ffmpeg/libavcodec/aacsbr.c
Alex Converse 0cb93dacee aac: Reset some state variables when turning SBR off
This makes sure the reset flag gets set when SBR gets turned back on
and sets control variables for unguided mode back to their defaults.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
2012-03-23 14:56:44 -07:00

1707 lines
63 KiB
C

/*
* AAC Spectral Band Replication decoding functions
* Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
* Copyright (c) 2009-2010 Alex Converse <alex.converse@gmail.com>
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* AAC Spectral Band Replication decoding functions
* @author Robert Swain ( rob opendot cl )
*/
#include "aac.h"
#include "sbr.h"
#include "aacsbr.h"
#include "aacsbrdata.h"
#include "fft.h"
#include "aacps.h"
#include "sbrdsp.h"
#include "libavutil/libm.h"
#include <stdint.h>
#include <float.h>
#define ENVELOPE_ADJUSTMENT_OFFSET 2
#define NOISE_FLOOR_OFFSET 6.0f
/**
* SBR VLC tables
*/
enum {
T_HUFFMAN_ENV_1_5DB,
F_HUFFMAN_ENV_1_5DB,
T_HUFFMAN_ENV_BAL_1_5DB,
F_HUFFMAN_ENV_BAL_1_5DB,
T_HUFFMAN_ENV_3_0DB,
F_HUFFMAN_ENV_3_0DB,
T_HUFFMAN_ENV_BAL_3_0DB,
F_HUFFMAN_ENV_BAL_3_0DB,
T_HUFFMAN_NOISE_3_0DB,
T_HUFFMAN_NOISE_BAL_3_0DB,
};
/**
* bs_frame_class - frame class of current SBR frame (14496-3 sp04 p98)
*/
enum {
FIXFIX,
FIXVAR,
VARFIX,
VARVAR,
};
enum {
EXTENSION_ID_PS = 2,
};
static VLC vlc_sbr[10];
static const int8_t vlc_sbr_lav[10] =
{ 60, 60, 24, 24, 31, 31, 12, 12, 31, 12 };
static const DECLARE_ALIGNED(16, float, zero64)[64];
#define SBR_INIT_VLC_STATIC(num, size) \
INIT_VLC_STATIC(&vlc_sbr[num], 9, sbr_tmp[num].table_size / sbr_tmp[num].elem_size, \
sbr_tmp[num].sbr_bits , 1, 1, \
sbr_tmp[num].sbr_codes, sbr_tmp[num].elem_size, sbr_tmp[num].elem_size, \
size)
#define SBR_VLC_ROW(name) \
{ name ## _codes, name ## _bits, sizeof(name ## _codes), sizeof(name ## _codes[0]) }
av_cold void ff_aac_sbr_init(void)
{
int n;
static const struct {
const void *sbr_codes, *sbr_bits;
const unsigned int table_size, elem_size;
} sbr_tmp[] = {
SBR_VLC_ROW(t_huffman_env_1_5dB),
SBR_VLC_ROW(f_huffman_env_1_5dB),
SBR_VLC_ROW(t_huffman_env_bal_1_5dB),
SBR_VLC_ROW(f_huffman_env_bal_1_5dB),
SBR_VLC_ROW(t_huffman_env_3_0dB),
SBR_VLC_ROW(f_huffman_env_3_0dB),
SBR_VLC_ROW(t_huffman_env_bal_3_0dB),
SBR_VLC_ROW(f_huffman_env_bal_3_0dB),
SBR_VLC_ROW(t_huffman_noise_3_0dB),
SBR_VLC_ROW(t_huffman_noise_bal_3_0dB),
};
// SBR VLC table initialization
SBR_INIT_VLC_STATIC(0, 1098);
SBR_INIT_VLC_STATIC(1, 1092);
SBR_INIT_VLC_STATIC(2, 768);
SBR_INIT_VLC_STATIC(3, 1026);
SBR_INIT_VLC_STATIC(4, 1058);
SBR_INIT_VLC_STATIC(5, 1052);
SBR_INIT_VLC_STATIC(6, 544);
SBR_INIT_VLC_STATIC(7, 544);
SBR_INIT_VLC_STATIC(8, 592);
SBR_INIT_VLC_STATIC(9, 512);
for (n = 1; n < 320; n++)
sbr_qmf_window_us[320 + n] = sbr_qmf_window_us[320 - n];
sbr_qmf_window_us[384] = -sbr_qmf_window_us[384];
sbr_qmf_window_us[512] = -sbr_qmf_window_us[512];
for (n = 0; n < 320; n++)
sbr_qmf_window_ds[n] = sbr_qmf_window_us[2*n];
ff_ps_init();
}
/** Places SBR in pure upsampling mode. */
static void sbr_turnoff(SpectralBandReplication *sbr) {
sbr->start = 0;
// Init defults used in pure upsampling mode
sbr->kx[1] = 32; //Typo in spec, kx' inits to 32
sbr->m[1] = 0;
// Reset values for first SBR header
sbr->data[0].e_a[1] = sbr->data[1].e_a[1] = -1;
memset(&sbr->spectrum_params, -1, sizeof(SpectrumParameters));
}
av_cold void ff_aac_sbr_ctx_init(AACContext *ac, SpectralBandReplication *sbr)
{
float mdct_scale;
sbr->kx[0] = sbr->kx[1];
sbr_turnoff(sbr);
sbr->data[0].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128);
sbr->data[1].synthesis_filterbank_samples_offset = SBR_SYNTHESIS_BUF_SIZE - (1280 - 128);
/* SBR requires samples to be scaled to +/-32768.0 to work correctly.
* mdct scale factors are adjusted to scale up from +/-1.0 at analysis
* and scale back down at synthesis. */
mdct_scale = ac->avctx->sample_fmt == AV_SAMPLE_FMT_FLT ? 32768.0f : 1.0f;
ff_mdct_init(&sbr->mdct, 7, 1, 1.0 / (64 * mdct_scale));
ff_mdct_init(&sbr->mdct_ana, 7, 1, -2.0 * mdct_scale);
ff_ps_ctx_init(&sbr->ps);
ff_sbrdsp_init(&sbr->dsp);
}
av_cold void ff_aac_sbr_ctx_close(SpectralBandReplication *sbr)
{
ff_mdct_end(&sbr->mdct);
ff_mdct_end(&sbr->mdct_ana);
}
static int qsort_comparison_function_int16(const void *a, const void *b)
{
return *(const int16_t *)a - *(const int16_t *)b;
}
static inline int in_table_int16(const int16_t *table, int last_el, int16_t needle)
{
int i;
for (i = 0; i <= last_el; i++)
if (table[i] == needle)
return 1;
return 0;
}
/// Limiter Frequency Band Table (14496-3 sp04 p198)
static void sbr_make_f_tablelim(SpectralBandReplication *sbr)
{
int k;
if (sbr->bs_limiter_bands > 0) {
static const float bands_warped[3] = { 1.32715174233856803909f, //2^(0.49/1.2)
1.18509277094158210129f, //2^(0.49/2)
1.11987160404675912501f }; //2^(0.49/3)
const float lim_bands_per_octave_warped = bands_warped[sbr->bs_limiter_bands - 1];
int16_t patch_borders[7];
uint16_t *in = sbr->f_tablelim + 1, *out = sbr->f_tablelim;
patch_borders[0] = sbr->kx[1];
for (k = 1; k <= sbr->num_patches; k++)
patch_borders[k] = patch_borders[k-1] + sbr->patch_num_subbands[k-1];
memcpy(sbr->f_tablelim, sbr->f_tablelow,
(sbr->n[0] + 1) * sizeof(sbr->f_tablelow[0]));
if (sbr->num_patches > 1)
memcpy(sbr->f_tablelim + sbr->n[0] + 1, patch_borders + 1,
(sbr->num_patches - 1) * sizeof(patch_borders[0]));
qsort(sbr->f_tablelim, sbr->num_patches + sbr->n[0],
sizeof(sbr->f_tablelim[0]),
qsort_comparison_function_int16);
sbr->n_lim = sbr->n[0] + sbr->num_patches - 1;
while (out < sbr->f_tablelim + sbr->n_lim) {
if (*in >= *out * lim_bands_per_octave_warped) {
*++out = *in++;
} else if (*in == *out ||
!in_table_int16(patch_borders, sbr->num_patches, *in)) {
in++;
sbr->n_lim--;
} else if (!in_table_int16(patch_borders, sbr->num_patches, *out)) {
*out = *in++;
sbr->n_lim--;
} else {
*++out = *in++;
}
}
} else {
sbr->f_tablelim[0] = sbr->f_tablelow[0];
sbr->f_tablelim[1] = sbr->f_tablelow[sbr->n[0]];
sbr->n_lim = 1;
}
}
static unsigned int read_sbr_header(SpectralBandReplication *sbr, GetBitContext *gb)
{
unsigned int cnt = get_bits_count(gb);
uint8_t bs_header_extra_1;
uint8_t bs_header_extra_2;
int old_bs_limiter_bands = sbr->bs_limiter_bands;
SpectrumParameters old_spectrum_params;
sbr->start = 1;
// Save last spectrum parameters variables to compare to new ones
memcpy(&old_spectrum_params, &sbr->spectrum_params, sizeof(SpectrumParameters));
sbr->bs_amp_res_header = get_bits1(gb);
sbr->spectrum_params.bs_start_freq = get_bits(gb, 4);
sbr->spectrum_params.bs_stop_freq = get_bits(gb, 4);
sbr->spectrum_params.bs_xover_band = get_bits(gb, 3);
skip_bits(gb, 2); // bs_reserved
bs_header_extra_1 = get_bits1(gb);
bs_header_extra_2 = get_bits1(gb);
if (bs_header_extra_1) {
sbr->spectrum_params.bs_freq_scale = get_bits(gb, 2);
sbr->spectrum_params.bs_alter_scale = get_bits1(gb);
sbr->spectrum_params.bs_noise_bands = get_bits(gb, 2);
} else {
sbr->spectrum_params.bs_freq_scale = 2;
sbr->spectrum_params.bs_alter_scale = 1;
sbr->spectrum_params.bs_noise_bands = 2;
