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submodule
ffmpeg
Commits
50d1f443
Commit
50d1f443
authored
Sep 02, 2012
by
Anton Khirnov
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mp3dec: read Xing frame TOC index
parent
2d1a1a7f
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1 changed file
with
57 additions
and
1 deletion
+57
-1
mp3dec.c
libavformat/mp3dec.c
+57
-1
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libavformat/mp3dec.c
View file @
50d1f443
...
...
@@ -31,6 +31,9 @@
#define XING_FLAG_FRAMES 0x01
#define XING_FLAG_SIZE 0x02
#define XING_FLAG_TOC 0x04
#define XING_TOC_COUNT 100
/* mp3 read */
...
...
@@ -94,6 +97,26 @@ static int mp3_read_probe(AVProbeData *p)
//mpegps_mp3_unrecognized_format.mpg has max_frames=3
}
static
void
read_xing_toc
(
AVFormatContext
*
s
,
int64_t
filesize
,
int64_t
duration
)
{
int
i
;
if
(
!
filesize
&&
!
(
filesize
=
avio_size
(
s
->
pb
)))
{
av_log
(
s
,
AV_LOG_WARNING
,
"Cannot determine file size, skipping TOC table.
\n
"
);
return
;
}
for
(
i
=
0
;
i
<
XING_TOC_COUNT
;
i
++
)
{
uint8_t
b
=
avio_r8
(
s
->
pb
);
av_add_index_entry
(
s
->
streams
[
0
],
av_rescale
(
b
,
filesize
,
256
),
av_rescale
(
i
,
duration
,
XING_TOC_COUNT
),
0
,
0
,
AVINDEX_KEYFRAME
);
}
}
/**
* Try to find Xing/Info/VBRI tags and compute duration from info therein
*/
...
...
@@ -115,6 +138,8 @@ static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
if
(
c
.
layer
!=
3
)
return
-
1
;
spf
=
c
.
lsf
?
576
:
1152
;
/* Samples per frame, layer 3 */
/* Check for Xing / Info tag */
avio_skip
(
s
->
pb
,
xing_offtbl
[
c
.
lsf
==
1
][
c
.
nb_channels
==
1
]);
v
=
avio_rb32
(
s
->
pb
);
...
...
@@ -124,6 +149,9 @@ static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
frames
=
avio_rb32
(
s
->
pb
);
if
(
v
&
XING_FLAG_SIZE
)
size
=
avio_rb32
(
s
->
pb
);
if
(
v
&
XING_FLAG_TOC
&&
frames
)
read_xing_toc
(
s
,
size
,
av_rescale_q
(
frames
,
(
AVRational
){
spf
,
c
.
sample_rate
},
st
->
time_base
));
}
/* Check for VBRI tag (always 32 bytes after end of mpegaudio header) */
...
...
@@ -145,7 +173,6 @@ static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
/* Skip the vbr tag frame */
avio_seek
(
s
->
pb
,
base
+
vbrtag_size
,
SEEK_SET
);
spf
=
c
.
lsf
?
576
:
1152
;
/* Samples per frame, layer 3 */
if
(
frames
)
st
->
duration
=
av_rescale_q
(
frames
,
(
AVRational
){
spf
,
c
.
sample_rate
},
st
->
time_base
);
...
...
@@ -206,12 +233,41 @@ static int mp3_read_packet(AVFormatContext *s, AVPacket *pkt)
return
ret
;
}
static
int
mp3_seek
(
AVFormatContext
*
s
,
int
stream_index
,
int64_t
timestamp
,
int
flags
)
{
AVIndexEntry
*
ie
;
AVStream
*
st
=
s
->
streams
[
0
];
int64_t
ret
=
av_index_search_timestamp
(
st
,
timestamp
,
flags
);
uint32_t
header
=
0
;
if
(
ret
<
0
)
return
ret
;
ie
=
&
st
->
index_entries
[
ret
];
ret
=
avio_seek
(
s
->
pb
,
ie
->
pos
,
SEEK_SET
);
if
(
ret
<
0
)
return
ret
;
while
(
!
s
->
pb
->
eof_reached
)
{
header
=
(
header
<<
8
)
+
avio_r8
(
s
->
pb
);
if
(
ff_mpa_check_header
(
header
)
>=
0
)
{
ff_update_cur_dts
(
s
,
st
,
ie
->
timestamp
);
ret
=
avio_seek
(
s
->
pb
,
-
4
,
SEEK_CUR
);
return
(
ret
>=
0
)
?
0
:
ret
;
}
}
return
AVERROR_EOF
;
}
AVInputFormat
ff_mp3_demuxer
=
{
.
name
=
"mp3"
,
.
long_name
=
NULL_IF_CONFIG_SMALL
(
"MP2/3 (MPEG audio layer 2/3)"
),
.
read_probe
=
mp3_read_probe
,
.
read_header
=
mp3_read_header
,
.
read_packet
=
mp3_read_packet
,
.
read_seek
=
mp3_seek
,
.
flags
=
AVFMT_GENERIC_INDEX
,
.
extensions
=
"mp2,mp3,m2a"
,
/* XXX: use probe */
};
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