[FFmpeg-cvslog] aacdec: Add support for Error Resilience syntax.
Alex Converse
git at videolan.org
Thu Sep 19 12:50:32 CEST 2013
ffmpeg | branch: master | Alex Converse <alex.converse at gmail.com> | Sun Sep 15 23:32:23 2013 -0700| [5cdefc02079a5b899bdec09e15e2bb099cb01734] | committer: Alex Converse
aacdec: Add support for Error Resilience syntax.
This does not add support for any error resilience tools.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5cdefc02079a5b899bdec09e15e2bb099cb01734
---
Changelog | 1 +
libavcodec/aacdec.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 103 insertions(+), 10 deletions(-)
diff --git a/Changelog b/Changelog
index 501e1c5..58daaa5 100644
--- a/Changelog
+++ b/Changelog
@@ -34,6 +34,7 @@ version 10:
data read from an input file
- incomplete Voxware MetaSound decoder
- WebP decoder
+- Error Resilient AAC syntax (ER AAC LC) decoding
version 9:
diff --git a/libavcodec/aacdec.c b/libavcodec/aacdec.c
index 62246b6..a7c4151 100644
--- a/libavcodec/aacdec.c
+++ b/libavcodec/aacdec.c
@@ -706,7 +706,7 @@ static int decode_ga_specific_config(AACContext *ac, AVCodecContext *avctx,
MPEG4AudioConfig *m4ac,
int channel_config)
{
- int extension_flag, ret;
+ int extension_flag, ret, ep_config, res_flags;
uint8_t layout_map[MAX_ELEM_ID*4][3];
int tags = 0;
@@ -752,14 +752,30 @@ static int decode_ga_specific_config(AACContext *ac, AVCodecContext *avctx,
case AOT_ER_AAC_LTP:
case AOT_ER_AAC_SCALABLE:
case AOT_ER_AAC_LD:
- skip_bits(gb, 3); /* aacSectionDataResilienceFlag
- * aacScalefactorDataResilienceFlag
- * aacSpectralDataResilienceFlag
- */
+ res_flags = get_bits(gb, 3);
+ if (res_flags) {
+ av_log(avctx, AV_LOG_ERROR,
+ "AAC data resilience not supported (flags %x)\n",
+ res_flags);
+ return AVERROR_PATCHWELCOME;
+ }
break;
}
skip_bits1(gb); // extensionFlag3 (TBD in version 3)
}
+ switch (m4ac->object_type) {
+ case AOT_ER_AAC_LC:
+ case AOT_ER_AAC_LTP:
+ case AOT_ER_AAC_SCALABLE:
+ case AOT_ER_AAC_LD:
+ ep_config = get_bits(gb, 2);
+ if (ep_config) {
+ av_log(avctx, AV_LOG_ERROR,
+ "epConfig %d is not supported.\n",
+ ep_config);
+ return AVERROR_PATCHWELCOME;
+ }
+ }
return 0;
}
@@ -808,6 +824,7 @@ static int decode_audio_specific_config(AACContext *ac,
case AOT_AAC_MAIN:
case AOT_AAC_LC:
case AOT_AAC_LTP:
+ case AOT_ER_AAC_LC:
if ((ret = decode_ga_specific_config(ac, avctx, &gb,
m4ac, m4ac->chan_config)) < 0)
return ret;
@@ -1079,7 +1096,8 @@ static int decode_ics_info(AACContext *ac, IndividualChannelStream *ics,
if (decode_prediction(ac, ics, gb)) {
return AVERROR_INVALIDDATA;
}
- } else if (ac->oc[1].m4ac.object_type == AOT_AAC_LC) {
+ } else if (ac->oc[1].m4ac.object_type == AOT_AAC_LC ||
+ ac->oc[1].m4ac.object_type == AOT_ER_AAC_LC) {
av_log(ac->avctx, AV_LOG_ERROR,
"Prediction is not allowed in AAC-LC.\n");
return AVERROR_INVALIDDATA;
@@ -1701,7 +1719,7 @@ static int decode_ics(AACContext *ac, SingleChannelElement *sce,
TemporalNoiseShaping *tns = &sce->tns;
IndividualChannelStream *ics = &sce->ics;
float *out = sce->coeffs;
- int global_gain, pulse_present = 0;
+ int global_gain, er_syntax, pulse_present = 0;
int ret;
/* This assignment is to silence a GCC warning about the variable being used
@@ -1724,6 +1742,9 @@ static int decode_ics(AACContext *ac, SingleChannelElement *sce,