}
// Check if spectrum parameters changed
if (memcmp(&old_spectrum_params, &sbr->spectrum_params, sizeof(SpectrumParameters)))
sbr->reset = 1;
if (bs_header_extra_2) {
sbr->bs_limiter_bands = get_bits(gb, 2);
sbr->bs_limiter_gains = get_bits(gb, 2);
sbr->bs_interpol_freq = get_bits1(gb);
sbr->bs_smoothing_mode = get_bits1(gb);
} else {
sbr->bs_limiter_bands = 2;
sbr->bs_limiter_gains = 2;
sbr->bs_interpol_freq = 1;
sbr->bs_smoothing_mode = 1;
}
if (sbr->bs_limiter_bands != old_bs_limiter_bands && !sbr->reset)
sbr_make_f_tablelim(sbr);
return get_bits_count(gb) - cnt;
}
static int array_min_int16(const int16_t *array, int nel)
{
int i, min = array[0];
for (i = 1; i < nel; i++)
min = FFMIN(array[i], min);
return min;
}
static void make_bands(int16_t* bands, int start, int stop, int num_bands)
{
int k, previous, present;
float base, prod;
base = powf((float)stop / start, 1.0f / num_bands);
prod = start;
previous = start;
for (k = 0; k < num_bands-1; k++) {
prod *= base;
present = lrintf(prod);
bands[k] = present - previous;
previous = present;
}
bands[num_bands-1] = stop - previous;
}
static int check_n_master(AVCodecContext *avctx, int n_master, int bs_xover_band)
{
// Requirements (14496-3 sp04 p205)
if (n_master <= 0) {
av_log(avctx, AV_LOG_ERROR, "Invalid n_master: %d\n", n_master);
return -1;
}
if (bs_xover_band >= n_master) {
av_log(avctx, AV_LOG_ERROR,
"Invalid bitstream, crossover band index beyond array bounds: %d\n",
bs_xover_band);
return -1;
}
return 0;
}
/// Master Frequency Band Table (14496-3 sp04 p194)
static int sbr_make_f_master(AACContext *ac, SpectralBandReplication *sbr,
SpectrumParameters *spectrum)
{
unsigned int temp, max_qmf_subbands;
unsigned int start_min, stop_min;
int k;
const int8_t *sbr_offset_ptr;
int16_t stop_dk[13];
if (sbr->sample_rate < 32000) {
temp = 3000;
} else if (sbr->sample_rate < 64000) {
temp = 4000;
} else
temp = 5000;
start_min = ((temp << 7) + (sbr->sample_rate >> 1)) / sbr->sample_rate;
stop_min = ((temp << 8) + (sbr->sample_rate >> 1)) / sbr->sample_rate;
switch (sbr->sample_rate) {
case 16000:
sbr_offset_ptr = sbr_offset[0];
break;
case 22050:
sbr_offset_ptr = sbr_offset[1];
break;
case 24000:
sbr_offset_ptr = sbr_offset[2];
break;
case 32000:
sbr_offset_ptr = sbr_offset[3];
break;
case 44100: case 48000: case 64000:
sbr_offset_ptr = sbr_offset[4];
break;
case 88200: case 96000: case 128000: case 176400: case 192000:
sbr_offset_ptr = sbr_offset[5];
break;
default:
av_log(ac->avctx, AV_LOG_ERROR,
"Unsupported sample rate for SBR: %d\n", sbr->sample_rate);
return -1;
}
sbr->k[0] = start_min + sbr_offset_ptr[spectrum->bs_start_freq];
if (spectrum->bs_stop_freq < 14) {
sbr->k[2] = stop_min;
make_bands(stop_dk, stop_min, 64, 13);
qsort(stop_dk, 13, sizeof(stop_dk[0]), qsort_comparison_function_int16);
for (k = 0; k < spectrum->bs_stop_freq; k++)
sbr->k[2] += stop_dk[k];
} else if (spectrum->bs_stop_freq == 14) {
sbr->k[2] = 2*sbr->k[0];
} else if (spectrum->bs_stop_freq == 15) {
sbr->k[2] = 3*sbr->k[0];
} else {
av_log(ac->avctx, AV_LOG_ERROR,
"Invalid bs_stop_freq: %d\n", spectrum->bs_stop_freq);
return -1;
}
sbr->k[2] = FFMIN(64, sbr->k[2]);
// Requirements (14496-3 sp04 p205)
if (sbr->sample_rate <= 32000) {
max_qmf_subbands = 48;
} else if (sbr->sample_rate == 44100) {
max_qmf_subbands = 35;
} else if (sbr->sample_rate >= 48000)
max_qmf_subbands = 32;
if (sbr->k[2] - sbr->k[0] > max_qmf_subbands) {
av_log(ac->avctx, AV_LOG_ERROR,
"Invalid bitstream, too many QMF subbands: %d\n", sbr->k[2] - sbr->k[0]);
return -1;
}
if (!spectrum->bs_freq_scale) {
int dk, k2diff;
dk = spectrum->bs_alter_scale + 1;
sbr->n_master = ((sbr->k[2] - sbr->k[0] + (dk&2)) >> dk) << 1;
if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))
return -1;
for (k = 1; k <= sbr->n_master; k++)
sbr->f_master[k] = dk;
k2diff = sbr->k[2] - sbr->k[0] - sbr->n_master * dk;
if (k2diff < 0) {
sbr->f_master[1]--;
sbr->f_master[2]-= (k2diff < -1);
} else if (k2diff) {
sbr->f_master[sbr->n_master]++;
}
sbr->f_master[0] = sbr->k[0];
for (k = 1; k <= sbr->n_master; k++)
sbr->f_master[k] += sbr->f_master[k - 1];
} else {
int half_bands = 7 - spectrum->bs_freq_scale; // bs_freq_scale = {1,2,3}
int two_regions, num_bands_0;
int vdk0_max, vdk1_min;
int16_t vk0[49];
if (49 * sbr->k[2] > 110 * sbr->k[0]) {
two_regions = 1;
sbr->k[1] = 2 * sbr->k[0];
} else {
two_regions = 0;
sbr->k[1] = sbr->k[2];
}
num_bands_0 = lrintf(half_bands * log2f(sbr->k[1] / (float)sbr->k[0])) * 2;
if (num_bands_0 <= 0) { // Requirements (14496-3 sp04 p205)
av_log(ac->avctx, AV_LOG_ERROR, "Invalid num_bands_0: %d\n", num_bands_0);
return -1;
}
vk0[0] = 0;
make_bands(vk0+1, sbr->k[0], sbr->k[1], num_bands_0);
qsort(vk0 + 1, num_bands_0, sizeof(vk0[1]), qsort_comparison_function_int16);
vdk0_max = vk0[num_bands_0];
vk0[0] = sbr->k[0];
for (k = 1; k <= num_bands_0; k++) {
if (vk0[k] <= 0) { // Requirements (14496-3 sp04 p205)
av_log(ac->avctx, AV_LOG_ERROR, "Invalid vDk0[%d]: %d\n", k, vk0[k]);
return -1;
}
vk0[k] += vk0[k-1];
}
if (two_regions) {
int16_t vk1[49];
float invwarp = spectrum->bs_alter_scale ? 0.76923076923076923077f
: 1.0f; // bs_alter_scale = {0,1}
int num_bands_1 = lrintf(half_bands * invwarp *
log2f(sbr->k[2] / (float)sbr->k[1])) * 2;
make_bands(vk1+1, sbr->k[1], sbr->k[2], num_bands_1);
vdk1_min = array_min_int16(vk1 + 1, num_bands_1);
if (vdk1_min < vdk0_max) {
int change;
qsort(vk1 + 1, num_bands_1, sizeof(vk1[1]), qsort_comparison_function_int16);
change = FFMIN(vdk0_max - vk1[1], (vk1[num_bands_1] - vk1[1]) >> 1);
vk1[1] += change;
vk1[num_bands_1] -= change;
}
qsort(vk1 + 1, num_bands_1, sizeof(vk1[1]), qsort_comparison_function_int16);
vk1[0] = sbr->k[1];
for (k = 1; k <= num_bands_1; k++) {
if (vk1[k] <= 0) { // Requirements (14496-3 sp04 p205)
av_log(ac->avctx, AV_LOG_ERROR, "Invalid vDk1[%d]: %d\n", k, vk1[k]);
return -1;
}
vk1[k] += vk1[k-1];
}
sbr->n_master = num_bands_0 + num_bands_1;
if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))
return -1;
memcpy(&sbr->f_master[0], vk0,
(num_bands_0 + 1) * sizeof(sbr->f_master[0]));
memcpy(&sbr->f_master[num_bands_0 + 1], vk1 + 1,
num_bands_1 * sizeof(sbr->f_master[0]));
} else {
sbr->n_master = num_bands_0;
if (check_n_master(ac->avctx, sbr->n_master, sbr->spectrum_params.bs_xover_band))
return -1;
memcpy(sbr->f_master, vk0, (num_bands_0 + 1) * sizeof(sbr->f_master[0]));
}
}
return 0;
}
/// High Frequency Generation - Patch Construction (14496-3 sp04 p216 fig. 4.46)
static int sbr_hf_calc_npatches(AACContext *ac, SpectralBandReplication *sbr)
{
int i, k, sb = 0;
int msb = sbr->k[0];
int usb = sbr->kx[1];
int goal_sb = ((1000 << 11) + (sbr->sample_rate >> 1)) / sbr->sample_rate;
sbr->num_patches = 0;
if (goal_sb < sbr->kx[1] + sbr->m[1]) {
for (k = 0; sbr->f_master[k] < goal_sb; k++) ;
} else
k = sbr->n_master;
do {
int odd = 0;
for (i = k; i == k || sb > (sbr->k[0] - 1 + msb - odd); i--) {
sb = sbr->f_master[i];
odd = (sb + sbr->k[0]) & 1;
}
// Requirements (14496-3 sp04 p205) sets the maximum number of patches to 5.
