Skip to content

F
ffmpeg.wasm-core
Commit 9ffd5c1c authored by Robert Swain's avatar Robert Swain
Browse files
Options

More OKed AAC decoder hunks 

Originally committed as revision 14774 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent aa6ed608
Hide whitespace changes
Inline Side-by-side
Showing with 283 additions and 5 deletions
libavcodec/aac.c
View file @ 9ffd5c1c
......@@ -90,10 +90,6 @@
#include <math.h>
#include <string.h>
#ifndef CONFIG_HARDCODED_TABLES
static float ff_aac_pow2sf_tab[316];
#endif /* CONFIG_HARDCODED_TABLES */
static VLC vlc_scalefactors;
static VLC vlc_spectral[11];
......@@ -413,6 +409,12 @@ static av_cold int aac_decode_init(AVCodecContext * avccontext) {
ff_mdct_init(&ac->mdct, 11, 1);
ff_mdct_init(&ac->mdct_small, 8, 1);
// window initialization
ff_kbd_window_init(ff_aac_kbd_long_1024, 4.0, 1024);
ff_kbd_window_init(ff_aac_kbd_short_128, 6.0, 128);
ff_sine_window_init(ff_sine_1024, 1024);
ff_sine_window_init(ff_sine_128, 128);
return 0;
}
......@@ -446,7 +448,27 @@ static int decode_ics_info(AACContext * ac, IndividualChannelStream * ics, GetBi
ics->use_kb_window[0] = get_bits1(gb);
ics->num_window_groups = 1;
ics->group_len[0] = 1;
if (ics->window_sequence[0] == EIGHT_SHORT_SEQUENCE) {
int i;
ics->max_sfb = get_bits(gb, 4);
for (i = 0; i < 7; i++) {
if (get_bits1(gb)) {
ics->group_len[ics->num_window_groups-1]++;
} else {
ics->num_window_groups++;
ics->group_len[ics->num_window_groups-1] = 1;
}
}
ics->num_windows = 8;
ics->swb_offset = swb_offset_128[ac->m4ac.sampling_index];
ics->num_swb = ff_aac_num_swb_128[ac->m4ac.sampling_index];
ics->tns_max_bands = tns_max_bands_128[ac->m4ac.sampling_index];
} else {
ics->max_sfb = get_bits(gb, 6);
ics->num_windows = 1;
ics->swb_offset = swb_offset_1024[ac->m4ac.sampling_index];
ics->num_swb = ff_aac_num_swb_1024[ac->m4ac.sampling_index];
ics->tns_max_bands = tns_max_bands_1024[ac->m4ac.sampling_index];
if (get_bits1(gb)) {
av_log_missing_feature(ac->avccontext, "Predictor bit set but LTP is", 1);
memset(ics, 0, sizeof(IndividualChannelStream));
......@@ -496,6 +518,10 @@ static int decode_band_types(AACContext * ac, enum BandType band_type[120],
sect_len, ics->max_sfb);
return -1;
}
for (; k < sect_len; k++) {
band_type [idx] = sect_band_type;
band_type_run_end[idx++] = sect_len;
}
}
}
return 0;
......@@ -596,6 +622,106 @@ static void decode_mid_side_stereo(ChannelElement * cpe, GetBitContext * gb,
}
}
/**
* Decode spectral data; reference: table 4.50.
* Dequantize and scale spectral data; reference: 4.6.3.3.
