---
Changelog | 1 +
libavcodec/aac.h | 1 +
libavcodec/aacdec.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++---
libavcodec/aactab.c | 36 +++++++++++++++++++++++++++++
libavcodec/aactab.h | 3 +++
5 files changed, 104 insertions(+), 3 deletions(-)
diff --git a/Changelog b/Changelog
index 5261c18..4e818ce 100644
--- a/Changelog
+++ b/Changelog
@@ -34,6 +34,7 @@ version 10:
data read from an input file
- incomplete Voxware MetaSound decoder
- Error Resiliant AAC syntax (ER AAC LC) decoding
+- Low Delay AAC (ER AAC LD) decoding
version 9:
diff --git a/libavcodec/aac.h b/libavcodec/aac.h
index a7c9995..40e8dfb 100644
--- a/libavcodec/aac.h
+++ b/libavcodec/aac.h
@@ -289,6 +289,7 @@ typedef struct AACContext {
*/
FFTContext mdct;
FFTContext mdct_small;
+ FFTContext mdct_ld;
FFTContext mdct_ltp;
FmtConvertContext fmt_conv;
AVFloatDSPContext fdsp;
diff --git a/libavcodec/aacdec.c b/libavcodec/aacdec.c
index 4a18946..7b28239 100644
--- a/libavcodec/aacdec.c
+++ b/libavcodec/aacdec.c
@@ -817,6 +817,13 @@ static int decode_audio_specific_config(AACContext *ac,
m4ac->sampling_index);
return AVERROR_INVALIDDATA;
}
+ if (m4ac->object_type == AOT_ER_AAC_LD &&
+ m4ac->sampling_index < 3 || m4ac->sampling_index > 7) {
+ av_log(avctx, AV_LOG_ERROR,
+ "invalid low delay sampling rate index %d\n",
+ m4ac->sampling_index);
+ return AVERROR_INVALIDDATA;
+ }
skip_bits_long(&gb, i);
@@ -825,6 +832,7 @@ static int decode_audio_specific_config(AACContext *ac,
case AOT_AAC_LC:
case AOT_AAC_LTP:
case AOT_ER_AAC_LC:
+ case AOT_ER_AAC_LD:
if ((ret = decode_ga_specific_config(ac, avctx, &gb,
m4ac, m4ac->chan_config)) < 0)
return ret;
@@ -985,12 +993,15 @@ static av_cold int aac_decode_init(AVCodecContext *avctx)
352);
ff_mdct_init(&ac->mdct, 11, 1, 1.0 / (32768.0 * 1024.0));
+ ff_mdct_init(&ac->mdct_ld, 10, 1, 1.0 / (32768.0 * 512.0));
ff_mdct_init(&ac->mdct_small, 8, 1, 1.0 / (32768.0 * 128.0));
ff_mdct_init(&ac->mdct_ltp, 11, 0, -2.0 * 32768.0);
// window initialization
ff_kbd_window_init(ff_aac_kbd_long_1024, 4.0, 1024);
+ ff_kbd_window_init(ff_aac_kbd_long_512, 4.0, 512);
ff_kbd_window_init(ff_aac_kbd_short_128, 6.0, 128);
ff_init_ff_sine_windows(10);
+ ff_init_ff_sine_windows( 9);
ff_init_ff_sine_windows( 7);
cbrt_tableinit();
@@ -1063,6 +1074,14 @@ static int decode_ics_info(AACContext *ac,
IndividualChannelStream *ics,
}
ics->window_sequence[1] = ics->window_sequence[0];
ics->window_sequence[0] = get_bits(gb, 2);
+ if (ac->oc[1].m4ac.object_type == AOT_ER_AAC_LD &&
+ ics->window_sequence[0] != ONLY_LONG_SEQUENCE) {
+ av_log(ac->avctx, AV_LOG_ERROR,
+ "AAC LD is only defined for ONLY_LONG_SEQUENCE but "
+ "window sequence %d found.\n", ics->window_sequence[0]);
+ ics->window_sequence[0] = ONLY_LONG_SEQUENCE;
+ return AVERROR_INVALIDDATA;
+ }
ics->use_kb_window[1] = ics->use_kb_window[0];
ics->use_kb_window[0] = get_bits1(gb);
ics->num_window_groups = 1;
@@ -1086,8 +1105,15 @@ static int decode_ics_info(AACContext *ac,
IndividualChannelStream *ics,
} else {
ics->max_sfb = get_bits(gb, 6);
ics->num_windows = 1;
- ics->swb_offset =
ff_swb_offset_1024[ac->oc[1].m4ac.sampling_index];
- ics->num_swb =
ff_aac_num_swb_1024[ac->oc[1].m4ac.sampling_index];
