FFmpeg  4.1.5
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/avassert.h"
24 #include "libavutil/intreadwrite.h"
25 #include "avformat.h"
26 #include "avio_internal.h"
27 #include "internal.h"
28 #include "id3v1.h"
29 #include "id3v2.h"
30 #include "apetag.h"
31 
32 #define ADTS_HEADER_SIZE 7
33 
35 {
36  int max_frames = 0, first_frames = 0;
37  int fsize, frames;
38  const uint8_t *buf0 = p->buf;
39  const uint8_t *buf2;
40  const uint8_t *buf;
41  const uint8_t *end = buf0 + p->buf_size - 7;
42 
43  buf = buf0;
44 
45  for (; buf < end; buf = buf2 + 1) {
46  buf2 = buf;
47 
48  for (frames = 0; buf2 < end; frames++) {
49  uint32_t header = AV_RB16(buf2);
50  if ((header & 0xFFF6) != 0xFFF0) {
51  if (buf != buf0) {
52  // Found something that isn't an ADTS header, starting
53  // from a position other than the start of the buffer.
54  // Discard the count we've accumulated so far since it
55  // probably was a false positive.
56  frames = 0;
57  }
58  break;
59  }
60  fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF;
61  if (fsize < 7)
62  break;
63  fsize = FFMIN(fsize, end - buf2);
64  buf2 += fsize;
65  }
66  max_frames = FFMAX(max_frames, frames);
67  if (buf == buf0)
68  first_frames = frames;
69  }
70 
71  if (first_frames >= 3)
72  return AVPROBE_SCORE_EXTENSION + 1;
73  else if (max_frames > 100)
75  else if (max_frames >= 3)
76  return AVPROBE_SCORE_EXTENSION / 2;
77  else if (first_frames >= 1)
78  return 1;
79  else
80  return 0;
81 }
82 
84 {
85  uint16_t state;
86 
87  // skip data until an ADTS frame is found
88  state = avio_r8(s->pb);
89  while (!avio_feof(s->pb) && avio_tell(s->pb) < s->probesize) {
90  state = (state << 8) | avio_r8(s->pb);
91  if ((state >> 4) != 0xFFF)
92  continue;
93  avio_seek(s->pb, -2, SEEK_CUR);
94  break;
95  }
96  if (s->pb->eof_reached)
97  return AVERROR_EOF;
98  if ((state >> 4) != 0xFFF)
99  return AVERROR_INVALIDDATA;
100 
101  return 0;
102 }
103 
105 {
106  AVStream *st;
107  int ret;
108 
109  st = avformat_new_stream(s, NULL);
110  if (!st)
111  return AVERROR(ENOMEM);
112 
116 
117  ff_id3v1_read(s);
118  if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) &&
120  int64_t cur = avio_tell(s->pb);
121  ff_ape_parse_tag(s);
122  avio_seek(s->pb, cur, SEEK_SET);
123  }
124 
125  ret = adts_aac_resync(s);
126  if (ret < 0)
127  return ret;
128 
129  // LCM of all possible ADTS sample rates
130  avpriv_set_pts_info(st, 64, 1, 28224000);
131 
132  return 0;
133 }
134 
136 {
137  AVDictionary *metadata = NULL;
138  AVIOContext ioctx;
139  ID3v2ExtraMeta *id3v2_extra_meta = NULL;
140  int ret;
141 
142  ret = av_append_packet(s->pb, pkt, ff_id3v2_tag_len(pkt->data) - pkt->size);
143  if (ret < 0) {
144  av_packet_unref(pkt);
145  return ret;
146  }
147 
148  ffio_init_context(&ioctx, pkt->data, pkt->size, 0, NULL, NULL, NULL, NULL);
149  ff_id3v2_read_dict(&ioctx, &metadata, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta);
150  if ((ret = ff_id3v2_parse_priv_dict(&metadata, &id3v2_extra_meta)) < 0)
151  goto error;
152 
153  if (metadata) {
154  if ((ret = av_dict_copy(&s->metadata, metadata, 0)) < 0)
155  goto error;
157  }
158 
159 error:
160  av_packet_unref(pkt);
161  ff_id3v2_free_extra_meta(&id3v2_extra_meta);
162  av_dict_free(&metadata);
163 
164  return ret;
165 }
166 
168 {
169  int ret, fsize;
170 
171 retry:
172  ret = av_get_packet(s->pb, pkt, ADTS_HEADER_SIZE);
173  if (ret < 0)
174  return ret;
175 
176  if (ret < ADTS_HEADER_SIZE) {
177  av_packet_unref(pkt);
178  return AVERROR(EIO);
179  }
180 
181  if ((AV_RB16(pkt->data) >> 4) != 0xfff) {
182  // Parse all the ID3 headers between frames
184 
185  av_assert2(append > 0);
186  ret = av_append_packet(s->pb, pkt, append);
187  if (ret != append) {
188  av_packet_unref(pkt);
189  return AVERROR(EIO);
190  }
192  av_packet_unref(pkt);
193  ret = adts_aac_resync(s);
194  } else
195  ret = handle_id3(s, pkt);
196  if (ret < 0)
197  return ret;
198 
199  goto retry;
200  }
201 
202  fsize = (AV_RB32(pkt->data + 3) >> 13) & 0x1FFF;
203  if (fsize < ADTS_HEADER_SIZE) {
204  av_packet_unref(pkt);
205  return AVERROR_INVALIDDATA;
206  }
207 
208  ret = av_append_packet(s->pb, pkt, fsize - pkt->size);
209  if (ret < 0)
210  av_packet_unref(pkt);
211 
212  return ret;
213 }
214 
216  .name = "aac",
217  .long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
218  .read_probe = adts_aac_probe,
219  .read_header = adts_aac_read_header,
220  .read_packet = adts_aac_read_packet,
221  .flags = AVFMT_GENERIC_INDEX,
222  .extensions = "aac",
223  .mime_type = "audio/aac,audio/aacp,audio/x-aac",
224  .raw_codec_id = AV_CODEC_ID_AAC,
225 };
int64_t probesize
Maximum size of the data read from input for determining the input container format.
