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FFmpeg/libavcodec/aacsbr.c

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  1. /*

  2.  * AAC Spectral Band Replication decoding functions

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

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

  5.  *

  6.  * This file is part of FFmpeg.

  7.  *

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

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

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

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

  12.  *

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

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

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

  16.  * Lesser General Public License for more details.

  17.  *

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

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

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

  21.  */

  22. 

  23. /**

  24.  * @file

  25.  * AAC Spectral Band Replication decoding functions

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

  27.  */

  28. 

  29. #include "aac.h"

  30. #include "sbr.h"

  31. #include "aacsbr.h"

  32. #include "aacsbrdata.h"

  33. #include "aacsbr_tablegen.h"

  34. #include "fft.h"

  35. #include "aacps.h"

  36. #include "sbrdsp.h"

  37. #include "libavutil/internal.h"

  38. #include "libavutil/libm.h"

  39. #include "libavutil/avassert.h"

  40. 

  41. #include <stdint.h>

  42. #include <float.h>

  43. #include <math.h>

  44. 

  45. #define ENVELOPE_ADJUSTMENT_OFFSET 2

  46. #define NOISE_FLOOR_OFFSET 6.0f

  47. 

  48. #if ARCH_MIPS

  49. #include "mips/aacsbr_mips.h"

  50. #endif /* ARCH_MIPS */

  51. 

  52. /**

  53.  * SBR VLC tables

  54.  */

  55. enum {

  56.     T_HUFFMAN_ENV_1_5DB,

  57.     F_HUFFMAN_ENV_1_5DB,

  58.     T_HUFFMAN_ENV_BAL_1_5DB,

  59.     F_HUFFMAN_ENV_BAL_1_5DB,

  60.     T_HUFFMAN_ENV_3_0DB,

  61.     F_HUFFMAN_ENV_3_0DB,

  62.     T_HUFFMAN_ENV_BAL_3_0DB,

  63.     F_HUFFMAN_ENV_BAL_3_0DB,

  64.     T_HUFFMAN_NOISE_3_0DB,

  65.     T_HUFFMAN_NOISE_BAL_3_0DB,

  66. };

  67. 

  68. /**

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

  70.  */

  71. enum {

  72.     FIXFIX,

  73.     FIXVAR,

  74.     VARFIX,

  75.     VARVAR,

  76. };

  77. 

  78. enum {

  79.     EXTENSION_ID_PS = 2,

  80. };

  81. 

  82. static VLC vlc_sbr[10];

  83. static const int8_t vlc_sbr_lav[10] =

  84.     { 60, 60, 24, 24, 31, 31, 12, 12, 31, 12 };

  85. 

  86. #define SBR_INIT_VLC_STATIC(num, size) \

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

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

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

  90.                     size)

  91. 

  92. #define SBR_VLC_ROW(name) \

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

  94. 

  95. static void aacsbr_func_ptr_init(AACSBRContext *c);

  96. 

  97. av_cold void ff_aac_sbr_init(void)

  98. {

  99.     static const struct {

  100.         const void *sbr_codes, *sbr_bits;

  101.         const unsigned int table_size, elem_size;

  102.     } sbr_tmp[] = {

  103.         SBR_VLC_ROW(t_huffman_env_1_5dB),

  104.         SBR_VLC_ROW(f_huffman_env_1_5dB),

  105.         SBR_VLC_ROW(t_huffman_env_bal_1_5dB),

  106.         SBR_VLC_ROW(f_huffman_env_bal_1_5dB),

  107.         SBR_VLC_ROW(t_huffman_env_3_0dB),

  108.         SBR_VLC_ROW(f_huffman_env_3_0dB),

  109.         SBR_VLC_ROW(t_huffman_env_bal_3_0dB),

  110.         SBR_VLC_ROW(f_huffman_env_bal_3_0dB),

  111.         SBR_VLC_ROW(t_huffman_noise_3_0dB),

  112.         SBR_VLC_ROW(t_huffman_noise_bal_3_0dB),

  113.     };

  114. 

  115.     // SBR VLC table initialization

  116.     SBR_INIT_VLC_STATIC(0, 1098);

  117.     SBR_INIT_VLC_STATIC(1, 1092);

  118.     SBR_INIT_VLC_STATIC(2, 768);

  119.     SBR_INIT_VLC_STATIC(3, 1026);

  120.     SBR_INIT_VLC_STATIC(4, 1058);

  121.     SBR_INIT_VLC_STATIC(5, 1052);

  122.     SBR_INIT_VLC_STATIC(6, 544);

  123.     SBR_INIT_VLC_STATIC(7, 544);

  124.     SBR_INIT_VLC_STATIC(8, 592);

  125.     SBR_INIT_VLC_STATIC(9, 512);

  126. 

  127.     aacsbr_tableinit();

  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.     if(sbr->mdct.mdct_bits)

  146.         return;

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

  148.     sbr_turnoff(sbr);

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

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

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

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

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

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

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

  156.     ff_ps_ctx_init(&sbr->ps);

  157.     ff_sbrdsp_init(&sbr->dsp);

  158.     aacsbr_func_ptr_init(&sbr->c);

  159. }

  160. 

  161. av_cold void ff_aac_sbr_ctx_close(SpectralBandReplication *sbr)

  162. {

  163.     ff_mdct_end(&sbr->mdct);

  164.     ff_mdct_end(&sbr->mdct_ana);

  165. }

  166. 

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

  168. {

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

  170. }

  171. 

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

  173. {

  174.     int i;

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

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

  177.             return 1;

  178.     return 0;

  179. }

  180. 

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

  182. static void sbr_make_f_tablelim(SpectralBandReplication *sbr)

  183. {

  184.     int k;

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

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

  187.                                                1.18509277094158210129f,   //2^(0.49/2)

  188.                                                1.11987160404675912501f }; //2^(0.49/3)

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

  190.         int16_t patch_borders[7];

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

  192. 

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

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

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

  196. 

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

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

  199.         if (sbr->num_patches > 1)

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

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

  202. 

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

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

  205.               qsort_comparison_function_int16);

  206. 

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

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

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

  210.                 *++out = *in++;

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

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

  213.                 in++;

  214.                 sbr->n_lim--;

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

  216.                 *out = *in++;

  217.                 sbr->n_lim--;

  218.             } else {

  219.                 *++out = *in++;

  220.             }

  221.         }

  222.     } else {

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

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

  225.         sbr->n_lim = 1;

  226.     }

  227. }

  228. 

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

  230. {

  231.     unsigned int cnt = get_bits_count(gb);

  232.     uint8_t bs_header_extra_1;

  233.     uint8_t bs_header_extra_2;

  234.     int old_bs_limiter_bands = sbr->bs_limiter_bands;

  235.     SpectrumParameters old_spectrum_params;

  236. 

  237.     sbr->start = 1;

  238. 

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

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

  241. 

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

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

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

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

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

  247. 

  248.     bs_header_extra_1 = get_bits1(gb);

  249.     bs_header_extra_2 = get_bits1(gb);

  250. 

  251.     if (bs_header_extra_1) {

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

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

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

  255.     } else {

  256.         sbr->spectrum_params.bs_freq_scale  = 2;

  257.         sbr->spectrum_params.bs_alter_scale = 1;

  258.         sbr->spectrum_params.bs_noise_bands = 2;

  259.     }

  260. 

  261.     // Check if spectrum parameters changed

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

  263.         sbr->reset = 1;

  264. 

