbr_offset[3];

  358.         break;

  359.     case 44100: case 48000: case 64000:

  360.         sbr_offset_ptr = sbr_offset[4];

  361.         break;

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

  363.         sbr_offset_ptr = sbr_offset[5];

  364.         break;

  365.     default:

  366.         av_log(ac->avctx, AV_LOG_ERROR,

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

  368.         return -1;

  369.     }

  370. 

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

  372. 

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

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

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

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

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

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

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

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

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

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

  383.     } else {

  384.         av_log(ac->avctx, AV_LOG_ERROR,

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

  386.         return -1;

  387.     }

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

  389. 

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

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

  392.         max_qmf_subbands = 48;

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

  394.         max_qmf_subbands = 35;

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

  396.         max_qmf_subbands = 32;

  397. 

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

  399.         av_log(ac->avctx, AV_LOG_ERROR,

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

  401.         return -1;

  402.     }

  403. 

  404.     if (!spectrum->bs_freq_scale) {

  405.         int dk, k2diff;

  406. 

  407.         dk = spectrum->bs_alter_scale + 1;

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

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

  410.             return -1;

  411. 

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

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

  414. 

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

  416.         if (k2diff < 0) {

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

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

  419.         } else if (k2diff) {

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

  421.         }

  422. 

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

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

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

  426. 

  427.     } else {

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

  429.         int two_regions, num_bands_0;

  430.         int vdk0_max, vdk1_min;

  431.         int16_t vk0[49];

  432. 

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

  434.             two_regions = 1;

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

  436.         } else {

  437.             two_regions = 0;

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

  439.         }

  440. 

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

  442. 

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

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

  445.             return -1;

  446.         }

  447. 

  448.         vk0[0] = 0;

  449. 

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

  451. 

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

  453.         vdk0_max = vk0[num_bands_0];

  454. 

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

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

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

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

  459.                 return -1;

  460.             }

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

  462.         }

  463. 

  464.         if (two_regions) {

  465.             int16_t vk1[49];

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

  467.                                                      : 1.0f; // bs_alter_scale = {0,1}

  468.             int num_bands_1 = lrintf(half_bands * invwarp *

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

  470. 

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

  472. 

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

  474. 

  475.             if (vdk1_min < vdk0_max) {

  476.                 int change;

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

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

  479.                 vk1[1]           += change;

  480.                 vk1[num_bands_1] -= change;

  481.             }

  482. 

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

  484. 

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

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

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

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

  489.                     return -1;

  490.                 }

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

  492.             }

  493. 

  494.             sbr->n_master = num_bands_0 + num_bands_1;

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

  496.                 return -1;

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

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

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

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

  501. 

  502.         } else {

  503.             sbr->n_master = num_bands_0;

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

  505.                 return -1;

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

  507.         }

  508.     }

  509. 

  510.     return 0;

  511. }

  512. 

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

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

  515. {

  516.     int i, k, sb = 0;

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

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

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

  520. 

  521.     sbr->num_patches = 0;

  522. 

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

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

  525.     } else

  526.         k = sbr->n_master;

  527. 

  528.     do {

  529.         int odd = 0;

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

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

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

  533.         }

  534. 

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

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

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

  538.         // count of 6 patches

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

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

  541.             return -1;

  542.         }

  543. 

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

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

  546. 

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

  548.             usb = sb;

  549.             msb = sb;

  550.             sbr->num_patches++;

  551.         } else

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

  553. 

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

  555.             k = sbr->n_master;

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

  557. 

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

  559.         sbr->num_patches--;

  560. 

  561.     return 0;

  562. }

  563. 

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

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

  566. {

  567.     int k, temp;

  568. 

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

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

  571. 

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

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

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

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

  576. 

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

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

  579.         av_log(ac->avctx, AV_LOG_ERROR,

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

  581.         return -1;

  582.     }

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

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

  585.         return -1;

  586.     }

  587. 

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

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

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

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

  592. 

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

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

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

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

  597.         return -1;

  598.     }

  599. 

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

  601.     temp = 0;

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

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

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

  605.     }

  606. 

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

  608.         return -1;

  609. 

  610.     sbr_make_f_tablelim(sbr);

  611. 

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

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

  614. 

  615.     return 0;

  616. }

  617. 

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

  619.                                               int elements)

  620. {

  621.     int i;

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

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

  624.     }

  625. }

  626. 

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

  628. static const int8_t ceil_log2[] = {

  629.     0, 1, 2, 2, 3, 3,

  630. };

  631. 

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

  633.                          GetBitContext *gb, SBRData *ch_data)

  634. {

  635.     int i;

  636.     unsigned bs_pointer = 0;

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

  638.     int abs_bord_trail = 16;

  639.     int num_rel_lead, num_rel_trail;

  640.     unsigned bs_num_env_old = ch_data->bs_num_env;

  641. 

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

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

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

  645. 

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

  647.     case FIXFIX:

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

  649.         num_rel_lead                        = ch_data->bs_num_env - 1;

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

  651.             ch_data->bs_amp_res = 0;

  652. 

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

  654.             av_log(ac->avctx, AV_LOG_ERROR,

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

  656.                    ch_data->bs_num_env);

  657.             return -1;

  658.         }

  659. 

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

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

  662. 

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

  664.                    ch_data->bs_num_env;

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

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

  667. 

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

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

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

  671.         break;

  672.     case FIXVAR:

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

  674.         num_rel_trail                       = get_bits(gb, 2);

  675.         ch_data->bs_num_env                 = num_rel_trail + 1;

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

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

  678. 

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

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

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

  682. 

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

  684. 

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

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

  687.         break;

  688.     case VARFIX:

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

  690.         num_rel_lead                        = get_bits(gb, 2);

  691.         ch_data->bs_num_env                 = num_rel_lead + 1;

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

  693. 

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

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

  696. 

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

  698. 