// After this check the final number of patches can still be six which is
// illegal however the Coding Technologies decoder check stream has a final
// count of 6 patches
if (sbr->num_patches > 5) {
av_log(ac->avctx, AV_LOG_ERROR, "Too many patches: %d\n", sbr->num_patches);
return -1;
}
sbr->patch_num_subbands[sbr->num_patches] = FFMAX(sb - usb, 0);
sbr->patch_start_subband[sbr->num_patches] = sbr->k[0] - odd - sbr->patch_num_subbands[sbr->num_patches];
if (sbr->patch_num_subbands[sbr->num_patches] > 0) {
usb = sb;
msb = sb;
sbr->num_patches++;
} else
msb = sbr->kx[1];
if (sbr->f_master[k] - sb < 3)
k = sbr->n_master;
} while (sb != sbr->kx[1] + sbr->m[1]);
if (sbr->patch_num_subbands[sbr->num_patches-1] < 3 && sbr->num_patches > 1)
sbr->num_patches--;
return 0;
}
/// Derived Frequency Band Tables (14496-3 sp04 p197)
static int sbr_make_f_derived(AACContext *ac, SpectralBandReplication *sbr)
{
int k, temp;
sbr->n[1] = sbr->n_master - sbr->spectrum_params.bs_xover_band;
sbr->n[0] = (sbr->n[1] + 1) >> 1;
memcpy(sbr->f_tablehigh, &sbr->f_master[sbr->spectrum_params.bs_xover_band],
(sbr->n[1] + 1) * sizeof(sbr->f_master[0]));
sbr->m[1] = sbr->f_tablehigh[sbr->n[1]] - sbr->f_tablehigh[0];
sbr->kx[1] = sbr->f_tablehigh[0];
// Requirements (14496-3 sp04 p205)
if (sbr->kx[1] + sbr->m[1] > 64) {
av_log(ac->avctx, AV_LOG_ERROR,
"Stop frequency border too high: %d\n", sbr->kx[1] + sbr->m[1]);
return -1;
}
if (sbr->kx[1] > 32) {
av_log(ac->avctx, AV_LOG_ERROR, "Start frequency border too high: %d\n", sbr->kx[1]);
return -1;
}
sbr->f_tablelow[0] = sbr->f_tablehigh[0];
temp = sbr->n[1] & 1;
for (k = 1; k <= sbr->n[0]; k++)
sbr->f_tablelow[k] = sbr->f_tablehigh[2 * k - temp];
sbr->n_q = FFMAX(1, lrintf(sbr->spectrum_params.bs_noise_bands *
log2f(sbr->k[2] / (float)sbr->kx[1]))); // 0 <= bs_noise_bands <= 3
if (sbr->n_q > 5) {
av_log(ac->avctx, AV_LOG_ERROR, "Too many noise floor scale factors: %d\n", sbr->n_q);
return -1;
}
sbr->f_tablenoise[0] = sbr->f_tablelow[0];
temp = 0;
for (k = 1; k <= sbr->n_q; k++) {
temp += (sbr->n[0] - temp) / (sbr->n_q + 1 - k);
sbr->f_tablenoise[k] = sbr->f_tablelow[temp];
}
if (sbr_hf_calc_npatches(ac, sbr) < 0)
return -1;
sbr_make_f_tablelim(sbr);
sbr->data[0].f_indexnoise = 0;
sbr->data[1].f_indexnoise = 0;
return 0;
}
static av_always_inline void get_bits1_vector(GetBitContext *gb, uint8_t *vec,
int elements)
{
int i;
for (i = 0; i < elements; i++) {
vec[i] = get_bits1(gb);
}
}
/** ceil(log2(index+1)) */
static const int8_t ceil_log2[] = {
0, 1, 2, 2, 3, 3,
};
static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr,
GetBitContext *gb, SBRData *ch_data)
{
int i;
unsigned bs_pointer = 0;
// frameLengthFlag ? 15 : 16; 960 sample length frames unsupported; this value is numTimeSlots
int abs_bord_trail = 16;
int num_rel_lead, num_rel_trail;
unsigned bs_num_env_old = ch_data->bs_num_env;
ch_data->bs_freq_res[0] = ch_data->bs_freq_res[ch_data->bs_num_env];
ch_data->bs_amp_res = sbr->bs_amp_res_header;
ch_data->t_env_num_env_old = ch_data->t_env[bs_num_env_old];
switch (ch_data->bs_frame_class = get_bits(gb, 2)) {
case FIXFIX:
ch_data->bs_num_env = 1 << get_bits(gb, 2);
num_rel_lead = ch_data->bs_num_env - 1;
if (ch_data->bs_num_env == 1)
ch_data->bs_amp_res = 0;
if (ch_data->bs_num_env > 4) {
av_log(ac->avctx, AV_LOG_ERROR,
"Invalid bitstream, too many SBR envelopes in FIXFIX type SBR frame: %d\n",
ch_data->bs_num_env);
return -1;
}
ch_data->t_env[0] = 0;
ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
abs_bord_trail = (abs_bord_trail + (ch_data->bs_num_env >> 1)) /
ch_data->bs_num_env;
for (i = 0; i < num_rel_lead; i++)
ch_data->t_env[i + 1] = ch_data->t_env[i] + abs_bord_trail;
ch_data->bs_freq_res[1] = get_bits1(gb);
for (i = 1; i < ch_data->bs_num_env; i++)
ch_data->bs_freq_res[i + 1] = ch_data->bs_freq_res[1];
break;
case FIXVAR:
abs_bord_trail += get_bits(gb, 2);
num_rel_trail = get_bits(gb, 2);
ch_data->bs_num_env = num_rel_trail + 1;
ch_data->t_env[0] = 0;
ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
for (i = 0; i < num_rel_trail; i++)
ch_data->t_env[ch_data->bs_num_env - 1 - i] =
ch_data->t_env[ch_data->bs_num_env - i] - 2 * get_bits(gb, 2) - 2;
bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);
for (i = 0; i < ch_data->bs_num_env; i++)
ch_data->bs_freq_res[ch_data->bs_num_env - i] = get_bits1(gb);
break;
case VARFIX:
ch_data->t_env[0] = get_bits(gb, 2);
num_rel_lead = get_bits(gb, 2);
ch_data->bs_num_env = num_rel_lead + 1;
ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
for (i = 0; i < num_rel_lead; i++)
ch_data->t_env[i + 1] = ch_data->t_env[i] + 2 * get_bits(gb, 2) + 2;
bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);
get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env);
break;
case VARVAR:
ch_data->t_env[0] = get_bits(gb, 2);
abs_bord_trail += get_bits(gb, 2);
num_rel_lead = get_bits(gb, 2);
num_rel_trail = get_bits(gb, 2);
ch_data->bs_num_env = num_rel_lead + num_rel_trail + 1;
if (ch_data->bs_num_env > 5) {
av_log(ac->avctx, AV_LOG_ERROR,
"Invalid bitstream, too many SBR envelopes in VARVAR type SBR frame: %d\n",
ch_data->bs_num_env);
return -1;
}
ch_data->t_env[ch_data->bs_num_env] = abs_bord_trail;
for (i = 0; i < num_rel_lead; i++)
ch_data->t_env[i + 1] = ch_data->t_env[i] + 2 * get_bits(gb, 2) + 2;
for (i = 0; i < num_rel_trail; i++)
ch_data->t_env[ch_data->bs_num_env - 1 - i] =
ch_data->t_env[ch_data->bs_num_env - i] - 2 * get_bits(gb, 2) - 2;
bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env]);
get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env);
break;
}
if (bs_pointer > ch_data->bs_num_env + 1) {
av_log(ac->avctx, AV_LOG_ERROR,
"Invalid bitstream, bs_pointer points to a middle noise border outside the time borders table: %d\n",
bs_pointer);
return -1;
}
