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

  78. 

  79. #define SBR_INIT_VLC_STATIC(num, size) \

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

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

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

  83.                     size)

  84. 

  85. #define SBR_VLC_ROW(name) \

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

  87. 

  88. av_cold void ff_aac_sbr_init(void)

  89. {

  90.     int n;

  91.     static const struct {

  92.         const void *sbr_codes, *sbr_bits;

  93.         const unsigned int table_size, elem_size;

  94.     } sbr_tmp[] = {

  95.         SBR_VLC_ROW(t_huffman_env_1_5dB),

  96.         SBR_VLC_ROW(f_huffman_env_1_5dB),

  97.         SBR_VLC_ROW(t_huffman_env_bal_1_5dB),

  98.         SBR_VLC_ROW(f_huffman_env_bal_1_5dB),

  99.         SBR_VLC_ROW(t_huffman_env_3_0dB),

  100.         SBR_VLC_ROW(f_huffman_env_3_0dB),

  101.         SBR_VLC_ROW(t_huffman_env_bal_3_0dB),

  102.         SBR_VLC_ROW(f_huffman_env_bal_3_0dB),

  103.         SBR_VLC_ROW(t_huffman_noise_3_0dB),

  104.         SBR_VLC_ROW(t_huffman_noise_bal_3_0dB),

  105.     };

  106. 

  107.     // SBR VLC table initialization

  108.     SBR_INIT_VLC_STATIC(0, 1098);

  109.     SBR_INIT_VLC_STATIC(1, 1092);

  110.     SBR_INIT_VLC_STATIC(2, 768);

  111.     SBR_INIT_VLC_STATIC(3, 1026);

  112.     SBR_INIT_VLC_STATIC(4, 1058);

  113.     SBR_INIT_VLC_STATIC(5, 1052);

  114.     SBR_INIT_VLC_STATIC(6, 544);

  115.     SBR_INIT_VLC_STATIC(7, 544);

  116.     SBR_INIT_VLC_STATIC(8, 592);

  117.     SBR_INIT_VLC_STATIC(9, 512);

  118. 

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

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

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

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

  123. 

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

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

  126. 

  127.     ff_ps_init();

  128. }

  129. 

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

  131. static void sbr_turnoff(SpectralBandReplication *sbr) {

  132.     sbr->start = 0;

  133.     // Init defults used in pure upsampling mode

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

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

  136.     // Reset values for first SBR header

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

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

  139. }

  140. 

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

  142. {

  143.     float mdct_scale;

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

  145.     sbr_turnoff(sbr);

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

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

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

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

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

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

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

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

  154.     ff_ps_ctx_init(&sbr->ps);

  155.     ff_sbrdsp_init(&sbr->dsp);

  156. }

  157. 

  158. av_cold void ff_aac_sbr_ctx_close(SpectralBandReplication *sbr)

  159. {

  160.     ff_mdct_end(&sbr->mdct);

  161.     ff_mdct_end(&sbr->mdct_ana);

  162. }

  163. 

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

  165. {

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

  167. }

  168. 

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

  170. {

  171.     int i;

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

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

  174.             return 1;

  175.     return 0;

  176. }

  177. 

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

  179. static void sbr_make_f_tablelim(SpectralBandReplication *sbr)

  180. {

  181.     int k;

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

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

  184.                                                1.18509277094158210129f,   //2^(0.49/2)

  185.                                                1.11987160404675912501f }; //2^(0.49/3)

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

  187.         int16_t patch_borders[7];

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

  189. 

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

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

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

  193. 

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

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

  196.         if (sbr->num_patches > 1)

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

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

  199. 

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

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

  202.               qsort_comparison_function_int16);

  203. 

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

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

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

  207.                 *++out = *in++;

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

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

  210.                 in++;

  211.                 sbr->n_lim--;

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

  213.                 *out = *in++;

  214.                 sbr->n_lim--;

  215.             } else {

  216.                 *++out = *in++;

  217.             }

  218.         }

  219.     } else {

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

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

  222.         sbr->n_lim = 1;

  223.     }

  224. }

  225. 

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

  227. {

  228.     unsigned int cnt = get_bits_count(gb);

  229.     uint8_t bs_header_extra_1;

  230.     uint8_t bs_header_extra_2;

  231.     int old_bs_limiter_bands = sbr->bs_limiter_bands;

  232.     SpectrumParameters old_spectrum_params;

  233. 

  234.     sbr->start = 1;

  235. 

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

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

  238. 

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

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

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

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

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

  244. 

  245.     bs_header_extra_1 = get_bits1(gb);

  246.     bs_header_extra_2 = get_bits1(gb);

  247. 

  248.     if (bs_header_extra_1) {

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

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

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

  252.     } else {

  253.         sbr->spectrum_params.bs_freq_scale  = 2;

  254.         sbr->spectrum_params.bs_alter_scale = 1;

  255.         sbr->spectrum_params.bs_noise_bands = 2;

  256.     }

  257. 

  258.     // Check if spectrum parameters changed

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

  260.         sbr->reset = 1;

  261. 

  262.     if (bs_header_extra_2) {

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

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

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

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

  267.     } else {

  268.         sbr->bs_limiter_bands  = 2;

  269.         sbr->bs_limiter_gains  = 2;

  270.         sbr->bs_interpol_freq  = 1;

  271.         sbr->bs_smoothing_mode = 1;

  272.     }

  273. 

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

  275.         sbr_make_f_tablelim(sbr);

  276. 

  277.     return get_bits_count(gb) - cnt;

  278. }

  279. 

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

  281. {

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

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

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

  285.     return min;

  286. }

  287. 

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

  289. {

  290.     int k, previous, present;

  291.     float base, prod;

  292. 

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

  294.     prod = start;

  295.     previous = start;

  296. 

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

  298.         prod *= base;

  299.         present  = lrintf(prod);

  300.         bands[k] = present - previous;

  301.         previous = present;

  302.     }

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

  304. }

  305. 

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

  307. {

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

  309.     if (n_master <= 0) {

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

  311.         return -1;

  312.     }

  313.     if (bs_xover_band >= n_master) {

  314.         av_log(avctx, AV_LOG_ERROR,

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

  316.                bs_xover_band);

  317.         return -1;

  318.     }

  319.     return 0;

  320. }

  321. 

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

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

  324.                              SpectrumParameters *spectrum)

  325. {

  326.     unsigned int temp, max_qmf_subbands;

  327.     unsigned int start_min, stop_min;

  328.     int k;

  329.     const int8_t *sbr_offset_ptr;

  330.     int16_t stop_dk[13];

  331. 