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

  700.         break;

  701.     case VARVAR:

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

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

  704.         num_rel_lead                        = get_bits(gb, 2);

  705.         num_rel_trail                       = get_bits(gb, 2);

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

  707. 

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

  709.             av_log(ac->avctx, AV_LOG_ERROR,

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

  711.                    ch_data->bs_num_env);

  712.             return -1;

  713.         }

  714. 

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

  716. 

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

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

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

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

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

  722. 

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

  724. 

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

  726.         break;

  727.     }

  728. 

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

  730.         av_log(ac->avctx, AV_LOG_ERROR,

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

  732.                bs_pointer);

  733.         return -1;

  734.     }

  735. 

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

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

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

  739.             return -1;

  740.         }

  741.     }

  742. 

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

  744. 

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

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

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

  748.         unsigned int idx;

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

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

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

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

  753.         } else { // VARFIX

  754.             if (!bs_pointer)

  755.                 idx = 1;

  756.             else if (bs_pointer == 1)

  757.                 idx = ch_data->bs_num_env - 1;

  758.             else // bs_pointer > 1

  759.                 idx = bs_pointer - 1;

  760.         }

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

  762.     }

  763. 

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

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

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

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

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

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

  770. 

  771.     return 0;

  772. }

  773. 

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

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

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

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

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

  779. 

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

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

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

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

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

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

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

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

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

  789. }

  790. 

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

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

  793.                           SBRData *ch_data)

  794. {

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

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

  797. }

  798. 

  799. /// Read inverse filtering data

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

  801.                           SBRData *ch_data)

  802. {

  803.     int i;

  804. 

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

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

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

  808. }

  809. 

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

  811.                               SBRData *ch_data, int ch)

  812. {

  813.     int bits;

  814.     int i, j, k;

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

  816.     int t_lav, f_lav;

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

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

  819. 

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

  821.         if (ch_data->bs_amp_res) {

  822.             bits   = 5;

  823.             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_3_0DB].table;

  824.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_3_0DB];

  825.             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;

  826.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];

  827.         } else {

  828.             bits   = 6;

  829.             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_1_5DB].table;

  830.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_1_5DB];

  831.             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_1_5DB].table;

  832.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_1_5DB];

  833.         }

  834.     } else {

  835.         if (ch_data->bs_amp_res) {

  836.             bits   = 6;

  837.             t_huff = vlc_sbr[T_HUFFMAN_ENV_3_0DB].table;

  838.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_3_0DB];

  839.             f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;

  840.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];

  841.         } else {

  842.             bits   = 7;

  843.             t_huff = vlc_sbr[T_HUFFMAN_ENV_1_5DB].table;

  844.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_1_5DB];

  845.             f_huff = vlc_sbr[F_HUFFMAN_ENV_1_5DB].table;

  846.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_1_5DB];

  847.         }

  848.     }

  849. 

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

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

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

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

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

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

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

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

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

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

  860.                 }

  861.             } else {

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

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

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

  865.                 }

  866.             }

  867.         } else {

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

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

  870.                 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);

  871.         }

  872.     }

  873. 

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

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

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

  877. }

  878. 

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

  880.                            SBRData *ch_data, int ch)

  881. {

  882.     int i, j;

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

  884.     int t_lav, f_lav;

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

  886. 

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

  888.         t_huff = vlc_sbr[T_HUFFMAN_NOISE_BAL_3_0DB].table;

  889.         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_BAL_3_0DB];

  890.         f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;

  891.         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];

  892.     } else {

  893.         t_huff = vlc_sbr[T_HUFFMAN_NOISE_3_0DB].table;

  894.         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_3_0DB];

  895.         f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;

  896.         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];

  897.     }

  898. 

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

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

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

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

  903.         } else {

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

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

  906.                 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);

  907.         }

  908.     }

  909. 

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

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

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

  913. }

  914. 

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

  916.                                GetBitContext *gb,

  917.                                int bs_extension_id, int *num_bits_left)

  918. {

  919.     switch (bs_extension_id) {

  920.     case EXTENSION_ID_PS:

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

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

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

  924.             *num_bits_left = 0;

  925.         } else {

  926. #if 1

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

  928. #else

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

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

  931.             *num_bits_left = 0;

  932. #endif

  933.         }

  934.         break;

  935.     default:

  936.         // some files contain 0-padding

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

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

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

  940.         *num_bits_left = 0;

  941.         break;

  942.     }

  943. }

  944. 

  945. static int read_sbr_single_channel_element(AACContext *ac,

  946.                                             SpectralBandReplication *sbr,

  947.                                             GetBitContext *gb)

  948. {

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

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

  951. 

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

  953.         return -1;

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

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

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

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

  958. 

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

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

  961. 

  962.     return 0;

  963. }

  964. 

  965. static int read_sbr_channel_pair_element(AACContext *ac,

  966.                                           SpectralBandReplication *sbr,

  967.                                           GetBitContext *gb)

  968. {

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

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

  971. 

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

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

  974.             return -1;

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

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

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

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

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

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

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

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

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

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

  985.     } else {

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

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

  988.             return -1;

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

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

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

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

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

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

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

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

  997.     }

  998. 

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

  1000.         get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);

  1001.     if ((sbr->data[1].bs_add_harmonic_flag = get_bits1(gb)))

  1002.         get_bits1_vector(gb, sbr->data[1].bs_add_harmonic, sbr->n[1]);

  1003. 

  1004.     return 0;

  1005. }

  1006. 

  1007. static unsigned int read_sbr_data(AACContext *ac, SpectralBandReplication *sbr,

  1008.                                   GetBitContext *gb, int id_aac)

  1009. {

  1010.     unsigned int cnt = get_bits_count(gb);

  1011. 

