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aacdec.c
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1 /*
2  * raw ADTS AAC demuxer
3  * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>
4  * Copyright (c) 2009 Robert Swain ( rob opendot cl )
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include "libavutil/intreadwrite.h"
24 #include "avformat.h"
25 #include "internal.h"
26 #include "rawdec.h"
27 #include "id3v1.h"
28 #include "apetag.h"
29 
31 {
32  int max_frames = 0, first_frames = 0;
33  int fsize, frames;
34  const uint8_t *buf0 = p->buf;
35  const uint8_t *buf2;
36  const uint8_t *buf;
37  const uint8_t *end = buf0 + p->buf_size - 7;
38 
39  buf = buf0;
40 
41  for (; buf < end; buf = buf2 + 1) {
42  buf2 = buf;
43 
44  for (frames = 0; buf2 < end; frames++) {
45  uint32_t header = AV_RB16(buf2);
46  if ((header & 0xFFF6) != 0xFFF0) {
47  if (buf != buf0) {
48  // Found something that isn't an ADTS header, starting
49  // from a position other than the start of the buffer.
50  // Discard the count we've accumulated so far since it
51  // probably was a false positive.
52  frames = 0;
53  }
54  break;
55  }
56  fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF;
57  if (fsize < 7)
58  break;
59  fsize = FFMIN(fsize, end - buf2);
60  buf2 += fsize;
61  }
62  max_frames = FFMAX(max_frames, frames);
63  if (buf == buf0)
64  first_frames = frames;
65  }
66 
67  if (first_frames >= 3)
68  return AVPROBE_SCORE_EXTENSION + 1;
69  else if (max_frames > 100)
71  else if (max_frames >= 3)
72  return AVPROBE_SCORE_EXTENSION / 2;
73  else if (max_frames >= 1)
74  return 1;
75  else
76  return 0;
77 }
78 
80 {
81  AVStream *st;
82 
83  st = avformat_new_stream(s, NULL);
84  if (!st)
85  return AVERROR(ENOMEM);
86 
90 
91  ff_id3v1_read(s);
92  if (s->pb->seekable &&
94  int64_t cur = avio_tell(s->pb);
96  avio_seek(s->pb, cur, SEEK_SET);
97  }
98 
99  // LCM of all possible ADTS sample rates
100  avpriv_set_pts_info(st, 64, 1, 28224000);
101 
102  return 0;
103 }
104 
106  .name = "aac",
107  .long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
108  .read_probe = adts_aac_probe,
109  .read_header = adts_aac_read_header,
110  .read_packet = ff_raw_read_partial_packet,
111  .flags = AVFMT_GENERIC_INDEX,
112  .extensions = "aac",
113  .mime_type = "audio/aac,audio/aacp,audio/x-aac",
114  .raw_codec_id = AV_CODEC_ID_AAC,
115 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4436
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3922
void ff_id3v1_read(AVFormatContext *s)
Read an ID3v1 tag.
Definition: id3v1.c:235
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:230
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:87
Format I/O context.
Definition: avformat.h:1325
uint8_t
static int adts_aac_read_header(AVFormatContext *s)
Definition: aacdec.c:79
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
enum AVStreamParseType need_parsing
Definition: avformat.h:1063
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4074
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:87
AVDictionaryEntry * av_dict_get(const AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags)
Get a dictionary entry with matching key.
Definition: dict.c:39
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:511
static const uint8_t header[24]
Definition: sdr2.c:67
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:810
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1539
#define AVERROR(e)
Definition: error.h:43
int ff_raw_read_partial_packet(AVFormatContext *s, AVPacket *pkt)
Definition: rawdec.c:35
AVInputFormat ff_aac_demuxer
Definition: aacdec.c:105
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3918
#define FFMAX(a, b)
Definition: common.h:94
int64_t ff_ape_parse_tag(AVFormatContext *s)
Read and parse an APE tag.
Definition: apetag.c:118
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:462
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:461
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:243
#define FFMIN(a, b)
Definition: common.h:96
int frames
Definition: movenc.c:65
Stream structure.
Definition: avformat.h:876
AVIOContext * pb
I/O context.
Definition: avformat.h:1367
void * buf
Definition: avisynth_c.h:553
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:485
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:469
This structure contains the data a format has to probe a file.
Definition: avformat.h:459
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:706
static int adts_aac_probe(AVProbeData *p)
Definition: aacdec.c:30
Main libavformat public API header.
struct AVInputFormat * iformat
The input container format.
Definition: avformat.h:1337
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:660
#define AV_DICT_IGNORE_SUFFIX
Return first entry in a dictionary whose first part corresponds to the search key, ignoring the suffix of the found key string.
Definition: dict.h:70
AVCodecParameters * codecpar
Definition: avformat.h:1228
static int64_t fsize(FILE *f)
Definition: audiomatch.c:28