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

  333.         temp = 3000;

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

  335.         temp = 4000;

  336.     } else

  337.         temp = 5000;

  338. 

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

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

  341. 

  342.     switch (sbr->sample_rate) {

  343.     case 16000:

  344.         sbr_offset_ptr = sbr_offset[0];

  345.         break;

  346.     case 22050:

  347.         sbr_offset_ptr = sbr_offset[1];

  348.         break;

  349.     case 24000:

  350.         sbr_offset_ptr = sbr_offset[2];

  351.         break;

  352.     case 32000:

  353.         sbr_offset_ptr = sbr_offset[3];

  354.         break;

  355.     case 44100: case 48000: case 64000:

  356.         sbr_offset_ptr = sbr_offset[4];

  357.         break;

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

  359.         sbr_offset_ptr = sbr_offset[5];

  360.         break;

  361.     default:

  362.         av_log(ac->avctx, AV_LOG_ERROR,

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

  364.         return -1;

  365.     }

  366. 

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

  368. 

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

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

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

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

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

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

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

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

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

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

  379.     } else {

  380.         av_log(ac->avctx, AV_LOG_ERROR,

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

  382.         return -1;

  383.     }

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

  385. 

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

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

  388.         max_qmf_subbands = 48;

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

  390.         max_qmf_subbands = 35;

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

  392.         max_qmf_subbands = 32;

  393. 

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

  395.         av_log(ac->avctx, AV_LOG_ERROR,

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

  397.         return -1;

  398.     }

  399. 

  400.     if (!spectrum->bs_freq_scale) {

  401.         int dk, k2diff;

  402. 

  403.         dk = spectrum->bs_alter_scale + 1;

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

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

  406.             return -1;

  407. 

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

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

  410. 

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

  412.         if (k2diff < 0) {

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

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

  415.         } else if (k2diff) {

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

  417.         }

  418. 

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

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

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

  422. 

  423.     } else {

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

  425.         int two_regions, num_bands_0;

  426.         int vdk0_max, vdk1_min;

  427.         int16_t vk0[49];

  428. 

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

  430.             two_regions = 1;

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

  432.         } else {

  433.             two_regions = 0;

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

  435.         }

  436. 

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

  438. 

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

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

  441.             return -1;

  442.         }

  443. 

  444.         vk0[0] = 0;

  445. 

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

  447. 

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

  449.         vdk0_max = vk0[num_bands_0];

  450. 

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

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

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

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

  455.                 return -1;

  456.             }

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

  458.         }

  459. 

  460.         if (two_regions) {

  461.             int16_t vk1[49];

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

  463.                                                      : 1.0f; // bs_alter_scale = {0,1}

  464.             int num_bands_1 = lrintf(half_bands * invwarp *

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

  466. 

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

  468. 

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

  470. 

  471.             if (vdk1_min < vdk0_max) {

  472.                 int change;

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

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

  475.                 vk1[1]           += change;

  476.                 vk1[num_bands_1] -= change;

  477.             }

  478. 

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

  480. 

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

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

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

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

  485.                     return -1;

  486.                 }

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

  488.             }

  489. 

  490.             sbr->n_master = num_bands_0 + num_bands_1;

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

  492.                 return -1;

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

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

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

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

  497. 

  498.         } else {

  499.             sbr->n_master = num_bands_0;

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

  501.                 return -1;

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

  503.         }

  504.     }

  505. 

  506.     return 0;

  507. }

  508. 

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

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

  511. {

  512.     int i, k, sb = 0;

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

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

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

  516. 

  517.     sbr->num_patches = 0;

  518. 

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

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

  521.     } else

  522.         k = sbr->n_master;

  523. 

  524.     do {

  525.         int odd = 0;

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

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

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

  529.         }

  530. 

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

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

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

  534.         // count of 6 patches

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

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

  537.             return -1;

  538.         }

  539. 

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

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

  542. 

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

  544.             usb = sb;

  545.             msb = sb;

  546.             sbr->num_patches++;

  547.         } else

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

  549. 

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

  551.             k = sbr->n_master;

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

  553. 

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

  555.         sbr->num_patches--;

  556. 

  557.     return 0;

  558. }

  559. 

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

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

  562. {

  563.     int k, temp;

  564. 

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

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

  567. 

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

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

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

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

  572. 

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

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

  575.         av_log(ac->avctx, AV_LOG_ERROR,

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

  577.         return -1;

  578.     }

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

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

  581.         return -1;

  582.     }

  583. 

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

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

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

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

  588. 

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

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

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

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

  593.         return -1;

  594.     }

  595. 

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

  597.     temp = 0;

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

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

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

  601.     }

  602. 

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

  604.         return -1;

  605. 

  606.     sbr_make_f_tablelim(sbr);

  607. 

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

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

  610. 

  611.     return 0;

  612. }

  613. 

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

  615.                                               int elements)

  616. {

  617.     int i;

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

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

  620.     }

  621. }

  622. 

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

  624. static const int8_t ceil_log2[] = {

  625.     0, 1, 2, 2, 3, 3,

  626. };

  627. 

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

  629.                          GetBitContext *gb, SBRData *ch_data)

  630. {

  631.     int i;

  632.     unsigned bs_pointer = 0;

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

  634.     int abs_bord_trail = 16;

  635.     int num_rel_lead, num_rel_trail;

  636.     unsigned bs_num_env_old = ch_data->bs_num_env;

  637. 

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

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

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

  641. 

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

  643.     case FIXFIX:

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

  645.         num_rel_lead                        = ch_data->bs_num_env - 1;

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

  647.             ch_data->bs_amp_res = 0;

  648. 

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

  650.             av_log(ac->avctx, AV_LOG_ERROR,

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

  652.                    ch_data->bs_num_env);

  653.             return -1;

  654.         }

  655. 

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

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

  658. 

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

  660.                    ch_data->bs_num_env;

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

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

  663. 

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

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

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

  667.         break;

  668.     case FIXVAR:

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

  670.         num_rel_trail                       = get_bits(gb, 2);

  671.         ch_data->bs_num_env                 = num_rel_trail + 1;

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

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

  674. 

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

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

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

  678. 

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

  680. 

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

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

  683.         break;

  684.     case VARFIX:

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

  686.         num_rel_lead                        = get_bits(gb, 2);

  687.         ch_data->bs_num_env                 = num_rel_lead + 1;

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

  689. 

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

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

  692. 

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

  694. 

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

  696.         break;

  697.     case VARVAR:

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

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

  700.         num_rel_lead                        = get_bits(gb, 2);

  701.         num_rel_trail                       = get_bits(gb, 2);

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

  703. 