  1012.     if (id_aac == TYPE_SCE || id_aac == TYPE_CCE) {

  1013.         if (read_sbr_single_channel_element(ac, sbr, gb)) {

  1014.             sbr_turnoff(sbr);

  1015.             return get_bits_count(gb) - cnt;

  1016.         }

  1017.     } else if (id_aac == TYPE_CPE) {

  1018.         if (read_sbr_channel_pair_element(ac, sbr, gb)) {

  1019.             sbr_turnoff(sbr);

  1020.             return get_bits_count(gb) - cnt;

  1021.         }

  1022.     } else {

  1023.         av_log(ac->avctx, AV_LOG_ERROR,

  1024.             "Invalid bitstream - cannot apply SBR to element type %d\n", id_aac);

  1025.         sbr_turnoff(sbr);

  1026.         return get_bits_count(gb) - cnt;

  1027.     }

  1028.     if (get_bits1(gb)) { // bs_extended_data

  1029.         int num_bits_left = get_bits(gb, 4); // bs_extension_size

  1030.         if (num_bits_left == 15)

  1031.             num_bits_left += get_bits(gb, 8); // bs_esc_count

  1032. 

  1033.         num_bits_left <<= 3;

  1034.         while (num_bits_left > 7) {

  1035.             num_bits_left -= 2;

  1036.             read_sbr_extension(ac, sbr, gb, get_bits(gb, 2), &num_bits_left); // bs_extension_id

  1037.         }

  1038.         if (num_bits_left < 0) {

  1039.             av_log(ac->avctx, AV_LOG_ERROR, "SBR Extension over read.\n");

  1040.         }

  1041.         if (num_bits_left > 0)

  1042.             skip_bits(gb, num_bits_left);

  1043.     }

  1044. 

  1045.     return get_bits_count(gb) - cnt;

  1046. }

  1047. 

  1048. static void sbr_reset(AACContext *ac, SpectralBandReplication *sbr)

  1049. {

  1050.     int err;

  1051.     err = sbr_make_f_master(ac, sbr, &sbr->spectrum_params);

  1052.     if (err >= 0)

  1053.         err = sbr_make_f_derived(ac, sbr);

  1054.     if (err < 0) {

  1055.         av_log(ac->avctx, AV_LOG_ERROR,

  1056.                "SBR reset failed. Switching SBR to pure upsampling mode.\n");

  1057.         sbr_turnoff(sbr);

  1058.     }

  1059. }

  1060. 

  1061. /**

  1062.  * Decode Spectral Band Replication extension data; reference: table 4.55.

  1063.  *

  1064.  * @param   crc flag indicating the presence of CRC checksum

  1065.  * @param   cnt length of TYPE_FIL syntactic element in bytes

  1066.  *

  1067.  * @return  Returns number of bytes consumed from the TYPE_FIL element.

  1068.  */

  1069. int ff_decode_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,

  1070.                             GetBitContext *gb_host, int crc, int cnt, int id_aac)

  1071. {

  1072.     unsigned int num_sbr_bits = 0, num_align_bits;

  1073.     unsigned bytes_read;

  1074.     GetBitContext gbc = *gb_host, *gb = &gbc;

  1075.     skip_bits_long(gb_host, cnt*8 - 4);

  1076. 

  1077.     sbr->reset = 0;

  1078. 

  1079.     if (!sbr->sample_rate)

  1080.         sbr->sample_rate = 2 * ac->oc[1].m4ac.sample_rate; //TODO use the nominal sample rate for arbitrary sample rate support

  1081.     if (!ac->oc[1].m4ac.ext_sample_rate)

  1082.         ac->oc[1].m4ac.ext_sample_rate = 2 * ac->oc[1].m4ac.sample_rate;

  1083. 

  1084.     if (crc) {

  1085.         skip_bits(gb, 10); // bs_sbr_crc_bits; TODO - implement CRC check

  1086.         num_sbr_bits += 10;

  1087.     }

  1088. 

  1089.     //Save some state from the previous frame.

  1090.     sbr->kx[0] = sbr->kx[1];

  1091.     sbr->m[0] = sbr->m[1];

  1092.     sbr->kx_and_m_pushed = 1;

  1093. 

  1094.     num_sbr_bits++;

  1095.     if (get_bits1(gb)) // bs_header_flag

  1096.         num_sbr_bits += read_sbr_header(sbr, gb);

  1097. 

  1098.     if (sbr->reset)

  1099.         sbr_reset(ac, sbr);

  1100. 

  1101.     if (sbr->start)

  1102.         num_sbr_bits  += read_sbr_data(ac, sbr, gb, id_aac);

  1103. 

  1104.     num_align_bits = ((cnt << 3) - 4 - num_sbr_bits) & 7;

  1105.     bytes_read = ((num_sbr_bits + num_align_bits + 4) >> 3);

  1106. 

  1107.     if (bytes_read > cnt) {

  1108.         av_log(ac->avctx, AV_LOG_ERROR,

  1109.                "Expected to read %d SBR bytes actually read %d.\n", cnt, bytes_read);

  1110.     }

  1111.     return cnt;

  1112. }

  1113. 

  1114. /// Dequantization and stereo decoding (14496-3 sp04 p203)

  1115. static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)

  1116. {

  1117.     int k, e;

  1118.     int ch;

  1119. 