for (i = 1; i <= ch_data->bs_num_env; i++) {
if (ch_data->t_env[i-1] > ch_data->t_env[i]) {
av_log(ac->avctx, AV_LOG_ERROR, "Non monotone time borders\n");
return -1;
}
}
ch_data->bs_num_noise = (ch_data->bs_num_env > 1) + 1;
ch_data->t_q[0] = ch_data->t_env[0];
ch_data->t_q[ch_data->bs_num_noise] = ch_data->t_env[ch_data->bs_num_env];
if (ch_data->bs_num_noise > 1) {
unsigned int idx;
if (ch_data->bs_frame_class == FIXFIX) {
idx = ch_data->bs_num_env >> 1;
} else if (ch_data->bs_frame_class & 1) { // FIXVAR or VARVAR
idx = ch_data->bs_num_env - FFMAX(bs_pointer - 1, 1);
} else { // VARFIX
if (!bs_pointer)
idx = 1;
else if (bs_pointer == 1)
idx = ch_data->bs_num_env - 1;
else // bs_pointer > 1
idx = bs_pointer - 1;
}
ch_data->t_q[1] = ch_data->t_env[idx];
}
ch_data->e_a[0] = -(ch_data->e_a[1] != bs_num_env_old); // l_APrev
ch_data->e_a[1] = -1;
if ((ch_data->bs_frame_class & 1) && bs_pointer) { // FIXVAR or VARVAR and bs_pointer != 0
ch_data->e_a[1] = ch_data->bs_num_env + 1 - bs_pointer;
} else if ((ch_data->bs_frame_class == 2) && (bs_pointer > 1)) // VARFIX and bs_pointer > 1
ch_data->e_a[1] = bs_pointer - 1;
return 0;
}
static void copy_sbr_grid(SBRData *dst, const SBRData *src) {
//These variables are saved from the previous frame rather than copied
dst->bs_freq_res[0] = dst->bs_freq_res[dst->bs_num_env];
dst->t_env_num_env_old = dst->t_env[dst->bs_num_env];
dst->e_a[0] = -(dst->e_a[1] != dst->bs_num_env);
//These variables are read from the bitstream and therefore copied
memcpy(dst->bs_freq_res+1, src->bs_freq_res+1, sizeof(dst->bs_freq_res)-sizeof(*dst->bs_freq_res));
memcpy(dst->t_env, src->t_env, sizeof(dst->t_env));
memcpy(dst->t_q, src->t_q, sizeof(dst->t_q));
dst->bs_num_env = src->bs_num_env;
dst->bs_amp_res = src->bs_amp_res;
dst->bs_num_noise = src->bs_num_noise;
dst->bs_frame_class = src->bs_frame_class;
dst->e_a[1] = src->e_a[1];
}
/// Read how the envelope and noise floor data is delta coded
static void read_sbr_dtdf(SpectralBandReplication *sbr, GetBitContext *gb,
SBRData *ch_data)
{
get_bits1_vector(gb, ch_data->bs_df_env, ch_data->bs_num_env);
get_bits1_vector(gb, ch_data->bs_df_noise, ch_data->bs_num_noise);
}
/// Read inverse filtering data
static void read_sbr_invf(SpectralBandReplication *sbr, GetBitContext *gb,
SBRData *ch_data)
{
int i;
memcpy(ch_data->bs_invf_mode[1], ch_data->bs_invf_mode[0], 5 * sizeof(uint8_t));
for (i = 0; i < sbr->n_q; i++)
ch_data->bs_invf_mode[0][i] = get_bits(gb, 2);
}
static void read_sbr_envelope(SpectralBandReplication *sbr, GetBitContext *gb,
SBRData *ch_data, int ch)
{
int bits;
int i, j, k;
VLC_TYPE (*t_huff)[2], (*f_huff)[2];
int t_lav, f_lav;
const int delta = (ch == 1 && sbr->bs_coupling == 1) + 1;
const int odd = sbr->n[1] & 1;
if (sbr->bs_coupling && ch) {
if (ch_data->bs_amp_res) {
bits = 5;
t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_3_0DB].table;
t_lav = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_3_0DB];
f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;
f_lav = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];
} else {
bits = 6;
t_huff = vlc_sbr[T_HUFFMAN_ENV_BAL_1_5DB].table;
t_lav = vlc_sbr_lav[T_HUFFMAN_ENV_BAL_1_5DB];
f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_1_5DB].table;
f_lav = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_1_5DB];
}
} else {
if (ch_data->bs_amp_res) {
bits = 6;
t_huff = vlc_sbr[T_HUFFMAN_ENV_3_0DB].table;
t_lav = vlc_sbr_lav[T_HUFFMAN_ENV_3_0DB];
f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;
f_lav = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];
} else {
bits = 7;
t_huff = vlc_sbr[T_HUFFMAN_ENV_1_5DB].table;
t_lav = vlc_sbr_lav[T_HUFFMAN_ENV_1_5DB];
f_huff = vlc_sbr[F_HUFFMAN_ENV_1_5DB].table;
f_lav = vlc_sbr_lav[F_HUFFMAN_ENV_1_5DB];
}
}
for (i = 0; i < ch_data->bs_num_env; i++) {
if (ch_data->bs_df_env[i]) {
// bs_freq_res[0] == bs_freq_res[bs_num_env] from prev frame
if (ch_data->bs_freq_res[i + 1] == ch_data->bs_freq_res[i]) {
for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++)
ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][j] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);
} else if (ch_data->bs_freq_res[i + 1]) {
for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) {
k = (j + odd) >> 1; // find k such that f_tablelow[k] <= f_tablehigh[j] < f_tablelow[k + 1]
ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][k] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);
}
} else {
for (j = 0; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++) {
k = j ? 2*j - odd : 0; // find k such that f_tablehigh[k] == f_tablelow[j]
ch_data->env_facs[i + 1][j] = ch_data->env_facs[i][k] + delta * (get_vlc2(gb, t_huff, 9, 3) - t_lav);
}
}
} else {
ch_data->env_facs[i + 1][0] = delta * get_bits(gb, bits); // bs_env_start_value_balance
for (j = 1; j < sbr->n[ch_data->bs_freq_res[i + 1]]; j++)
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);
}
}
//assign 0th elements of env_facs from last elements
memcpy(ch_data->env_facs[0], ch_data->env_facs[ch_data->bs_num_env],
sizeof(ch_data->env_facs[0]));
}
static void read_sbr_noise(SpectralBandReplication *sbr, GetBitContext *gb,
SBRData *ch_data, int ch)
{
int i, j;
VLC_TYPE (*t_huff)[2], (*f_huff)[2];
int t_lav, f_lav;
int delta = (ch == 1 && sbr->bs_coupling == 1) + 1;
if (sbr->bs_coupling && ch) {
t_huff = vlc_sbr[T_HUFFMAN_NOISE_BAL_3_0DB].table;
t_lav = vlc_sbr_lav[T_HUFFMAN_NOISE_BAL_3_0DB];
f_huff = vlc_sbr[F_HUFFMAN_ENV_BAL_3_0DB].table;
f_lav = vlc_sbr_lav[F_HUFFMAN_ENV_BAL_3_0DB];
} else {
t_huff = vlc_sbr[T_HUFFMAN_NOISE_3_0DB].table;
t_lav = vlc_sbr_lav[T_HUFFMAN_NOISE_3_0DB];
f_huff = vlc_sbr[F_HUFFMAN_ENV_3_0DB].table;
f_lav = vlc_sbr_lav[F_HUFFMAN_ENV_3_0DB];
}
for (i = 0; i < ch_data->bs_num_noise; i++) {
if (ch_data->bs_df_noise[i]) {