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

  705.             av_log(ac->avctx, AV_LOG_ERROR,

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

  707.                    ch_data->bs_num_env);

  708.             return -1;

  709.         }

  710. 

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

  712. 

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

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

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

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

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

  718. 

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

  720. 

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

  722.         break;

  723.     }

  724. 

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

  726.         av_log(ac->avctx, AV_LOG_ERROR,

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

  728.                bs_pointer);

  729.         return -1;

  730.     }

  731. 

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

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

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

  735.             return -1;

  736.         }

  737.     }

  738. 

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

  740. 

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

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

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

  744.         unsigned int idx;

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

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

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

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

  749.         } else { // VARFIX

  750.             if (!bs_pointer)

  751.                 idx = 1;

  752.             else if (bs_pointer == 1)

  753.                 idx = ch_data->bs_num_env - 1;

  754.             else // bs_pointer > 1

  755.                 idx = bs_pointer - 1;

  756.         }

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

  758.     }

  759. 

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

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

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

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

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

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

  766. 

  767.     return 0;

  768. }

  769. 

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

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

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

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

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

  775. 

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

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

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

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

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

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

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

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

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

  785. }

  786. 

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

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

  789.                           SBRData *ch_data)

  790. {

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

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

  793. }

  794. 

  795. /// Read inverse filtering data

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

  797.                           SBRData *ch_data)

  798. {

  799.     int i;

  800. 

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

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

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

  804. }

  805. 

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

  807.                               SBRData *ch_data, int ch)

  808. {

  809.     int bits;

  810.     int i, j, k;

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

  812.     int t_lav, f_lav;

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

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

  815. 

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

  817.         if (ch_data->bs_amp_res) {

  818.             bits   = 5;

  819.             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_3_0DB].table;

  820.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_3_0DB];

  821.             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;

  822.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];

  823.         } else {

  824.             bits   = 6;

  825.             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_1_5DB].table;

  826.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_1_5DB];

  827.             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_1_5DB].table;

  828.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_1_5DB];

  829.         }

  830.     } else {

  831.         if (ch_data->bs_amp_res) {

  832.             bits   = 6;

  833.             t_huff = vlc_sbr[T_HUFFMAN_ENV_3_0DB].table;

  834.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_3_0DB];

  835.             f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;

  836.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];

  837.         } else {

  838.             bits   = 7;

  839.             t_huff = vlc_sbr[T_HUFFMAN_ENV_1_5DB].table;

  840.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_1_5DB];

  841.             f_huff = vlc_sbr[F_HUFFMAN_ENV_1_5DB].table;

  842.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_1_5DB];

  843.         }

  844.     }

  845. 

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

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

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

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

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

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

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

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

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

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

  856.                 }

  857.             } else {

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

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

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

  861.                 }

  862.             }

  863.         } else {

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

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

  866.                 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);

  867.         }

  868.     }

  869. 

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

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

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

  873. }

  874. 

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

  876.                            SBRData *ch_data, int ch)

  877. {

  878.     int i, j;

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

  880.     int t_lav, f_lav;

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

  882. 

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

  884.         t_huff = vlc_sbr[T_HUFFMAN_NOISE_BAL_3_0DB].table;

  885.         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_BAL_3_0DB];

  886.         f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;

  887.         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];

  888.     } else {

  889.         t_huff = vlc_sbr[T_HUFFMAN_NOISE_3_0DB].table;

  890.         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_3_0DB];

  891.         f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;

  892.         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];

  893.     }

  894. 

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

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

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

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

  899.         } else {

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

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

  902.                 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);

  903.         }

  904.     }

  905. 

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

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

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

  909. }

  910. 

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

  912.                                GetBitContext *gb,

  913.                                int bs_extension_id, int *num_bits_left)

  914. {

  915.     switch (bs_extension_id) {

  916.     case EXTENSION_ID_PS:

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

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

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

  920.             *num_bits_left = 0;

  921.         } else {

  922. #if 1

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

  924. #else

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

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

  927.             *num_bits_left = 0;

  928. #endif

  929.         }

  930.         break;

  931.     default:

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

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

  934.         *num_bits_left = 0;

  935.         break;

  936.     }

  937. }

  938. 

  939. static int read_sbr_single_channel_element(AACContext *ac,

  940.                                             SpectralBandReplication *sbr,

  941.                                             GetBitContext *gb)

  942. {

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

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

  945. 

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

  947.         return -1;

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

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

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

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

  952. 

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

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

  955. 

  956.     return 0;

  957. }

  958. 

  959. static int read_sbr_channel_pair_element(AACContext *ac,

  960.                                           SpectralBandReplication *sbr,

  961.                                           GetBitContext *gb)

  962. {

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

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

  965. 

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

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

  968.             return -1;

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

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

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

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

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

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

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

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

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

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

  979.     } else {

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

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

  982.             return -1;

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

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

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

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

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

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

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

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

  991.     }

  992. 

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

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

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

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

  997. 

  998.     return 0;

  999. }

  1000. 

  1001. static unsigned int read_sbr_data(AACContext *ac, SpectralBandReplication *sbr,

  1002.                                   GetBitContext *gb, int id_aac)

  1003. {

  1004.     unsigned int cnt = get_bits_count(gb);

  1005. 

  1006.     if (id_aac == TYPE_SCE || id_aac == TYPE_CCE) {

  1007.         if (read_sbr_single_channel_element(ac, sbr, gb)) {

  1008.             sbr_turnoff(sbr);

  1009.             return get_bits_count(gb) - cnt;

  1010.         }

  1011.     } else if (id_aac == TYPE_CPE) {

  1012.         if (read_sbr_channel_pair_element(ac, sbr, gb)) {

  1013.             sbr_turnoff(sbr);

  1014.             return get_bits_count(gb) - cnt;

  1015.         }

  1016.     } else {

  1017.         av_log(ac->avctx, AV_LOG_ERROR,

  1018.             "Invalid bitstream - cannot apply SBR to element type %d\n", id_aac);

  1019.         sbr_turnoff(sbr);

  1020.         return get_bits_count(gb) - cnt;

  1021.     }

  1022.     if (get_bits1(gb)) { // bs_extended_data

  1023.         int num_bits_left = get_bits(gb, 4); // bs_extension_size

  1024.         if (num_bits_left == 15)

  1025.             num_bits_left += get_bits(gb, 8); // bs_esc_count

  1026. 