  1120.     if (id_aac == TYPE_CPE && sbr->bs_coupling) {

  1121.         float alpha      = sbr->data[0].bs_amp_res ?  1.0f :  0.5f;

  1122.         float pan_offset = sbr->data[0].bs_amp_res ? 12.0f : 24.0f;

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

  1124.             for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {

  1125.                 float temp1 = exp2f(sbr->data[0].env_facs[e][k] * alpha + 7.0f);

  1126.                 float temp2 = exp2f((pan_offset - sbr->data[1].env_facs[e][k]) * alpha);

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

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

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

  1130.             }

  1131.         }

  1132.         for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {

  1133.             for (k = 0; k < sbr->n_q; k++) {

  1134.                 float temp1 = exp2f(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs[e][k] + 1);

  1135.                 float temp2 = exp2f(12 - sbr->data[1].noise_facs[e][k]);

  1136.                 float fac   = temp1 / (1.0f + temp2);

  1137.                 sbr->data[0].noise_facs[e][k] = fac;

  1138.                 sbr->data[1].noise_facs[e][k] = fac * temp2;

  1139.             }

  1140.         }

  1141.     } else { // SCE or one non-coupled CPE

  1142.         for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {

  1143.             float alpha = sbr->data[ch].bs_amp_res ? 1.0f : 0.5f;

  1144.             for (e = 1; e <= sbr->data[ch].bs_num_env; e++)

  1145.                 for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++)

  1146.                     sbr->data[ch].env_facs[e][k] =

  1147.                         exp2f(alpha * sbr->data[ch].env_facs[e][k] + 6.0f);

  1148.             for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)

  1149.                 for (k = 0; k < sbr->n_q; k++)

  1150.                     sbr->data[ch].noise_facs[e][k] =

  1151.                         exp2f(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs[e][k]);

  1152.         }

  1153.     }

  1154. }

  1155. 

  1156. /**

  1157.  * Analysis QMF Bank (14496-3 sp04 p206)

  1158.  *

  1159.  * @param   x       pointer to the beginning of the first sample window

  1160.  * @param   W       array of complex-valued samples split into subbands

  1161.  */

  1162. static void sbr_qmf_analysis(DSPContext *dsp, FFTContext *mdct,

  1163.                              SBRDSPContext *sbrdsp, const float *in, float *x,

  1164.                              float z[320], float W[2][32][32][2])

  1165. {

  1166.     int i;

  1167.     memcpy(W[0], W[1], sizeof(W[0]));

  1168.     memcpy(x    , x+1024, (320-32)*sizeof(x[0]));

  1169.     memcpy(x+288, in,         1024*sizeof(x[0]));

  1170.     for (i = 0; i < 32; i++) { // numTimeSlots*RATE = 16*2 as 960 sample frames

  1171.                                // are not supported

  1172.         dsp->vector_fmul_reverse(z, sbr_qmf_window_ds, x, 320);

  1173.         sbrdsp->sum64x5(z);

  1174.         sbrdsp->qmf_pre_shuffle(z);

  1175.         mdct->imdct_half(mdct, z, z+64);

  1176.         sbrdsp->qmf_post_shuffle(W[1][i], z);

  1177.         x += 32;

  1178.     }

  1179. }

  1180. 

  1181. /**

  1182.  * Synthesis QMF Bank (14496-3 sp04 p206) and Downsampled Synthesis QMF Bank

  1183.  * (14496-3 sp04 p206)

  1184.  */

  1185. static void sbr_qmf_synthesis(DSPContext *dsp, FFTContext *mdct,

  1186.                               SBRDSPContext *sbrdsp,

  1187.                               float *out, float X[2][38][64],

  1188.                               float mdct_buf[2][64],

  1189.                               float *v0, int *v_off, const unsigned int div)

  1190. {

  1191.     int i, n;

  1192.     const float *sbr_qmf_window = div ? sbr_qmf_window_ds : sbr_qmf_window_us;

  1193.     const int step = 128 >> div;

  1194.     float *v;

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

  1196.         if (*v_off < step) {

  1197.             int saved_samples = (1280 - 128) >> div;

  1198.             memcpy(&v0[SBR_SYNTHESIS_BUF_SIZE - saved_samples], v0, saved_samples * sizeof(float));

  1199.             *v_off = SBR_SYNTHESIS_BUF_SIZE - saved_samples - step;

  1200.         } else {

  1201.             *v_off -= step;

  1202.         }

  1203.         v = v0 + *v_off;

  1204.         if (div) {

  1205.             for (n = 0; n < 32; n++) {

  1206.                 X[0][i][   n] = -X[0][i][n];

  1207.                 X[0][i][32+n] =  X[1][i][31-n];

  1208.             }

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

  1210.             sbrdsp->qmf_deint_neg(v, mdct_buf[0]);

  1211.         } else {

  1212.             sbrdsp->neg_odd_64(X[1][i]);

  1213.             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);

  1214.             mdct->imdct_half(mdct, mdct_buf[1], X[1][i]);

  1215.             sbrdsp->qmf_deint_bfly(v, mdct_buf[1], mdct_buf[0]);

  1216.         }

  1217.         dsp->vector_fmul_add(out, v                , sbr_qmf_window               , zero64, 64 >> div);

  1218.         dsp->vector_fmul_add(out, v + ( 192 >> div), sbr_qmf_window + ( 64 >> div), out   , 64 >> div);

  1219.         dsp->vector_fmul_add(out, v + ( 256 >> div), sbr_qmf_window + (128 >> div), out   , 64 >> div);

  1220.         dsp->vector_fmul_add(out, v + ( 448 >> div), sbr_qmf_window + (192 >> div), out   , 64 >> div);

  1221.         dsp->vector_fmul_add(out, v + ( 512 >> div), sbr_qmf_window + (256 >> div), out   , 64 >> div);

  1222.         dsp->vector_fmul_add(out, v + ( 704 >> div), sbr_qmf_window + (320 >> div), out   , 64 >> div);

  1223.         dsp->vector_fmul_add(out, v + ( 768 >> div), sbr_qmf_window + (384 >> div), out   , 64 >> div);

  1224.         dsp->vector_fmul_add(out, v + ( 960 >> div), sbr_qmf_window + (448 >> div), out   , 64 >> div);

  1225.         dsp->vector_fmul_add(out, v + (1024 >> div), sbr_qmf_window + (512 >> div), out   , 64 >> div);

  1226.         dsp->vector_fmul_add(out, v + (1216 >> div), sbr_qmf_window + (576 >> div), out   , 64 >> div);

  1227.         out += 64 >> div;

  1228.     }

  1229. }

  1230. 

