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FFmpeg/libavcodec/aacsbr.c

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  1. /*

  2.  * AAC Spectral Band Replication decoding functions

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

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

  5.  *

  6.  * This file is part of FFmpeg.

  7.  *

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

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

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

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

  12.  *

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

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

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

  16.  * Lesser General Public License for more details.

  17.  *

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

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

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

  21.  */

  22. 

  23. /**

  24.  * @file

  25.  * AAC Spectral Band Replication decoding functions

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

  27.  */

  28. 

  29. #include "aac.h"

  30. #include "sbr.h"

  31. #include "aacsbr.h"

  32. #include "aacsbrdata.h"

  33. #include "fft.h"

  34. #include "aacps.h"

  35. #include "sbrdsp.h"

  36. #include "libavutil/internal.h"

  37. #include "libavutil/libm.h"

  38. #include "libavutil/avassert.h"

  39. 

  40. #include <stdint.h>

  41. #include <float.h>

  42. #include <math.h>

  43. 

  44. #define ENVELOPE_ADJUSTMENT_OFFSET 2

  45. #define NOISE_FLOOR_OFFSET 6.0f

  46. 

  47. #if ARCH_MIPS

  48. #include "mips/aacsbr_mips.h"

  49. #endif /* ARCH_MIPS */

  50. 

  51. /**

  52.  * SBR VLC tables

  53.  */

  54. enum {

  55.     T_HUFFMAN_ENV_1_5DB,

  56.     F_HUFFMAN_ENV_1_5DB,

  57.     T_HUFFMAN_ENV_BAL_1_5DB,

  58.     F_HUFFMAN_ENV_BAL_1_5DB,

  59.     T_HUFFMAN_ENV_3_0DB,

  60.     F_HUFFMAN_ENV_3_0DB,

  61.     T_HUFFMAN_ENV_BAL_3_0DB,

  62.     F_HUFFMAN_ENV_BAL_3_0DB,

  63.     T_HUFFMAN_NOISE_3_0DB,

  64.     T_HUFFMAN_NOISE_BAL_3_0DB,

  65. };

  66. 

  67. /**

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

  69.  */

  70. enum {

  71.     FIXFIX,

  72.     FIXVAR,

  73.     VARFIX,

  74.     VARVAR,

  75. };

  76. 

  77. enum {

  78.     EXTENSION_ID_PS = 2,

  79. };

  80. 

  81. static VLC vlc_sbr[10];

  82. static const int8_t vlc_sbr_lav[10] =

  83.     { 60, 60, 24, 24, 31, 31, 12, 12, 31, 12 };

  84. 

  85. #define SBR_INIT_VLC_STATIC(num, size) \

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

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

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

  89.                     size)

  90. 

  91. #define SBR_VLC_ROW(name) \

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

  93. 

  94. static void aacsbr_func_ptr_init(AACSBRContext *c);

  95. 

  96. av_cold void ff_aac_sbr_init(void)

  97. {

  98.     int n;

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

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

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

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

  131. 

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

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

  134. 

  135.     ff_ps_init();

  136. }

  137. 

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

  139. static void sbr_turnoff(SpectralBandReplication *sbr) {

  140.     sbr->start = 0;

  141.     // Init defults used in pure upsampling mode

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

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

  144.     // Reset values for first SBR header

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

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

  147. }

  148. 

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

  150. {

  151.     if(sbr->mdct.mdct_bits)

  152.         return;

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

  154.     sbr_turnoff(sbr);

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

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

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

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

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

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

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

  162.     ff_ps_ctx_init(&sbr->ps);

  163.     ff_sbrdsp_init(&sbr->dsp);

  164.     aacsbr_func_ptr_init(&sbr->c);

  165. }

  166. 

  167. av_cold void ff_aac_sbr_ctx_close(SpectralBandReplication *sbr)

  168. {

  169.     ff_mdct_end(&sbr->mdct);

  170.     ff_mdct_end(&sbr->mdct_ana);

  171. }

  172. 

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

  174. {

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

  176. }

  177. 

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

  179. {

  180.     int i;

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

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

  183.             return 1;

  184.     return 0;

  185. }

  186. 

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

  188. static void sbr_make_f_tablelim(SpectralBandReplication *sbr)

  189. {

  190.     int k;

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

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

  193.                                                1.18509277094158210129f,   //2^(0.49/2)

  194.                                                1.11987160404675912501f }; //2^(0.49/3)

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

  196.         int16_t patch_borders[7];

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

  198. 

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

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

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

  202. 

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

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

  205.         if (sbr->num_patches > 1)

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

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

  208. 

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

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

  211.               qsort_comparison_function_int16);

  212. 

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

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

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

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

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

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

  219.                 in++;

  220.                 sbr->n_lim--;

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

  222.                 *out = *in++;

  223.                 sbr->n_lim--;

  224.             } else {

  225.                 *++out = *in++;

  226.             }

  227.         }

  228.     } else {

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

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

  231.         sbr->n_lim = 1;

  232.     }

  233. }

  234. 

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

  236. {

  237.     unsigned int cnt = get_bits_count(gb);

  238.     uint8_t bs_header_extra_1;

  239.     uint8_t bs_header_extra_2;

  240.     int old_bs_limiter_bands = sbr->bs_limiter_bands;

  241.     SpectrumParameters old_spectrum_params;

  242. 

  243.     sbr->start = 1;

  244. 

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

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

  247. 

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

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

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

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

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

  253. 

  254.     bs_header_extra_1 = get_bits1(gb);

  255.     bs_header_extra_2 = get_bits1(gb);

  256. 

  257.     if (bs_header_extra_1) {

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

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

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

  261.     } else {

  262.         sbr->spectrum_params.bs_freq_scale  = 2;

  263.         sbr->spectrum_params.bs_alter_scale = 1;

  264.         sbr->spectrum_params.bs_noise_bands = 2;

  265.     }

  266. 

  267.     // Check if spectrum parameters changed

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

  269.         sbr->reset = 1;

  270. 

  271.     if (bs_header_extra_2) {

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

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

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

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

  276.     } else {

  277.         sbr->bs_limiter_bands  = 2;

  278.         sbr->bs_limiter_gains  = 2;

  279.         sbr->bs_interpol_freq  = 1;

  280.         sbr->bs_smoothing_mode = 1;

  281.     }

  282. 

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

  284.         sbr_make_f_tablelim(sbr);

  285. 

  286.     return get_bits_count(gb) - cnt;

  287. }

  288. 

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

  290. {

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

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

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

  294.     return min;

  295. }

  296. 

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

  298. {

  299.     int k, previous, present;

  300.     float base, prod;

  301. 

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

  303.     prod = start;

  304.     previous = start;

  305. 

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

  307.         prod *= base;

  308.         present  = lrintf(prod);

  309.         bands[k] = present - previous;

  310.         previous = present;

  311.     }

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

  313. }

  314. 

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

  316. {

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

  318.     if (n_master <= 0) {

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

  320.         return -1;

  321.     }

  322.     if (bs_xover_band >= n_master) {

  323.         av_log(avctx, AV_LOG_ERROR,

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

  325.                bs_xover_band);

  326.         return -1;

  327.     }

  328.     return 0;

  329. }

  330. 