  1027.         num_bits_left <<= 3;

  1028.         while (num_bits_left > 7) {

  1029.             num_bits_left -= 2;

  1030.             read_sbr_extension(ac, sbr, gb, get_bits(gb, 2), &num_bits_left); // bs_extension_id

  1031.         }

  1032.         if (num_bits_left < 0) {

  1033.             av_log(ac->avctx, AV_LOG_ERROR, "SBR Extension over read.\n");

  1034.         }

  1035.         if (num_bits_left > 0)

  1036.             skip_bits(gb, num_bits_left);

  1037.     }

  1038. 

  1039.     return get_bits_count(gb) - cnt;

  1040. }

  1041. 

  1042. static void sbr_reset(AACContext *ac, SpectralBandReplication *sbr)

  1043. {

  1044.     int err;

  1045.     err = sbr_make_f_master(ac, sbr, &sbr->spectrum_params);

  1046.     if (err >= 0)

  1047.         err = sbr_make_f_derived(ac, sbr);

  1048.     if (err < 0) {

  1049.         av_log(ac->avctx, AV_LOG_ERROR,

  1050.                "SBR reset failed. Switching SBR to pure upsampling mode.\n");

  1051.         sbr_turnoff(sbr);

  1052.     }

  1053. }

  1054. 

  1055. /**

  1056.  * Decode Spectral Band Replication extension data; reference: table 4.55.

  1057.  *

  1058.  * @param   crc flag indicating the presence of CRC checksum

  1059.  * @param   cnt length of TYPE_FIL syntactic element in bytes

  1060.  *

  1061.  * @return  Returns number of bytes consumed from the TYPE_FIL element.

  1062.  */

  1063. int ff_decode_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,

  1064.                             GetBitContext *gb_host, int crc, int cnt, int id_aac)

  1065. {

  1066.     unsigned int num_sbr_bits = 0, num_align_bits;

  1067.     unsigned bytes_read;

  1068.     GetBitContext gbc = *gb_host, *gb = &gbc;

  1069.     skip_bits_long(gb_host, cnt*8 - 4);

  1070. 

  1071.     sbr->reset = 0;

  1072. 

  1073.     if (!sbr->sample_rate)

  1074.         sbr->sample_rate = 2 * ac->oc[1].m4ac.sample_rate; //TODO use the nominal sample rate for arbitrary sample rate support

  1075.     if (!ac->oc[1].m4ac.ext_sample_rate)

  1076.         ac->oc[1].m4ac.ext_sample_rate = 2 * ac->oc[1].m4ac.sample_rate;

  1077. 

  1078.     if (crc) {

  1079.         skip_bits(gb, 10); // bs_sbr_crc_bits; TODO - implement CRC check

  1080.         num_sbr_bits += 10;

  1081.     }

  1082. 

  1083.     //Save some state from the previous frame.

  1084.     sbr->kx[0] = sbr->kx[1];

  1085.     sbr->m[0] = sbr->m[1];

  1086.     sbr->kx_and_m_pushed = 1;

  1087. 

  1088.     num_sbr_bits++;

  1089.     if (get_bits1(gb)) // bs_header_flag

  1090.         num_sbr_bits += read_sbr_header(sbr, gb);

  1091. 

  1092.     if (sbr->reset)

  1093.         sbr_reset(ac, sbr);

  1094. 

  1095.     if (sbr->start)

  1096.         num_sbr_bits  += read_sbr_data(ac, sbr, gb, id_aac);

  1097. 

  1098.     num_align_bits = ((cnt << 3) - 4 - num_sbr_bits) & 7;

  1099.     bytes_read = ((num_sbr_bits + num_align_bits + 4) >> 3);

  1100. 

  1101.     if (bytes_read > cnt) {

  1102.         av_log(ac->avctx, AV_LOG_ERROR,

  1103.                "Expected to read %d SBR bytes actually read %d.\n", cnt, bytes_read);

  1104.     }

  1105.     return cnt;

  1106. }

  1107. 

  1108. /// Dequantization and stereo decoding (14496-3 sp04 p203)

  1109. static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)

  1110. {

  1111.     int k, e;

  1112.     int ch;

  1113. 

  1114.     if (id_aac == TYPE_CPE && sbr->bs_coupling) {

  1115.         float alpha      = sbr->data[0].bs_amp_res ?  1.0f :  0.5f;

  1116.         float pan_offset = sbr->data[0].bs_amp_res ? 12.0f : 24.0f;

  1117.         for (e = 1; e <= sbr->data[0].bs_num_env; e++) {

  1118.             for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {

  1119.                 float temp1 = exp2f(sbr->data[0].env_facs[e][k] * alpha + 7.0f);

  1120.                 float temp2 = exp2f((pan_offset - sbr->data[1].env_facs[e][k]) * alpha);

  1121.                 float fac   = temp1 / (1.0f + temp2);

  1122.                 sbr->data[0].env_facs[e][k] = fac;

  1123.                 sbr->data[1].env_facs[e][k] = fac * temp2;

  1124.             }

  1125.         }

  1126.         for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {

  1127.             for (k = 0; k < sbr->n_q; k++) {

  1128.                 float temp1 = exp2f(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs[e][k] + 1);

  1129.                 float temp2 = exp2f(12 - sbr->data[1].noise_facs[e][k]);

  1130.                 float fac   = temp1 / (1.0f + temp2);

  1131.                 sbr->data[0].noise_facs[e][k] = fac;

  1132.                 sbr->data[1].noise_facs[e][k] = fac * temp2;

  1133.             }

  1134.         }

  1135.     } else { // SCE or one non-coupled CPE

  1136.         for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {

  1137.             float alpha = sbr->data[ch].bs_amp_res ? 1.0f : 0.5f;

  1138.             for (e = 1; e <= sbr->data[ch].bs_num_env; e++)

  1139.                 for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++)

  1140.                     sbr->data[ch].env_facs[e][k] =

  1141.                         exp2f(alpha * sbr->data[ch].env_facs[e][k] + 6.0f);

  1142.             for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)

  1143.                 for (k = 0; k < sbr->n_q; k++)

  1144.                     sbr->data[ch].noise_facs[e][k] =

  1145.                         exp2f(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs[e][k]);

  1146.         }

  1147.     }

  1148. }

  1149. 