  265.     if (bs_header_extra_2) {

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

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

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

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

  270.     } else {

  271.         sbr->bs_limiter_bands  = 2;

  272.         sbr->bs_limiter_gains  = 2;

  273.         sbr->bs_interpol_freq  = 1;

  274.         sbr->bs_smoothing_mode = 1;

  275.     }

  276. 

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

  278.         sbr_make_f_tablelim(sbr);

  279. 

  280.     return get_bits_count(gb) - cnt;

  281. }

  282. 

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

  284. {

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

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

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

  288.     return min;

  289. }

  290. 

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

  292. {

  293.     int k, previous, present;

  294.     float base, prod;

  295. 

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

  297.     prod = start;

  298.     previous = start;

  299. 

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

  301.         prod *= base;

  302.         present  = lrintf(prod);

  303.         bands[k] = present - previous;

  304.         previous = present;

  305.     }

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

  307. }

  308. 

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

  310. {

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

  312.     if (n_master <= 0) {

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

  314.         return -1;

  315.     }

  316.     if (bs_xover_band >= n_master) {

  317.         av_log(avctx, AV_LOG_ERROR,

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

  319.                bs_xover_band);

  320.         return -1;

  321.     }

  322.     return 0;

  323. }

  324. 

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

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

  327.                              SpectrumParameters *spectrum)

  328. {

  329.     unsigned int temp, max_qmf_subbands;

  330.     unsigned int start_min, stop_min;

  331.     int k;

  332.     const int8_t *sbr_offset_ptr;

  333.     int16_t stop_dk[13];

  334. 

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

  336.         temp = 3000;

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

  338.         temp = 4000;

  339.     } else

  340.         temp = 5000;

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

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

  369. 

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

  371. 

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

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

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

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

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

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

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

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

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

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

  382.     } else {

  383.         av_log(ac->avctx, AV_LOG_ERROR,

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

  385.         return -1;

  386.     }

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

  388. 

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

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

  391.         max_qmf_subbands = 48;

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

  393.         max_qmf_subbands = 35;

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

  395.         max_qmf_subbands = 32;

  396.     else

  397.         av_assert0(0);

  398. 

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

  400.         av_log(ac->avctx, AV_LOG_ERROR,

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

  402.         return -1;

  403.     }

  404. 

  405.     if (!spectrum->bs_freq_scale) {

  406.         int dk, k2diff;

  407. 

  408.         dk = spectrum->bs_alter_scale + 1;

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

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

  411.             return -1;

  412. 

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

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

  415. 

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

  417.         if (k2diff < 0) {

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

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

  420.         } else if (k2diff) {

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

  422.         }

  423. 

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

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

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

  427. 

  428.     } else {

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

  430.         int two_regions, num_bands_0;

  431.         int vdk0_max, vdk1_min;

  432.         int16_t vk0[49];

  433. 

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

  435.             two_regions = 1;

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

  437.         } else {

  438.             two_regions = 0;

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

  440.         }

  441. 

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

  443. 

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

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

  446.             return -1;

  447.         }

  448. 

  449.         vk0[0] = 0;

  450. 

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

  452. 

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

  454.         vdk0_max = vk0[num_bands_0];

  455. 

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

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

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

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

  460.                 return -1;

  461.             }

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

  463.         }

  464. 

  465.         if (two_regions) {

  466.             int16_t vk1[49];

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

  468.                                                      : 1.0f; // bs_alter_scale = {0,1}

  469.             int num_bands_1 = lrintf(half_bands * invwarp *

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

  471. 

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

  473. 

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

  475. 

  476.             if (vdk1_min < vdk0_max) {

  477.                 int change;

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

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

  480.                 vk1[1]           += change;

  481.                 vk1[num_bands_1] -= change;

  482.             }

  483. 

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

  485. 

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

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

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

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

  490.                     return -1;

  491.                 }

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

  493.             }

  494. 

  495.             sbr->n_master = num_bands_0 + num_bands_1;

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

  497.                 return -1;

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

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

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

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

  502. 

  503.         } else {

  504.             sbr->n_master = num_bands_0;

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

  506.                 return -1;

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

  508.         }

  509.     }

  510. 

  511.     return 0;

  512. }

  513. 

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

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

  516. {

  517.     int i, k, last_k = -1, last_msb = -1, sb = 0;

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

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

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

  521. 

  522.     sbr->num_patches = 0;

  523. 

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

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

  526.     } else

  527.         k = sbr->n_master;

  528. 

  529.     do {

  530.         int odd = 0;

  531.         if (k == last_k && msb == last_msb) {

  532.             av_log(ac->avctx, AV_LOG_ERROR, "patch construction failed\n");

  533.             return AVERROR_INVALIDDATA;

  534.         }

  535.         last_k = k;

  536.         last_msb = msb;

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

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

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

  540.         }

  541. 

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

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

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

  545.         // count of 6 patches

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

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

  548.             return -1;

  549.         }

  550. 

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

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

  553. 

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

  555.             usb = sb;

  556.             msb = sb;

  557.             sbr->num_patches++;

  558.         } else

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

  560. 

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

  562.             k = sbr->n_master;

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

  564. 

  565.     if (sbr->num_patches > 1 &&

  566.         sbr->patch_num_subbands[sbr->num_patches - 1] < 3)

  567.         sbr->num_patches--;

  568. 

  569.     return 0;

  570. }

  571. 

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

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

  574. {

  575.     int k, temp;

  576. 

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

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

  579. 

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

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

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

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

  584. 

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

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

  587.         av_log(ac->avctx, AV_LOG_ERROR,

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

  589.         return -1;

  590.     }

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

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

  593.         return -1;

  594.     }

  595. 

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

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

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

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

  600. 

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

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

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

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

  605.         return -1;

  606.     }

  607. 

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

  609.     temp = 0;

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

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

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

  613.     }

  614. 

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

  616.         return -1;

  617. 

  618.     sbr_make_f_tablelim(sbr);

  619. 

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

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

  622. 

  623.     return 0;

  624. }

  625. 

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

  627.                                               int elements)

  628. {

  629.     int i;

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

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

  632.     }

  633. }

  634. 

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

  636. static const int8_t ceil_log2[] = {

  637.     0, 1, 2, 2, 3, 3,

  638. };

  639. 

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

  641.                          GetBitContext *gb, SBRData *ch_data)

  642. {

  643.     int i;

  644.     unsigned bs_pointer = 0;

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

  646.     int abs_bord_trail = 16;

  647.     int num_rel_lead, num_rel_trail;

  648.     unsigned bs_num_env_old = ch_data->bs_num_env;

  649. 

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

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

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

  653. 

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

  655.     case FIXFIX:

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

  657.         num_rel_lead                        = ch_data->bs_num_env - 1;

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

  659.             ch_data->bs_amp_res = 0;

  660. 

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

  662.             av_log(ac->avctx, AV_LOG_ERROR,

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

  664.                    ch_data->bs_num_env);

  665.             ch_data->bs_num_env = 2;

  666.             return -1;

  667.         }

  668. 

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

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

  671. 

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

  673.                    ch_data->bs_num_env;

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

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

  676. 

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

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

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

  680.         break;

  681.     case FIXVAR:

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

  683.         num_rel_trail                       = get_bits(gb, 2);

  684.         ch_data->bs_num_env                 = num_rel_trail + 1;

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

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

  687. 

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

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

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

  691. 

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

  693. 

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

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

  696.         break;

  697.     case VARFIX:

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

  699.         num_rel_lead                        = get_bits(gb, 2);

  700.         ch_data->bs_num_env                 = num_rel_lead + 1;

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

  702. 