  1231. /** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering

  1232.  * (14496-3 sp04 p214)

  1233.  * Warning: This routine does not seem numerically stable.

  1234.  */

  1235. static void sbr_hf_inverse_filter(SBRDSPContext *dsp,

  1236.                                   float (*alpha0)[2], float (*alpha1)[2],

  1237.                                   const float X_low[32][40][2], int k0)

  1238. {

  1239.     int k;

  1240.     for (k = 0; k < k0; k++) {

  1241.         LOCAL_ALIGNED_16(float, phi, [3], [2][2]);

  1242.         float dk;

  1243. 

  1244.         dsp->autocorrelate(X_low[k], phi);

  1245. 

  1246.         dk =  phi[2][1][0] * phi[1][0][0] -

  1247.              (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;

  1248. 

  1249.         if (!dk) {

  1250.             alpha1[k][0] = 0;

  1251.             alpha1[k][1] = 0;

  1252.         } else {

  1253.             float temp_real, temp_im;

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

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

  1256.                         phi[0][1][0] * phi[1][0][0];

  1257.             temp_im   = phi[0][0][0] * phi[1][1][1] +

  1258.                         phi[0][0][1] * phi[1][1][0] -

  1259.                         phi[0][1][1] * phi[1][0][0];

  1260. 

  1261.             alpha1[k][0] = temp_real / dk;

  1262.             alpha1[k][1] = temp_im   / dk;

  1263.         }

  1264. 

  1265.         if (!phi[1][0][0]) {

  1266.             alpha0[k][0] = 0;

  1267.             alpha0[k][1] = 0;

  1268.         } else {

  1269.             float temp_real, temp_im;

  1270.             temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +

  1271.                                        alpha1[k][1] * phi[1][1][1];

  1272.             temp_im   = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -

  1273.                                        alpha1[k][0] * phi[1][1][1];

  1274. 

  1275.             alpha0[k][0] = -temp_real / phi[1][0][0];

  1276.             alpha0[k][1] = -temp_im   / phi[1][0][0];

  1277.         }

  1278. 

  1279.         if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||

  1280.            alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {

  1281.             alpha1[k][0] = 0;

  1282.             alpha1[k][1] = 0;

  1283.             alpha0[k][0] = 0;

  1284.             alpha0[k][1] = 0;

  1285.         }

  1286.     }

  1287. }

  1288. 

  1289. /// Chirp Factors (14496-3 sp04 p214)

  1290. static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)

  1291. {

  1292.     int i;

  1293.     float new_bw;

  1294.     static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };

  1295. 

  1296.     for (i = 0; i < sbr->n_q; i++) {

  1297.         if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {

  1298.             new_bw = 0.6f;

  1299.         } else

  1300.             new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];

  1301. 

  1302.         if (new_bw < ch_data->bw_array[i]) {

  1303.             new_bw = 0.75f    * new_bw + 0.25f    * ch_data->bw_array[i];

  1304.         } else

  1305.             new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];

  1306.         ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;

  1307.     }

  1308. }

  1309. 

  1310. /// Generate the subband filtered lowband

  1311. static int sbr_lf_gen(AACContext *ac, SpectralBandReplication *sbr,

  1312.                       float X_low[32][40][2], const float W[2][32][32][2])

  1313. {

  1314.     int i, k;

  1315.     const int t_HFGen = 8;

  1316.     const int i_f = 32;

  1317.     memset(X_low, 0, 32*sizeof(*X_low));

  1318.     for (k = 0; k < sbr->kx[1]; k++) {

  1319.         for (i = t_HFGen; i < i_f + t_HFGen; i++) {

  1320.             X_low[k][i][0] = W[1][i - t_HFGen][k][0];

  1321.             X_low[k][i][1] = W[1][i - t_HFGen][k][1];

  1322.         }

  1323.     }

  1324.     for (k = 0; k < sbr->kx[0]; k++) {

  1325.         for (i = 0; i < t_HFGen; i++) {

  1326.             X_low[k][i][0] = W[0][i + i_f - t_HFGen][k][0];

  1327.             X_low[k][i][1] = W[0][i + i_f - t_HFGen][k][1];

  1328.         }

  1329.     }

  1330.     return 0;

  1331. }

  1332. 

  1333. /// High Frequency Generator (14496-3 sp04 p215)

  1334. static int sbr_hf_gen(AACContext *ac, SpectralBandReplication *sbr,

  1335.                       float X_high[64][40][2], const float X_low[32][40][2],

  1336.                       const float (*alpha0)[2], const float (*alpha1)[2],

  1337.                       const float bw_array[5], const uint8_t *t_env,

  1338.                       int bs_num_env)

  1339. {

  1340.     int j, x;

  1341.     int g = 0;

  1342.     int k = sbr->kx[1];

  1343.     for (j = 0; j < sbr->num_patches; j++) {

  1344.         for (x = 0; x < sbr->patch_num_subbands[j]; x++, k++) {

  1345.             const int p = sbr->patch_start_subband[j] + x;

  1346.             while (g <= sbr->n_q && k >= sbr->f_tablenoise[g])

  1347.                 g++;

  1348.             g--;

  1349. 

  1350.             if (g < 0) {

  1351.                 av_log(ac->avctx, AV_LOG_ERROR,

  1352.                        "ERROR : no subband found for frequency %d\n", k);

  1353.                 return -1;

  1354.             }

  1355. 

  1356.             sbr->dsp.hf_gen(X_high[k] + ENVELOPE_ADJUSTMENT_OFFSET,

  1357.                             X_low[p]  + ENVELOPE_ADJUSTMENT_OFFSET,

  1358.                             alpha0[p], alpha1[p], bw_array[g],

  1359.                             2 * t_env[0], 2 * t_env[bs_num_env]);

  1360.         }

  1361.     }

  1362.     if (k < sbr->m[1] + sbr->kx[1])

  1363.         memset(X_high + k, 0, (sbr->m[1] + sbr->kx[1] - k) * sizeof(*X_high));

  1364. 