  1150. /**

  1151.  * Analysis QMF Bank (14496-3 sp04 p206)

  1152.  *

  1153.  * @param   x       pointer to the beginning of the first sample window

  1154.  * @param   W       array of complex-valued samples split into subbands

  1155.  */

  1156. static void sbr_qmf_analysis(DSPContext *dsp, FFTContext *mdct,

  1157.                              SBRDSPContext *sbrdsp, const float *in, float *x,

  1158.                              float z[320], float W[2][32][32][2])

  1159. {

  1160.     int i;

  1161.     memcpy(W[0], W[1], sizeof(W[0]));

  1162.     memcpy(x    , x+1024, (320-32)*sizeof(x[0]));

  1163.     memcpy(x+288, in,         1024*sizeof(x[0]));

  1164.     for (i = 0; i < 32; i++) { // numTimeSlots*RATE = 16*2 as 960 sample frames

  1165.                                // are not supported

  1166.         dsp->vector_fmul_reverse(z, sbr_qmf_window_ds, x, 320);

  1167.         sbrdsp->sum64x5(z);

  1168.         sbrdsp->qmf_pre_shuffle(z);

  1169.         mdct->imdct_half(mdct, z, z+64);

  1170.         sbrdsp->qmf_post_shuffle(W[1][i], z);

  1171.         x += 32;

  1172.     }

  1173. }

  1174. 

  1175. /**

  1176.  * Synthesis QMF Bank (14496-3 sp04 p206) and Downsampled Synthesis QMF Bank

  1177.  * (14496-3 sp04 p206)

  1178.  */

  1179. static void sbr_qmf_synthesis(DSPContext *dsp, FFTContext *mdct,

  1180.                               SBRDSPContext *sbrdsp,

  1181.                               float *out, float X[2][38][64],

  1182.                               float mdct_buf[2][64],

  1183.                               float *v0, int *v_off, const unsigned int div)

  1184. {

  1185.     int i, n;

  1186.     const float *sbr_qmf_window = div ? sbr_qmf_window_ds : sbr_qmf_window_us;

  1187.     const int step = 128 >> div;

  1188.     float *v;

  1189.     for (i = 0; i < 32; i++) {

  1190.         if (*v_off < step) {

  1191.             int saved_samples = (1280 - 128) >> div;

  1192.             memcpy(&v0[SBR_SYNTHESIS_BUF_SIZE - saved_samples], v0, saved_samples * sizeof(float));

  1193.             *v_off = SBR_SYNTHESIS_BUF_SIZE - saved_samples - step;

  1194.         } else {

  1195.             *v_off -= step;

  1196.         }

  1197.         v = v0 + *v_off;

  1198.         if (div) {

  1199.             for (n = 0; n < 32; n++) {

  1200.                 X[0][i][   n] = -X[0][i][n];

  1201.                 X[0][i][32+n] =  X[1][i][31-n];

  1202.             }

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

  1204.             sbrdsp->qmf_deint_neg(v, mdct_buf[0]);

  1205.         } else {

  1206.             sbrdsp->neg_odd_64(X[1][i]);

  1207.             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);

  1208.             mdct->imdct_half(mdct, mdct_buf[1], X[1][i]);

  1209.             sbrdsp->qmf_deint_bfly(v, mdct_buf[1], mdct_buf[0]);

  1210.         }

  1211.         dsp->vector_fmul_add(out, v                , sbr_qmf_window               , zero64, 64 >> div);

  1212.         dsp->vector_fmul_add(out, v + ( 192 >> div), sbr_qmf_window + ( 64 >> div), out   , 64 >> div);

  1213.         dsp->vector_fmul_add(out, v + ( 256 >> div), sbr_qmf_window + (128 >> div), out   , 64 >> div);

  1214.         dsp->vector_fmul_add(out, v + ( 448 >> div), sbr_qmf_window + (192 >> div), out   , 64 >> div);

  1215.         dsp->vector_fmul_add(out, v + ( 512 >> div), sbr_qmf_window + (256 >> div), out   , 64 >> div);

  1216.         dsp->vector_fmul_add(out, v + ( 704 >> div), sbr_qmf_window + (320 >> div), out   , 64 >> div);

  1217.         dsp->vector_fmul_add(out, v + ( 768 >> div), sbr_qmf_window + (384 >> div), out   , 64 >> div);

  1218.         dsp->vector_fmul_add(out, v + ( 960 >> div), sbr_qmf_window + (448 >> div), out   , 64 >> div);

  1219.         dsp->vector_fmul_add(out, v + (1024 >> div), sbr_qmf_window + (512 >> div), out   , 64 >> div);

  1220.         dsp->vector_fmul_add(out, v + (1216 >> div), sbr_qmf_window + (576 >> div), out   , 64 >> div);

  1221.         out += 64 >> div;

  1222.     }

  1223. }

  1224. 

  1225. /** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering

  1226.  * (14496-3 sp04 p214)

  1227.  * Warning: This routine does not seem numerically stable.

  1228.  */

  1229. static void sbr_hf_inverse_filter(SBRDSPContext *dsp,

  1230.                                   float (*alpha0)[2], float (*alpha1)[2],

  1231.                                   const float X_low[32][40][2], int k0)

  1232. {

  1233.     int k;

  1234.     for (k = 0; k < k0; k++) {

  1235.         LOCAL_ALIGNED_16(float, phi, [3], [2][2]);

  1236.         float dk;

  1237. 

  1238.         dsp->autocorrelate(X_low[k], phi);

  1239. 

  1240.         dk =  phi[2][1][0] * phi[1][0][0] -

  1241.              (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;

  1242. 

  1243.         if (!dk) {

  1244.             alpha1[k][0] = 0;

  1245.             alpha1[k][1] = 0;

  1246.         } else {

  1247.             float temp_real, temp_im;

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

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

  1250.                         phi[0][1][0] * phi[1][0][0];

  1251.             temp_im   = phi[0][0][0] * phi[1][1][1] +

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

  1253.                         phi[0][1][1] * phi[1][0][0];

  1254. 

  1255.             alpha1[k][0] = temp_real / dk;

  1256.             alpha1[k][1] = temp_im   / dk;

  1257.         }

  1258. 

  1259.         if (!phi[1][0][0]) {

  1260.             alpha0[k][0] = 0;

  1261.             alpha0[k][1] = 0;

  1262.         } else {

  1263.             float temp_real, temp_im;

  1264.             temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +

  1265.                                        alpha1[k][1] * phi[1][1][1];

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

  1267.                                        alpha1[k][0] * phi[1][1][1];

  1268. 

  1269.             alpha0[k][0] = -temp_real / phi[1][0][0];

  1270.             alpha0[k][1] = -temp_im   / phi[1][0][0];

  1271.         }

  1272. 

  1273.         if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||

  1274.            alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {

  1275.             alpha1[k][0] = 0;

  1276.             alpha1[k][1] = 0;

  1277.             alpha0[k][0] = 0;

  1278.             alpha0[k][1] = 0;

  1279.         }

  1280.     }

  1281. }

  1282. 