*
* @param coef array of dequantized, scaled spectral data
* @param sf array of scalefactors or intensity stereo positions
* @param pulse_present set if pulses are present
* @param pulse pointer to pulse data struct
* @param band_type array of the used band type
*
* @return Returns error status. 0 - OK, !0 - error
*/
static int decode_spectrum_and_dequant(AACContext * ac, float coef[1024], GetBitContext * gb, float sf[120],
int pulse_present, const Pulse * pulse, const IndividualChannelStream * ics, enum BandType band_type[120]) {
int i, k, g, idx = 0;
const int c = 1024/ics->num_windows;
const uint16_t * offsets = ics->swb_offset;
float *coef_base = coef;
for (g = 0; g < ics->num_windows; g++)
memset(coef + g * 128 + offsets[ics->max_sfb], 0, sizeof(float)*(c - offsets[ics->max_sfb]));
for (g = 0; g < ics->num_window_groups; g++) {
for (i = 0; i < ics->max_sfb; i++, idx++) {
const int cur_band_type = band_type[idx];
const int dim = cur_band_type >= FIRST_PAIR_BT ? 2 : 4;
const int is_cb_unsigned = IS_CODEBOOK_UNSIGNED(cur_band_type);
int group;
if (cur_band_type == ZERO_BT) {
for (group = 0; group < ics->group_len[g]; group++) {
memset(coef + group * 128 + offsets[i], 0, (offsets[i+1] - offsets[i])*sizeof(float));
}
}else if (cur_band_type == NOISE_BT) {
const float scale = sf[idx] / ((offsets[i+1] - offsets[i]) * PNS_MEAN_ENERGY);
for (group = 0; group < ics->group_len[g]; group++) {
for (k = offsets[i]; k < offsets[i+1]; k++) {
ac->random_state = lcg_random(ac->random_state);
coef[group*128+k] = ac->random_state * scale;
}
}
}else if (cur_band_type != INTENSITY_BT2 && cur_band_type != INTENSITY_BT) {
for (group = 0; group < ics->group_len[g]; group++) {
for (k = offsets[i]; k < offsets[i+1]; k += dim) {
const int index = get_vlc2(gb, vlc_spectral[cur_band_type - 1].table, 6, 3);
const int coef_tmp_idx = (group << 7) + k;
const float *vq_ptr;
int j;
if(index >= ff_aac_spectral_sizes[cur_band_type - 1]) {
av_log(ac->avccontext, AV_LOG_ERROR,
"Read beyond end of ff_aac_codebook_vectors[%d][]. index %d >= %d\n",
cur_band_type - 1, index, ff_aac_spectral_sizes[cur_band_type - 1]);
return -1;
}
vq_ptr = &ff_aac_codebook_vectors[cur_band_type - 1][index * dim];
if (is_cb_unsigned) {
for (j = 0; j < dim; j++)
if (vq_ptr[j])
coef[coef_tmp_idx + j] = 1 - 2*(int)get_bits1(gb);
}else {
for (j = 0; j < dim; j++)
coef[coef_tmp_idx + j] = 1.0f;
}
if (cur_band_type == ESC_BT) {
for (j = 0; j < 2; j++) {
if (vq_ptr[j] == 64.0f) {
int n = 4;
/* The total length of escape_sequence must be < 22 bits according
to the specification (i.e. max is 11111111110xxxxxxxxxx). */
while (get_bits1(gb) && n < 15) n++;
if(n == 15) {
av_log(ac->avccontext, AV_LOG_ERROR, "error in spectral data, ESC overflow\n");
return -1;
}
n = (1<<n) + get_bits(gb, n);
coef[coef_tmp_idx + j] *= cbrtf(fabsf(n)) * n;
}else
coef[coef_tmp_idx + j] *= vq_ptr[j];
}
}else
for (j = 0; j < dim; j++)
coef[coef_tmp_idx + j] *= vq_ptr[j];
for (j = 0; j < dim; j++)
coef[coef_tmp_idx + j] *= sf[idx];
}
}
}
}
coef += ics->group_len[g]<<7;
}
if (pulse_present) {
for(i = 0; i < pulse->num_pulse; i++){
float co = coef_base[ pulse->pos[i] ];
float ico = co / sqrtf(sqrtf(fabsf(co))) + pulse->amp[i];
coef_base[ pulse->pos[i] ] = cbrtf(fabsf(ico)) * ico;
}
}
return 0;
}
/**
* Decode an individual_channel_stream payload; reference: table 4.44.
*
......@@ -650,6 +776,72 @@ static int decode_ics(AACContext * ac, SingleChannelElement * sce, GetBitContext
return 0;
}
/**
* Mid/Side stereo decoding; reference: 4.6.8.1.3.