for (j = 0; j < sbr->n_q; j++)
ch_data->noise_facs[i + 1][j] = ch_data->noise_facs[i][j] + delta * (get_vlc2(gb, t_huff, 9, 2) - t_lav);
} else {
ch_data->noise_facs[i + 1][0] = delta * get_bits(gb, 5); // bs_noise_start_value_balance or bs_noise_start_value_level
for (j = 1; j < sbr->n_q; j++)
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);
}
}
//assign 0th elements of noise_facs from last elements
memcpy(ch_data->noise_facs[0], ch_data->noise_facs[ch_data->bs_num_noise],
sizeof(ch_data->noise_facs[0]));
}
static void read_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,
GetBitContext *gb,
int bs_extension_id, int *num_bits_left)
{
switch (bs_extension_id) {
case EXTENSION_ID_PS:
if (!ac->m4ac.ps) {
av_log(ac->avctx, AV_LOG_ERROR, "Parametric Stereo signaled to be not-present but was found in the bitstream.\n");
skip_bits_long(gb, *num_bits_left); // bs_fill_bits
*num_bits_left = 0;
} else {
#if 1
*num_bits_left -= ff_ps_read_data(ac->avctx, gb, &sbr->ps, *num_bits_left);
#else
av_log_missing_feature(ac->avctx, "Parametric Stereo is", 0);
skip_bits_long(gb, *num_bits_left); // bs_fill_bits
*num_bits_left = 0;
#endif
}
break;
default:
av_log_missing_feature(ac->avctx, "Reserved SBR extensions are", 1);
skip_bits_long(gb, *num_bits_left); // bs_fill_bits
*num_bits_left = 0;
break;
}
}
static int read_sbr_single_channel_element(AACContext *ac,
SpectralBandReplication *sbr,
GetBitContext *gb)
{
if (get_bits1(gb)) // bs_data_extra
skip_bits(gb, 4); // bs_reserved
if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]))
return -1;
read_sbr_dtdf(sbr, gb, &sbr->data[0]);
read_sbr_invf(sbr, gb, &sbr->data[0]);
read_sbr_envelope(sbr, gb, &sbr->data[0], 0);
read_sbr_noise(sbr, gb, &sbr->data[0], 0);
if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb)))
get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);
return 0;
}
static int read_sbr_channel_pair_element(AACContext *ac,
SpectralBandReplication *sbr,
GetBitContext *gb)
{
if (get_bits1(gb)) // bs_data_extra
skip_bits(gb, 8); // bs_reserved
if ((sbr->bs_coupling = get_bits1(gb))) {
if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]))
return -1;
copy_sbr_grid(&sbr->data[1], &sbr->data[0]);
read_sbr_dtdf(sbr, gb, &sbr->data[0]);
read_sbr_dtdf(sbr, gb, &sbr->data[1]);
read_sbr_invf(sbr, gb, &sbr->data[0]);
memcpy(sbr->data[1].bs_invf_mode[1], sbr->data[1].bs_invf_mode[0], sizeof(sbr->data[1].bs_invf_mode[0]));
memcpy(sbr->data[1].bs_invf_mode[0], sbr->data[0].bs_invf_mode[0], sizeof(sbr->data[1].bs_invf_mode[0]));
read_sbr_envelope(sbr, gb, &sbr->data[0], 0);
read_sbr_noise(sbr, gb, &sbr->data[0], 0);
read_sbr_envelope(sbr, gb, &sbr->data[1], 1);
read_sbr_noise(sbr, gb, &sbr->data[1], 1);
} else {
if (read_sbr_grid(ac, sbr, gb, &sbr->data[0]) ||
read_sbr_grid(ac, sbr, gb, &sbr->data[1]))
return -1;
read_sbr_dtdf(sbr, gb, &sbr->data[0]);
read_sbr_dtdf(sbr, gb, &sbr->data[1]);
read_sbr_invf(sbr, gb, &sbr->data[0]);
read_sbr_invf(sbr, gb, &sbr->data[1]);
read_sbr_envelope(sbr, gb, &sbr->data[0], 0);
read_sbr_envelope(sbr, gb, &sbr->data[1], 1);
read_sbr_noise(sbr, gb, &sbr->data[0], 0);
read_sbr_noise(sbr, gb, &sbr->data[1], 1);
}
if ((sbr->data[0].bs_add_harmonic_flag = get_bits1(gb)))
get_bits1_vector(gb, sbr->data[0].bs_add_harmonic, sbr->n[1]);
if ((sbr->data[1].bs_add_harmonic_flag = get_bits1(gb)))
get_bits1_vector(gb, sbr->data[1].bs_add_harmonic, sbr->n[1]);
return 0;
}
static unsigned int read_sbr_data(AACContext *ac, SpectralBandReplication *sbr,
GetBitContext *gb, int id_aac)
{
unsigned int cnt = get_bits_count(gb);
if (id_aac == TYPE_SCE || id_aac == TYPE_CCE) {
if (read_sbr_single_channel_element(ac, sbr, gb)) {
sbr_turnoff(sbr);
return get_bits_count(gb) - cnt;
}
} else if (id_aac == TYPE_CPE) {
if (read_sbr_channel_pair_element(ac, sbr, gb)) {
sbr_turnoff(sbr);
return get_bits_count(gb) - cnt;
}
} else {
av_log(ac->avctx, AV_LOG_ERROR,
"Invalid bitstream - cannot apply SBR to element type %d\n", id_aac);
sbr_turnoff(sbr);
return get_bits_count(gb) - cnt;
}
if (get_bits1(gb)) { // bs_extended_data
int num_bits_left = get_bits(gb, 4); // bs_extension_size
if (num_bits_left == 15)
num_bits_left += get_bits(gb, 8); // bs_esc_count
num_bits_left <<= 3;
while (num_bits_left > 7) {
num_bits_left -= 2;
read_sbr_extension(ac, sbr, gb, get_bits(gb, 2), &num_bits_left); // bs_extension_id
}
if (num_bits_left < 0) {
av_log(ac->avctx, AV_LOG_ERROR, "SBR Extension over read.\n");
}
if (num_bits_left > 0)
skip_bits(gb, num_bits_left);
}
return get_bits_count(gb) - cnt;
}
static void sbr_reset(AACContext *ac, SpectralBandReplication *sbr)
{
int err;
err = sbr_make_f_master(ac, sbr, &sbr->spectrum_params);
if (err >= 0)
err = sbr_make_f_derived(ac, sbr);
if (err < 0) {
av_log(ac->avctx, AV_LOG_ERROR,
"SBR reset failed. Switching SBR to pure upsampling mode.\n");
sbr_turnoff(sbr);
}
}
/**
* Decode Spectral Band Replication extension data; reference: table 4.55.
*
* @param crc flag indicating the presence of CRC checksum
* @param cnt length of TYPE_FIL syntactic element in bytes
*
* @return Returns number of bytes consumed from the TYPE_FIL element.
*/
int ff_decode_sbr_extension(AACContext *ac, SpectralBandReplication *sbr,
GetBitContext *gb_host, int crc, int cnt, int id_aac)
{
unsigned int num_sbr_bits = 0, num_align_bits;
unsigned bytes_read;
GetBitContext gbc = *gb_host, *gb = &gbc;
skip_bits_long(gb_host, cnt*8 - 4);
sbr->reset = 0;
if (!sbr->sample_rate)
sbr->sample_rate = 2 * ac->m4ac.sample_rate; //TODO use the nominal sample rate for arbitrary sample rate support
if (!ac->m4ac.ext_sample_rate)
ac->m4ac.ext_sample_rate = 2 * ac->m4ac.sample_rate;
if (crc) {
skip_bits(gb, 10); // bs_sbr_crc_bits; TODO - implement CRC check
num_sbr_bits += 10;
}
//Save some state from the previous frame.