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

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

  705. 

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

  707. 

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

  709.         break;

  710.     case VARVAR:

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

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

  713.         num_rel_lead                        = get_bits(gb, 2);

  714.         num_rel_trail                       = get_bits(gb, 2);

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

  716. 

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

  718.             av_log(ac->avctx, AV_LOG_ERROR,

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

  720.                    ch_data->bs_num_env);

  721.             ch_data->bs_num_env = 2;

  722.             return -1;

  723.         }

  724. 

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

  726. 

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

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

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

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

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

  732. 

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

  734. 

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

  736.         break;

  737.     }

  738. 

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

  740.         av_log(ac->avctx, AV_LOG_ERROR,

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

  742.                bs_pointer);

  743.         return -1;

  744.     }

  745. 

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

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

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

  749.             return -1;

  750.         }

  751.     }

  752. 

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

  754. 

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

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

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

  758.         unsigned int idx;

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

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

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

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

  763.         } else { // VARFIX

  764.             if (!bs_pointer)

  765.                 idx = 1;

  766.             else if (bs_pointer == 1)

  767.                 idx = ch_data->bs_num_env - 1;

  768.             else // bs_pointer > 1

  769.                 idx = bs_pointer - 1;

  770.         }

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

  772.     }

  773. 

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

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

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

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

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

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

  780. 

  781.     return 0;

  782. }

  783. 

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

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

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

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

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

  789. 

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

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

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

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

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

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

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

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

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

  799. }

  800. 

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

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

  803.                           SBRData *ch_data)

  804. {

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

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

  807. }

  808. 

  809. /// Read inverse filtering data

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

  811.                           SBRData *ch_data)

  812. {

  813.     int i;

  814. 

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

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

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

  818. }

  819. 

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

  821.                               SBRData *ch_data, int ch)

  822. {

  823.     int bits;

  824.     int i, j, k;

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

  826.     int t_lav, f_lav;

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

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

  829. 

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

  831.         if (ch_data->bs_amp_res) {

  832.             bits   = 5;

  833.             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_3_0DB].table;

  834.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_3_0DB];

  835.             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;

  836.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];

  837.         } else {

  838.             bits   = 6;

  839.             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_1_5DB].table;

  840.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_1_5DB];

  841.             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_1_5DB].table;

  842.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_1_5DB];

  843.         }

  844.     } else {

  845.         if (ch_data->bs_amp_res) {

  846.             bits   = 6;

  847.             t_huff = vlc_sbr[T_HUFFMAN_ENV_3_0DB].table;

  848.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_3_0DB];

  849.             f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;

  850.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];

  851.         } else {

  852.             bits   = 7;

  853.             t_huff = vlc_sbr[T_HUFFMAN_ENV_1_5DB].table;

  854.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_1_5DB];

  855.             f_huff = vlc_sbr[F_HUFFMAN_ENV_1_5DB].table;

  856.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_1_5DB];

  857.         }

  858.     }

  859. 

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

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

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

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

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

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

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

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

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

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

  870.                 }

  871.             } else {

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

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

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

  875.                 }

  876.             }

  877.         } else {

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

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

  880.                 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);

  881.         }

  882.     }

  883. 

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

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

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

  887. }

  888. 

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

  890.                            SBRData *ch_data, int ch)

  891. {

  892.     int i, j;

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

  894.     int t_lav, f_lav;

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

  896. 

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

  898.         t_huff = vlc_sbr[T_HUFFMAN_NOISE_BAL_3_0DB].table;

  899.         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_BAL_3_0DB];

  900.         f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;

  901.         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];

  902.     } else {

  903.         t_huff = vlc_sbr[T_HUFFMAN_NOISE_3_0DB].table;

  904.         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_3_0DB];

  905.         f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;

  906.         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];

  907.     }

  908. 

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

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

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

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

  913.         } else {

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

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

  916.                 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);

  917.         }

  918.     }

  919. 

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

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

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

  923. }

  924. 

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

  926.                                GetBitContext *gb,

  927.                                int bs_extension_id, int *num_bits_left)

  928. {

  929.     switch (bs_extension_id) {

  930.     case EXTENSION_ID_PS:

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

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

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

  934.             *num_bits_left = 0;

  935.         } else {

  936. #if 1

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

  938.             ac->avctx->profile = FF_PROFILE_AAC_HE_V2;

  939. #else

  940.             avpriv_report_missing_feature(ac->avctx, "Parametric Stereo");

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

  942.             *num_bits_left = 0;

  943. #endif

  944.         }

  945.         break;

  946.     default:

  947.         // some files contain 0-padding

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

  949.             avpriv_request_sample(ac->avctx, "Reserved SBR extensions");

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

  951.         *num_bits_left = 0;

  952.         break;

  953.     }

  954. }

  955. 

  956. static int read_sbr_single_channel_element(AACContext *ac,

  957.                                             SpectralBandReplication *sbr,

  958.                                             GetBitContext *gb)

  959. {

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

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

  962. 

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

  964.         return -1;

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

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

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

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

  969. 

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

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

  972. 

  973.     return 0;

  974. }

  975. 

  976. static int read_sbr_channel_pair_element(AACContext *ac,

  977.                                           SpectralBandReplication *sbr,

  978.                                           GetBitContext *gb)

  979. {

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

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

  982. 

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

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

  985.             return -1;

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

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

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

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

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

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

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

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

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

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

  996.     } else {

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

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

  999.             return -1;

  1000.         read_sbr_dtdf(sbr, gb, &sbr->data[0]);

  1001.         read_sbr_dtdf(sbr, gb, &sbr->data[1]);

  1002.         read_sbr_invf(sbr, gb, &sbr->data[0]);

  1003.         read_sbr_invf(sbr, gb, &sbr->data[1]);

  1004.         read_sbr_envelope(sbr, gb, &sbr->data[0], 0);

  1005.         read_sbr_envelope(sbr, gb, &sbr->data[1], 1);

  1006.         read_sbr_noise(sbr, gb, &sbr->data[0], 0);

  1007.         read_sbr_noise(sbr, gb, &sbr->data[1], 1);

  1008.     }

  1009. 

  1010.     if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb)))

  1011.         get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);

  1012.     if ((sbr->data[1].bs_add_harmonic_flag = get_bits1(gb)))

  1013.         get_bits1_vector(gb, sbr->data[1].bs_add_harmonic, sbr->n[1]);

  1014. 

  1015.     return 0;

  1016. }

  1017. 

  1018. static unsigned int read_sbr_data(AACContext *ac, SpectralBandReplication *sbr,

  1019.                                   GetBitContext *gb, int id_aac)

  1020. {

  1021.     unsigned int cnt = get_bits_count(gb);

  1022. 

  1023.     sbr->id_aac = id_aac;

  1024. 

  1025.     if (id_aac == TYPE_SCE || id_aac == TYPE_CCE) {

  1026.         if (read_sbr_single_channel_element(ac, sbr, gb)) {

  1027.             sbr_turnoff(sbr);

  1028.             return get_bits_count(gb) - cnt;

  1029.         }

  1030.     } else if (id_aac == TYPE_CPE) {

  1031.         if (read_sbr_channel_pair_element(ac, sbr, gb)) {

  1032.             sbr_turnoff(sbr);

  1033.             return get_bits_count(gb) - cnt;

  1034.         }

  1035.     } else {

  1036.         av_log(ac->avctx, AV_LOG_ERROR,

  1037.             "Invalid bitstream - cannot apply SBR to element type %d\n", id_aac);

  1038.         sbr_turnoff(sbr);

  1039.         return get_bits_count(gb) - cnt;

  1040.     }

  1041.     if (get_bits1(gb)) { // bs_extended_data

  1042.         int num_bits_left = get_bits(gb, 4); // bs_extension_size

  1043.         if (num_bits_left == 15)

  1044.             num_bits_left += get_bits(gb, 8); // bs_esc_count

  1045. 