*/
static void apply_mid_side_stereo(ChannelElement * cpe) {
const IndividualChannelStream * ics = &cpe->ch[0].ics;
float *ch0 = cpe->ch[0].coeffs;
float *ch1 = cpe->ch[1].coeffs;
int g, i, k, group, idx = 0;
const uint16_t * offsets = ics->swb_offset;
for (g = 0; g < ics->num_window_groups; g++) {
for (i = 0; i < ics->max_sfb; i++, idx++) {
if (cpe->ms_mask[idx] &&
cpe->ch[0].band_type[idx] < NOISE_BT && cpe->ch[1].band_type[idx] < NOISE_BT) {
for (group = 0; group < ics->group_len[g]; group++) {
for (k = offsets[i]; k < offsets[i+1]; k++) {
float tmp = ch0[group*128 + k] - ch1[group*128 + k];
ch0[group*128 + k] += ch1[group*128 + k];
ch1[group*128 + k] = tmp;
}
}
}
}
ch0 += ics->group_len[g]*128;
ch1 += ics->group_len[g]*128;
}
}
/**
* intensity stereo decoding; reference: 4.6.8.2.3
*
* @param ms_present Indicates mid/side stereo presence. [0] mask is all 0s;
* [1] mask is decoded from bitstream; [2] mask is all 1s;
* [3] reserved for scalable AAC
*/
static void apply_intensity_stereo(ChannelElement * cpe, int ms_present) {
const IndividualChannelStream * ics = &cpe->ch[1].ics;
SingleChannelElement * sce1 = &cpe->ch[1];
float *coef0 = cpe->ch[0].coeffs, *coef1 = cpe->ch[1].coeffs;
const uint16_t * offsets = ics->swb_offset;
int g, group, i, k, idx = 0;
int c;
float scale;
for (g = 0; g < ics->num_window_groups; g++) {
for (i = 0; i < ics->max_sfb;) {
if (sce1->band_type[idx] == INTENSITY_BT || sce1->band_type[idx] == INTENSITY_BT2) {
const int bt_run_end = sce1->band_type_run_end[idx];
for (; i < bt_run_end; i++, idx++) {
c = -1 + 2 * (sce1->band_type[idx] - 14);
if (ms_present)
c *= 1 - 2 * cpe->ms_mask[idx];
scale = c * sce1->sf[idx];
for (group = 0; group < ics->group_len[g]; group++)
for (k = offsets[i]; k < offsets[i+1]; k++)
coef1[group*128 + k] = scale * coef0[group*128 + k];
}
} else {
int bt_run_end = sce1->band_type_run_end[idx];
idx += bt_run_end - i;
i = bt_run_end;
}
}
coef0 += ics->group_len[g]*128;
coef1 += ics->group_len[g]*128;
}
}
/**
* Decode a channel_pair_element; reference: table 4.4.
*
......@@ -688,6 +880,21 @@ static int decode_cpe(AACContext * ac, GetBitContext * gb, int elem_id) {
return 0;
}
/**
* Decode coupling_channel_element; reference: table 4.8.
*
* @param elem_id Identifies the instance of a syntax element.
*
* @return Returns error status. 0 - OK, !0 - error
*/
static int decode_cce(AACContext * ac, GetBitContext * gb, ChannelElement * che) {
int num_gain = 0;
int c, g, sfb, ret, idx = 0;
int sign;
float scale;
SingleChannelElement * sce = &che->ch[0];
ChannelCoupling * coup = &che->coup;
coup->coupling_point = 2*get_bits1(gb);
coup->num_coupled = get_bits(gb, 3);
for (c = 0; c <= coup->num_coupled; c++) {
......@@ -966,6 +1173,58 @@ static void apply_independent_coupling(AACContext * ac, SingleChannelElement * s
sce->ret[i] += cc->coup.gain[index][0] * (cc->ch[0].ret[i] - ac->add_bias);
}
/**
* channel coupling transformation interface
*
* @param index index into coupling gain array
* @param apply_coupling_method pointer to (in)dependent coupling function
*/
static void apply_channel_coupling(AACContext * ac, ChannelElement * cc,
void (*apply_coupling_method)(AACContext * ac, SingleChannelElement * sce, ChannelElement * cc, int index))
{
int c;
int index = 0;
ChannelCoupling * coup = &cc->coup;
for (c = 0; c <= coup->num_coupled; c++) {
if (ac->che[coup->type[c]][coup->id_select[c]]) {
if (coup->ch_select[c] != 2) {
apply_coupling_method(ac, &ac->che[coup->type[c]][coup->id_select[c]]->ch[0], cc, index);
if (coup->ch_select[c] != 0)
index++;
}
if (coup->ch_select[c] != 1)
apply_coupling_method(ac, &ac->che[coup->type[c]][coup->id_select[c]]->ch[1], cc, index++);
} else {
av_log(ac->avccontext, AV_LOG_ERROR,
"coupling target %sE[%d] not available\n",
coup->type[c] == TYPE_CPE ? "CP" : "SC", coup->id_select[c]);
break;
}
}
}
/**
* Convert spectral data to float samples, applying all supported tools as appropriate.