sbr->kx[0] = sbr->kx[1];
sbr->m[0] = sbr->m[1];
sbr->kx_and_m_pushed = 1;
num_sbr_bits++;
if (get_bits1(gb)) // bs_header_flag
num_sbr_bits += read_sbr_header(sbr, gb);
if (sbr->reset)
sbr_reset(ac, sbr);
if (sbr->start)
num_sbr_bits += read_sbr_data(ac, sbr, gb, id_aac);
num_align_bits = ((cnt << 3) - 4 - num_sbr_bits) & 7;
bytes_read = ((num_sbr_bits + num_align_bits + 4) >> 3);
if (bytes_read > cnt) {
av_log(ac->avctx, AV_LOG_ERROR,
"Expected to read %d SBR bytes actually read %d.\n", cnt, bytes_read);
}
return cnt;
}
/// Dequantization and stereo decoding (14496-3 sp04 p203)
static void sbr_dequant(SpectralBandReplication *sbr, int id_aac)
{
int k, e;
int ch;
if (id_aac == TYPE_CPE && sbr->bs_coupling) {
float alpha = sbr->data[0].bs_amp_res ? 1.0f : 0.5f;
float pan_offset = sbr->data[0].bs_amp_res ? 12.0f : 24.0f;
for (e = 1; e <= sbr->data[0].bs_num_env; e++) {
for (k = 0; k < sbr->n[sbr->data[0].bs_freq_res[e]]; k++) {
float temp1 = exp2f(sbr->data[0].env_facs[e][k] * alpha + 7.0f);
float temp2 = exp2f((pan_offset - sbr->data[1].env_facs[e][k]) * alpha);
float fac = temp1 / (1.0f + temp2);
sbr->data[0].env_facs[e][k] = fac;
sbr->data[1].env_facs[e][k] = fac * temp2;
}
}
for (e = 1; e <= sbr->data[0].bs_num_noise; e++) {
for (k = 0; k < sbr->n_q; k++) {
float temp1 = exp2f(NOISE_FLOOR_OFFSET - sbr->data[0].noise_facs[e][k] + 1);
float temp2 = exp2f(12 - sbr->data[1].noise_facs[e][k]);
float fac = temp1 / (1.0f + temp2);
sbr->data[0].noise_facs[e][k] = fac;
sbr->data[1].noise_facs[e][k] = fac * temp2;
}
}
} else { // SCE or one non-coupled CPE
for (ch = 0; ch < (id_aac == TYPE_CPE) + 1; ch++) {
float alpha = sbr->data[ch].bs_amp_res ? 1.0f : 0.5f;
for (e = 1; e <= sbr->data[ch].bs_num_env; e++)
for (k = 0; k < sbr->n[sbr->data[ch].bs_freq_res[e]]; k++)
sbr->data[ch].env_facs[e][k] =
exp2f(alpha * sbr->data[ch].env_facs[e][k] + 6.0f);
for (e = 1; e <= sbr->data[ch].bs_num_noise; e++)
for (k = 0; k < sbr->n_q; k++)
sbr->data[ch].noise_facs[e][k] =
exp2f(NOISE_FLOOR_OFFSET - sbr->data[ch].noise_facs[e][k]);
}
}
}
/**
* Analysis QMF Bank (14496-3 sp04 p206)
*
* @param x pointer to the beginning of the first sample window
* @param W array of complex-valued samples split into subbands
*/
static void sbr_qmf_analysis(DSPContext *dsp, FFTContext *mdct,
SBRDSPContext *sbrdsp, const float *in, float *x,
float z[320], float W[2][32][32][2])
{
int i;
memcpy(W[0], W[1], sizeof(W[0]));
memcpy(x , x+1024, (320-32)*sizeof(x[0]));
memcpy(x+288, in, 1024*sizeof(x[0]));
for (i = 0; i < 32; i++) { // numTimeSlots*RATE = 16*2 as 960 sample frames
// are not supported
dsp->vector_fmul_reverse(z, sbr_qmf_window_ds, x, 320);
sbrdsp->sum64x5(z);
sbrdsp->qmf_pre_shuffle(z);
mdct->imdct_half(mdct, z, z+64);
sbrdsp->qmf_post_shuffle(W[1][i], z);
x += 32;
}
}
/**
* Synthesis QMF Bank (14496-3 sp04 p206) and Downsampled Synthesis QMF Bank
* (14496-3 sp04 p206)
*/
static void sbr_qmf_synthesis(DSPContext *dsp, FFTContext *mdct,
SBRDSPContext *sbrdsp,
float *out, float X[2][38][64],
float mdct_buf[2][64],
float *v0, int *v_off, const unsigned int div)
{
int i, n;
const float *sbr_qmf_window = div ? sbr_qmf_window_ds : sbr_qmf_window_us;
const int step = 128 >> div;
float *v;
for (i = 0; i < 32; i++) {
if (*v_off < step) {
int saved_samples = (1280 - 128) >> div;
memcpy(&v0[SBR_SYNTHESIS_BUF_SIZE - saved_samples], v0, saved_samples * sizeof(float));
*v_off = SBR_SYNTHESIS_BUF_SIZE - saved_samples - step;
} else {
*v_off -= step;
}
v = v0 + *v_off;
if (div) {
for (n = 0; n < 32; n++) {
X[0][i][ n] = -X[0][i][n];
X[0][i][32+n] = X[1][i][31-n];
}
mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);
sbrdsp->qmf_deint_neg(v, mdct_buf[0]);
} else {
sbrdsp->neg_odd_64(X[1][i]);
mdct->imdct_half(mdct, mdct_buf[0], X[0][i]);
mdct->imdct_half(mdct, mdct_buf[1], X[1][i]);
sbrdsp->qmf_deint_bfly(v, mdct_buf[1], mdct_buf[0]);
}
dsp->vector_fmul_add(out, v , sbr_qmf_window , zero64, 64 >> div);
dsp->vector_fmul_add(out, v + ( 192 >> div), sbr_qmf_window + ( 64 >> div), out , 64 >> div);
dsp->vector_fmul_add(out, v + ( 256 >> div), sbr_qmf_window + (128 >> div), out , 64 >> div);
dsp->vector_fmul_add(out, v + ( 448 >> div), sbr_qmf_window + (192 >> div), out , 64 >> div);
dsp->vector_fmul_add(out, v + ( 512 >> div), sbr_qmf_window + (256 >> div), out , 64 >> div);
dsp->vector_fmul_add(out, v + ( 704 >> div), sbr_qmf_window + (320 >> div), out , 64 >> div);
dsp->vector_fmul_add(out, v + ( 768 >> div), sbr_qmf_window + (384 >> div), out , 64 >> div);
dsp->vector_fmul_add(out, v + ( 960 >> div), sbr_qmf_window + (448 >> div), out , 64 >> div);
dsp->vector_fmul_add(out, v + (1024 >> div), sbr_qmf_window + (512 >> div), out , 64 >> div);
dsp->vector_fmul_add(out, v + (1216 >> div), sbr_qmf_window + (576 >> div), out , 64 >> div);
out += 64 >> div;
}
}
/** High Frequency Generation (14496-3 sp04 p214+) and Inverse Filtering
* (14496-3 sp04 p214)
* Warning: This routine does not seem numerically stable.
*/
static void sbr_hf_inverse_filter(SBRDSPContext *dsp,
float (*alpha0)[2], float (*alpha1)[2],
const float X_low[32][40][2], int k0)
{
int k;
for (k = 0; k < k0; k++) {
LOCAL_ALIGNED_16(float, phi, [3], [2][2]);
float dk;
dsp->autocorrelate(X_low[k], phi);
dk = phi[2][1][0] * phi[1][0][0] -
(phi[1][1][0] * phi[1][1][0] + phi[1][1][1] * phi[1][1][1]) / 1.000001f;
if (!dk) {
alpha1[k][0] = 0;
alpha1[k][1] = 0;
} else {
float temp_real, temp_im;
temp_real = phi[0][0][0] * phi[1][1][0] -
phi[0][0][1] * phi[1][1][1] -
phi[0][1][0] * phi[1][0][0];
temp_im = phi[0][0][0] * phi[1][1][1] +
phi[0][0][1] * phi[1][1][0] -
phi[0][1][1] * phi[1][0][0];
alpha1[k][0] = temp_real / dk;
alpha1[k][1] = temp_im / dk;
}
if (!phi[1][0][0]) {
alpha0[k][0] = 0;
alpha0[k][1] = 0;
} else {
float temp_real, temp_im;
temp_real = phi[0][0][0] + alpha1[k][0] * phi[1][1][0] +
alpha1[k][1] * phi[1][1][1];
temp_im = phi[0][0][1] + alpha1[k][1] * phi[1][1][0] -
alpha1[k][0] * phi[1][1][1];
alpha0[k][0] = -temp_real / phi[1][0][0];
alpha0[k][1] = -temp_im / phi[1][0][0];
}
if (alpha1[k][0] * alpha1[k][0] + alpha1[k][1] * alpha1[k][1] >= 16.0f ||
alpha0[k][0] * alpha0[k][0] + alpha0[k][1] * alpha0[k][1] >= 16.0f) {
alpha1[k][0] = 0;
alpha1[k][1] = 0;
alpha0[k][0] = 0;
alpha0[k][1] = 0;
}
}
}
/// Chirp Factors (14496-3 sp04 p214)
static void sbr_chirp(SpectralBandReplication *sbr, SBRData *ch_data)
{