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

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

  333.                              SpectrumParameters *spectrum)

  334. {

  335.     unsigned int temp, max_qmf_subbands;

  336.     unsigned int start_min, stop_min;

  337.     int k;

  338.     const int8_t *sbr_offset_ptr;

  339.     int16_t stop_dk[13];

  340. 

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

  342.         temp = 3000;

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

  344.         temp = 4000;

  345.     } else

  346.         temp = 5000;

  347. 

  348.     switch (sbr->sample_rate) {

  349.     case 16000:

  350.         sbr_offset_ptr = sbr_offset[0];

  351.         break;

  352.     case 22050:

  353.         sbr_offset_ptr = sbr_offset[1];

  354.         break;

  355.     case 24000:

  356.         sbr_offset_ptr = sbr_offset[2];

  357.         break;

  358.     case 32000:

  359.         sbr_offset_ptr = sbr_offset[3];

  360.         break;

  361.     case 44100: case 48000: case 64000:

  362.         sbr_offset_ptr = sbr_offset[4];

  363.         break;

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

  365.         sbr_offset_ptr = sbr_offset[5];

  366.         break;

  367.     default:

  368.         av_log(ac->avctx, AV_LOG_ERROR,

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

  370.         return -1;

  371.     }

  372. 

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

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

  375. 

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

  377. 

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

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

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

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

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

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

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

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

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

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

  388.     } else {

  389.         av_log(ac->avctx, AV_LOG_ERROR,

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

  391.         return -1;

  392.     }

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

  394. 

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

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

  397.         max_qmf_subbands = 48;

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

  399.         max_qmf_subbands = 35;

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

  401.         max_qmf_subbands = 32;

  402.     else

  403.         av_assert0(0);

  404. 

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

  406.         av_log(ac->avctx, AV_LOG_ERROR,

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

  408.         return -1;

  409.     }

  410. 

  411.     if (!spectrum->bs_freq_scale) {

  412.         int dk, k2diff;

  413. 

  414.         dk = spectrum->bs_alter_scale + 1;

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

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

  417.             return -1;

  418. 

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

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

  421. 

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

  423.         if (k2diff < 0) {

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

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

  426.         } else if (k2diff) {

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

  428.         }

  429. 

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

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

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

  433. 

  434.     } else {

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

  436.         int two_regions, num_bands_0;

  437.         int vdk0_max, vdk1_min;

  438.         int16_t vk0[49];

  439. 

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

  441.             two_regions = 1;

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

  443.         } else {

  444.             two_regions = 0;

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

  446.         }

  447. 

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

  449. 

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

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

  452.             return -1;

  453.         }

  454. 

  455.         vk0[0] = 0;

  456. 

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

  458. 

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

  460.         vdk0_max = vk0[num_bands_0];

  461. 

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

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

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

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

  466.                 return -1;

  467.             }

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

  469.         }

  470. 

  471.         if (two_regions) {

  472.             int16_t vk1[49];

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

  474.                                                      : 1.0f; // bs_alter_scale = {0,1}

  475.             int num_bands_1 = lrintf(half_bands * invwarp *

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

  477. 

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

  479. 

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

  481. 

  482.             if (vdk1_min < vdk0_max) {

  483.                 int change;

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

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

  486.                 vk1[1]           += change;

  487.                 vk1[num_bands_1] -= change;

  488.             }

  489. 

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

  491. 

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

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

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

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

  496.                     return -1;

  497.                 }

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

  499.             }

  500. 

  501.             sbr->n_master = num_bands_0 + num_bands_1;

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

  503.                 return -1;

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

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

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

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

  508. 

  509.         } else {

  510.             sbr->n_master = num_bands_0;

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

  512.                 return -1;

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

  514.         }

  515.     }

  516. 

  517.     return 0;

  518. }

  519. 

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

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

  522. {

  523.     int i, k, sb = 0;

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

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

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

  527. 

  528.     sbr->num_patches = 0;

  529. 

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

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

  532.     } else

  533.         k = sbr->n_master;

  534. 

  535.     do {

  536.         int odd = 0;

  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 && sbr->patch_num_subbands[sbr->num_patches-1] < 3)

  566.         sbr->num_patches--;

  567. 

  568.     return 0;

  569. }

  570. 

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

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

  573. {

  574.     int k, temp;

  575. 

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

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

  578. 

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

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

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

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

  583. 

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

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

  586.         av_log(ac->avctx, AV_LOG_ERROR,

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

  588.         return -1;

  589.     }

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

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

  592.         return -1;

  593.     }

  594. 

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

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

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

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

  599. 

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

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

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

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

  604.         return -1;

  605.     }

  606. 

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

  608.     temp = 0;

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

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

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

  612.     }

  613. 

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

  615.         return -1;

  616. 

  617.     sbr_make_f_tablelim(sbr);

  618. 

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

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

  621. 

  622.     return 0;

  623. }

  624. 

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

  626.                                               int elements)

  627. {

  628.     int i;

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

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

  631.     }

  632. }

  633. 

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

  635. static const int8_t ceil_log2[] = {

  636.     0, 1, 2, 2, 3, 3,

  637. };

  638. 

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

  640.                          GetBitContext *gb, SBRData *ch_data)

  641. {

  642.     int i;

  643.     unsigned bs_pointer = 0;

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

  645.     int abs_bord_trail = 16;

  646.     int num_rel_lead, num_rel_trail;

  647.     unsigned bs_num_env_old = ch_data->bs_num_env;

  648. 

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

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

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

  652. 

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

  654.     case FIXFIX:

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

  656.         num_rel_lead                        = ch_data->bs_num_env - 1;

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

  658.             ch_data->bs_amp_res = 0;

  659. 

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

  661.             av_log(ac->avctx, AV_LOG_ERROR,

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

  663.                    ch_data->bs_num_env);

  664.             return -1;

  665.         }

  666. 

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

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

  669. 

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

  671.                    ch_data->bs_num_env;

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

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

  674. 

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

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

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

  678.         break;

  679.     case FIXVAR:

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

  681.         num_rel_trail                       = get_bits(gb, 2);

  682.         ch_data->bs_num_env                 = num_rel_trail + 1;

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

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

  685. 

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

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

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

  689. 

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

  691. 

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

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

  694.         break;

  695.     case VARFIX:

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

  697.         num_rel_lead                        = get_bits(gb, 2);

  698.         ch_data->bs_num_env                 = num_rel_lead + 1;

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

  700. 

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

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

  703. 

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

  705. 

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

  707.         break;

  708.     case VARVAR:

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

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

  711.         num_rel_lead                        = get_bits(gb, 2);

  712.         num_rel_trail                       = get_bits(gb, 2);

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

  714. 

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

  716.             av_log(ac->avctx, AV_LOG_ERROR,

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

  718.                    ch_data->bs_num_env);

  719.             return -1;

  720.         }

  721. 

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

  723. 

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

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

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

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

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

  729. 

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

  731. 

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

  733.         break;

  734.     }

  735. 

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

  737.         av_log(ac->avctx, AV_LOG_ERROR,

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

  739.                bs_pointer);

  740.         return -1;

  741.     }

  742. 