return ret;
pulse_present = 0;
+ er_syntax = ac->oc[1].m4ac.object_type == AOT_ER_AAC_LC ||
+ ac->oc[1].m4ac.object_type == AOT_ER_AAC_LTP ||
+ ac->oc[1].m4ac.object_type == AOT_ER_AAC_LD;
if (!scale_flag) {
if ((pulse_present = get_bits1(gb))) {
if (ics->window_sequence[0] == EIGHT_SHORT_SEQUENCE) {
@@ -1737,12 +1758,19 @@ static int decode_ics(AACContext *ac, SingleChannelElement *sce,
return AVERROR_INVALIDDATA;
}
}
- if ((tns->present = get_bits1(gb)) && decode_tns(ac, tns, gb, ics))
- return AVERROR_INVALIDDATA;
+ tns->present = get_bits1(gb);
+ if (tns->present && !er_syntax)
+ if (decode_tns(ac, tns, gb, ics) < 0)
+ return AVERROR_INVALIDDATA;
if (get_bits1(gb)) {
avpriv_request_sample(ac->avctx, "SSR");
return AVERROR_PATCHWELCOME;
}
+ // I see no textual basis in the spec for this occuring after SSR gain
+ // control, but this is what both reference and real implmentations do
+ if (tns->present && er_syntax)
+ if (decode_tns(ac, tns, gb, ics) < 0)
+ return AVERROR_INVALIDDATA;
}
if (decode_spectrum_and_dequant(ac, out, gb, sce->sf, pulse_present,
@@ -2466,6 +2494,61 @@ static int parse_adts_frame_header(AACContext *ac, GetBitContext *gb)
return size;
}
+static int aac_decode_er_frame(AVCodecContext *avctx, void *data,
+ int *got_frame_ptr, GetBitContext *gb)
+{
+ AACContext *ac = avctx->priv_data;
+ ChannelElement *che;
+ int err, i;
+ int samples = 1024;
+ int chan_config = ac->oc[1].m4ac.chan_config;
+
+ ac->frame = data;
+
+ if ((err = frame_configure_elements(avctx)) < 0)
+ return err;
+
+ ac->tags_mapped = 0;
+
+ if (chan_config < 0 || chan_config >= 8) {
+ avpriv_request_sample(avctx, "Unknown ER channel configuration %d",
+ ac->oc[1].m4ac.chan_config);
+ return AVERROR_INVALIDDATA;
+ }
+ for (i = 0; i < tags_per_config[chan_config]; i++) {
+ const int elem_type = aac_channel_layout_map[chan_config-1][i][0];
+ const int elem_id = aac_channel_layout_map[chan_config-1][i][1];
+ if (!(che=get_che(ac, elem_type, elem_id))) {
+ av_log(ac->avctx, AV_LOG_ERROR,
+ "channel element %d.%d is not allocated\n",
+ elem_type, elem_id);
+ return AVERROR_INVALIDDATA;
+ }
+ skip_bits(gb, 4);
+ switch (elem_type) {
+ case TYPE_SCE:
+ err = decode_ics(ac, &che->ch[0], gb, 0, 0);
+ break;
+ case TYPE_CPE:
+ err = decode_cpe(ac, gb, che);
+ break;
+ case TYPE_LFE:
+ err = decode_ics(ac, &che->ch[0], gb, 0, 0);
+ break;
+ }
+ if (err < 0)
+ return err;
+ }
+
+ spectral_to_sample(ac);
+
+ ac->frame->nb_samples = samples;
+ *got_frame_ptr = 1;
+
+ skip_bits_long(gb, get_bits_left(gb));
+ return 0;
+}
+
static int aac_decode_frame_int(AVCodecContext *avctx, void *data,
int *got_frame_ptr, GetBitContext *gb)
{
@@ -2639,7 +2722,16 @@ static int aac_decode_frame(AVCodecContext *avctx, void *data,
if ((err = init_get_bits(&gb, buf, buf_size * 8)) < 0)
return err;
- if ((err = aac_decode_frame_int(avctx, data, got_frame_ptr, &gb)) < 0)
+ switch (ac->oc[1].m4ac.object_type) {
+ case AOT_ER_AAC_LC:
+ case AOT_ER_AAC_LTP:
+ case AOT_ER_AAC_LD:
+ err = aac_decode_er_frame(avctx, data, got_frame_ptr, &gb);
+ break;
+ default:
+ err = aac_decode_frame_int(avctx, data, got_frame_ptr, &gb);
+ }
+ if (err < 0)
return err;
buf_consumed = (get_bits_count(&gb) + 7) >> 3;
More information about the ffmpeg-cvslog
mailing list