  1283. /// Chirp Factors (14496-3 sp04 p214)

  1284. static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)

  1285. {

  1286.     int i;

  1287.     float new_bw;

  1288.     static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };

  1289. 

  1290.     for (i = 0; i < sbr->n_q; i++) {

  1291.         if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {

  1292.             new_bw = 0.6f;

  1293.         } else

  1294.             new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];

  1295. 

  1296.         if (new_bw < ch_data->bw_array[i]) {

  1297.             new_bw = 0.75f    * new_bw + 0.25f    * ch_data->bw_array[i];

  1298.         } else

  1299.             new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];

  1300.         ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;

  1301.     }

  1302. }

  1303. 

  1304. /// Generate the subband filtered lowband

  1305. static int sbr_lf_gen(AACContext *ac, SpectralBandReplication *sbr,

  1306.                       float X_low[32][40][2], const float W[2][32][32][2])

  1307. {

  1308.     int i, k;

  1309.     const int t_HFGen = 8;

  1310.     const int i_f = 32;

  1311.     memset(X_low, 0, 32*sizeof(*X_low));

  1312.     for (k = 0; k < sbr->kx[1]; k++) {

  1313.         for (i = t_HFGen; i < i_f + t_HFGen; i++) {

  1314.             X_low[k][i][0] = W[1][i - t_HFGen][k][0];

  1315.             X_low[k][i][1] = W[1][i - t_HFGen][k][1];

  1316.         }

  1317.     }

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

  1319.         for (i = 0; i < t_HFGen; i++) {

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

  1321.             X_low[k][i][1] = W[0][i + i_f - t_HFGen][k][1];

  1322.         }

  1323.     }

  1324.     return 0;

  1325. }

  1326. 

  1327. /// High Frequency Generator (14496-3 sp04 p215)

  1328. static int sbr_hf_gen(AACContext *ac, SpectralBandReplication *sbr,

  1329.                       float X_high[64][40][2], const float X_low[32][40][2],

  1330.                       const float (*alpha0)[2], const float (*alpha1)[2],

  1331.                       const float bw_array[5], const uint8_t *t_env,

  1332.                       int bs_num_env)

  1333. {

  1334.     int j, x;

  1335.     int g = 0;

  1336.     int k = sbr->kx[1];

  1337.     for (j = 0; j < sbr->num_patches; j++) {

  1338.         for (x = 0; x < sbr->patch_num_subbands[j]; x++, k++) {

  1339.             const int p = sbr->patch_start_subband[j] + x;

  1340.             while (g <= sbr->n_q && k >= sbr->f_tablenoise[g])

  1341.                 g++;

  1342.             g--;

  1343. 

  1344.             if (g < 0) {

  1345.                 av_log(ac->avctx, AV_LOG_ERROR,

  1346.                        "ERROR : no subband found for frequency %d\n", k);

  1347.                 return -1;

  1348.             }

  1349. 

  1350.             sbr->dsp.hf_gen(X_high[k] + ENVELOPE_ADJUSTMENT_OFFSET,

  1351.                             X_low[p]  + ENVELOPE_ADJUSTMENT_OFFSET,

  1352.                             alpha0[p], alpha1[p], bw_array[g],

  1353.                             2 * t_env[0], 2 * t_env[bs_num_env]);

  1354.         }

  1355.     }

  1356.     if (k < sbr->m[1] + sbr->kx[1])

  1357.         memset(X_high + k, 0, (sbr->m[1] + sbr->kx[1] - k) * sizeof(*X_high));

  1358. 

  1359.     return 0;

  1360. }

  1361. 

  1362. /// Generate the subband filtered lowband

  1363. static int sbr_x_gen(SpectralBandReplication *sbr, float X[2][38][64],

  1364.                      const float Y0[38][64][2], const float Y1[38][64][2],

  1365.                      const float X_low[32][40][2], int ch)

  1366. {

  1367.     int k, i;

  1368.     const int i_f = 32;

  1369.     const int i_Temp = FFMAX(2*sbr->data[ch].t_env_num_env_old - i_f, 0);

  1370.     memset(X, 0, 2*sizeof(*X));

  1371.     for (k = 0; k < sbr->kx[0]; k++) {

  1372.         for (i = 0; i < i_Temp; i++) {

  1373.             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];

  1374.             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];

  1375.         }

  1376.     }

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

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

  1379.             X[0][i][k] = Y0[i + i_f][k][0];

  1380.             X[1][i][k] = Y0[i + i_f][k][1];

  1381.         }

  1382.     }

  1383. 

  1384.     for (k = 0; k < sbr->kx[1]; k++) {

  1385.         for (i = i_Temp; i < 38; i++) {

  1386.             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];

  1387.             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];

  1388.         }

  1389.     }

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

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

  1392.             X[0][i][k] = Y1[i][k][0];

  1393.             X[1][i][k] = Y1[i][k][1];

  1394.         }

  1395.     }

  1396.     return 0;

  1397. }

  1398. 

  1399. /** High Frequency Adjustment (14496-3 sp04 p217) and Mapping

  1400.  * (14496-3 sp04 p217)

  1401.  */

  1402. static int sbr_mapping(AACContext *ac, SpectralBandReplication *sbr,

  1403.                         SBRData *ch_data, int e_a[2])

  1404. {

  1405.     int e, i, m;

  1406. 

  1407.     memset(ch_data->s_indexmapped[1], 0, 7*sizeof(ch_data->s_indexmapped[1]));

  1408.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1409.         const unsigned int ilim = sbr->n[ch_data->bs_freq_res[e + 1]];

  1410.         uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

  1411.         int k;

  1412. 

  1413.         if (sbr->kx[1] != table[0]) {

  1414.             av_log(ac->avctx, AV_LOG_ERROR, "kx != f_table{high,low}[0]. "

  1415.                    "Derived frequency tables were not regenerated.\n");

  1416.             sbr_turnoff(sbr);

  1417.             return AVERROR_BUG;

  1418.         }

  1419.         for (i = 0; i < ilim; i++)

  1420.             for (m = table[i]; m < table[i + 1]; m++)

  1421.                 sbr->e_origmapped[e][m - sbr->kx[1]] = ch_data->env_facs[e+1][i];

  1422. 