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

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

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

  746.             return -1;

  747.         }

  748.     }

  749. 

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

  751. 

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

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

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

  755.         unsigned int idx;

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

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

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

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

  760.         } else { // VARFIX

  761.             if (!bs_pointer)

  762.                 idx = 1;

  763.             else if (bs_pointer == 1)

  764.                 idx = ch_data->bs_num_env - 1;

  765.             else // bs_pointer > 1

  766.                 idx = bs_pointer - 1;

  767.         }

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

  769.     }

  770. 

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

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

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

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

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

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

  777. 

  778.     return 0;

  779. }

  780. 

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

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

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

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

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

  786. 

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

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

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

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

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

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

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

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

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

  796. }

  797. 

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

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

  800.                           SBRData *ch_data)

  801. {

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

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

  804. }

  805. 

  806. /// Read inverse filtering data

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

  808.                           SBRData *ch_data)

  809. {

  810.     int i;

  811. 

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

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

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

  815. }

  816. 

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

  818.                               SBRData *ch_data, int ch)

  819. {

  820.     int bits;

  821.     int i, j, k;

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

  823.     int t_lav, f_lav;

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

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

  826. 

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

  828.         if (ch_data->bs_amp_res) {

  829.             bits   = 5;

  830.             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_3_0DB].table;

  831.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_3_0DB];

  832.             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;

  833.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];

  834.         } else {

  835.             bits   = 6;

  836.             t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_1_5DB].table;

  837.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_1_5DB];

  838.             f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_1_5DB].table;

  839.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_1_5DB];

  840.         }

  841.     } else {

  842.         if (ch_data->bs_amp_res) {

  843.             bits   = 6;

  844.             t_huff = vlc_sbr[T_HUFFMAN_ENV_3_0DB].table;

  845.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_3_0DB];

  846.             f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;

  847.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];

  848.         } else {

  849.             bits   = 7;

  850.             t_huff = vlc_sbr[T_HUFFMAN_ENV_1_5DB].table;

  851.             t_lav  = vlc_sbr_lav[T_HUFFMAN_ENV_1_5DB];

  852.             f_huff = vlc_sbr[F_HUFFMAN_ENV_1_5DB].table;

  853.             f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_1_5DB];

  854.         }

  855.     }

  856. 

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

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

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

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

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

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

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

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

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

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

  867.                 }

  868.             } else {

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

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

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

  872.                 }

  873.             }

  874.         } else {

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

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

  877.                 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);

  878.         }

  879.     }

  880. 

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

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

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

  884. }

  885. 

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

  887.                            SBRData *ch_data, int ch)

  888. {

  889.     int i, j;

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

  891.     int t_lav, f_lav;

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

  893. 

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

  895.         t_huff = vlc_sbr[T_HUFFMAN_NOISE_BAL_3_0DB].table;

  896.         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_BAL_3_0DB];

  897.         f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;

  898.         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];

  899.     } else {

  900.         t_huff = vlc_sbr[T_HUFFMAN_NOISE_3_0DB].table;

  901.         t_lav  = vlc_sbr_lav[T_HUFFMAN_NOISE_3_0DB];

  902.         f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;

  903.         f_lav  = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];

  904.     }

  905. 

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

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

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

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

  910.         } else {

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

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

  913.                 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);

  914.         }

  915.     }

  916. 

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

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

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

  920. }

  921. 

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

  923.                                GetBitContext *gb,

  924.                                int bs_extension_id, int *num_bits_left)

  925. {

  926.     switch (bs_extension_id) {

  927.     case EXTENSION_ID_PS:

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

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

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

  931.             *num_bits_left = 0;

  932.         } else {

  933. #if 1

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

  935. #else

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

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

  938.             *num_bits_left = 0;

  939. #endif

  940.         }

  941.         break;

  942.     default:

  943.         // some files contain 0-padding

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

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

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

  947.         *num_bits_left = 0;

  948.         break;

  949.     }

  950. }

  951. 

  952. static int read_sbr_single_channel_element(AACContext *ac,

  953.                                             SpectralBandReplication *sbr,

  954.                                             GetBitContext *gb)

  955. {

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

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

  958. 

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

  960.         return -1;

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

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

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

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

  965. 

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

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

  968. 

  969.     return 0;

  970. }

  971. 

  972. static int read_sbr_channel_pair_element(AACContext *ac,

  973.                                           SpectralBandReplication *sbr,

  974.                                           GetBitContext *gb)

  975. {

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

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

  978. 

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

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

  981.             return -1;

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

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

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

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

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

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

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

  992.     } else {

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

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

  995.             return -1;

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

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

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

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

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

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

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

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

  1004.     }

  1005. 

  1006.     if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb)))

  1007.         get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);

  1008.     if ((sbr->data[1].bs_add_harmonic_flag = get_bits1(gb)))

  1009.         get_bits1_vector(gb, sbr->data[1].bs_add_harmonic, sbr->n[1]);

  1010. 

  1011.     return 0;

  1012. }

  1013. 

  1014. static unsigned int read_sbr_data(AACContext *ac, SpectralBandReplication *sbr,

  1015.                                   GetBitContext *gb, int id_aac)

  1016. {

  1017.     unsigned int cnt = get_bits_count(gb);

  1018. 

  1019.     if (id_aac == TYPE_SCE || id_aac == TYPE_CCE) {

  1020.         if (read_sbr_single_channel_element(ac, sbr, gb)) {

  1021.             sbr_turnoff(sbr);

  1022.             return get_bits_count(gb) - cnt;

  1023.         }

  1024.     } else if (id_aac == TYPE_CPE) {

  1025.         if (read_sbr_channel_pair_element(ac, sbr, gb)) {

  1026.             sbr_turnoff(sbr);

  1027.             return get_bits_count(gb) - cnt;

  1028.         }

  1029.     } else {

  1030.         av_log(ac->avctx, AV_LOG_ERROR,

  1031.             "Invalid bitstream - cannot apply SBR to element type %d\n", id_aac);

  1032.         sbr_turnoff(sbr);

  1033.         return get_bits_count(gb) - cnt;

  1034.     }

  1035.     if (get_bits1(gb)) { // bs_extended_data

  1036.         int num_bits_left = get_bits(gb, 4); // bs_extension_size

  1037.         if (num_bits_left == 15)

  1038.             num_bits_left += get_bits(gb, 8); // bs_esc_count

  1039. 

  1040.         num_bits_left <<= 3;

  1041.         while (num_bits_left > 7) {

  1042.             num_bits_left -= 2;

  1043.             read_sbr_extension(ac, sbr, gb, get_bits(gb, 2), &num_bits_left); // bs_extension_id

  1044.         }

  1045.         if (num_bits_left < 0) {

  1046.             av_log(ac->avctx, AV_LOG_ERROR, "SBR Extension over read.\n");

  1047.         }

  1048.         if (num_bits_left > 0)

  1049.             skip_bits(gb, num_bits_left);

  1050.     }

  1051. 

  1052.     return get_bits_count(gb) - cnt;

  1053. }

  1054. 