int i;
float new_bw;
static const float bw_tab[] = { 0.0f, 0.75f, 0.9f, 0.98f };
for (i = 0; i < sbr->n_q; i++) {
if (ch_data->bs_invf_mode[0][i] + ch_data->bs_invf_mode[1][i] == 1) {
new_bw = 0.6f;
} else
new_bw = bw_tab[ch_data->bs_invf_mode[0][i]];
if (new_bw < ch_data->bw_array[i]) {
new_bw = 0.75f * new_bw + 0.25f * ch_data->bw_array[i];
} else
new_bw = 0.90625f * new_bw + 0.09375f * ch_data->bw_array[i];
ch_data->bw_array[i] = new_bw < 0.015625f ? 0.0f : new_bw;
}
}
/// Generate the subband filtered lowband
static int sbr_lf_gen(AACContext *ac, SpectralBandReplication *sbr,
float X_low[32][40][2], const float W[2][32][32][2])
{
int i, k;
const int t_HFGen = 8;
const int i_f = 32;
memset(X_low, 0, 32*sizeof(*X_low));
for (k = 0; k < sbr->kx[1]; k++) {
for (i = t_HFGen; i < i_f + t_HFGen; i++) {
X_low[k][i][0] = W[1][i - t_HFGen][k][0];
X_low[k][i][1] = W[1][i - t_HFGen][k][1];
}
}
for (k = 0; k < sbr->kx[0]; k++) {
for (i = 0; i < t_HFGen; i++) {
X_low[k][i][0] = W[0][i + i_f - t_HFGen][k][0];
X_low[k][i][1] = W[0][i + i_f - t_HFGen][k][1];
}
}
return 0;
}
/// High Frequency Generator (14496-3 sp04 p215)
static int sbr_hf_gen(AACContext *ac, SpectralBandReplication *sbr,
float X_high[64][40][2], const float X_low[32][40][2],
const float (*alpha0)[2], const float (*alpha1)[2],
const float bw_array[5], const uint8_t *t_env,
int bs_num_env)
{
int j, x;
int g = 0;
int k = sbr->kx[1];
for (j = 0; j < sbr->num_patches; j++) {
for (x = 0; x < sbr->patch_num_subbands[j]; x++, k++) {
const int p = sbr->patch_start_subband[j] + x;
while (g <= sbr->n_q && k >= sbr->f_tablenoise[g])
g++;
g--;
if (g < 0) {
av_log(ac->avctx, AV_LOG_ERROR,
"ERROR : no subband found for frequency %d\n", k);
return -1;
}
sbr->dsp.hf_gen(X_high[k] + ENVELOPE_ADJUSTMENT_OFFSET,
X_low[p] + ENVELOPE_ADJUSTMENT_OFFSET,
alpha0[p], alpha1[p], bw_array[g],
2 * t_env[0], 2 * t_env[bs_num_env]);
}
}
if (k < sbr->m[1] + sbr->kx[1])
memset(X_high + k, 0, (sbr->m[1] + sbr->kx[1] - k) * sizeof(*X_high));
return 0;
}
/// Generate the subband filtered lowband
static int sbr_x_gen(SpectralBandReplication *sbr, float X[2][38][64],
const float Y0[38][64][2], const float Y1[38][64][2],
const float X_low[32][40][2], int ch)
{
int k, i;
const int i_f = 32;
const int i_Temp = FFMAX(2*sbr->data[ch].t_env_num_env_old - i_f, 0);
memset(X, 0, 2*sizeof(*X));
for (k = 0; k < sbr->kx[0]; k++) {
for (i = 0; i < i_Temp; i++) {
X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];
X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];
}
}
for (; k < sbr->kx[0] + sbr->m[0]; k++) {
for (i = 0; i < i_Temp; i++) {
X[0][i][k] = Y0[i + i_f][k][0];
X[1][i][k] = Y0[i + i_f][k][1];
}
}
for (k = 0; k < sbr->kx[1]; k++) {
for (i = i_Temp; i < 38; i++) {
X[0][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][0];
X[1][i][k] = X_low[k][i + ENVELOPE_ADJUSTMENT_OFFSET][1];
}
}
for (; k < sbr->kx[1] + sbr->m[1]; k++) {
for (i = i_Temp; i < i_f; i++) {
X[0][i][k] = Y1[i][k][0];
X[1][i][k] = Y1[i][k][1];
}
}
return 0;
}
/** High Frequency Adjustment (14496-3 sp04 p217) and Mapping
* (14496-3 sp04 p217)
*/
static void sbr_mapping(AACContext *ac, SpectralBandReplication *sbr,
SBRData *ch_data, int e_a[2])
{
int e, i, m;
memset(ch_data->s_indexmapped[1], 0, 7*sizeof(ch_data->s_indexmapped[1]));
for (e = 0; e < ch_data->bs_num_env; e++) {
const unsigned int ilim = sbr->n[ch_data->bs_freq_res[e + 1]];
uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;
int k;
for (i = 0; i < ilim; i++)
for (m = table[i]; m < table[i + 1]; m++)
sbr->e_origmapped[e][m - sbr->kx[1]] = ch_data->env_facs[e+1][i];
// ch_data->bs_num_noise > 1 => 2 noise floors
k = (ch_data->bs_num_noise > 1) && (ch_data->t_env[e] >= ch_data->t_q[1]);
for (i = 0; i < sbr->n_q; i++)
for (m = sbr->f_tablenoise[i]; m < sbr->f_tablenoise[i + 1]; m++)
sbr->q_mapped[e][m - sbr->kx[1]] = ch_data->noise_facs[k+1][i];
for (i = 0; i < sbr->n[1]; i++) {
if (ch_data->bs_add_harmonic_flag) {
const unsigned int m_midpoint =
(sbr->f_tablehigh[i] + sbr->f_tablehigh[i + 1]) >> 1;
ch_data->s_indexmapped[e + 1][m_midpoint - sbr->kx[1]] = ch_data->bs_add_harmonic[i] *
(e >= e_a[1] || (ch_data->s_indexmapped[0][m_midpoint - sbr->kx[1]] == 1));
}
}
for (i = 0; i < ilim; i++) {
int additional_sinusoid_present = 0;
for (m = table[i]; m < table[i + 1]; m++) {
if (ch_data->s_indexmapped[e + 1][m - sbr->kx[1]]) {
additional_sinusoid_present = 1;
break;
}
}
memset(&sbr->s_mapped[e][table[i] - sbr->kx[1]], additional_sinusoid_present,
(table[i + 1] - table[i]) * sizeof(sbr->s_mapped[e][0]));
}
}
memcpy(ch_data->s_indexmapped[0], ch_data->s_indexmapped[ch_data->bs_num_env], sizeof(ch_data->s_indexmapped[0]));
}
/// Estimation of current envelope (14496-3 sp04 p218)
static void sbr_env_estimate(float (*e_curr)[48], float X_high[64][40][2],
SpectralBandReplication *sbr, SBRData *ch_data)
{
int e, m;
int kx1 = sbr->kx[1];
if (sbr->bs_interpol_freq) {
for (e = 0; e < ch_data->bs_num_env; e++) {
const float recip_env_size = 0.5f / (ch_data->t_env[e + 1] - ch_data->t_env[e]);
int ilb = ch_data->t_env[e] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
for (m = 0; m < sbr->m[1]; m++) {
float sum = sbr->dsp.sum_square(X_high[m+kx1] + ilb, iub - ilb);
e_curr[e][m] = sum * recip_env_size;
}
}
} else {
int k, p;
for (e = 0; e < ch_data->bs_num_env; e++) {
const int env_size = 2 * (ch_data->t_env[e + 1] - ch_data->t_env[e]);
int ilb = ch_data->t_env[e] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
int iub = ch_data->t_env[e + 1] * 2 + ENVELOPE_ADJUSTMENT_OFFSET;
const uint16_t *table = ch_data->bs_freq_res[e + 1] ? sbr->f_tablehigh : sbr->f_tablelow;
for (p = 0; p < sbr->n[ch_data->bs_freq_res[e + 1]]; p++) {
float sum = 0.0f;
const int den = env_size * (table[p + 1] - table[p]);
for (k = table[p]; k < table[p + 1]; k++) {
sum += sbr->dsp.sum_square(X_high[k] + ilb, iub - ilb);
}
sum /= den;
for (k = table[p]; k < table[p + 1]; k++) {
e_curr[e][k - kx1] = sum;
}
}
}
}
}
/**
* Calculation of levels of additional HF signal components (14496-3 sp04 p219)
* and Calculation of gain (14496-3 sp04 p219)
*/
static void sbr_gain_calc(AACContext *ac, SpectralBandReplication *sbr,
SBRData *ch_data, const int e_a[2])
{
int e, k, m;
// max gain limits : -3dB, 0dB, 3dB, inf dB (limiter off)
static const float limgain[4] = { 0.70795, 1.0, 1.41254, 10000000000 };
