[FFmpeg-devel] [PATCH 1/4] aac_latm: Allow unaligned AudioSpecificConfig
Alex Converse
alex.converse at gmail.com
Thu Feb 9 19:40:36 EET 2017
Fixes ticket 4730
---
libavcodec/aacdec.c | 26 ++++++++------
libavcodec/aacdec_template.c | 82 ++++++++++++++++++++++++++++----------------
libavcodec/mpeg4audio.c | 76 ++++++++++++++++++++++------------------
libavcodec/mpeg4audio.h | 12 ++++++-
4 files changed, 120 insertions(+), 76 deletions(-)
diff --git a/libavcodec/aacdec.c b/libavcodec/aacdec.c
index ee9b4eb45f..709ac7cdf8 100644
--- a/libavcodec/aacdec.c
+++ b/libavcodec/aacdec.c
@@ -284,9 +284,10 @@ static int latm_decode_audio_specific_config(struct LATMContext *latmctx,
AACContext *ac = &latmctx->aac_ctx;
AVCodecContext *avctx = ac->avctx;
MPEG4AudioConfig m4ac = { 0 };
+ GetBitContext gbc;
int config_start_bit = get_bits_count(gb);
int sync_extension = 0;
- int bits_consumed, esize;
+ int bits_consumed, esize, i;
if (asclen) {
sync_extension = 1;
@@ -294,19 +295,19 @@ static int latm_decode_audio_specific_config(struct LATMContext *latmctx,
} else
asclen = get_bits_left(gb);
- if (config_start_bit % 8) {
- avpriv_request_sample(latmctx->aac_ctx.avctx,
- "Non-byte-aligned audio-specific config");
- return AVERROR_PATCHWELCOME;
- }
if (asclen <= 0)
return AVERROR_INVALIDDATA;
- bits_consumed = decode_audio_specific_config(NULL, avctx, &m4ac,
- gb->buffer + (config_start_bit / 8),
- asclen, sync_extension);
- if (bits_consumed < 0)
+ init_get_bits(&gbc, gb->buffer, config_start_bit + asclen);
+ skip_bits_long(&gbc, config_start_bit);
+
+ bits_consumed = decode_audio_specific_config_gb(NULL, avctx, &m4ac,
+ &gbc, config_start_bit,
+ sync_extension);
+
+ if (bits_consumed < config_start_bit)
return AVERROR_INVALIDDATA;
+ bits_consumed -= config_start_bit;
if (!latmctx->initialized ||
ac->oc[1].m4ac.sample_rate != m4ac.sample_rate ||
@@ -329,7 +330,10 @@ static int latm_decode_audio_specific_config(struct LATMContext *latmctx,
}
avctx->extradata_size = esize;
- memcpy(avctx->extradata, gb->buffer + (config_start_bit/8), esize);
+ gbc = *gb;
+ for (i = 0; i < esize; i++) {
+ avctx->extradata[i] = get_bits(&gbc, 8);
+ }
memset(avctx->extradata+esize, 0, AV_INPUT_BUFFER_PADDING_SIZE);
}
skip_bits_long(gb, bits_consumed);
diff --git a/libavcodec/aacdec_template.c b/libavcodec/aacdec_template.c
index 83e9fb55ba..2a06f82efe 100644
--- a/libavcodec/aacdec_template.c
+++ b/libavcodec/aacdec_template.c
@@ -715,6 +715,13 @@ static void decode_channel_map(uint8_t layout_map[][3],
}
}
+static inline void relative_align_get_bits(GetBitContext *gb,
+ int reference_position) {
+ int n = (reference_position - get_bits_count(gb) & 7);
+ if (n)
+ skip_bits(gb, n);
+}
+
/**
* Decode program configuration element; reference: table 4.2.
*
@@ -722,7 +729,7 @@ static void decode_channel_map(uint8_t layout_map[][3],
*/
static int decode_pce(AVCodecContext *avctx, MPEG4AudioConfig *m4ac,
uint8_t (*layout_map)[3],
- GetBitContext *gb)
+ GetBitContext *gb, int byte_align_ref)
{
int num_front, num_side, num_back, num_lfe, num_assoc_data, num_cc;
int sampling_index;
@@ -770,7 +777,7 @@ static int decode_pce(AVCodecContext *avctx, MPEG4AudioConfig *m4ac,
decode_channel_map(layout_map + tags, AAC_CHANNEL_CC, gb, num_cc);
tags += num_cc;
- align_get_bits(gb);
+ relative_align_get_bits(gb, byte_align_ref);
/* comment field, first byte is length */
comment_len = get_bits(gb, 8) * 8;
@@ -792,6 +799,7 @@ static int decode_pce(AVCodecContext *avctx, MPEG4AudioConfig *m4ac,
*/
static int decode_ga_specific_config(AACContext *ac, AVCodecContext *avctx,
GetBitContext *gb,
+ int get_bit_alignment,
MPEG4AudioConfig *m4ac,
int channel_config)
{
@@ -815,7 +823,7 @@ static int decode_ga_specific_config(AACContext *ac, AVCodecContext *avctx,
if (channel_config == 0) {
skip_bits(gb, 4); // element_instance_tag
- tags = decode_pce(avctx, m4ac, layout_map, gb);
+ tags = decode_pce(avctx, m4ac, layout_map, gb, get_bit_alignment);
if (tags < 0)
return tags;
} else {
@@ -937,37 +945,25 @@ static int decode_eld_specific_config(AACContext *ac, AVCodecContext *avctx,
* @param ac pointer to AACContext, may be null
* @param avctx pointer to AVCCodecContext, used for logging
* @param m4ac pointer to MPEG4AudioConfig, used for parsing
- * @param data pointer to buffer holding an audio specific config
- * @param bit_size size of audio specific config or data in bits
+ * @param gb buffer holding an audio specific config
+ * @param get_bit_alignment relative alignment for byte align operations
* @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, int64_t bit_size,
- int sync_extension)
+static int decode_audio_specific_config_gb(AACContext *ac,
+ AVCodecContext *avctx,
+ MPEG4AudioConfig *m4ac,
+ GetBitContext *gb,
+ int get_bit_alignment,
+ int sync_extension)
{
- GetBitContext gb;
int i, ret;
+ GetBitContext gbc = *gb;
- if (bit_size < 0 || bit_size > INT_MAX) {
- av_log(avctx, AV_LOG_ERROR, "Audio specific config size is invalid\n");
+ if ((i = avpriv_mpeg4audio_get_config_gb(m4ac, &gbc, sync_extension)) < 0)
return AVERROR_INVALIDDATA;
- }
- ff_dlog(avctx, "audio specific config size %d\n", (int)bit_size >> 3);
- for (i = 0; i < bit_size >> 3; i++)
- ff_dlog(avctx, "%02x ", data[i]);
- ff_dlog(avctx, "\n");
-
- if ((ret = init_get_bits(&gb, data, bit_size)) < 0)
- return ret;
-
- if ((i = avpriv_mpeg4audio_get_config(m4ac, data, bit_size,
- sync_extension)) < 0)
- return AVERROR_INVALIDDATA;
if (m4ac->sampling_index > 12) {
av_log(avctx, AV_LOG_ERROR,
"invalid sampling rate index %d\n",
@@ -982,7 +978,7 @@ static int decode_audio_specific_config(AACContext *ac,
return AVERROR_INVALIDDATA;
}
- skip_bits_long(&gb, i);
+ skip_bits_long(gb, i);
switch (m4ac->object_type) {
case AOT_AAC_MAIN:
@@ -990,12 +986,12 @@ static int decode_audio_specific_config(AACContext *ac,
case AOT_AAC_LTP:
case AOT_ER_AAC_LC:
case AOT_ER_AAC_LD:
- if ((ret = decode_ga_specific_config(ac, avctx, &gb,
+ if ((ret = decode_ga_specific_config(ac, avctx, gb, get_bit_alignment,
m4ac, m4ac->chan_config)) < 0)
return ret;
break;
case AOT_ER_AAC_ELD:
- if ((ret = decode_eld_specific_config(ac, avctx, &gb,
+ if ((ret = decode_eld_specific_config(ac, avctx, gb,
m4ac, m4ac->chan_config)) < 0)
return ret;
break;
@@ -1013,7 +1009,33 @@ static int decode_audio_specific_config(AACContext *ac,
m4ac->sample_rate, m4ac->sbr,
m4ac->ps);
- return get_bits_count(&gb);
+ return get_bits_count(gb);
+}
+
+static int decode_audio_specific_config(AACContext *ac,
+ AVCodecContext *avctx,
+ MPEG4AudioConfig *m4ac,
+ const uint8_t *data, int64_t bit_size,
+ int sync_extension)
+{
+ int i, ret;
+ GetBitContext gb;
+
+ if (bit_size < 0 || bit_size > INT_MAX) {
+ av_log(avctx, AV_LOG_ERROR, "Audio specific config size is invalid\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ ff_dlog(avctx, "audio specific config size %d\n", (int)bit_size >> 3);
+ for (i = 0; i < bit_size >> 3; i++)
+ ff_dlog(avctx, "%02x ", data[i]);
+ ff_dlog(avctx, "\n");
+
+ if ((ret = init_get_bits(&gb, data, bit_size)) < 0)
+ return ret;
+
+ return decode_audio_specific_config_gb(ac, avctx, m4ac, &gb, 0,
+ sync_extension);
}
/**
@@ -3003,7 +3025,7 @@ static int aac_decode_frame_int(AVCodecContext *avctx, void *data,
uint8_t layout_map[MAX_ELEM_ID*4][3];
int tags;
push_output_configuration(ac);
- tags = decode_pce(avctx, &ac->oc[1].m4ac, layout_map, gb);
+ tags = decode_pce(avctx, &ac->oc[1].m4ac, layout_map, gb, 0);
if (tags < 0) {
err = tags;
break;
diff --git a/libavcodec/mpeg4audio.c b/libavcodec/mpeg4audio.c
index 5f85b64cb8..9fe257838c 100644
--- a/libavcodec/mpeg4audio.c
+++ b/libavcodec/mpeg4audio.c
@@ -83,70 +83,62 @@ 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 bit_size, int sync_extension)
+int avpriv_mpeg4audio_get_config_gb(MPEG4AudioConfig *c, GetBitContext *gb,
+ int sync_extension)
{
- GetBitContext gb;
int specific_config_bitindex, ret;
-
- if (bit_size <= 0)
- return AVERROR_INVALIDDATA;
-
- ret = init_get_bits(&gb, buf, bit_size);
- if (ret < 0)
- return ret;
-
- c->object_type = get_object_type(&gb);
- c->sample_rate = get_sample_rate(&gb, &c->sampling_index);
- c->chan_config = get_bits(&gb, 4);
+ int start_bit_index = get_bits_count(gb);
+ c->object_type = get_object_type(gb);
+ c->sample_rate = get_sample_rate(gb, &c->sampling_index);
+ c->chan_config = get_bits(gb, 4);
if (c->chan_config < FF_ARRAY_ELEMS(ff_mpeg4audio_channels))
c->channels = ff_mpeg4audio_channels[c->chan_config];
c->sbr = -1;
c->ps = -1;
if (c->object_type == AOT_SBR || (c->object_type == AOT_PS &&
// check for W6132 Annex YYYY draft MP3onMP4
- !(show_bits(&gb, 3) & 0x03 && !(show_bits(&gb, 9) & 0x3F)))) {
+ !(show_bits(gb, 3) & 0x03 && !(show_bits(gb, 9) & 0x3F)))) {
if (c->object_type == AOT_PS)
c->ps = 1;
c->ext_object_type = AOT_SBR;
c->sbr = 1;
- c->ext_sample_rate = get_sample_rate(&gb, &c->ext_sampling_index);
- c->object_type = get_object_type(&gb);
+ c->ext_sample_rate = get_sample_rate(gb, &c->ext_sampling_index);
+ c->object_type = get_object_type(gb);
if (c->object_type == AOT_ER_BSAC)
- c->ext_chan_config = get_bits(&gb, 4);
+ c->ext_chan_config = get_bits(gb, 4);
} else {
c->ext_object_type = AOT_NULL;
c->ext_sample_rate = 0;
}
- specific_config_bitindex = get_bits_count(&gb);
+ specific_config_bitindex = get_bits_count(gb);
if (c->object_type == AOT_ALS) {
- skip_bits(&gb, 5);
- if (show_bits_long(&gb, 24) != MKBETAG('\0','A','L','S'))
- skip_bits_long(&gb, 24);
+ skip_bits(gb, 5);
+ if (show_bits_long(gb, 24) != MKBETAG('\0','A','L','S'))
+ skip_bits_long(gb, 24);
- specific_config_bitindex = get_bits_count(&gb);
+ specific_config_bitindex = get_bits_count(gb);
- ret = parse_config_ALS(&gb, c);
+ ret = parse_config_ALS(gb, c);
if (ret < 0)
return ret;
}
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);
- c->ext_object_type = get_object_type(&gb);
- if (c->ext_object_type == AOT_SBR && (c->sbr = get_bits1(&gb)) == 1) {
- c->ext_sample_rate = get_sample_rate(&gb, &c->ext_sampling_index);
+ while (get_bits_left(gb) > 15) {
+ if (show_bits(gb, 11) == 0x2b7) { // sync extension
+ get_bits(gb, 11);
+ c->ext_object_type = get_object_type(gb);
+ if (c->ext_object_type == AOT_SBR && (c->sbr = get_bits1(gb)) == 1) {
+ c->ext_sample_rate = get_sample_rate(gb, &c->ext_sampling_index);
if (c->ext_sample_rate == c->sample_rate)
c->sbr = -1;
}
- if (get_bits_left(&gb) > 11 && get_bits(&gb, 11) == 0x548)
- c->ps = get_bits1(&gb);
+ if (get_bits_left(gb) > 11 && get_bits(gb, 11) == 0x548)
+ c->ps = get_bits1(gb);
break;
} else
- get_bits1(&gb); // skip 1 bit
+ get_bits1(gb); // skip 1 bit
}
}
@@ -157,7 +149,23 @@ int avpriv_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf,
if ((c->ps == -1 && c->object_type != AOT_AAC_LC) || c->channels & ~0x01)
c->ps = 0;
- return specific_config_bitindex;
+ return specific_config_bitindex - start_bit_index;
+}
+
+int avpriv_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf,
+ int bit_size, int sync_extension)
+{
+ GetBitContext gb;
+ int ret;
+
+ if (bit_size <= 0)
+ return AVERROR_INVALIDDATA;
+
+ ret = init_get_bits(&gb, buf, bit_size);
+ if (ret < 0)
+ return ret;
+
+ return avpriv_mpeg4audio_get_config_gb(c, &gb, sync_extension);
}
static av_always_inline unsigned int copy_bits(PutBitContext *pb,
diff --git a/libavcodec/mpeg4audio.h b/libavcodec/mpeg4audio.h
index 8239081747..5f362e87e3 100644
--- a/libavcodec/mpeg4audio.h
+++ b/libavcodec/mpeg4audio.h
@@ -45,7 +45,17 @@ extern av_export const int avpriv_mpeg4audio_sample_rates[16];
extern const uint8_t ff_mpeg4audio_channels[8];
/**
- * Parse MPEG-4 systems extradata to retrieve audio configuration.
+ * Parse MPEG-4 systems extradata from a potentially unaligned GetBitContext to retrieve audio configuration.
+ * @param[in] c MPEG4AudioConfig structure to fill.
+ * @param[in] gb Extradata from container.
+ * @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 avpriv_mpeg4audio_get_config_gb(MPEG4AudioConfig *c, GetBitContext *gb,
+ int sync_extension);
+
+/**
+ * Parse MPEG-4 systems extradata from a raw buffer 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.
--
2.11.0.483.g087da7b7c-goog
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