  1055. static void sbr_reset(AACContext *ac, SpectralBandReplication *sbr)

  1056. {

  1057.     int err;

  1058.     err = sbr_make_f_master(ac, sbr, &sbr->spectrum_params);

  1059.     if (err >= 0)

  1060.         err = sbr_make_f_derived(ac, sbr);

  1061.     if (err < 0) {

  1062.         av_log(ac->avctx, AV_LOG_ERROR,

  1063.                "SBR reset failed. Switching SBR to pure upsampling mode.\n");

  1064.         sbr_turnoff(sbr);

  1065.     }

  1066. }

  1067. 

  1068. /**

  1069.  * Decode Spectral Band Replication extension data; reference: table 4.55.

  1070.  *

  1071.  * @param   crc flag indicating the presence of CRC checksum

  1072.  * @param   cnt length of TYPE_FIL syntactic element in bytes

  1073.  *

  1074.  * @return  Returns number of bytes consumed from the TYPE_FIL element.

  1075.  */

  1076. int ff_decode_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,

  1077.                             GetBitContext *gb_host, int crc, int cnt, int id_aac)

  1078. {

  1079.     unsigned int num_sbr_bits = 0, num_align_bits;

  1080.     unsigned bytes_read;

  1081.     GetBitContext gbc = *gb_host, *gb = &gbc;

  1082.     skip_bits_long(gb_host, cnt*8 - 4);

  1083. 

  1084.     sbr->reset = 0;

  1085. 

  1086.     if (!sbr->sample_rate)

  1087.         sbr->sample_rate = 2 * ac->oc[1].m4ac.sample_rate; //TODO use the nominal sample rate for arbitrary sample rate support

  1088.     if (!ac->oc[1].m4ac.ext_sample_rate)

  1089.         ac->oc[1].m4ac.ext_sample_rate = 2 * ac->oc[1].m4ac.sample_rate;

  1090. 

  1091.     if (crc) {

  1092.         skip_bits(gb, 10); // bs_sbr_crc_bits; TODO - implement CRC check

  1093.         num_sbr_bits += 10;

  1094.     }

  1095. 

  1096.     //Save some state from the previous frame.

  1097.     sbr->kx[0] = sbr->kx[1];

  1098.     sbr->m[0] = sbr->m[1];

  1099.     sbr->kx_and_m_pushed = 1;

  1100. 

  1101.     num_sbr_bits++;

  1102.     if (get_bits1(gb)) // bs_header_flag

  1103.         num_sbr_bits += read_sbr_header(sbr, gb);

  1104. 

  1105.     if (sbr->reset)

  1106.         sbr_reset(ac, sbr);

  1107. 

  1108.     if (sbr->start)

  1109.         num_sbr_bits  += read_sbr_data(ac, sbr, gb, id_aac);

  1110. 

  1111.     num_align_bits = ((cnt << 3) - 4 - num_sbr_bits) & 7;

  1112.     bytes_read = ((num_sbr_bits + num_align_bits + 4) >> 3);

  1113. 

  1114.     if (bytes_read > cnt) {

  1115.         av_log(ac->avctx, AV_LOG_ERROR,

  1116.                "Expected to read %d SBR bytes actually read %d.\n", cnt, bytes_read);

  1117.     }

  1118.     return cnt;

  1119. }

  1120. 

  1121. /// Dequantization and stereo decoding (14496-3 sp04 p203)

  1122. static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)

  1123. {

  1124.     int k, e;

  1125.     int ch;

  1126. 

  1127.     if (id_aac == TYPE_CPE && sbr->bs_coupling) {

  1128.         float alpha      = sbr->data[0].bs_amp_res ?  1.0f :  0.5f;

  1129.         float pan_offset = sbr->data[0].bs_amp_res ? 12.0f : 24.0f;

  1130.         for (e = 1; e <= sbr->data[0].bs_num_env; e++) {

  1131.             for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {

  1132.                 float temp1 = exp2f(sbr->data[0].env_facs[e][k] * alpha + 7.0f);

  1133.                 float temp2 = exp2f((pan_offset - sbr->data[1].env_facs[e][k]) * alpha);

  1134.                 float fac;

  1135.                 if (temp1 > 1E20) {

  1136.                     av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");

  1137.                     temp1 = 1;

  1138.                 }

  1139.                 fac   = temp1 / (1.0f + temp2);

  1140.                 sbr->data[0].env_facs[e][k] = fac;

  1141.                 sbr->data[1].env_facs[e][k] = fac * temp2;

  1142.             }

  1143.         }

  1144.         for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {

  1145.             for (k = 0; k < sbr->n_q; k++) {

  1146.                 float temp1 = exp2f(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs[e][k] + 1);

  1147.                 float temp2 = exp2f(12 - sbr->data[1].noise_facs[e][k]);

  1148.                 float fac;

  1149.                 if (temp1 > 1E20) {

  1150.                     av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");

  1151.                     temp1 = 1;

  1152.                 }

  1153.                 fac = temp1 / (1.0f + temp2);

  1154.                 sbr->data[0].noise_facs[e][k] = fac;

  1155.                 sbr->data[1].noise_facs[e][k] = fac * temp2;

  1156.             }

  1157.         }

  1158.     } else { // SCE or one non-coupled CPE

  1159.         for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {

  1160.             float alpha = sbr->data[ch].bs_amp_res ? 1.0f : 0.5f;

  1161.             for (e = 1; e <= sbr->data[ch].bs_num_env; e++)

  1162.                 for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++){

  1163.                     sbr->data[ch].env_facs[e][k] =

  1164.                         exp2f(alpha * sbr->data[ch].env_facs[e][k] + 6.0f);

  1165.                     if (sbr->data[ch].env_facs[e][k] > 1E20) {

  1166.                         av_log(NULL, AV_LOG_ERROR, "envelope scalefactor overflow in dequant\n");

  1167.                         sbr->data[ch].env_facs[e][k] = 1;

  1168.                     }

  1169.                 }

  1170. 

  1171.             for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)

  1172.                 for (k = 0; k < sbr->n_q; k++)

  1173.                     sbr->data[ch].noise_facs[e][k] =

  1174.                         exp2f(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs[e][k]);

  1175.         }

  1176.     }

  1177. }

  1178. 

  1179. /**

  1180.  * Analysis QMF Bank (14496-3 sp04 p206)

  1181.  *

  1182.  * @param   x       pointer to the beginning of the first sample window

  1183.  * @param   W       array of complex-valued samples split into subbands

  1184.  */

  1185. #ifndef sbr_qmf_analysis

  1186. static void sbr_qmf_analysis(AVFloatDSPContext *dsp, FFTContext *mdct,

  1187.                              SBRDSPContext *sbrdsp, const float *in, float *x,

  1188.                              float z[320], float W[2][32][32][2], int buf_idx)

  1189. {

  1190.     int i;

  1191.     memcpy(x    , x+1024, (320-32)*sizeof(x[0]));

  1192.     memcpy(x+288, in,         1024*sizeof(x[0]));

  1193.     for (i = 0; i < 32; i++) { // numTimeSlots*RATE = 16*2 as 960 sample frames

  1194.                                // are not supported

  1195.         dsp->vector_fmul_reverse(z, sbr_qmf_window_ds, x, 320);

  1196.         sbrdsp->sum64x5(z);

  1197.         sbrdsp->qmf_pre_shuffle(z);

  1198.         mdct->imdct_half(mdct, z, z+64);

  1199.         sbrdsp->qmf_post_shuffle(W[buf_idx][i], z);

  1200.         x += 32;

  1201.     }

  1202. }

  1203. #endif

  1204. 