  1365.     return 0;

  1366. }

  1367. 

  1368. /// Generate the subband filtered lowband

  1369. static int sbr_x_gen(SpectralBandReplication *sbr, float X[2][38][64],

  1370.                      const float Y0[38][64][2], const float Y1[38][64][2],

  1371.                      const float X_low[32][40][2], int ch)

  1372. {

  1373.     int k, i;

  1374.     const int i_f = 32;

  1375.     const int i_Temp = FFMAX(2*sbr->data[ch].t_env_num_env_old - i_f, 0);

  1376.     memset(X, 0, 2*sizeof(*X));

  1377.     for (k = 0; k < sbr->kx[0]; k++) {

  1378.         for (i = 0; i < i_Temp; i++) {

  1379.             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];

  1380.             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];

  1381.         }

  1382.     }

  1383.     for (; k < sbr->kx[0] + sbr->m[0]; k++) {

  1384.         for (i = 0; i < i_Temp; i++) {

  1385.             X[0][i][k] = Y0[i + i_f][k][0];

  1386.             X[1][i][k] = Y0[i + i_f][k][1];

  1387.         }

  1388.     }

  1389. 

  1390.     for (k = 0; k < sbr->kx[1]; k++) {

  1391.         for (i = i_Temp; i < 38; i++) {

  1392.             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];

  1393.             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];

  1394.         }

  1395.     }

  1396.     for (; k < sbr->kx[1] + sbr->m[1]; k++) {

  1397.         for (i = i_Temp; i < i_f; i++) {

  1398.             X[0][i][k] = Y1[i][k][0];

  1399.             X[1][i][k] = Y1[i][k][1];

  1400.         }

  1401.     }

  1402.     return 0;

  1403. }

  1404. 

  1405. /** High Frequency Adjustment (14496-3 sp04 p217) and Mapping

  1406.  * (14496-3 sp04 p217)

  1407.  */

  1408. static int sbr_mapping(AACContext *ac, SpectralBandReplication *sbr,

  1409.                         SBRData *ch_data, int e_a[2])

  1410. {

  1411.     int e, i, m;

  1412. 

  1413.     memset(ch_data->s_indexmapped[1], 0, 7*sizeof(ch_data->s_indexmapped[1]));

  1414.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1415.         const unsigned int ilim = sbr->n[ch_data->bs_freq_res[e + 1]];

  1416.         uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

  1417.         int k;

  1418. 

  1419.         if (sbr->kx[1] != table[0]) {

  1420.             av_log(ac->avctx, AV_LOG_ERROR, "kx != f_table{high,low}[0]. "

  1421.                    "Derived frequency tables were not regenerated.\n");

  1422.             sbr_turnoff(sbr);

  1423.             return AVERROR_BUG;

  1424.         }

  1425.         for (i = 0; i < ilim; i++)

  1426.             for (m = table[i]; m < table[i + 1]; m++)

  1427.                 sbr->e_origmapped[e][m - sbr->kx[1]] = ch_data->env_facs[e+1][i];

  1428. 

  1429.         // ch_data->bs_num_noise > 1 => 2 noise floors

  1430.         k = (ch_data->bs_num_noise > 1) && (ch_data->t_env[e] >= ch_data->t_q[1]);

  1431.         for (i = 0; i < sbr->n_q; i++)

  1432.             for (m = sbr->f_tablenoise[i]; m < sbr->f_tablenoise[i + 1]; m++)

  1433.                 sbr->q_mapped[e][m - sbr->kx[1]] = ch_data->noise_facs[k+1][i];

  1434. 

  1435.         for (i = 0; i < sbr->n[1]; i++) {

  1436.             if (ch_data->bs_add_harmonic_flag) {

  1437.                 const unsigned int m_midpoint =

  1438.                     (sbr->f_tablehigh[i] + sbr->f_tablehigh[i + 1]) >> 1;

  1439. 

  1440.                 ch_data->s_indexmapped[e + 1][m_midpoint - sbr->kx[1]] = ch_data->bs_add_harmonic[i] *

  1441.                     (e >= e_a[1] || (ch_data->s_indexmapped[0][m_midpoint - sbr->kx[1]] == 1));

  1442.             }

  1443.         }

  1444. 

  1445.         for (i = 0; i < ilim; i++) {

  1446.             int additional_sinusoid_present = 0;

  1447.             for (m = table[i]; m < table[i + 1]; m++) {

  1448.                 if (ch_data->s_indexmapped[e + 1][m - sbr->kx[1]]) {

  1449.                     additional_sinusoid_present = 1;

  1450.                     break;

  1451.                 }

  1452.             }

  1453.             memset(&sbr->s_mapped[e][table[i] - sbr->kx[1]], additional_sinusoid_present,

  1454.                    (table[i + 1] - table[i]) * sizeof(sbr->s_mapped[e][0]));

  1455.         }

  1456.     }

  1457. 

  1458.     memcpy(ch_data->s_indexmapped[0], ch_data->s_indexmapped[ch_data->bs_num_env], sizeof(ch_data->s_indexmapped[0]));

  1459.     return 0;

  1460. }

  1461. 

  1462. /// Estimation of current envelope (14496-3 sp04 p218)

  1463. static void sbr_env_estimate(float (*e_curr)[48], float X_high[64][40][2],

  1464.                              SpectralBandReplication *sbr, SBRData *ch_data)

  1465. {

  1466.     int e, m;

  1467.     int kx1 = sbr->kx[1];

  1468. 

  1469.     if (sbr->bs_interpol_freq) {

  1470.         for (e = 0; e < ch_data->bs_num_env; e++) {

  1471.             const float recip_env_size = 0.5f / (ch_data->t_env[e + 1] - ch_data->t_env[e]);

  1472.             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1473.             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1474. 