*/
static void spectral_to_sample(AACContext * ac) {
int i, type;
for (i = 0; i < MAX_ELEM_ID; i++) {
for(type = 0; type < 4; type++) {
ChannelElement *che = ac->che[type][i];
if(che) {
if(che->coup.coupling_point == BEFORE_TNS)
apply_channel_coupling(ac, che, apply_dependent_coupling);
if(che->ch[0].tns.present)
apply_tns(che->ch[0].coeffs, &che->ch[0].tns, &che->ch[0].ics, 1);
if(che->ch[1].tns.present)
apply_tns(che->ch[1].coeffs, &che->ch[1].tns, &che->ch[1].ics, 1);
if(che->coup.coupling_point == BETWEEN_TNS_AND_IMDCT)
apply_channel_coupling(ac, che, apply_dependent_coupling);
imdct_and_windowing(ac, &che->ch[0]);
if(type == TYPE_CPE)
imdct_and_windowing(ac, &che->ch[1]);
if(che->coup.coupling_point == AFTER_IMDCT)
apply_channel_coupling(ac, che, apply_independent_coupling);
}
}
}
......
libavcodec/aac.h
View file @ 9ffd5c1c
......@@ -45,6 +45,9 @@
#define MAX_CHANNELS 64
#define MAX_ELEM_ID 16
#define TNS_MAX_ORDER 20
#define PNS_MEAN_ENERGY 3719550720.0f // sqrt(3.0) * 1<<31
enum AudioObjectType {
AOT_NULL,
// Support? Name
......
libavcodec/aactab.c
View file @ 9ffd5c1c
......@@ -32,6 +32,9 @@
#include <stdint.h>
DECLARE_ALIGNED(16, float, ff_aac_kbd_long_1024[1024]);
DECLARE_ALIGNED(16, float, ff_aac_kbd_short_128[128]);
const uint8_t ff_aac_num_swb_1024[] = {
41, 41, 47, 49, 49, 51, 47, 47, 43, 43, 43, 40
};
......@@ -983,4 +986,8 @@ const float ff_aac_pow2sf_tab[316] = {
2.68435456e+08, 3.19225354e+08, 3.79625062e+08, 4.51452825e+08,
};
#else
float ff_aac_pow2sf_tab[316];
#endif /* CONFIG_HARDCODED_TABLES */
libavcodec/aactab.h
View file @ 9ffd5c1c
......@@ -40,6 +40,13 @@
* encoder.
*/
/* @name window coefficients
* @{
*/
DECLARE_ALIGNED(16, extern float, ff_aac_kbd_long_1024[1024]);
DECLARE_ALIGNED(16, extern float, ff_aac_kbd_short_128[128]);
// @}
/* @name number of scalefactor window bands for long and short transform windows respectively
* @{
*/
......@@ -58,6 +65,8 @@ extern const float *ff_aac_codebook_vectors[];
#ifdef CONFIG_HARDCODED_TABLES
extern const float ff_aac_pow2sf_tab[316];
#else
extern float ff_aac_pow2sf_tab[316];
#endif /* CONFIG_HARDCODED_TABLES */
#endif /* FFMPEG_AACTAB_H */
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment