Pass the correct size in bits to mpeg4audio_get_config and add a flag
to disable parsing of the sync extension when the size is not known.
Latm with AudioMuxVersion 0 does not specify the size of the audio
specific config. Data after the audio specific config can be
misinterpreted as sync extension resulting in random and wrong configs.
Since all other users og avpriv_mpeg4audio_get_config know the size
in bytes and have zero padding after the config a wrapper function
is added to retain API/ABI compatibility.
---
libavcodec/aacdec.c | 33 +++++++++++++++++++++------------
libavcodec/mpeg4audio.c | 13 ++++++++++---
libavcodec/mpeg4audio.h | 12 ++++++++++++
3 files changed, 43 insertions(+), 15 deletions(-)
diff --git a/libavcodec/aacdec.c b/libavcodec/aacdec.c
index ca69e77..d59e1a8 100644
--- a/libavcodec/aacdec.c
+++ b/libavcodec/aacdec.c
@@ -453,14 +453,16 @@ static int decode_ga_specific_config(AACContext *ac,
AVCodecContext *avctx,
* @param avctx pointer to AVCCodecContext, used for logging
* @param m4ac pointer to MPEG4AudioConfig, used for parsing
* @param data pointer to AVCodecContext extradata
- * @param data_size size of AVCCodecContext extradata
+ * @param bit_size size of AVCCodecContext extradata in bits
+ * @param sync_extension look for an appended sync extension
*
* @return Returns error status or number of consumed bits. <0 - error
*/
static int decode_audio_specific_config(AACContext *ac,
AVCodecContext *avctx,
MPEG4AudioConfig *m4ac,
- const uint8_t *data, int data_size)
+ const uint8_t *data, int bit_size,
+ int sync_extension)
{
GetBitContext gb;
int i;
@@ -470,9 +472,9 @@ static int decode_audio_specific_config(AACContext *ac,
av_dlog(avctx, "%02x ", avctx->extradata[i]);
av_dlog(avctx, "\n");
- init_get_bits(&gb, data, data_size * 8);
+ init_get_bits(&gb, data, bit_size);
- if ((i = avpriv_mpeg4audio_get_config(m4ac, data, data_size)) < 0)
+ if ((i = ff_mpeg4audio_get_config(m4ac, data, bit_size, sync_extension)) <
0)
return -1;
if (m4ac->sampling_index > 12) {
av_log(avctx, AV_LOG_ERROR, "invalid sampling rate index %d\n",
m4ac->sampling_index);
@@ -572,7 +574,7 @@ static av_cold int aac_decode_init(AVCodecContext *avctx)
if (avctx->extradata_size > 0) {
if (decode_audio_specific_config(ac, ac->avctx, &ac->m4ac,
avctx->extradata,
- avctx->extradata_size) < 0)
+ avctx->extradata_size*8, 1) < 0)
return -1;
} else {
int sr, i;
@@ -2309,12 +2311,19 @@ static inline uint32_t latm_get_value(GetBitContext *b)
}
static int latm_decode_audio_specific_config(struct LATMContext *latmctx,
- GetBitContext *gb)
+ GetBitContext *gb, int asclen)
{
AVCodecContext *avctx = latmctx->aac_ctx.avctx;
MPEG4AudioConfig m4ac;
- int config_start_bit = get_bits_count(gb);
- int bits_consumed, esize;
+ int config_start_bit = get_bits_count(gb);
+ int bits_consumed, esize;
+ int sync_extension = 0;
+
+ if (asclen) {
+ sync_extension = 0;
+ asclen = FFMIN(asclen, get_bits_left(gb));
+ } else
+ asclen = get_bits_left(gb);
if (config_start_bit % 8) {
av_log_missing_feature(latmctx->aac_ctx.avctx, "audio specific "
@@ -2324,7 +2333,7 @@ static int latm_decode_audio_specific_config(struct
LATMContext *latmctx,
bits_consumed =
decode_audio_specific_config(NULL, avctx, &m4ac,
gb->buffer + (config_start_bit / 8),
- get_bits_left(gb) / 8);
+ asclen, sync_extension);
if (bits_consumed < 0)
return AVERROR_INVALIDDATA;
@@ -2382,11 +2391,11 @@ static int read_stream_mux_config(struct LATMContext
*latmctx,
// for all but first stream: use_same_config = get_bits(gb, 1);
if (!audio_mux_version) {
- if ((ret = latm_decode_audio_specific_config(latmctx, gb)) < 0)
+ if ((ret = latm_decode_audio_specific_config(latmctx, gb, 0)) < 0)
return ret;
} else {
int ascLen = latm_get_value(gb);
- if ((ret = latm_decode_audio_specific_config(latmctx, gb)) < 0)
+ if ((ret = latm_decode_audio_specific_config(latmctx, gb, ascLen))
< 0)
return ret;
ascLen -= ret;
skip_bits_long(gb, ascLen);
@@ -2508,7 +2517,7 @@ static int latm_decode_frame(AVCodecContext *avctx, void
*out, int *out_size,
} else {
if ((err = decode_audio_specific_config(
&latmctx->aac_ctx, avctx, &latmctx->aac_ctx.m4ac,
- avctx->extradata, avctx->extradata_size)) < 0)
+ avctx->extradata, avctx->extradata_size*8, 1)) < 0)
return err;
latmctx->initialized = 1;
}
diff --git a/libavcodec/mpeg4audio.c b/libavcodec/mpeg4audio.c
index f9e866f..cee508e 100644
--- a/libavcodec/mpeg4audio.c
+++ b/libavcodec/mpeg4audio.c
@@ -76,12 +76,13 @@ static inline int get_sample_rate(GetBitContext *gb, int
*index)
avpriv_mpeg4audio_sample_rates[*index];
}
-int avpriv_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf, int
buf_size)
+int ff_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf,
+ int bit_size, int sync_extension)
{
GetBitContext gb;
int specific_config_bitindex;
- init_get_bits(&gb, buf, buf_size*8);
+ init_get_bits(&gb, buf, bit_size);
c->object_type = get_object_type(&gb);
c->sample_rate = get_sample_rate(&gb, &c->sampling_index);
c->chan_config = get_bits(&gb, 4);
@@ -117,7 +118,7 @@ int avpriv_mpeg4audio_get_config(MPEG4AudioConfig *c, const
uint8_t *buf, int bu
return -1;
}
- if (c->ext_object_type != AOT_SBR) {
+ if (c->ext_object_type != AOT_SBR && sync_extension) {
while (get_bits_left(&gb) > 15) {
if (show_bits(&gb, 11) == 0x2b7) { // sync extension
get_bits(&gb, 11);
@@ -142,6 +143,12 @@ int avpriv_mpeg4audio_get_config(MPEG4AudioConfig *c,
const uint8_t *buf, int bu
return specific_config_bitindex;
}
+int avpriv_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf,
+ int buf_size)
+{
+ return ff_mpeg4audio_get_config(c, buf, buf_size * 8, 1);
+}
+
static av_always_inline unsigned int copy_bits(PutBitContext *pb,
GetBitContext *gb,
int bits)
diff --git a/libavcodec/mpeg4audio.h b/libavcodec/mpeg4audio.h
index d6730b9..6468ddc 100644
--- a/libavcodec/mpeg4audio.h
+++ b/libavcodec/mpeg4audio.h
@@ -51,6 +51,18 @@ extern const uint8_t ff_mpeg4audio_channels[8];
*/
int avpriv_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf, int
buf_size);
+
+/**
+ * Parse MPEG-4 systems extradata to retrieve audio configuration.
+ * @param[in] c MPEG4AudioConfig structure to fill.
+ * @param[in] buf Extradata from container.
+ * @param[in] bit_size Extradata size in bits.
+ * @param[in] sync_extension look for a sync extension after config if true.
+ * @return On error -1 is returned, on success AudioSpecificConfig bit index
in extradata.
+ */
+int ff_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf,
+ int bit_size, int sync_extension);
+
enum AudioObjectType {
AOT_NULL,
// Support? Name
--
1.7.7.1
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