  1475.             for (m = 0; m < sbr->m[1]; m++) {

  1476.                 float sum = sbr->dsp.sum_square(X_high[m+kx1] + ilb, iub - ilb);

  1477.                 e_curr[e][m] = sum * recip_env_size;

  1478.             }

  1479.         }

  1480.     } else {

  1481.         int k, p;

  1482. 

  1483.         for (e = 0; e < ch_data->bs_num_env; e++) {

  1484.             const int env_size = 2 * (ch_data->t_env[e + 1] - ch_data->t_env[e]);

  1485.             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1486.             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1487.             const uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

  1488. 

  1489.             for (p = 0; p < sbr->n[ch_data->bs_freq_res[e + 1]]; p++) {

  1490.                 float sum = 0.0f;

  1491.                 const int den = env_size * (table[p + 1] - table[p]);

  1492. 

  1493.                 for (k = table[p]; k < table[p + 1]; k++) {

  1494.                     sum += sbr->dsp.sum_square(X_high[k] + ilb, iub - ilb);

  1495.                 }

  1496.                 sum /= den;

  1497.                 for (k = table[p]; k < table[p + 1]; k++) {

  1498.                     e_curr[e][k - kx1] = sum;

  1499.                 }

  1500.             }

  1501.         }

  1502.     }

  1503. }

  1504. 

  1505. /**

  1506.  * Calculation of levels of additional HF signal components (14496-3 sp04 p219)

  1507.  * and Calculation of gain (14496-3 sp04 p219)

  1508.  */

  1509. static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,

  1510.                           SBRData *ch_data, const int e_a[2])

  1511. {

  1512.     int e, k, m;

  1513.     // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)

  1514.     static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };

  1515. 

  1516.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1517.         int delta = !((e == e_a[1]) || (e == e_a[0]));

  1518.         for (k = 0; k < sbr->n_lim; k++) {

  1519.             float gain_boost, gain_max;

  1520.             float sum[2] = { 0.0f, 0.0f };

  1521.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1522.                 const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);

  1523.                 sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);

  1524.                 sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);

  1525.                 if (!sbr->s_mapped[e][m]) {

  1526.                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /

  1527.                                             ((1.0f + sbr->e_curr[e][m]) *

  1528.                                              (1.0f + sbr->q_mapped[e][m] * delta)));

  1529.                 } else {

  1530.                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /

  1531.                                             ((1.0f + sbr->e_curr[e][m]) *

  1532.                                              (1.0f + sbr->q_mapped[e][m])));

  1533.                 }

  1534.             }

  1535.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1536.                 sum[0] += sbr->e_origmapped[e][m];

  1537.                 sum[1] += sbr->e_curr[e][m];

  1538.             }

  1539.             gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));

  1540.             gain_max = FFMIN(100000.f, gain_max);

  1541.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1542.                 float q_m_max   = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];

  1543.                 sbr->q_m[e][m]  = FFMIN(sbr->q_m[e][m], q_m_max);

  1544.                 sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);

  1545.             }

  1546.             sum[0] = sum[1] = 0.0f;

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

  1548.                 sum[0] += sbr->e_origmapped[e][m];

  1549.                 sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]

  1550.                           + sbr->s_m[e][m] * sbr->s_m[e][m]

  1551.                           + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];

  1552.             }

  1553.             gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));

  1554.             gain_boost = FFMIN(1.584893192f, gain_boost);

  1555.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

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

  1557.                 sbr->q_m[e][m]  *= gain_boost;

  1558.                 sbr->s_m[e][m]  *= gain_boost;

  1559.             }

  1560.         }

  1561.     }

  1562. }

  1563. 

  1564. /// Assembling HF Signals (14496-3 sp04 p220)

  1565. static void sbr_hf_assemble(float Y1[38][64][2],

  1566.                             const float X_high[64][40][2],

  1567.                             SpectralBandReplication *sbr, SBRData *ch_data,

  1568.                             const int e_a[2])

  1569. {

  1570.     int e, i, j, m;

  1571.     const int h_SL = 4 * !sbr->bs_smoothing_mode;

  1572.     const int kx = sbr->kx[1];

  1573.     const int m_max = sbr->m[1];

  1574.     static const float h_smooth[5] = {

  1575.         0.33333333333333,

  1576.         0.30150283239582,

  1577.         0.21816949906249,

  1578.         0.11516383427084,

  1579.         0.03183050093751,

  1580.     };

  1581.     float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;

  1582.     int indexnoise = ch_data->f_indexnoise;

  1583.     int indexsine  = ch_data->f_indexsine;

  1584. 

  1585.     if (sbr->reset) {

  1586.         for (i = 0; i < h_SL; i++) {

  1587.             memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));

  1588.             memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0],  m_max * sizeof(sbr->q_m[0][0]));

  1589.         }

  1590.     } else if (h_SL) {

  1591.         memcpy(g_temp[2*ch_data->t_env[0]], g_temp[2*ch_data->t_env_num_env_old], 4*sizeof(g_temp[0]));

  1592.         memcpy(q_temp[2*ch_data->t_env[0]], q_temp[2*ch_data->t_env_num_env_old], 4*sizeof(q_temp[0]));

  1593.     }

  1594. 

  1595.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1596.         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {

  1597.             memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));

  1598.             memcpy(q_temp[h_SL + i], sbr->q_m[e],  m_max * sizeof(sbr->q_m[0][0]));

  1599.         }

  1600.     }

  1601. 

  1602.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1603.         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {

  1604.             LOCAL_ALIGNED_16(float, g_filt_tab, [48]);

  1605.             LOCAL_ALIGNED_16(float, q_filt_tab, [48]);

  1606.             float *g_filt, *q_filt;

  1607. 

