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aacsbr.c
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aacsbr.c
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/*
* AAC Spectral Band Replication decoding functions
* Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
* Copyright (c) 2009-2010 Alex Converse <[email protected]>
*
* 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->oc[1].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;
}