  1205. /**

  1206.  * Synthesis QMF Bank (14496-3 sp04 p206) and Downsampled Synthesis QMF Bank

  1207.  * (14496-3 sp04 p206)

  1208.  */

  1209. #ifndef sbr_qmf_synthesis

  1210. static void sbr_qmf_synthesis(FFTContext *mdct,

  1211.                               SBRDSPContext *sbrdsp, AVFloatDSPContext *dsp,

  1212.                               float *out, float X[2][38][64],

  1213.                               float mdct_buf[2][64],

  1214.                               float *v0, int *v_off, const unsigned int div)

  1215. {

  1216.     int i, n;

  1217.     const float *sbr_qmf_window = div ? sbr_qmf_window_ds : sbr_qmf_window_us;

  1218.     const int step = 128 >> div;

  1219.     float *v;

  1220.     for (i = 0; i < 32; i++) {

  1221.         if (*v_off < step) {

  1222.             int saved_samples = (1280 - 128) >> div;

  1223.             memcpy(&v0[SBR_SYNTHESIS_BUF_SIZE - saved_samples], v0, saved_samples * sizeof(float));

  1224.             *v_off = SBR_SYNTHESIS_BUF_SIZE - saved_samples - step;

  1225.         } else {

  1226.             *v_off -= step;

  1227.         }

  1228.         v = v0 + *v_off;

  1229.         if (div) {

  1230.             for (n = 0; n < 32; n++) {

  1231.                 X[0][i][   n] = -X[0][i][n];

  1232.                 X[0][i][32+n] =  X[1][i][31-n];

  1233.             }

  1234.             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);

  1235.             sbrdsp->qmf_deint_neg(v, mdct_buf[0]);

  1236.         } else {

  1237.             sbrdsp->neg_odd_64(X[1][i]);

  1238.             mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);

  1239.             mdct->imdct_half(mdct, mdct_buf[1], X[1][i]);

  1240.             sbrdsp->qmf_deint_bfly(v, mdct_buf[1], mdct_buf[0]);

  1241.         }

  1242.         dsp->vector_fmul    (out, v                , sbr_qmf_window                       , 64 >> div);

  1243.         dsp->vector_fmul_add(out, v + ( 192 >> div), sbr_qmf_window + ( 64 >> div), out   , 64 >> div);

  1244.         dsp->vector_fmul_add(out, v + ( 256 >> div), sbr_qmf_window + (128 >> div), out   , 64 >> div);

  1245.         dsp->vector_fmul_add(out, v + ( 448 >> div), sbr_qmf_window + (192 >> div), out   , 64 >> div);

  1246.         dsp->vector_fmul_add(out, v + ( 512 >> div), sbr_qmf_window + (256 >> div), out   , 64 >> div);

  1247.         dsp->vector_fmul_add(out, v + ( 704 >> div), sbr_qmf_window + (320 >> div), out   , 64 >> div);

  1248.         dsp->vector_fmul_add(out, v + ( 768 >> div), sbr_qmf_window + (384 >> div), out   , 64 >> div);

  1249.         dsp->vector_fmul_add(out, v + ( 960 >> div), sbr_qmf_window + (448 >> div), out   , 64 >> div);

  1250.         dsp->vector_fmul_add(out, v + (1024 >> div), sbr_qmf_window + (512 >> div), out   , 64 >> div);

  1251.         dsp->vector_fmul_add(out, v + (1216 >> div), sbr_qmf_window + (576 >> div), out   , 64 >> div);

  1252.         out += 64 >> div;

  1253.     }

  1254. }

  1255. #endif

  1256. 

  1257. /** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering

  1258.  * (14496-3 sp04 p214)

  1259.  * Warning: This routine does not seem numerically stable.

  1260.  */

  1261. static void sbr_hf_inverse_filter(SBRDSPContext *dsp,

  1262.                                   float (*alpha0)[2], float (*alpha1)[2],

  1263.                                   const float X_low[32][40][2], int k0)

  1264. {

  1265.     int k;

  1266.     for (k = 0; k < k0; k++) {

  1267.         LOCAL_ALIGNED_16(float, phi, [3], [2][2]);

  1268.         float dk;

  1269. 

  1270.         dsp->autocorrelate(X_low[k], phi);

  1271. 

  1272.         dk =  phi[2][1][0] * phi[1][0][0] -

  1273.              (phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;

  1274. 

  1275.         if (!dk) {

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

  1277.             alpha1[k][1] = 0;

  1278.         } else {

  1279.             float temp_real, temp_im;

  1280.             temp_real = phi[0][0][0] * phi[1][1][0] -

  1281.                         phi[0][0][1] * phi[1][1][1] -

  1282.                         phi[0][1][0] * phi[1][0][0];

  1283.             temp_im   = phi[0][0][0] * phi[1][1][1] +

  1284.                         phi[0][0][1] * phi[1][1][0] -

  1285.                         phi[0][1][1] * phi[1][0][0];

  1286. 

  1287.             alpha1[k][0] = temp_real / dk;

  1288.             alpha1[k][1] = temp_im   / dk;

  1289.         }

  1290. 

  1291.         if (!phi[1][0][0]) {

  1292.             alpha0[k][0] = 0;

  1293.             alpha0[k][1] = 0;

  1294.         } else {

  1295.             float temp_real, temp_im;

  1296.             temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +

  1297.                                        alpha1[k][1] * phi[1][1][1];

  1298.             temp_im   = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -

  1299.                                        alpha1[k][0] * phi[1][1][1];

  1300. 

  1301.             alpha0[k][0] = -temp_real / phi[1][0][0];

  1302.             alpha0[k][1] = -temp_im   / phi[1][0][0];

  1303.         }

  1304. 

  1305.         if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||

  1306.            alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {

  1307.             alpha1[k][0] = 0;

  1308.             alpha1[k][1] = 0;

  1309.             alpha0[k][0] = 0;

  1310.             alpha0[k][1] = 0;

  1311.         }

  1312.     }

  1313. }

  1314. 

  1315. /// Chirp Factors (14496-3 sp04 p214)

  1316. static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)

  1317. {

  1318.     int i;

  1319.     float new_bw;

  1320.     static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };

  1321. 

  1322.     for (i = 0; i < sbr->n_q; i++) {

  1323.         if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {

  1324.             new_bw = 0.6f;

  1325.         } else

  1326.             new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];

  1327. 

  1328.         if (new_bw < ch_data->bw_array[i]) {

  1329.             new_bw = 0.75f    * new_bw + 0.25f    * ch_data->bw_array[i];

  1330.         } else

  1331.             new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];

  1332.         ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;

  1333.     }

  1334. }

  1335. 