  1046.         num_bits_left <<= 3;

  1047.         while (num_bits_left > 7) {

  1048.             num_bits_left -= 2;

  1049.             read_sbr_extension(ac, sbr, gb, get_bits(gb, 2), &num_bits_left); // bs_extension_id

  1050.         }

  1051.         if (num_bits_left < 0) {

  1052.             av_log(ac->avctx, AV_LOG_ERROR, "SBR Extension over read.\n");

  1053.         }

  1054.         if (num_bits_left > 0)

  1055.             skip_bits(gb, num_bits_left);

  1056.     }

  1057. 

  1058.     return get_bits_count(gb) - cnt;

  1059. }

  1060. 

  1061. static void sbr_reset(AACContext *ac, SpectralBandReplication *sbr)

  1062. {

  1063.     int err;

  1064.     err = sbr_make_f_master(ac, sbr, &sbr->spectrum_params);

  1065.     if (err >= 0)

  1066.         err = sbr_make_f_derived(ac, sbr);

  1067.     if (err < 0) {

  1068.         av_log(ac->avctx, AV_LOG_ERROR,

  1069.                "SBR reset failed. Switching SBR to pure upsampling mode.\n");

  1070.         sbr_turnoff(sbr);

  1071.     }

  1072. }

  1073. 

  1074. /**

  1075.  * Decode Spectral Band Replication extension data; reference: table 4.55.

  1076.  *

  1077.  * @param   crc flag indicating the presence of CRC checksum

  1078.  * @param   cnt length of TYPE_FIL syntactic element in bytes

  1079.  *

  1080.  * @return  Returns number of bytes consumed from the TYPE_FIL element.

  1081.  */

  1082. int ff_decode_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,

  1083.                             GetBitContext *gb_host, int crc, int cnt, int id_aac)

  1084. {

  1085.     unsigned int num_sbr_bits = 0, num_align_bits;

  1086.     unsigned bytes_read;

  1087.     GetBitContext gbc = *gb_host, *gb = &gbc;

  1088.     skip_bits_long(gb_host, cnt*8 - 4);

  1089. 

  1090.     sbr->reset = 0;

  1091. 

  1092.     if (!sbr->sample_rate)

  1093.         sbr->sample_rate = 2 * ac->oc[1].m4ac.sample_rate; //TODO use the nominal sample rate for arbitrary sample rate support

  1094.     if (!ac->oc[1].m4ac.ext_sample_rate)

  1095.         ac->oc[1].m4ac.ext_sample_rate = 2 * ac->oc[1].m4ac.sample_rate;

  1096. 

  1097.     if (crc) {

  1098.         skip_bits(gb, 10); // bs_sbr_crc_bits; TODO - implement CRC check

  1099.         num_sbr_bits += 10;

  1100.     }

  1101. 

  1102.     //Save some state from the previous frame.

  1103.     sbr->kx[0] = sbr->kx[1];

  1104.     sbr->m[0] = sbr->m[1];

  1105.     sbr->kx_and_m_pushed = 1;

  1106. 

  1107.     num_sbr_bits++;

  1108.     if (get_bits1(gb)) // bs_header_flag

  1109.         num_sbr_bits += read_sbr_header(sbr, gb);

  1110. 

  1111.     if (sbr->reset)

  1112.         sbr_reset(ac, sbr);

  1113. 

  1114.     if (sbr->start)

  1115.         num_sbr_bits  += read_sbr_data(ac, sbr, gb, id_aac);

  1116. 

  1117.     num_align_bits = ((cnt << 3) - 4 - num_sbr_bits) & 7;

  1118.     bytes_read = ((num_sbr_bits + num_align_bits + 4) >> 3);

  1119. 

  1120.     if (bytes_read > cnt) {

  1121.         av_log(ac->avctx, AV_LOG_ERROR,

  1122.                "Expected to read %d SBR bytes actually read %d.\n", cnt, bytes_read);

  1123.     }

  1124.     return cnt;

  1125. }

  1126. 

  1127. /// Dequantization and stereo decoding (14496-3 sp04 p203)

  1128. static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)

  1129. {

  1130.     int k, e;

  1131.     int ch;

  1132. 

  1133.     if (id_aac == TYPE_CPE && sbr->bs_coupling) {

  1134.         float alpha      = sbr->data[0].bs_amp_res ?  1.0f :  0.5f;

  1135.         float pan_offset = sbr->data[0].bs_amp_res ? 12.0f : 24.0f;

  1136.         for (e = 1; e <= sbr->data[0].bs_num_env; e++) {

  1137.             for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {

  1138.                 float temp1 = exp2f(sbr->data[0].env_facs[e][k] * alpha + 7.0f);

  1139.                 float temp2 = exp2f((pan_offset - sbr->data[1].env_facs[e][k]) * alpha);

  1140.                 float fac;

  1141.                 if (temp1 > 1E20) {

  1142.                     av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");

  1143.                     temp1 = 1;

  1144.                 }

  1145.                 fac   = temp1 / (1.0f + temp2);

  1146.                 sbr->data[0].env_facs[e][k] = fac;

  1147.                 sbr->data[1].env_facs[e][k] = fac * temp2;

  1148.             }

  1149.         }

  1150.         for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {

  1151.             for (k = 0; k < sbr->n_q; k++) {

  1152.                 float temp1 = exp2f(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs[e][k] + 1);

  1153.                 float temp2 = exp2f(12 - sbr->data[1].noise_facs[e][k]);

  1154.                 float fac;

  1155.                 if (temp1 > 1E20) {

  1156.                     av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");

  1157.                     temp1 = 1;

  1158.                 }

  1159.                 fac = temp1 / (1.0f + temp2);

  1160.                 sbr->data[0].noise_facs[e][k] = fac;

  1161.                 sbr->data[1].noise_facs[e][k] = fac * temp2;

  1162.             }

  1163.         }

  1164.     } else { // SCE or one non-coupled CPE

  1165.         for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {

  1166.             float alpha = sbr->data[ch].bs_amp_res ? 1.0f : 0.5f;

  1167.             for (e = 1; e <= sbr->data[ch].bs_num_env; e++)

  1168.                 for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++){

  1169.                     sbr->data[ch].env_facs[e][k] =

  1170.                         exp2f(alpha * sbr->data[ch].env_facs[e][k] + 6.0f);

  1171.                     if (sbr->data[ch].env_facs[e][k] > 1E20) {

  1172.                         av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");

  1173.                         sbr->data[ch].env_facs[e][k] = 1;

  1174.                     }

  1175.                 }

  1176. 

  1177.             for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)

  1178.                 for (k = 0; k < sbr->n_q; k++)

  1179.                     sbr->data[ch].noise_facs[e][k] =

  1180.                         exp2f(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs[e][k]);

  1181.         }

  1182.     }

  1183. }

  1184. 