  1423.         // ch_data->bs_num_noise > 1 => 2 noise floors

  1424.         k = (ch_data->bs_num_noise > 1) && (ch_data->t_env[e] >= ch_data->t_q[1]);

  1425.         for (i = 0; i < sbr->n_q; i++)

  1426.             for (m = sbr->f_tablenoise[i]; m < sbr->f_tablenoise[i + 1]; m++)

  1427.                 sbr->q_mapped[e][m - sbr->kx[1]] = ch_data->noise_facs[k+1][i];

  1428. 

  1429.         for (i = 0; i < sbr->n[1]; i++) {

  1430.             if (ch_data->bs_add_harmonic_flag) {

  1431.                 const unsigned int m_midpoint =

  1432.                     (sbr->f_tablehigh[i] + sbr->f_tablehigh[i + 1]) >> 1;

  1433. 

  1434.                 ch_data->s_indexmapped[e + 1][m_midpoint - sbr->kx[1]] = ch_data->bs_add_harmonic[i] *

  1435.                     (e >= e_a[1] || (ch_data->s_indexmapped[0][m_midpoint - sbr->kx[1]] == 1));

  1436.             }

  1437.         }

  1438. 

  1439.         for (i = 0; i < ilim; i++) {

  1440.             int additional_sinusoid_present = 0;

  1441.             for (m = table[i]; m < table[i + 1]; m++) {

  1442.                 if (ch_data->s_indexmapped[e + 1][m - sbr->kx[1]]) {

  1443.                     additional_sinusoid_present = 1;

  1444.                     break;

  1445.                 }

  1446.             }

  1447.             memset(&sbr->s_mapped[e][table[i] - sbr->kx[1]], additional_sinusoid_present,

  1448.                    (table[i + 1] - table[i]) * sizeof(sbr->s_mapped[e][0]));

  1449.         }

  1450.     }

  1451. 

  1452.     memcpy(ch_data->s_indexmapped[0], ch_data->s_indexmapped[ch_data->bs_num_env], sizeof(ch_data->s_indexmapped[0]));

  1453.     return 0;

  1454. }

  1455. 

  1456. /// Estimation of current envelope (14496-3 sp04 p218)

  1457. static void sbr_env_estimate(float (*e_curr)[48], float X_high[64][40][2],

  1458.                              SpectralBandReplication *sbr, SBRData *ch_data)

  1459. {

  1460.     int e, m;

  1461.     int kx1 = sbr->kx[1];

  1462. 

  1463.     if (sbr->bs_interpol_freq) {

  1464.         for (e = 0; e < ch_data->bs_num_env; e++) {

  1465.             const float recip_env_size = 0.5f / (ch_data->t_env[e + 1] - ch_data->t_env[e]);

  1466.             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1467.             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1468. 

  1469.             for (m = 0; m < sbr->m[1]; m++) {

  1470.                 float sum = sbr->dsp.sum_square(X_high[m+kx1] + ilb, iub - ilb);

  1471.                 e_curr[e][m] = sum * recip_env_size;

  1472.             }

  1473.         }

  1474.     } else {

  1475.         int k, p;

  1476. 

  1477.         for (e = 0; e < ch_data->bs_num_env; e++) {

  1478.             const int env_size = 2 * (ch_data->t_env[e + 1] - ch_data->t_env[e]);

  1479.             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1480.             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1481.             const uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

  1482. 

  1483.             for (p = 0; p < sbr->n[ch_data->bs_freq_res[e + 1]]; p++) {

  1484.                 float sum = 0.0f;

  1485.                 const int den = env_size * (table[p + 1] - table[p]);

  1486. 

  1487.                 for (k = table[p]; k < table[p + 1]; k++) {

  1488.                     sum += sbr->dsp.sum_square(X_high[k] + ilb, iub - ilb);

  1489.                 }

  1490.                 sum /= den;

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

  1492.                     e_curr[e][k - kx1] = sum;

  1493.                 }

  1494.             }

  1495.         }

  1496.     }

  1497. }

  1498. 

  1499. /**

  1500.  * Calculation of levels of additional HF signal components (14496-3 sp04 p219)

  1501.  * and Calculation of gain (14496-3 sp04 p219)

  1502.  */

  1503. static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,

  1504.                           SBRData *ch_data, const int e_a[2])

  1505. {

  1506.     int e, k, m;

  1507.     // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)

  1508.     static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };

  1509. 

  1510.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1511.         int delta = !((e == e_a[1]) || (e == e_a[0]));

  1512.         for (k = 0; k < sbr->n_lim; k++) {

  1513.             float gain_boost, gain_max;

  1514.             float sum[2] = { 0.0f, 0.0f };

  1515.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1516.                 const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);

  1517.                 sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);

  1518.                 sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);

  1519.                 if (!sbr->s_mapped[e][m]) {

  1520.                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /

  1521.                                             ((1.0f + sbr->e_curr[e][m]) *

  1522.                                              (1.0f + sbr->q_mapped[e][m] * delta)));

  1523.                 } else {

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

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

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

  1527.                 }

  1528.             }

  1529.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1530.                 sum[0] += sbr->e_origmapped[e][m];

  1531.                 sum[1] += sbr->e_curr[e][m];

  1532.             }

  1533.             gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));

  1534.             gain_max = FFMIN(100000.f, gain_max);

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

  1536.                 float q_m_max   = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];

  1537.                 sbr->q_m[e][m]  = FFMIN(sbr->q_m[e][m], q_m_max);

  1538.                 sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);

  1539.             }

  1540.             sum[0] = sum[1] = 0.0f;

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

  1542.                 sum[0] += sbr->e_origmapped[e][m];

  1543.                 sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]

  1544.                           + sbr->s_m[e][m] * sbr->s_m[e][m]

  1545.                           + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];

  1546.             }

  1547.             gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));

  1548.             gain_boost = FFMIN(1.584893192f, gain_boost);

  1549.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

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

  1551.                 sbr->q_m[e][m]  *= gain_boost;

  1552.                 sbr->s_m[e][m]  *= gain_boost;

  1553.             }

  1554.         }

  1555.     }

  1556. }

  1557. 

  1558. /// Assembling HF Signals (14496-3 sp04 p220)

  1559. static void sbr_hf_assemble(float Y1[38][64][2],

  1560.                             const float X_high[64][40][2],

  1561.                             SpectralBandReplication *sbr, SBRData *ch_data,

  1562.                             const int e_a[2])

  1563. {

  1564.     int e, i, j, m;

  1565.     const int h_SL = 4 * !sbr->bs_smoothing_mode;

  1566.     const int kx = sbr->kx[1];

  1567.     const int m_max = sbr->m[1];

  1568.     static const float h_smooth[5] = {

  1569.         0.33333333333333,

  1570.         0.30150283239582,

  1571.         0.21816949906249,

  1572.         0.11516383427084,

  1573.         0.03183050093751,

  1574.     };

  1575.     static const int8_t phi[2][4] = {

  1576.         {  1,  0, -1,  0}, // real

  1577.         {  0,  1,  0, -1}, // imaginary

  1578.     };

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

  1580.     int indexnoise = ch_data->f_indexnoise;

  1581.     int indexsine  = ch_data->f_indexsine;

  1582. 