  1336. /// Generate the subband filtered lowband

  1337. static int sbr_lf_gen(AACContext *ac, SpectralBandReplication *sbr,

  1338.                       float X_low[32][40][2], const float W[2][32][32][2],

  1339.                       int buf_idx)

  1340. {

  1341.     int i, k;

  1342.     const int t_HFGen = 8;

  1343.     const int i_f = 32;

  1344.     memset(X_low, 0, 32*sizeof(*X_low));

  1345.     for (k = 0; k < sbr->kx[1]; k++) {

  1346.         for (i = t_HFGen; i < i_f + t_HFGen; i++) {

  1347.             X_low[k][i][0] = W[buf_idx][i - t_HFGen][k][0];

  1348.             X_low[k][i][1] = W[buf_idx][i - t_HFGen][k][1];

  1349.         }

  1350.     }

  1351.     buf_idx = 1-buf_idx;

  1352.     for (k = 0; k < sbr->kx[0]; k++) {

  1353.         for (i = 0; i < t_HFGen; i++) {

  1354.             X_low[k][i][0] = W[buf_idx][i + i_f - t_HFGen][k][0];

  1355.             X_low[k][i][1] = W[buf_idx][i + i_f - t_HFGen][k][1];

  1356.         }

  1357.     }

  1358.     return 0;

  1359. }

  1360. 

  1361. /// High Frequency Generator (14496-3 sp04 p215)

  1362. static int sbr_hf_gen(AACContext *ac, SpectralBandReplication *sbr,

  1363.                       float X_high[64][40][2], const float X_low[32][40][2],

  1364.                       const float (*alpha0)[2], const float (*alpha1)[2],

  1365.                       const float bw_array[5], const uint8_t *t_env,

  1366.                       int bs_num_env)

  1367. {

  1368.     int j, x;

  1369.     int g = 0;

  1370.     int k = sbr->kx[1];

  1371.     for (j = 0; j < sbr->num_patches; j++) {

  1372.         for (x = 0; x < sbr->patch_num_subbands[j]; x++, k++) {

  1373.             const int p = sbr->patch_start_subband[j] + x;

  1374.             while (g <= sbr->n_q && k >= sbr->f_tablenoise[g])

  1375.                 g++;

  1376.             g--;

  1377. 

  1378.             if (g < 0) {

  1379.                 av_log(ac->avctx, AV_LOG_ERROR,

  1380.                        "ERROR : no subband found for frequency %d\n", k);

  1381.                 return -1;

  1382.             }

  1383. 

  1384.             sbr->dsp.hf_gen(X_high[k] + ENVELOPE_ADJUSTMENT_OFFSET,

  1385.                             X_low[p]  + ENVELOPE_ADJUSTMENT_OFFSET,

  1386.                             alpha0[p], alpha1[p], bw_array[g],

  1387.                             2 * t_env[0], 2 * t_env[bs_num_env]);

  1388.         }

  1389.     }

  1390.     if (k < sbr->m[1] + sbr->kx[1])

  1391.         memset(X_high + k, 0, (sbr->m[1] + sbr->kx[1] - k) * sizeof(*X_high));

  1392. 

  1393.     return 0;

  1394. }

  1395. 

  1396. /// Generate the subband filtered lowband

  1397. static int sbr_x_gen(SpectralBandReplication *sbr, float X[2][38][64],

  1398.                      const float Y0[38][64][2], const float Y1[38][64][2],

  1399.                      const float X_low[32][40][2], int ch)

  1400. {

  1401.     int k, i;

  1402.     const int i_f = 32;

  1403.     const int i_Temp = FFMAX(2*sbr->data[ch].t_env_num_env_old - i_f, 0);

  1404.     memset(X, 0, 2*sizeof(*X));

  1405.     for (k = 0; k < sbr->kx[0]; k++) {

  1406.         for (i = 0; i < i_Temp; i++) {

  1407.             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];

  1408.             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];

  1409.         }

  1410.     }

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

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

  1413.             X[0][i][k] = Y0[i + i_f][k][0];

  1414.             X[1][i][k] = Y0[i + i_f][k][1];

  1415.         }

  1416.     }

  1417. 

  1418.     for (k = 0; k < sbr->kx[1]; k++) {

  1419.         for (i = i_Temp; i < 38; i++) {

  1420.             X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];

  1421.             X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];

  1422.         }

  1423.     }

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

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

  1426.             X[0][i][k] = Y1[i][k][0];

  1427.             X[1][i][k] = Y1[i][k][1];

  1428.         }

  1429.     }

  1430.     return 0;

  1431. }

  1432. 

  1433. /** High Frequency Adjustment (14496-3 sp04 p217) and Mapping

  1434.  * (14496-3 sp04 p217)

  1435.  */

  1436. static int sbr_mapping(AACContext *ac, SpectralBandReplication *sbr,

  1437.                         SBRData *ch_data, int e_a[2])

  1438. {

  1439.     int e, i, m;

  1440. 

  1441.     memset(ch_data->s_indexmapped[1], 0, 7*sizeof(ch_data->s_indexmapped[1]));

  1442.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1443.         const unsigned int ilim = sbr->n[ch_data->bs_freq_res[e + 1]];

  1444.         uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

  1445.         int k;

  1446. 

  1447.         if (sbr->kx[1] != table[0]) {

  1448.             av_log(ac->avctx, AV_LOG_ERROR, "kx != f_table{high,low}[0]. "

  1449.                    "Derived frequency tables were not regenerated.\n");

  1450.             sbr_turnoff(sbr);

  1451.             return AVERROR_BUG;

  1452.         }

  1453.         for (i = 0; i < ilim; i++)

  1454.             for (m = table[i]; m < table[i + 1]; m++)

  1455.                 sbr->e_origmapped[e][m - sbr->kx[1]] = ch_data->env_facs[e+1][i];

  1456. 

  1457.         // ch_data->bs_num_noise > 1 => 2 noise floors

  1458.         k = (ch_data->bs_num_noise > 1) && (ch_data->t_env[e] >= ch_data->t_q[1]);

  1459.         for (i = 0; i < sbr->n_q; i++)

  1460.             for (m = sbr->f_tablenoise[i]; m < sbr->f_tablenoise[i + 1]; m++)

  1461.                 sbr->q_mapped[e][m - sbr->kx[1]] = ch_data->noise_facs[k+1][i];

  1462. 

  1463.         for (i = 0; i < sbr->n[1]; i++) {

  1464.             if (ch_data->bs_add_harmonic_flag) {

  1465.                 const unsigned int m_midpoint =

  1466.                     (sbr->f_tablehigh[i] + sbr->f_tablehigh[i + 1]) >> 1;

  1467. 

  1468.                 ch_data->s_indexmapped[e + 1][m_midpoint - sbr->kx[1]] = ch_data->bs_add_harmonic[i] *

  1469.                     (e >= e_a[1] || (ch_data->s_indexmapped[0][m_midpoint - sbr->kx[1]] == 1));

  1470.             }

  1471.         }

  1472. 