  1185. /**

  1186.  * Analysis QMF Bank (14496-3 sp04 p206)

  1187.  *

  1188.  * @param   x       pointer to the beginning of the first sample window

  1189.  * @param   W       array of complex-valued samples split into subbands

  1190.  */

  1191. #ifndef sbr_qmf_analysis

  1192. static void sbr_qmf_analysis(AVFloatDSPContext *dsp, FFTContext *mdct,

  1193.                              SBRDSPContext *sbrdsp, const float *in, float *x,

  1194.                              float z[320], float W[2][32][32][2], int buf_idx)

  1195. {

  1196.     int i;

  1197.     memcpy(x    , x+1024, (320-32)*sizeof(x[0]));

  1198.     memcpy(x+288, in,         1024*sizeof(x[0]));

  1199.     for (i = 0; i < 32; i++) { // numTimeSlots*RATE = 16*2 as 960 sample frames

  1200.                                // are not supported

  1201.         dsp->vector_fmul_reverse(z, sbr_qmf_window_ds, x, 320);

  1202.         sbrdsp->sum64x5(z);

  1203.         sbrdsp->qmf_pre_shuffle(z);

  1204.         mdct->imdct_half(mdct, z, z+64);

  1205.         sbrdsp->qmf_post_shuffle(W[buf_idx][i], z);

  1206.         x += 32;

  1207.     }

  1208. }

  1209. #endif

  1210. 

  1211. /**

  1212.  * Synthesis QMF Bank (14496-3 sp04 p206) and Downsampled Synthesis QMF Bank

  1213.  * (14496-3 sp04 p206)

  1214.  */

  1215. #ifndef sbr_qmf_synthesis

  1216. static void sbr_qmf_synthesis(FFTContext *mdct,

  1217.                               SBRDSPContext *sbrdsp, AVFloatDSPContext *dsp,

  1218.                               float *out, float X[2][38][64],

  1219.                               float mdct_buf[2][64],

  1220.                               float *v0, int *v_off, const unsigned int div)

  1221. {

  1222.     int i, n;

  1223.     const float *sbr_qmf_window = div ? sbr_qmf_window_ds : sbr_qmf_window_us;

  1224.     const int step = 128 >> div;

  1225.     float *v;

  1226.     for (i = 0; i < 32; i++) {

  1227.         if (*v_off < step) {

  1228.             int saved_samples = (1280 - 128) >> div;

  1229.             memcpy(&v0[SBR_SYNTHESIS_BUF_SIZE - saved_samples], v0, saved_samples * sizeof(float));

  1230.             *v_off = SBR_SYNTHESIS_BUF_SIZE - saved_samples - step;

  1231.         } else {

  1232.             *v_off -= step;

  1233.         }

  1234.         v = v0 + *v_off;

  1235.         if (div) {

  1236.             for (n = 0; n < 32; n++) {

  1237.                 X[0][i][   n] = -X[0][i][n];

  1238.                 X[0][i][32+n] =  X[1][i][31-n];

  1239.             }

  1240.             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);

  1241.             sbrdsp->qmf_deint_neg(v, mdct_buf[0]);

  1242.         } else {

  1243.             sbrdsp->neg_odd_64(X[1][i]);

  1244.             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);

  1245.             mdct->imdct_half(mdct, mdct_buf[1], X[1][i]);

  1246.             sbrdsp->qmf_deint_bfly(v, mdct_buf[1], mdct_buf[0]);

  1247.         }

  1248.         dsp->vector_fmul    (out, v                , sbr_qmf_window                       , 64 >> div);

  1249.         dsp->vector_fmul_add(out, v + ( 192 >> div), sbr_qmf_window + ( 64 >> div), out   , 64 >> div);

  1250.         dsp->vector_fmul_add(out, v + ( 256 >> div), sbr_qmf_window + (128 >> div), out   , 64 >> div);

  1251.         dsp->vector_fmul_add(out, v + ( 448 >> div), sbr_qmf_window + (192 >> div), out   , 64 >> div);

  1252.         dsp->vector_fmul_add(out, v + ( 512 >> div), sbr_qmf_window + (256 >> div), out   , 64 >> div);

  1253.         dsp->vector_fmul_add(out, v + ( 704 >> div), sbr_qmf_window + (320 >> div), out   , 64 >> div);

  1254.         dsp->vector_fmul_add(out, v + ( 768 >> div), sbr_qmf_window + (384 >> div), out   , 64 >> div);

  1255.         dsp->vector_fmul_add(out, v + ( 960 >> div), sbr_qmf_window + (448 >> div), out   , 64 >> div);

  1256.         dsp->vector_fmul_add(out, v + (1024 >> div), sbr_qmf_window + (512 >> div), out   , 64 >> div);

  1257.         dsp->vector_fmul_add(out, v + (1216 >> div), sbr_qmf_window + (576 >> div), out   , 64 >> div);

  1258.         out += 64 >> div;

  1259.     }

  1260. }

  1261. #endif

  1262. 

  1263. /** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering

  1264.  * (14496-3 sp04 p214)

  1265.  * Warning: This routine does not seem numerically stable.

  1266.  */

  1267. static void sbr_hf_inverse_filter(SBRDSPContext *dsp,

  1268.                                   float (*alpha0)[2], float (*alpha1)[2],

  1269.                                   const float X_low[32][40][2], int k0)

  1270. {

  1271.     int k;

  1272.     for (k = 0; k < k0; k++) {

  1273.         LOCAL_ALIGNED_16(float, phi, [3], [2][2]);

  1274.         float dk;

  1275. 

  1276.         dsp->autocorrelate(X_low[k], phi);

  1277. 

  1278.         dk =  phi[2][1][0] * phi[1][0][0] -

  1279.              (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;

  1280. 

  1281.         if (!dk) {

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

  1283.             alpha1[k][1] = 0;

  1284.         } else {

  1285.             float temp_real, temp_im;

  1286.             temp_real = phi[0][0][0] * phi[1][1][0] -

  1287.                         phi[0][0][1] * phi[1][1][1] -

  1288.                         phi[0][1][0] * phi[1][0][0];

  1289.             temp_im   = phi[0][0][0] * phi[1][1][1] +

  1290.                         phi[0][0][1] * phi[1][1][0] -

  1291.                         phi[0][1][1] * phi[1][0][0];

  1292. 

  1293.             alpha1[k][0] = temp_real / dk;

  1294.             alpha1[k][1] = temp_im   / dk;

  1295.         }

  1296. 

  1297.         if (!phi[1][0][0]) {

  1298.             alpha0[k][0] = 0;

  1299.             alpha0[k][1] = 0;

  1300.         } else {

  1301.             float temp_real, temp_im;

  1302.             temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +

  1303.                                        alpha1[k][1] * phi[1][1][1];

  1304.             temp_im   = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -

  1305.                                        alpha1[k][0] * phi[1][1][1];

  1306. 

  1307.             alpha0[k][0] = -temp_real / phi[1][0][0];

  1308.             alpha0[k][1] = -temp_im   / phi[1][0][0];

  1309.         }

  1310. 

  1311.         if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||

  1312.            alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {

  1313.             alpha1[k][0] = 0;

  1314.             alpha1[k][1] = 0;

  1315.             alpha0[k][0] = 0;

  1316.             alpha0[k][1] = 0;

  1317.         }

  1318.     }

  1319. }

  1320. 

  1321. /// Chirp Factors (14496-3 sp04 p214)

  1322. static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)

  1323. {

  1324.     int i;

  1325.     float new_bw;

  1326.     static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };

  1327. 

  1328.     for (i = 0; i < sbr->n_q; i++) {

  1329.         if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {

  1330.             new_bw = 0.6f;

  1331.         } else

  1332.             new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];

  1333. 