  1583.     if (sbr->reset) {

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

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

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

  1587.         }

  1588.     } else if (h_SL) {

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

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

  1591.     }

  1592. 

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

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

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

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

  1597.         }

  1598.     }

  1599. 

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

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

  1602.             int phi_sign = (1 - 2*(kx & 1));

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

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

  1605.             float *g_filt, *q_filt;

  1606. 

  1607.             if (h_SL && e != e_a[0] && e != e_a[1]) {

  1608.                 g_filt = g_filt_tab;

  1609.                 q_filt = q_filt_tab;

  1610.                 for (m = 0; m < m_max; m++) {

  1611.                     const int idx1 = i + h_SL;

  1612.                     g_filt[m] = 0.0f;

  1613.                     q_filt[m] = 0.0f;

  1614.                     for (j = 0; j <= h_SL; j++) {

  1615.                         g_filt[m] += g_temp[idx1 - j][m] * h_smooth[j];

  1616.                         q_filt[m] += q_temp[idx1 - j][m] * h_smooth[j];

  1617.                     }

  1618.                 }

  1619.             } else {

  1620.                 g_filt = g_temp[i + h_SL];

  1621.                 q_filt = q_temp[i];

  1622.             }

  1623. 

  1624.             sbr->dsp.hf_g_filt(Y1[i] + kx, X_high + kx, g_filt, m_max,

  1625.                                i + ENVELOPE_ADJUSTMENT_OFFSET);

  1626. 

  1627.             if (e != e_a[0] && e != e_a[1]) {

  1628.                 sbr->dsp.hf_apply_noise[indexsine](Y1[i] + kx, sbr->s_m[e],

  1629.                                                    q_filt, indexnoise,

  1630.                                                    kx, m_max);

  1631.             } else {

  1632.                 for (m = 0; m < m_max; m++) {

  1633.                     Y1[i][m + kx][0] +=

  1634.                         sbr->s_m[e][m] * phi[0][indexsine];

  1635.                     Y1[i][m + kx][1] +=

  1636.                         sbr->s_m[e][m] * (phi[1][indexsine] * phi_sign);

  1637.                     phi_sign = -phi_sign;

  1638.                 }

  1639.             }

  1640.             indexnoise = (indexnoise + m_max) & 0x1ff;

  1641.             indexsine = (indexsine + 1) & 3;

  1642.         }

  1643.     }

  1644.     ch_data->f_indexnoise = indexnoise;

  1645.     ch_data->f_indexsine  = indexsine;

  1646. }

  1647. 

  1648. void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,

  1649.                   float* L, float* R)

  1650. {

  1651.     int downsampled = ac->oc[1].m4ac.ext_sample_rate < sbr->sample_rate;

  1652.     int ch;

  1653.     int nch = (id_aac == TYPE_CPE) ? 2 : 1;

  1654.     int err;

  1655. 

  1656.     if (!sbr->kx_and_m_pushed) {

  1657.         sbr->kx[0] = sbr->kx[1];

  1658.         sbr->m[0] = sbr->m[1];

  1659.     } else {

  1660.         sbr->kx_and_m_pushed = 0;

  1661.     }

  1662. 

  1663.     if (sbr->start) {

  1664.         sbr_dequant(sbr, id_aac);

  1665.     }

  1666.     for (ch = 0; ch < nch; ch++) {

  1667.         /* decode channel */

  1668.         sbr_qmf_analysis(&ac->dsp, &sbr->mdct_ana, &sbr->dsp, ch ? R : L, sbr->data[ch].analysis_filterbank_samples,

  1669.                          (float*)sbr->qmf_filter_scratch,

  1670.                          sbr->data[ch].W);

  1671.         sbr_lf_gen(ac, sbr, sbr->X_low, sbr->data[ch].W);

  1672.         sbr->data[ch].Ypos ^= 1;

  1673.         if (sbr->start) {

  1674.             sbr_hf_inverse_filter(&sbr->dsp, sbr->alpha0, sbr->alpha1, sbr->X_low, sbr->k[0]);

  1675.             sbr_chirp(sbr, &sbr->data[ch]);

  1676.             sbr_hf_gen(ac, sbr, sbr->X_high, sbr->X_low, sbr->alpha0, sbr->alpha1,

  1677.                        sbr->data[ch].bw_array, sbr->data[ch].t_env,

  1678.                        sbr->data[ch].bs_num_env);

  1679. 

  1680.             // hf_adj

  1681.             err = sbr_mapping(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);

  1682.             if (!err) {

  1683.                 sbr_env_estimate(sbr->e_curr, sbr->X_high, sbr, &sbr->data[ch]);

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

  1685.                 sbr_hf_assemble(sbr->data[ch].Y[sbr->data[ch].Ypos],

  1686.                                 sbr->X_high, sbr, &sbr->data[ch],

  1687.                                 sbr->data[ch].e_a);

  1688.             }

  1689.         }

  1690. 

  1691.         /* synthesis */

  1692.         sbr_x_gen(sbr, sbr->X[ch],

  1693.                   sbr->data[ch].Y[1-sbr->data[ch].Ypos],

  1694.                   sbr->data[ch].Y[  sbr->data[ch].Ypos],

  1695.                   sbr->X_low, ch);

  1696.     }

  1697. 

  1698.     if (ac->oc[1].m4ac.ps == 1) {

  1699.         if (sbr->ps.start) {

  1700.             ff_ps_apply(ac->avctx, &sbr->ps, sbr->X[0], sbr->X[1], sbr->kx[1] + sbr->m[1]);

  1701.         } else {

  1702.             memcpy(sbr->X[1], sbr->X[0], sizeof(sbr->X[0]));

  1703.         }

  1704.         nch = 2;

  1705.     }

  1706. 

  1707.     sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, &sbr->dsp, L, sbr->X[0], sbr->qmf_filter_scratch,

  1708.                       sbr->data[0].synthesis_filterbank_samples,

  1709.                       &sbr->data[0].synthesis_filterbank_samples_offset,

  1710.                       downsampled);

  1711.     if (nch == 2)

  1712.         sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, &sbr->dsp, 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. }