  1473.         for (i = 0; i < ilim; i++) {

  1474.             int additional_sinusoid_present = 0;

  1475.             for (m = table[i]; m < table[i + 1]; m++) {

  1476.                 if (ch_data->s_indexmapped[e + 1][m - sbr->kx[1]]) {

  1477.                     additional_sinusoid_present = 1;

  1478.                     break;

  1479.                 }

  1480.             }

  1481.             memset(&sbr->s_mapped[e][table[i] - sbr->kx[1]], additional_sinusoid_present,

  1482.                    (table[i + 1] - table[i]) * sizeof(sbr->s_mapped[e][0]));

  1483.         }

  1484.     }

  1485. 

  1486.     memcpy(ch_data->s_indexmapped[0], ch_data->s_indexmapped[ch_data->bs_num_env], sizeof(ch_data->s_indexmapped[0]));

  1487.     return 0;

  1488. }

  1489. 

  1490. /// Estimation of current envelope (14496-3 sp04 p218)

  1491. static void sbr_env_estimate(float (*e_curr)[48], float X_high[64][40][2],

  1492.                              SpectralBandReplication *sbr, SBRData *ch_data)

  1493. {

  1494.     int e, m;

  1495.     int kx1 = sbr->kx[1];

  1496. 

  1497.     if (sbr->bs_interpol_freq) {

  1498.         for (e = 0; e < ch_data->bs_num_env; e++) {

  1499.             const float recip_env_size = 0.5f / (ch_data->t_env[e + 1] - ch_data->t_env[e]);

  1500.             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1501.             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1502. 

  1503.             for (m = 0; m < sbr->m[1]; m++) {

  1504.                 float sum = sbr->dsp.sum_square(X_high[m+kx1] + ilb, iub - ilb);

  1505.                 e_curr[e][m] = sum * recip_env_size;

  1506.             }

  1507.         }

  1508.     } else {

  1509.         int k, p;

  1510. 

  1511.         for (e = 0; e < ch_data->bs_num_env; e++) {

  1512.             const int env_size = 2 * (ch_data->t_env[e + 1] - ch_data->t_env[e]);

  1513.             int ilb = ch_data->t_env[e]     * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1514.             int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;

  1515.             const uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;

  1516. 

  1517.             for (p = 0; p < sbr->n[ch_data->bs_freq_res[e + 1]]; p++) {

  1518.                 float sum = 0.0f;

  1519.                 const int den = env_size * (table[p + 1] - table[p]);

  1520. 

  1521.                 for (k = table[p]; k < table[p + 1]; k++) {

  1522.                     sum += sbr->dsp.sum_square(X_high[k] + ilb, iub - ilb);

  1523.                 }

  1524.                 sum /= den;

  1525.                 for (k = table[p]; k < table[p + 1]; k++) {

  1526.                     e_curr[e][k - kx1] = sum;

  1527.                 }

  1528.             }

  1529.         }

  1530.     }

  1531. }

  1532. 

  1533. /**

  1534.  * Calculation of levels of additional HF signal components (14496-3 sp04 p219)

  1535.  * and Calculation of gain (14496-3 sp04 p219)

  1536.  */

  1537. static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,

  1538.                           SBRData *ch_data, const int e_a[2])

  1539. {

  1540.     int e, k, m;

  1541.     // max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)

  1542.     static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };

  1543. 

  1544.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1545.         int delta = !((e == e_a[1]) || (e == e_a[0]));

  1546.         for (k = 0; k < sbr->n_lim; k++) {

  1547.             float gain_boost, gain_max;

  1548.             float sum[2] = { 0.0f, 0.0f };

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

  1550.                 const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);

  1551.                 sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);

  1552.                 sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);

  1553.                 if (!sbr->s_mapped[e][m]) {

  1554.                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /

  1555.                                             ((1.0f + sbr->e_curr[e][m]) *

  1556.                                              (1.0f + sbr->q_mapped[e][m] * delta)));

  1557.                 } else {

  1558.                     sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /

  1559.                                             ((1.0f + sbr->e_curr[e][m]) *

  1560.                                              (1.0f + sbr->q_mapped[e][m])));

  1561.                 }

  1562.             }

  1563.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1564.                 sum[0] += sbr->e_origmapped[e][m];

  1565.                 sum[1] += sbr->e_curr[e][m];

  1566.             }

  1567.             gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));

  1568.             gain_max = FFMIN(100000.f, gain_max);

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

  1570.                 float q_m_max   = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];

  1571.                 sbr->q_m[e][m]  = FFMIN(sbr->q_m[e][m], q_m_max);

  1572.                 sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);

  1573.             }

  1574.             sum[0] = sum[1] = 0.0f;

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

  1576.                 sum[0] += sbr->e_origmapped[e][m];

  1577.                 sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]

  1578.                           + sbr->s_m[e][m] * sbr->s_m[e][m]

  1579.                           + (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];

  1580.             }

  1581.             gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));

  1582.             gain_boost = FFMIN(1.584893192f, gain_boost);

  1583.             for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {

  1584.                 sbr->gain[e][m] *= gain_boost;

  1585.                 sbr->q_m[e][m]  *= gain_boost;

  1586.                 sbr->s_m[e][m]  *= gain_boost;

  1587.             }

  1588.         }

  1589.     }

  1590. }

  1591. 

  1592. /// Assembling HF Signals (14496-3 sp04 p220)

  1593. static void sbr_hf_assemble(float Y1[38][64][2],

  1594.                             const float X_high[64][40][2],

  1595.                             SpectralBandReplication *sbr, SBRData *ch_data,

  1596.                             const int e_a[2])

  1597. {

  1598.     int e, i, j, m;

  1599.     const int h_SL = 4 * !sbr->bs_smoothing_mode;

  1600.     const int kx = sbr->kx[1];

  1601.     const int m_max = sbr->m[1];

  1602.     static const float h_smooth[5] = {

  1603.         0.33333333333333,

  1604.         0.30150283239582,

  1605.         0.21816949906249,

  1606.         0.11516383427084,

  1607.         0.03183050093751,

  1608.     };

  1609.     float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;

  1610.     int indexnoise = ch_data->f_indexnoise;

  1611.     int indexsine  = ch_data->f_indexsine;

  1612. 

  1613.     if (sbr->reset) {

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

  1615.             memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));

  1616.             memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0],  m_max * sizeof(sbr->q_m[0][0]));

  1617.         }

  1618.     } else if (h_SL) {

  1619.         memcpy(g_temp[2*ch_data->t_env[0]], g_temp[2*ch_data->t_env_num_env_old], 4*sizeof(g_temp[0]));

  1620.         memcpy(q_temp[2*ch_data->t_env[0]], q_temp[2*ch_data->t_env_num_env_old], 4*sizeof(q_temp[0]));

  1621.     }

  1622. 

  1623.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1624.         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {

  1625.             memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));

  1626.             memcpy(q_temp[h_SL + i], sbr->q_m[e],  m_max * sizeof(sbr->q_m[0][0]));

  1627.         }

  1628.     }

  1629. 

  1630.     for (e = 0; e < ch_data->bs_num_env; e++) {

  1631.         for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {

  1632.             LOCAL_ALIGNED_16(float, g_filt_tab, [48]);

  1633.             LOCAL_ALIGNED_16(float, q_filt_tab, [48]);

  1634.             float *g_filt, *q_filt;

  1635. 