  1334.         if (new_bw < ch_data->bw_array[i]) {

  1335.             new_bw = 0.75f    * new_bw + 0.25f    * ch_data->bw_array[i];

  1336.         } else

  1337.             new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];

  1338.         ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;

  1339.     }

  1340. }

  1341. 

  1342. /// Generate the subband filtered lowband

  1343. static int sbr_lf_gen(AACContext *ac, SpectralBandReplication *sbr,

  1344.                       float X_low[32][40][2], const float W[2][32][32][2],

  1345.                       int buf_idx)

  1346. {

  1347.     int i, k;

  1348.     const int t_HFGen = 8;

  1349.     const int i_f = 32;

  1350.     memset(X_low, 0, 32*sizeof(*X_low));

  1351.     for (k = 0; k < sbr->kx[1]; k++) {

  1352.         for (i = t_HFGen; i < i_f + t_HFGen; i++) {

  1353.             X_low[k][i][0] = W[buf_idx][i - t_HFGen][k][0];

  1354.             X_low[k][i][1] = W[buf_idx][i - t_HFGen][k][1];

  1355.         }

  1356.     }

  1357.     buf_idx = 1-buf_idx;

  1358.     for (k = 0; k < sbr->kx[0]; k++) {

  1359.         for (i = 0; i < t_HFGen; i++) {

  1360.             X_low[k][i][0] = W[buf_idx][i + i_f - t_HFGen][k][0];

  1361.             X_low[k][i][1] = W[buf_idx][i + i_f - t_HFGen][k][1];

  1362.         }

  1363.     }

  1364.     return 0;

  1365. }

  1366. 

  1367. /// High Frequency Generator (14496-3 sp04 p215)

  1368. static int sbr_hf_gen(AACContext *ac, SpectralBandReplication *sbr,

  1369.                       float X_high[64][40][2], const float X_low[32][40][2],

  1370.                       const float (*alpha0)[2], const float (*alpha1)[2],

  1371.                       const float bw_array[5], const uint8_t *t_env,

  1372.                       int bs_num_env)

  1373. {

  1374.     int j, x;

  1375.     int g = 0;

  1376.     int k = sbr->kx[1];

  1377.     for (j = 0; j < sbr->num_patches; j++) {

  1378.         for (x = 0; x < sbr->patch_num_subbands[j]; x++, k++) {

  1379.             const int p = sbr->patch_start_subband[j] + x;

  1380.             while (g <= sbr->n_q && k >= sbr->f_tablenoise[g])

  1381.                 g++;

  1382.             g--;

  1383. 

  1384.             if (g < 0) {

  1385.                 av_log(ac->avctx, AV_LOG_ERROR,

  1386.                        "ERROR : no subband found for frequency %d\n", k);

  1387.                 return -1;

  1388.             }

  1389. 

  1390.             sbr->dsp.hf_gen(X_high[k] + ENVELOPE_ADJUSTMENT_OFFSET,

  1391.                             X_low[p]  + ENVELOPE_ADJUSTMENT_OFFSET,

  1392.                             alpha0[p], alpha1[p], bw_array[g],

  1393.                             2 * t_env[0], 2 * t_env[bs_num_env]);

  1394.         }

  1395.     }

  1396.     if (k < sbr->m[1] + sbr->kx[1])

  1397.         memset(X_high + k, 0, (sbr->m[1] + sbr->kx[1] - k) * sizeof(*X_high));

  1398. 

  1399.     return 0;

  1400. }

  1401. 

  1402. /// Generate the subband filtered lowband

  1403. static int sbr_x_gen(SpectralBandReplication *sbr, float X[2][38][64],

  1404.                      const float Y0[38][64][2], const float Y1[38][64][2],

  1405.                      const float X_low[32][40][2], int ch)

  1406. {

  1407.     int k, i;

  1408.     const int i_f = 32;

  1409.     const int i_Temp = FFMAX(2*sbr->data[ch].t_env_num_env_old - i_f, 0);

  1410.     memset(X, 0, 2*sizeof(*X));

  1411.     for (k = 0; k < sbr->kx[0]; k++) {

  1412.         for (i = 0; i < i_Temp; i++) {

  1413.             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];

  1414.             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];

  1415.         }

  1416.     }

  1417.     for (; k < sbr->kx[0] + sbr->m[0]; k++) {

  1418.         for (i = 0; i < i_Temp; i++) {

  1419.             X[0][i][k] = Y0[i + i_f][k][0];

  1420.             X[1][i][k] = Y0[i + i_f][k][1];

  1421.         }

  1422.     }

  1423. 

  1424.     for (k = 0; k < sbr->kx[1]; k++) {

  1425.         for (i = i_Temp; i < 38; i++) {

  1426.             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];

  1427.             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];

  1428.         }

  1429.     }

  1430.     for (; k < sbr->kx[1] + sbr->m[1]; k++) {

  1431.         for (i = i_Temp; i < i_f; i++) {

  1432.             X[0][i][k] = Y1[i][k][0];

  1433.             X[1][i][k] = Y1[i][k][1];

  1434.         }

  1435.     }

  1436.     return 0;

  1437. }

  1438. 

  1439. /** High Frequency Adjustment (14496-3 sp04 p217) and Mapping

  1440.  * (14496-3 sp04 p217)

  1441.  */

  1442. static int sbr_mapping(AACContext *ac, SpectralBandReplication *sbr,

  1443.                         SBRData *ch_data, int e_a[2])

  1444. {

  1445.     int e, i, m;

  1446. 

  1447.     memset(ch_data->s_indexmapped[1], 0, 7*sizeof(ch_data->s_indexmapped[1]));

  1448.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1449.         const unsigned int ilim = sbr->n[ch_data->bs_freq_res[e + 1]];

  1450.         uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

  1451.         int k;

  1452. 

  1453.         if (sbr->kx[1] != table[0]) {

  1454.             av_log(ac->avctx, AV_LOG_ERROR, "kx != f_table{high,low}[0]. "

  1455.                    "Derived frequency tables were not regenerated.\n");

  1456.             sbr_turnoff(sbr);

  1457.             return AVERROR_BUG;

  1458.         }

  1459.         for (i = 0; i < ilim; i++)

  1460.             for (m = table[i]; m < table[i + 1]; m++)

  1461.                 sbr->e_origmapped[e][m - sbr->kx[1]] = ch_data->env_facs[e+1][i];

  1462. 

  1463.         // ch_data->bs_num_noise > 1 => 2 noise floors

  1464.         k = (ch_data->bs_num_noise > 1) && (ch_data->t_env[e] >= ch_data->t_q[1]);

  1465.         for (i = 0; i < sbr->n_q; i++)

  1466.             for (m = sbr->f_tablenoise[i]; m < sbr->f_tablenoise[i + 1]; m++)

  1467.                 sbr->q_mapped[e][m - sbr->kx[1]] = ch_data->noise_facs[k+1][i];

  1468. 

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

  1470.             if (ch_data->bs_add_harmonic_flag) {

  1471.                 const unsigned int m_midpoint =

  1472.                     (sbr->f_tablehigh[i] + sbr->f_tablehigh[i + 1]) >> 1;

  1473. 

  1474.                 ch_data->s_indexmapped[e + 1][m_midpoint - sbr->kx[1]] = ch_data->bs_add_harmonic[i] *

  1475.                     (e >= e_a[1] || (ch_data->s_indexmapped[0][m_midpoint - sbr->kx[1]] == 1));

  1476.             }

  1477.         }

  1478. 