  1608.             if (h_SL && e != e_a[0] && e != e_a[1]) {

  1609.                 g_filt = g_filt_tab;

  1610.                 q_filt = q_filt_tab;

  1611.                 for (m = 0; m < m_max; m++) {

  1612.                     const int idx1 = i + h_SL;

  1613.                     g_filt[m] = 0.0f;

  1614.                     q_filt[m] = 0.0f;

  1615.                     for (j = 0; j <= h_SL; j++) {

  1616.                         g_filt[m] += g_temp[idx1 - j][m] * h_smooth[j];

  1617.                         q_filt[m] += q_temp[idx1 - j][m] * h_smooth[j];

  1618.                     }

  1619.                 }

  1620.             } else {

  1621.                 g_filt = g_temp[i + h_SL];

  1622.                 q_filt = q_temp[i];

  1623.             }

  1624. 

  1625.             sbr->dsp.hf_g_filt(Y1[i] + kx, X_high + kx, g_filt, m_max,

  1626.                                i + ENVELOPE_ADJUSTMENT_OFFSET);

  1627. 

  1628.             if (e != e_a[0] && e != e_a[1]) {

  1629.                 sbr->dsp.hf_apply_noise[indexsine](Y1[i] + kx, sbr->s_m[e],

  1630.                                                    q_filt, indexnoise,

  1631.                                                    kx, m_max);

  1632.             } else {

  1633.                 int idx = indexsine&1;

  1634.                 int A = (1-((indexsine+(kx & 1))&2));

  1635.                 int B = (A^(-idx)) + idx;

  1636.                 float *out = &Y1[i][kx][idx];

  1637.                 float *in  = sbr->s_m[e];

  1638.                 for (m = 0; m+1 < m_max; m+=2) {

  1639.                     out[2*m  ] += in[m  ] * A;

  1640.                     out[2*m+2] += in[m+1] * B;

  1641.                 }

  1642.                 if(m_max&1)

  1643.                     out[2*m  ] += in[m  ] * A;

  1644.             }

  1645.             indexnoise = (indexnoise + m_max) & 0x1ff;

  1646.             indexsine = (indexsine + 1) & 3;

  1647.         }

  1648.     }

  1649.     ch_data->f_indexnoise = indexnoise;

  1650.     ch_data->f_indexsine  = indexsine;

  1651. }

  1652. 

  1653. void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,

  1654.                   float* L, float* R)

  1655. {

  1656.     int downsampled = ac->oc[1].m4ac.ext_sample_rate < sbr->sample_rate;

  1657.     int ch;

  1658.     int nch = (id_aac == TYPE_CPE) ? 2 : 1;

  1659.     int err;

  1660. 

  1661.     if (!sbr->kx_and_m_pushed) {

  1662.         sbr->kx[0] = sbr->kx[1];

  1663.         sbr->m[0] = sbr->m[1];

  1664.     } else {

  1665.         sbr->kx_and_m_pushed = 0;

  1666.     }

  1667. 

  1668.     if (sbr->start) {

  1669.         sbr_dequant(sbr, id_aac);

  1670.     }

  1671.     for (ch = 0; ch < nch; ch++) {

  1672.         /* decode channel */

  1673.         sbr_qmf_analysis(&ac->dsp, &sbr->mdct_ana, &sbr->dsp, ch ? R : L, sbr->data[ch].analysis_filterbank_samples,

  1674.                          (float*)sbr->qmf_filter_scratch,

  1675.                          sbr->data[ch].W);

  1676.         sbr_lf_gen(ac, sbr, sbr->X_low, sbr->data[ch].W);

  1677.         sbr->data[ch].Ypos ^= 1;

  1678.         if (sbr->start) {

  1679.             sbr_hf_inverse_filter(&sbr->dsp, sbr->alpha0, sbr->alpha1, sbr->X_low, sbr->k[0]);

  1680.             sbr_chirp(sbr, &sbr->data[ch]);

  1681.             sbr_hf_gen(ac, sbr, sbr->X_high, sbr->X_low, sbr->alpha0, sbr->alpha1,

  1682.                        sbr->data[ch].bw_array, sbr->data[ch].t_env,

  1683.                        sbr->data[ch].bs_num_env);

  1684. 

  1685.             // hf_adj

  1686.             err = sbr_mapping(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);

  1687.             if (!err) {

  1688.                 sbr_env_estimate(sbr->e_curr, sbr->X_high, sbr, &sbr->data[ch]);

  1689.                 sbr_gain_calc(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);

  1690.                 sbr_hf_assemble(sbr->data[ch].Y[sbr->data[ch].Ypos],

  1691.                                 sbr->X_high, sbr, &sbr->data[ch],

  1692.                                 sbr->data[ch].e_a);

  1693.             }

  1694.         }

  1695. 

  1696.         /* synthesis */

  1697.         sbr_x_gen(sbr, sbr->X[ch],

  1698.                   sbr->data[ch].Y[1-sbr->data[ch].Ypos],

  1699.                   sbr->data[ch].Y[  sbr->data[ch].Ypos],

  1700.                   sbr->X_low, ch);

  1701.     }

  1702. 

  1703.     if (ac->oc[1].m4ac.ps == 1) {

  1704.         if (sbr->ps.start) {

  1705.             ff_ps_apply(ac->avctx, &sbr->ps, sbr->X[0], sbr->X[1], sbr->kx[1] + sbr->m[1]);

  1706.         } else {

  1707.             memcpy(sbr->X[1], sbr->X[0], sizeof(sbr->X[0]));

  1708.         }

  1709.         nch = 2;

  1710.     }

  1711. 

  1712.     sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, &sbr->dsp, L, sbr->X[0], sbr->qmf_filter_scratch,

  1713.                       sbr->data[0].synthesis_filterbank_samples,

  1714.                       &sbr->data[0].synthesis_filterbank_samples_offset,

  1715.                       downsampled);

  1716.     if (nch == 2)

  1717.         sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, &sbr->dsp, 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. }