  1636.             if (h_SL && e != e_a[0] && e != e_a[1]) {

  1637.                 g_filt = g_filt_tab;

  1638.                 q_filt = q_filt_tab;

  1639.                 for (m = 0; m < m_max; m++) {

  1640.                     const int idx1 = i + h_SL;

  1641.                     g_filt[m] = 0.0f;

  1642.                     q_filt[m] = 0.0f;

  1643.                     for (j = 0; j <= h_SL; j++) {

  1644.                         g_filt[m] += g_temp[idx1 - j][m] * h_smooth[j];

  1645.                         q_filt[m] += q_temp[idx1 - j][m] * h_smooth[j];

  1646.                     }

  1647.                 }

  1648.             } else {

  1649.                 g_filt = g_temp[i + h_SL];

  1650.                 q_filt = q_temp[i];

  1651.             }

  1652. 

  1653.             sbr->dsp.hf_g_filt(Y1[i] + kx, X_high + kx, g_filt, m_max,

  1654.                                i + ENVELOPE_ADJUSTMENT_OFFSET);

  1655. 

  1656.             if (e != e_a[0] && e != e_a[1]) {

  1657.                 sbr->dsp.hf_apply_noise[indexsine](Y1[i] + kx, sbr->s_m[e],

  1658.                                                    q_filt, indexnoise,

  1659.                                                    kx, m_max);

  1660.             } else {

  1661.                 int idx = indexsine&1;

  1662.                 int A = (1-((indexsine+(kx & 1))&2));

  1663.                 int B = (A^(-idx)) + idx;

  1664.                 float *out = &Y1[i][kx][idx];

  1665.                 float *in  = sbr->s_m[e];

  1666.                 for (m = 0; m+1 < m_max; m+=2) {

  1667.                     out[2*m  ] += in[m  ] * A;

  1668.                     out[2*m+2] += in[m+1] * B;

  1669.                 }

  1670.                 if(m_max&1)

  1671.                     out[2*m  ] += in[m  ] * A;

  1672.             }

  1673.             indexnoise = (indexnoise + m_max) & 0x1ff;

  1674.             indexsine = (indexsine + 1) & 3;

  1675.         }

  1676.     }

  1677.     ch_data->f_indexnoise = indexnoise;

  1678.     ch_data->f_indexsine  = indexsine;

  1679. }

  1680. 

  1681. void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,

  1682.                   float* L, float* R)

  1683. {

  1684.     int downsampled = ac->oc[1].m4ac.ext_sample_rate < sbr->sample_rate;

  1685.     int ch;

  1686.     int nch = (id_aac == TYPE_CPE) ? 2 : 1;

  1687.     int err;

  1688. 

  1689.     if (!sbr->kx_and_m_pushed) {

  1690.         sbr->kx[0] = sbr->kx[1];

  1691.         sbr->m[0] = sbr->m[1];

  1692.     } else {

  1693.         sbr->kx_and_m_pushed = 0;

  1694.     }

  1695. 

  1696.     if (sbr->start) {

  1697.         sbr_dequant(sbr, id_aac);

  1698.     }

  1699.     for (ch = 0; ch < nch; ch++) {

  1700.         /* decode channel */

  1701.         sbr_qmf_analysis(&ac->fdsp, &sbr->mdct_ana, &sbr->dsp, ch ? R : L, sbr->data[ch].analysis_filterbank_samples,

  1702.                          (float*)sbr->qmf_filter_scratch,

  1703.                          sbr->data[ch].W, sbr->data[ch].Ypos);

  1704.         sbr->c.sbr_lf_gen(ac, sbr, sbr->X_low, sbr->data[ch].W, sbr->data[ch].Ypos);

  1705.         sbr->data[ch].Ypos ^= 1;

  1706.         if (sbr->start) {

  1707.             sbr->c.sbr_hf_inverse_filter(&sbr->dsp, sbr->alpha0, sbr->alpha1, sbr->X_low, sbr->k[0]);

  1708.             sbr_chirp(sbr, &sbr->data[ch]);

  1709.             sbr_hf_gen(ac, sbr, sbr->X_high, sbr->X_low, sbr->alpha0, sbr->alpha1,

  1710.                        sbr->data[ch].bw_array, sbr->data[ch].t_env,

  1711.                        sbr->data[ch].bs_num_env);

  1712. 

  1713.             // hf_adj

  1714.             err = sbr_mapping(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);

  1715.             if (!err) {

  1716.                 sbr_env_estimate(sbr->e_curr, sbr->X_high, sbr, &sbr->data[ch]);

  1717.                 sbr_gain_calc(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);

  1718.                 sbr->c.sbr_hf_assemble(sbr->data[ch].Y[sbr->data[ch].Ypos],

  1719.                                 sbr->X_high, sbr, &sbr->data[ch],

  1720.                                 sbr->data[ch].e_a);

  1721.             }

  1722.         }

  1723. 

  1724.         /* synthesis */

  1725.         sbr->c.sbr_x_gen(sbr, sbr->X[ch],

  1726.                   sbr->data[ch].Y[1-sbr->data[ch].Ypos],

  1727.                   sbr->data[ch].Y[  sbr->data[ch].Ypos],

  1728.                   sbr->X_low, ch);

  1729.     }

  1730. 

  1731.     if (ac->oc[1].m4ac.ps == 1) {

  1732.         if (sbr->ps.start) {

  1733.             ff_ps_apply(ac->avctx, &sbr->ps, sbr->X[0], sbr->X[1], sbr->kx[1] + sbr->m[1]);

  1734.         } else {

  1735.             memcpy(sbr->X[1], sbr->X[0], sizeof(sbr->X[0]));

  1736.         }

  1737.         nch = 2;

  1738.     }

  1739. 

  1740.     sbr_qmf_synthesis(&sbr->mdct, &sbr->dsp, &ac->fdsp,

  1741.                       L, sbr->X[0], sbr->qmf_filter_scratch,

  1742.                       sbr->data[0].synthesis_filterbank_samples,

  1743.                       &sbr->data[0].synthesis_filterbank_samples_offset,

  1744.                       downsampled);

  1745.     if (nch == 2)

  1746.         sbr_qmf_synthesis(&sbr->mdct, &sbr->dsp, &ac->fdsp,

  1747.                           R, sbr->X[1], sbr->qmf_filter_scratch,

  1748.                           sbr->data[1].synthesis_filterbank_samples,

  1749.                           &sbr->data[1].synthesis_filterbank_samples_offset,

  1750.                           downsampled);

  1751. }

  1752. 

  1753. static void aacsbr_func_ptr_init(AACSBRContext *c)

  1754. {

  1755.     c->sbr_lf_gen            = sbr_lf_gen;

  1756.     c->sbr_hf_assemble       = sbr_hf_assemble;

  1757.     c->sbr_x_gen             = sbr_x_gen;

  1758.     c->sbr_hf_inverse_filter = sbr_hf_inverse_filter;

  1759. 

  1760.     if(ARCH_MIPS)

  1761.         ff_aacsbr_func_ptr_init_mips(c);

  1762. }