  1479.         for (i = 0; i < ilim; i++) {

  1480.             int additional_sinusoid_present = 0;

  1481.             for (m = table[i]; m < table[i + 1]; m++) {

  1482.                 if (ch_data->s_indexmapped[e + 1][m - sbr->kx[1]]) {

  1483.                     additional_sinusoid_present = 1;

  1484.                     break;

  1485.                 }

  1486.             }

  1487.             memset(&sbr->s_mapped[e][table[i] - sbr->kx[1]], additional_sinusoid_present,

  1488.                    (table[i + 1] - table[i]) * sizeof(sbr->s_mapped[e][0]));

  1489.         }

  1490.     }

  1491. 

  1492.     memcpy(ch_data->s_indexmapped[0], ch_data->s_indexmapped[ch_data->bs_num_env], sizeof(ch_data->s_indexmapped[0]));

  1493.     return 0;

  1494. }

  1495. 

  1496. /// Estimation of current envelope (14496-3 sp04 p218)

  1497. static void sbr_env_estimate(float (*e_curr)[48], float X_high[64][40][2],

  1498.                              SpectralBandReplication *sbr, SBRData *ch_data)

  1499. {

  1500.     int e, m;

  1501.     int kx1 = sbr->kx[1];

  1502. 

  1503.     if (sbr->bs_interpol_freq) {

  1504.         for (e = 0; e < ch_data->bs_num_env; e++) {

  1505.             const float recip_env_size = 0.5f / (ch_data->t_env[e + 1] - ch_data->t_env[e]);

  1506.             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1507.             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1508. 

  1509.             for (m = 0; m < sbr->m[1]; m++) {

  1510.                 float sum = sbr->dsp.sum_square(X_high[m+kx1] + ilb, iub - ilb);

  1511.                 e_curr[e][m] = sum * recip_env_size;

  1512.             }

  1513.         }

  1514.     } else {

  1515.         int k, p;

  1516. 

  1517.         for (e = 0; e < ch_data->bs_num_env; e++) {

  1518.             const int env_size = 2 * (ch_data->t_env[e + 1] - ch_data->t_env[e]);

  1519.             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1520.             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1521.             const uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

  1522. 

  1523.             for (p = 0; p < sbr->n[ch_data->bs_freq_res[e + 1]]; p++) {

  1524.                 float sum = 0.0f;

  1525.                 const int den = env_size * (table[p + 1] - table[p]);

  1526. 

  1527.                 for (k = table[p]; k < table[p + 1]; k++) {

  1528.                     sum += sbr->dsp.sum_square(X_high[k] + ilb, iub - ilb);

  1529.                 }

  1530.                 sum /= den;

  1531.                 for (k = table[p]; k < table[p + 1]; k++) {

  1532.                     e_curr[e][k - kx1] = sum;

  1533.                 }

  1534.             }

  1535.         }

  1536.     }

  1537. }

  1538. 

  1539. /**

  1540.  * Calculation of levels of additional HF signal components (14496-3 sp04 p219)

  1541.  * and Calculation of gain (14496-3 sp04 p219)

  1542.  */

  1543. static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,

  1544.                           SBRData *ch_data, const int e_a[2])

  1545. {

  1546.     int e, k, m;

  1547.     // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)

  1548.     static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };

  1549. 

  1550.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1551.         int delta = !((e == e_a[1]) || (e == e_a[0]));

  1552.         for (k = 0; k < sbr->n_lim; k++) {

  1553.             float gain_boost, gain_max;

  1554.             float sum[2] = { 0.0f, 0.0f };

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

  1556.                 const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);

  1557.                 sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);

  1558.                 sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);

  1559.                 if (!sbr->s_mapped[e][m]) {

  1560.                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /

  1561.                                             ((1.0f + sbr->e_curr[e][m]) *

  1562.                                              (1.0f + sbr->q_mapped[e][m] * delta)));

  1563.                 } else {

  1564.                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /

  1565.                                             ((1.0f + sbr->e_curr[e][m]) *

  1566.                                              (1.0f + sbr->q_mapped[e][m])));

  1567.                 }

  1568.             }

  1569.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1570.                 sum[0] += sbr->e_origmapped[e][m];

  1571.                 sum[1] += sbr->e_curr[e][m];

  1572.             }

  1573.             gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));

  1574.             gain_max = FFMIN(100000.f, gain_max);

  1575.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1576.                 float q_m_max   = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];

  1577.                 sbr->q_m[e][m]  = FFMIN(sbr->q_m[e][m], q_m_max);

  1578.                 sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);

  1579.             }

  1580.             sum[0] = sum[1] = 0.0f;

  1581.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1582.                 sum[0] += sbr->e_origmapped[e][m];

  1583.                 sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]

  1584.                           + sbr->s_m[e][m] * sbr->s_m[e][m]

  1585.                           + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];

  1586.             }

  1587.             gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));

  1588.             gain_boost = FFMIN(1.584893192f, gain_boost);

  1589.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1590.                 sbr->gain[e][m] *= gain_boost;

  1591.                 sbr->q_m[e][m]  *= gain_boost;

  1592.                 sbr->s_m[e][m]  *= gain_boost;

  1593.             }

  1594.         }

  1595.     }

  1596. }

  1597. 

  1598. /// Assembling HF Signals (14496-3 sp04 p220)

  1599. static void sbr_hf_assemble(float Y1[38][64][2],

  1600.                             const float X_high[64][40][2],

  1601.                             SpectralBandReplication *sbr, SBRData *ch_data,

  1602.                             const int e_a[2])

  1603. {

  1604.     int e, i, j, m;

  1605.     const int h_SL = 4 * !sbr->bs_smoothing_mode;

  1606.     const int kx = sbr->kx[1];

  1607.     const int m_max = sbr->m[1];

  1608.     static const float h_smooth[5] = {

  1609.         0.33333333333333,

  1610.         0.30150283239582,

  1611.         0.21816949906249,

  1612.         0.11516383427084,

  1613.         0.03183050093751,

  1614.     };

  1615.     float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;

  1616.     int indexnoise = ch_data->f_indexnoise;

  1617.     int indexsine  = ch_data->f_indexsine;

  1618. 

  1619.     if (sbr->reset) {

  1620.         for (i = 0; i < h_SL; i++) {

  1621.             memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));

  1622.             memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0],  m_max * sizeof(sbr->q_m[0][0]));

  1623.         }

  1624.     } else if (h_SL) {

  1625.         memcpy(g_temp[2*ch_data->t_env[0]], g_temp[2*ch_data->t_env_num_env_old], 4*sizeof(g_temp[0]));

  1626.         memcpy(q_temp[2*ch_data->t_env[0]], q_temp[2*ch_data->t_env_num_env_old], 4*sizeof(q_temp[0]));

  1627.     }

  1628. 

  1629.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1630.         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {

  1631.             memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));

  1632.             memcpy(q_temp[h_SL + i], sbr->q_m[e],  m_max * sizeof(sbr->q_m[0][0]));

  1633.         }

  1634.     }

  1635. 

  1636.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1637.         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {

  1638.             LOCAL_ALIGNED_16(float, g_filt_tab, [48]);

  1639.             LOCAL_ALIGNED_16(float, q_filt_tab, [48]);

  1640.             float *g_filt, *q_filt;

  1641. 

