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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 "id3v1.h"
27 #include "apetag.h"
28 
29 #define ADTS_HEADER_SIZE 7
30 
32 {
33  int max_frames = 0, first_frames = 0;
34  int fsize, frames;
35  const uint8_t *buf0 = p->buf;
36  const uint8_t *buf2;
37  const uint8_t *buf;
38  const uint8_t *end = buf0 + p->buf_size - 7;
39 
40  buf = buf0;
41 
42  for (; buf < end; buf = buf2 + 1) {
43  buf2 = buf;
44 
45  for (frames = 0; buf2 < end; frames++) {
46  uint32_t header = AV_RB16(buf2);
47  if ((header & 0xFFF6) != 0xFFF0) {
48  if (buf != buf0) {
49  // Found something that isn't an ADTS header, starting
50  // from a position other than the start of the buffer.
51  // Discard the count we've accumulated so far since it
52  // probably was a false positive.
53  frames = 0;
54  }
55  break;
56  }
57  fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF;
58  if (fsize < 7)
59  break;
60  fsize = FFMIN(fsize, end - buf2);
61  buf2 += fsize;
62  }
63  max_frames = FFMAX(max_frames, frames);
64  if (buf == buf0)
65  first_frames = frames;
66  }
67 
68  if (first_frames >= 3)
69  return AVPROBE_SCORE_EXTENSION + 1;
70  else if (max_frames > 100)
72  else if (max_frames >= 3)
73  return AVPROBE_SCORE_EXTENSION / 2;
74  else if (first_frames >= 1)
75  return 1;
76  else
77  return 0;
78 }
79 
81 {
82  AVStream *st;
83  uint16_t state;
84 
85  st = avformat_new_stream(s, NULL);
86  if (!st)
87  return AVERROR(ENOMEM);
88 
92 
93  ff_id3v1_read(s);
94  if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) &&
96  int64_t cur = avio_tell(s->pb);
98  avio_seek(s->pb, cur, SEEK_SET);
99  }
100 
101  // skip data until the first ADTS frame is found
102  state = avio_r8(s->pb);
103  while (!avio_feof(s->pb) && avio_tell(s->pb) < s->probesize) {
104  state = (state << 8) | avio_r8(s->pb);
105  if ((state >> 4) != 0xFFF)
106  continue;
107  avio_seek(s->pb, -2, SEEK_CUR);
108  break;
109  }
110  if ((state >> 4) != 0xFFF)
111  return AVERROR_INVALIDDATA;
112 
113  // LCM of all possible ADTS sample rates
114  avpriv_set_pts_info(st, 64, 1, 28224000);
115 
116  return 0;
117 }
118 
120 {
121  int ret, fsize;
122 
123  ret = av_get_packet(s->pb, pkt, ADTS_HEADER_SIZE);
124  if (ret < 0)
125  return ret;
126  if (ret < ADTS_HEADER_SIZE) {
127  av_packet_unref(pkt);
128  return AVERROR(EIO);
129  }
130 
131  if ((AV_RB16(pkt->data) >> 4) != 0xfff) {
132  av_packet_unref(pkt);
133  return AVERROR_INVALIDDATA;
134  }
135 
136  fsize = (AV_RB32(pkt->data + 3) >> 13) & 0x1FFF;
137  if (fsize < ADTS_HEADER_SIZE) {
138  av_packet_unref(pkt);
139  return AVERROR_INVALIDDATA;
140  }
141 
142  return av_append_packet(s->pb, pkt, fsize - ADTS_HEADER_SIZE);
143 }
144 
146  .name = "aac",
147  .long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
148  .read_probe = adts_aac_probe,
149  .read_header = adts_aac_read_header,
150  .read_packet = adts_aac_read_packet,
151  .flags = AVFMT_GENERIC_INDEX,
152  .extensions = "aac",
153  .mime_type = "audio/aac,audio/aacp,audio/x-aac",
154  .raw_codec_id = AV_CODEC_ID_AAC,
155 };
int64_t probesize
Maximum size of the data read from input for determining the input container format.
Definition: avformat.h:1493
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:768
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
static struct @260 state
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:4739
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:4143
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:244
static AVPacket pkt
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
static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: aacdec.c:119
Format I/O context.
Definition: avformat.h:1349
uint8_t
static int adts_aac_read_header(AVFormatContext *s)
Definition: aacdec.c:80
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
enum AVStreamParseType need_parsing
Definition: avformat.h:1081
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4369
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:40
uint8_t * data
Definition: avcodec.h:1672
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:289
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:556
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:814
int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
Read data and append it to the current content of the AVPacket.
Definition: utils.c:299
#define ADTS_HEADER_SIZE
Definition: aacdec.c:29
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1567
#define AVERROR(e)
Definition: error.h:43
AVInputFormat ff_aac_demuxer
Definition: aacdec.c:145
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:179
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:4139
#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 avio_r8(AVIOContext *s)
Definition: aviobuf.c:628
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:464
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:463
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:261
#define FFMIN(a, b)
Definition: common.h:96
int frames
Definition: movenc.c:65
Stream structure.
Definition: avformat.h:889
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:40
AVIOContext * pb
I/O context.
Definition: avformat.h:1391
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:617
void * buf
Definition: avisynth_c.h:690
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:487
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:471
This structure contains the data a format has to probe a file.
Definition: avformat.h:461
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:710
static int adts_aac_probe(AVProbeData *p)
Definition: aacdec.c:31
Main libavformat public API header.
struct AVInputFormat * iformat
The input container format.
Definition: avformat.h:1361
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:664
#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:1252
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:356
static int64_t fsize(FILE *f)
Definition: audiomatch.c:28
This structure stores compressed data.
Definition: avcodec.h:1649