for (e = 0; e < ch_data->bs_num_env; e++) {
int delta = !((e == e_a[1]) || (e == e_a[0]));
for (k = 0; k < sbr->n_lim; k++) {
float gain_boost, gain_max;
float sum[2] = { 0.0f, 0.0f };
for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
const float temp = sbr->e_origmapped[e][m] / (1.0f + sbr->q_mapped[e][m]);
sbr->q_m[e][m] = sqrtf(temp * sbr->q_mapped[e][m]);
sbr->s_m[e][m] = sqrtf(temp * ch_data->s_indexmapped[e + 1][m]);
if (!sbr->s_mapped[e][m]) {
sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] /
((1.0f + sbr->e_curr[e][m]) *
(1.0f + sbr->q_mapped[e][m] * delta)));
} else {
sbr->gain[e][m] = sqrtf(sbr->e_origmapped[e][m] * sbr->q_mapped[e][m] /
((1.0f + sbr->e_curr[e][m]) *
(1.0f + sbr->q_mapped[e][m])));
}
}
for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
sum[0] += sbr->e_origmapped[e][m];
sum[1] += sbr->e_curr[e][m];
}
gain_max = limgain[sbr->bs_limiter_gains] * sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
gain_max = FFMIN(100000.f, gain_max);
for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
float q_m_max = sbr->q_m[e][m] * gain_max / sbr->gain[e][m];
sbr->q_m[e][m] = FFMIN(sbr->q_m[e][m], q_m_max);
sbr->gain[e][m] = FFMIN(sbr->gain[e][m], gain_max);
}
sum[0] = sum[1] = 0.0f;
for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
sum[0] += sbr->e_origmapped[e][m];
sum[1] += sbr->e_curr[e][m] * sbr->gain[e][m] * sbr->gain[e][m]
+ sbr->s_m[e][m] * sbr->s_m[e][m]
+ (delta && !sbr->s_m[e][m]) * sbr->q_m[e][m] * sbr->q_m[e][m];
}
gain_boost = sqrtf((FLT_EPSILON + sum[0]) / (FLT_EPSILON + sum[1]));
gain_boost = FFMIN(1.584893192f, gain_boost);
for (m = sbr->f_tablelim[k] - sbr->kx[1]; m < sbr->f_tablelim[k + 1] - sbr->kx[1]; m++) {
sbr->gain[e][m] *= gain_boost;
sbr->q_m[e][m] *= gain_boost;
sbr->s_m[e][m] *= gain_boost;
}
}
}
}
/// Assembling HF Signals (14496-3 sp04 p220)
static void sbr_hf_assemble(float Y1[38][64][2],
const float X_high[64][40][2],
SpectralBandReplication *sbr, SBRData *ch_data,
const int e_a[2])
{
int e, i, j, m;
const int h_SL = 4 * !sbr->bs_smoothing_mode;
const int kx = sbr->kx[1];
const int m_max = sbr->m[1];
static const float h_smooth[5] = {
0.33333333333333,
0.30150283239582,
0.21816949906249,
0.11516383427084,
0.03183050093751,
};
static const int8_t phi[2][4] = {
{ 1, 0, -1, 0}, // real
{ 0, 1, 0, -1}, // imaginary
};
float (*g_temp)[48] = ch_data->g_temp, (*q_temp)[48] = ch_data->q_temp;
int indexnoise = ch_data->f_indexnoise;
int indexsine = ch_data->f_indexsine;
if (sbr->reset) {
for (i = 0; i < h_SL; i++) {
memcpy(g_temp[i + 2*ch_data->t_env[0]], sbr->gain[0], m_max * sizeof(sbr->gain[0][0]));
memcpy(q_temp[i + 2*ch_data->t_env[0]], sbr->q_m[0], m_max * sizeof(sbr->q_m[0][0]));
}
} else if (h_SL) {
memcpy(g_temp[2*ch_data->t_env[0]], g_temp[2*ch_data->t_env_num_env_old], 4*sizeof(g_temp[0]));
memcpy(q_temp[2*ch_data->t_env[0]], q_temp[2*ch_data->t_env_num_env_old], 4*sizeof(q_temp[0]));
}
for (e = 0; e < ch_data->bs_num_env; e++) {
for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
memcpy(g_temp[h_SL + i], sbr->gain[e], m_max * sizeof(sbr->gain[0][0]));
memcpy(q_temp[h_SL + i], sbr->q_m[e], m_max * sizeof(sbr->q_m[0][0]));
}
}
for (e = 0; e < ch_data->bs_num_env; e++) {
for (i = 2 * ch_data->t_env[e]; i < 2 * ch_data->t_env[e + 1]; i++) {
int phi_sign = (1 - 2*(kx & 1));
LOCAL_ALIGNED_16(float, g_filt_tab, [48]);
LOCAL_ALIGNED_16(float, q_filt_tab, [48]);
float *g_filt, *q_filt;
if (h_SL && e != e_a[0] && e != e_a[1]) {
g_filt = g_filt_tab;
q_filt = q_filt_tab;
for (m = 0; m < m_max; m++) {
const int idx1 = i + h_SL;
g_filt[m] = 0.0f;
q_filt[m] = 0.0f;
for (j = 0; j <= h_SL; j++) {
g_filt[m] += g_temp[idx1 - j][m] * h_smooth[j];
q_filt[m] += q_temp[idx1 - j][m] * h_smooth[j];
}
}
} else {
g_filt = g_temp[i + h_SL];
q_filt = q_temp[i];
}
sbr->dsp.hf_g_filt(Y1[i] + kx, X_high + kx, g_filt, m_max,
i + ENVELOPE_ADJUSTMENT_OFFSET);
if (e != e_a[0] && e != e_a[1]) {
sbr->dsp.hf_apply_noise[indexsine](Y1[i] + kx, sbr->s_m[e],
q_filt, indexnoise,
kx, m_max);
} else {
for (m = 0; m < m_max; m++) {
Y1[i][m + kx][0] +=
sbr->s_m[e][m] * phi[0][indexsine];
Y1[i][m + kx][1] +=
sbr->s_m[e][m] * (phi[1][indexsine] * phi_sign);
phi_sign = -phi_sign;
}
}
indexnoise = (indexnoise + m_max) & 0x1ff;
indexsine = (indexsine + 1) & 3;
}
}
ch_data->f_indexnoise = indexnoise;
ch_data->f_indexsine = indexsine;
}
void ff_sbr_apply(AACContext *ac, SpectralBandReplication *sbr, int id_aac,
float* L, float* R)
{
int downsampled = ac->m4ac.ext_sample_rate < sbr->sample_rate;
int ch;
int nch = (id_aac == TYPE_CPE) ? 2 : 1;
if (!sbr->kx_and_m_pushed) {
sbr->kx[0] = sbr->kx[1];
sbr->m[0] = sbr->m[1];
} else {
sbr->kx_and_m_pushed = 0;
}
if (sbr->start) {
sbr_dequant(sbr, id_aac);
}
for (ch = 0; ch < nch; ch++) {
/* decode channel */
sbr_qmf_analysis(&ac->dsp, &sbr->mdct_ana, &sbr->dsp, ch ? R : L, sbr->data[ch].analysis_filterbank_samples,
(float*)sbr->qmf_filter_scratch,
sbr->data[ch].W);
sbr_lf_gen(ac, sbr, sbr->X_low, sbr->data[ch].W);
sbr->data[ch].Ypos ^= 1;
if (sbr->start) {
sbr_hf_inverse_filter(&sbr->dsp, sbr->alpha0, sbr->alpha1, sbr->X_low, sbr->k[0]);
sbr_chirp(sbr, &sbr->data[ch]);
sbr_hf_gen(ac, sbr, sbr->X_high, sbr->X_low, sbr->alpha0, sbr->alpha1,
sbr->data[ch].bw_array, sbr->data[ch].t_env,
sbr->data[ch].bs_num_env);
// hf_adj
sbr_mapping(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);
sbr_env_estimate(sbr->e_curr, sbr->X_high, sbr, &sbr->data[ch]);
sbr_gain_calc(ac, sbr, &sbr->data[ch], sbr->data[ch].e_a);
sbr_hf_assemble(sbr->data[ch].Y[sbr->data[ch].Ypos],
sbr->X_high, sbr, &sbr->data[ch],
sbr->data[ch].e_a);
}
/* synthesis */
sbr_x_gen(sbr, sbr->X[ch],
sbr->data[ch].Y[1-sbr->data[ch].Ypos],
sbr->data[ch].Y[ sbr->data[ch].Ypos],
sbr->X_low, ch);
}
if (ac->m4ac.ps == 1) {
if (sbr->ps.start) {
ff_ps_apply(ac->avctx, &sbr->ps, sbr->X[0], sbr->X[1], sbr->kx[1] + sbr->m[1]);
} else {
memcpy(sbr->X[1], sbr->X[0], sizeof(sbr->X[0]));
}
nch = 2;
}
sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, &sbr->dsp, L, sbr->X[0], sbr->qmf_filter_scratch,
sbr->data[0].synthesis_filterbank_samples,
&sbr->data[0].synthesis_filterbank_samples_offset,
downsampled);
if (nch == 2)
sbr_qmf_synthesis(&ac->dsp, &sbr->mdct, &sbr->dsp, R, sbr->X[1], sbr->qmf_filter_scratch,
sbr->data[1].synthesis_filterbank_samples,
&sbr->data[1].synthesis_filterbank_samples_offset,
downsampled);
}