  1642.             if (h_SL && e != e_a[0] && e != e_a[1]) {

  1643.                 g_filt = g_filt_tab;

  1644.                 q_filt = q_filt_tab;

  1645.                 for (m = 0; m < m_max; m++) {

  1646.                     const int idx1 = i + h_SL;

  1647.                     g_filt[m] = 0.0f;

  1648.                     q_filt[m] = 0.0f;

  1649.                     for (j = 0; j <= h_SL; j++) {

  1650.                         g_filt[m] += g_temp[idx1 - j][m] * h_smooth[j];

  1651.                         q_filt[m] += q_temp[idx1 - j][m] * h_smooth[j];

  1652.                     }

  1653.                 }

  1654.             } else {

  1655.                 g_filt = g_temp[i + h_SL];

  1656.                 q_filt = q_temp[i];

  1657.             }

  1658. 

  1659.             sbr->dsp.hf_g_filt(Y1[i] + kx, X_high + kx, g_filt, m_max,

  1660.                                i + ENVELOPE_ADJUSTMENT_OFFSET);

  1661. 

  1662.             if (e != e_a[0] && e != e_a[1]) {

  1663.                 sbr->dsp.hf_apply_noise[indexsine](Y1[i] + kx, sbr->s_m[e],

  1664.                                                    q_filt, indexnoise,

  1665.                                                    kx, m_max);

  1666.             } else {

  1667.                 int idx = indexsine&1;

  1668.                 int A = (1-((indexsine+(kx & 1))&2));

  1669.                 int B = (A^(-idx)) + idx;

  1670.                 float *out = &Y1[i][kx][idx];

  1671.                 float *in  = sbr->s_m[e];

  1672.                 for (m = 0; m+1 < m_max; m+=2) {

  1673.                     out[2*m  ] += in[m  ] * A;

  1674.                     out[2*m+2] += in[m+1] * B;

  1675.                 }

  1676.                 if(m_max&1)

  1677.                     out[2*m  ] += in[m  ] * A;

  1678.             }

  1679.             indexnoise = (indexnoise + m_max) & 0x1ff;

  1680.             indexsine = (indexsine + 1) & 3;

  1681.         }

  1682.     }

  1683.     ch_data->f_indexnoise = indexnoise;

  1684.     ch_data->f_indexsine  = indexsine;

  1685. }

  1686. 

  1687. void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,

  1688.                   float* L, float* R)

  1689. {

  1690.     int downsampled = ac->oc[1].m4ac.ext_sample_rate < sbr->sample_rate;

  1691.     int ch;

  1692.     int nch = (id_aac == TYPE_CPE) ? 2 : 1;

  1693.     int err;

  1694. 

  1695.     if (id_aac != sbr->id_aac) {

  1696.         av_log(ac->avctx, AV_LOG_ERROR,

  1697.             "element type mismatch %d != %d\n", id_aac, sbr->id_aac);

  1698.         sbr_turnoff(sbr);

  1699.     }

  1700. 

  1701.     if (!sbr->kx_and_m_pushed) {

  1702.         sbr->kx[0] = sbr->kx[1];

  1703.         sbr->m[0] = sbr->m[1];

  1704.     } else {

  1705.         sbr->kx_and_m_pushed = 0;

  1706.     }

  1707. 

  1708.     if (sbr->start) {

  1709.         sbr_dequant(sbr, id_aac);

  1710.     }

  1711.     for (ch = 0; ch < nch; ch++) {

  1712.         /* decode channel */

  1713.         sbr_qmf_analysis(&ac->fdsp, &sbr->mdct_ana, &sbr->dsp, ch ? R : L, sbr->data[ch].analysis_filterbank_samples,

  1714.                          (float*)sbr->qmf_filter_scratch,

  1715.                          sbr->data[ch].W, sbr->data[ch].Ypos);

  1716.         sbr->c.sbr_lf_gen(ac, sbr, sbr->X_low,

  1717.                           (const float (*)[32][32][2]) sbr->data[ch].W,

  1718.                           sbr->data[ch].Ypos);

  1719.         sbr->data[ch].Ypos ^= 1;

  1720.         if (sbr->start) {

  1721.             sbr->c.sbr_hf_inverse_filter(&sbr->dsp, sbr->alpha0, sbr->alpha1,

  1722.                                          (const float (*)[40][2]) sbr->X_low, sbr->k[0]);

  1723.             sbr_chirp(sbr, &sbr->data[ch]);

  1724.             av_assert0(sbr->data[ch].bs_num_env > 0);

  1725.             sbr_hf_gen(ac, sbr, sbr->X_high,

  1726.                        (const float (*)[40][2]) sbr->X_low,

  1727.                        (const float (*)[2]) sbr->alpha0,

  1728.                        (const float (*)[2]) sbr->alpha1,

  1729.                        sbr->data[ch].bw_array, sbr->data[ch].t_env,

  1730.                        sbr->data[ch].bs_num_env);

  1731. 

  1732.             // hf_adj

  1733.             err = sbr_mapping(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);

  1734.             if (!err) {

  1735.                 sbr_env_estimate(sbr->e_curr, sbr->X_high, sbr, &sbr->data[ch]);

  1736.                 sbr_gain_calc(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);

  1737.                 sbr->c.sbr_hf_assemble(sbr->data[ch].Y[sbr->data[ch].Ypos],

  1738.                                 (const float (*)[40][2]) sbr->X_high,

  1739.                                 sbr, &sbr->data[ch],

  1740.                                 sbr->data[ch].e_a);

  1741.             }

  1742.         }

  1743. 

  1744.         /* synthesis */

  1745.         sbr->c.sbr_x_gen(sbr, sbr->X[ch],

  1746.                   (const float (*)[64][2]) sbr->data[ch].Y[1-sbr->data[ch].Ypos],

  1747.                   (const float (*)[64][2]) sbr->data[ch].Y[  sbr->data[ch].Ypos],

  1748.                   (const float (*)[40][2]) sbr->X_low, ch);

  1749.     }

  1750. 

  1751.     if (ac->oc[1].m4ac.ps == 1) {

  1752.         if (sbr->ps.start) {

  1753.             ff_ps_apply(ac->avctx, &sbr->ps, sbr->X[0], sbr->X[1], sbr->kx[1] + sbr->m[1]);

  1754.         } else {

  1755.             memcpy(sbr->X[1], sbr->X[0], sizeof(sbr->X[0]));

  1756.         }

  1757.         nch = 2;

  1758.     }

  1759. 

  1760.     sbr_qmf_synthesis(&sbr->mdct, &sbr->dsp, &ac->fdsp,

  1761.                       L, sbr->X[0], sbr->qmf_filter_scratch,

  1762.                       sbr->data[0].synthesis_filterbank_samples,

  1763.                       &sbr->data[0].synthesis_filterbank_samples_offset,

  1764.                       downsampled);

  1765.     if (nch == 2)

  1766.         sbr_qmf_synthesis(&sbr->mdct, &sbr->dsp, &ac->fdsp,

  1767.                           R, sbr->X[1], sbr->qmf_filter_scratch,

  1768.                           sbr->data[1].synthesis_filterbank_samples,

  1769.                           &sbr->data[1].synthesis_filterbank_samples_offset,

  1770.                           downsampled);

  1771. }

  1772. 

  1773. static void aacsbr_func_ptr_init(AACSBRContext *c)

  1774. {

  1775.     c->sbr_lf_gen            = sbr_lf_gen;

  1776.     c->sbr_hf_assemble       = sbr_hf_assemble;

  1777.     c->sbr_x_gen             = sbr_x_gen;

  1778.     c->sbr_hf_inverse_filter = sbr_hf_inverse_filter;

  1779. 

  1780.     if(ARCH_MIPS)

  1781.         ff_aacsbr_func_ptr_init_mips(c);

  1782. }