+ if (ac->oc[1].m4ac.object_type == AOT_ER_AAC_LD) {
+ ics->swb_offset =
ff_swb_offset_512[ac->oc[1].m4ac.sampling_index];
+ ics->num_swb =
ff_aac_num_swb_512[ac->oc[1].m4ac.sampling_index];
+ if (!ics->num_swb || !ics->swb_offset)
+ return AVERROR_BUG;
+ } else {
+ ics->swb_offset =
ff_swb_offset_1024[ac->oc[1].m4ac.sampling_index];
+ ics->num_swb =
ff_aac_num_swb_1024[ac->oc[1].m4ac.sampling_index];
+ }
ics->tns_max_bands =
ff_tns_max_bands_1024[ac->oc[1].m4ac.sampling_index];
ics->predictor_present = get_bits1(gb);
ics->predictor_reset_group = 0;
@@ -1102,6 +1128,11 @@ static int decode_ics_info(AACContext *ac,
IndividualChannelStream *ics,
"Prediction is not allowed in AAC-LC.\n");
return AVERROR_INVALIDDATA;
} else {
+ if (ac->oc[1].m4ac.object_type == AOT_ER_AAC_LD) {
+ av_log(ac->avctx, AV_LOG_ERROR,
+ "LTP in ER AAC LD not yet implemented.\n");
+ return AVERROR_PATCHWELCOME;
+ }
if ((ics->ltp.present = get_bits(gb, 1)))
decode_ltp(&ics->ltp, gb, ics->max_sfb);
}
@@ -2254,7 +2285,7 @@ static void update_ltp(AACContext *ac,
SingleChannelElement *sce)
/**
* Conduct IMDCT and windowing.
*/
-static void imdct_and_windowing(AACContext *ac, SingleChannelElement *sce)
+static void imdct_and_windowing_classic(AACContext *ac, SingleChannelElement
*sce)
{
IndividualChannelStream *ics = &sce->ics;
float *in = sce->coeffs;
@@ -2314,6 +2345,25 @@ static void imdct_and_windowing(AACContext *ac,
SingleChannelElement *sce)
}
}
+static void imdct_and_windowing_ld(AACContext *ac, SingleChannelElement *sce)
+{
+ IndividualChannelStream *ics = &sce->ics;
+ float *in = sce->coeffs;
+ float *out = sce->ret;
+ float *saved = sce->saved;
+ const float *lwindow_prev = ics->use_kb_window[1] ? ff_aac_kbd_long_512 :
ff_sine_512;
+ float *buf = ac->buf_mdct;
+
+ // imdct
+ ac->mdct.imdct_half(&ac->mdct_ld, buf, in);
+
+ /* window overlapping */
+ ac->fdsp.vector_fmul_window( out, saved, buf,
lwindow_prev, 256);
+
+ // buffer update
+ memcpy( saved, buf + 256, 256 *
sizeof(float));
+}
+
/**
* Apply dependent channel coupling (applied before IMDCT).
*
@@ -2410,6 +2460,12 @@ static void apply_channel_coupling(AACContext *ac,
ChannelElement *cc,
static void spectral_to_sample(AACContext *ac)
{
int i, type;
+ void (*imdct_and_windowing)(AACContext *ac, SingleChannelElement *sce);
+ if (ac->oc[1].m4ac.object_type == AOT_ER_AAC_LD) {
+ imdct_and_windowing = imdct_and_windowing_ld;
+ } else {
+ imdct_and_windowing = imdct_and_windowing_classic;
+ }
for (type = 3; type >= 0; type--) {
for (i = 0; i < MAX_ELEM_ID; i++) {
ChannelElement *che = ac->che[type][i];
@@ -2503,6 +2559,9 @@ static int aac_decode_er_frame(AVCodecContext *avctx,
void *data,
int samples = 1024;
int chan_config = ac->oc[1].m4ac.chan_config;
+ if (ac->oc[1].m4ac.object_type == AOT_ER_AAC_LD)
+ samples >>= 1;
+
ac->frame = data;
if ((err = frame_configure_elements(avctx)) < 0)
@@ -2761,6 +2820,7 @@ static av_cold int aac_decode_close(AVCodecContext *avctx)
ff_mdct_end(&ac->mdct);
ff_mdct_end(&ac->mdct_small);
+ ff_mdct_end(&ac->mdct_ld);
ff_mdct_end(&ac->mdct_ltp);
return 0;
}
diff --git a/libavcodec/aactab.c b/libavcodec/aactab.c
index 9176e37..b96a7d5 100644
--- a/libavcodec/aactab.c
+++ b/libavcodec/aactab.c
@@ -34,12 +34,17 @@
#include <stdint.h>
DECLARE_ALIGNED(32, float, ff_aac_kbd_long_1024)[1024];
+DECLARE_ALIGNED(32, float, ff_aac_kbd_long_512 )[512];
DECLARE_ALIGNED(32, 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, 40
};
+const uint8_t ff_aac_num_swb_512[] = {
+ 0, 0, 0, 36, 36, 37, 31, 31, 0, 0, 0, 0, 0
+};
+
const uint8_t ff_aac_num_swb_128[] = {
12, 12, 12, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15
};
@@ -1114,6 +1119,14 @@ static const uint16_t swb_offset_1024_48[] = {
928, 1024
};
+static const uint16_t swb_offset_512_48[] = {
+ 0, 4, 8, 12, 16, 20, 24, 28,
+ 32, 36, 40, 44, 48, 52, 56, 60,
+ 68, 76, 84, 92, 100, 112, 124, 136,
+ 148, 164, 184, 208, 236, 268, 300, 332,
+ 364, 396, 428, 460, 512
+};
+
static const uint16_t swb_offset_128_48[] = {
0, 4, 8, 12, 16, 20, 28, 36,
44, 56, 68, 80, 96, 112, 128
@@ -1129,6 +1142,14 @@ static const uint16_t swb_offset_1024_32[] = {
928, 960, 992, 1024
};
+static const uint16_t swb_offset_512_32[] = {
+ 0, 4, 8, 12, 16, 20, 24, 28,
+ 32, 36, 40, 44, 48, 52, 56, 64,
+ 72, 80, 88, 96, 108, 120, 132, 144,
+ 160, 176, 192, 212, 236, 260, 288, 320,
+ 352, 384, 416, 448, 480, 512
+};
+
static const uint16_t swb_offset_1024_24[] = {
0, 4, 8, 12, 16, 20, 24, 28,
32, 36, 40, 44, 52, 60, 68, 76,
@@ -1138,6 +1159,13 @@ static const uint16_t swb_offset_1024_24[] = {
600, 652, 704, 768, 832, 896, 960, 1024
};
+static const uint16_t swb_offset_512_24[] = {
+ 0, 4, 8, 12, 16, 20, 24, 28,
+ 32, 36, 40, 44, 52, 60, 68, 80,
+ 92, 104, 120, 140, 164, 192, 224, 256,
+ 288, 320, 352, 384, 416, 448, 480, 512,
+};
+
static const uint16_t swb_offset_128_24[] = {
0, 4, 8, 12, 16, 20, 24, 28,
36, 44, 52, 64, 76, 92, 108, 128
@@ -1179,6 +1207,14 @@ const uint16_t * const ff_swb_offset_1024[] = {
swb_offset_1024_8
};
+const uint16_t * const ff_swb_offset_512[] = {
+ NULL, NULL, NULL,
+ swb_offset_512_48, swb_offset_512_48, swb_offset_512_32,
+ swb_offset_512_24, swb_offset_512_24, NULL,
+ NULL, NULL, NULL,
+ NULL
+};
+
const uint16_t * const ff_swb_offset_128[] = {
/* The last entry on the following row is swb_offset_128_64 but is a
duplicate of swb_offset_128_96. */
diff --git a/libavcodec/aactab.h b/libavcodec/aactab.h
index 56e5796..bf1576e 100644
--- a/libavcodec/aactab.h
+++ b/libavcodec/aactab.h
@@ -45,6 +45,7 @@
* @{
*/
DECLARE_ALIGNED(32, extern float, ff_aac_kbd_long_1024)[1024];
+DECLARE_ALIGNED(32, extern float, ff_aac_kbd_long_512 )[512];
DECLARE_ALIGNED(32, extern float, ff_aac_kbd_short_128)[128];
// @}
@@ -52,6 +53,7 @@ DECLARE_ALIGNED(32, extern float, ff_aac_kbd_short_128)[128];
* @{
*/
extern const uint8_t ff_aac_num_swb_1024[];
+extern const uint8_t ff_aac_num_swb_512 [];
extern const uint8_t ff_aac_num_swb_128 [];
// @}
@@ -69,6 +71,7 @@ extern const float *ff_aac_codebook_vector_vals[];
extern const uint16_t *ff_aac_codebook_vector_idx[];
extern const uint16_t * const ff_swb_offset_1024[13];
+extern const uint16_t * const ff_swb_offset_512 [13];
extern const uint16_t * const ff_swb_offset_128 [13];
extern const uint8_t ff_tns_max_bands_1024[13];
--
1.8.1.2
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