Definition: avformat.h:1517
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
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:4885
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3900
void ff_id3v1_read(AVFormatContext *s)
Read an ID3v1 tag.
Definition: id3v1.c:235
int size
Definition: avcodec.h:1446
#define ID3v2_DEFAULT_MAGIC
Default magic bytes for ID3v2 header: "ID3".
Definition: id3v2.h:35
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:246
int event_flags
Flags for the user to detect events happening on the file.
Definition: avformat.h:1666
int av_dict_copy(AVDictionary **dst, const AVDictionary *src, int flags)
Copy entries from one AVDictionary struct into another.
Definition: dict.c:217
static AVPacket pkt
static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: aacdec.c:167
Format I/O context.
Definition: avformat.h:1351
#define ID3v2_HEADER_SIZE
Definition: id3v2.h:30
uint8_t
#define av_assert2(cond)
assert() equivalent, that does lie in speed critical code.
Definition: avassert.h:64
static int adts_aac_read_header(AVFormatContext *s)
Definition: aacdec.c:104
#define AV_RB32
Definition: intreadwrite.h:130
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
enum AVStreamParseType need_parsing
Definition: avformat.h:1092
int ff_id3v2_parse_priv_dict(AVDictionary **metadata, ID3v2ExtraMeta **extra_meta)
Parse PRIV tags into a dictionary.
Definition: id3v2.c:1233
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4458
static uint8_t * append(uint8_t *buf, const uint8_t *src, int size)
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:1445
#define AVERROR_EOF
End of file.
Definition: error.h:55
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:310
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
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:797
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:320
#define ADTS_HEADER_SIZE
Definition: aacdec.c:32
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1591
#define AV_RB16
Definition: intreadwrite.h:53
#define AVERROR(e)
Definition: error.h:43
AVInputFormat ff_aac_demuxer
Definition: aacdec.c:215
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
void av_dict_free(AVDictionary **pm)
Free all the memory allocated for an AVDictionary struct and all keys and values. ...
Definition: dict.c:203
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3896
void ff_id3v2_free_extra_meta(ID3v2ExtraMeta **extra_meta)
Free memory allocated parsing special (non-text) metadata.
Definition: id3v2.c:1126
simple assert() macros that are a bit more flexible than ISO C assert().
#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:638
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:451
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:450
static struct @303 state
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:260
#define FFMIN(a, b)
Definition: common.h:96
#define AVFMT_EVENT_FLAG_METADATA_UPDATED
The call resulted in updated metadata.
Definition: avformat.h:1667
#define s(width, name)
Definition: cbs_vp9.c:257
int frames
Definition: movenc.c:65
static void error(const char *err)
Stream structure.
Definition: avformat.h:874
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:40
AVIOContext * pb
I/O context.
Definition: avformat.h:1393
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:598
void * buf
Definition: avisynth_c.h:690
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:470
static int handle_id3(AVFormatContext *s, AVPacket *pkt)
Definition: aacdec.c:135
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:458
This structure contains the data a format has to probe a file.
Definition: avformat.h:448
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:693
static int adts_aac_probe(AVProbeData *p)
Definition: aacdec.c:34
Main libavformat public API header.
int ff_id3v2_match(const uint8_t *buf, const char *magic)
Detect ID3v2 Header.
Definition: id3v2.c:142
int ffio_init_context(AVIOContext *s, unsigned char *buffer, int buffer_size, int write_flag, void *opaque, int(*read_packet)(void *opaque, uint8_t *buf, int buf_size), int(*write_packet)(void *opaque, uint8_t *buf, int buf_size), int64_t(*seek)(void *opaque, int64_t offset, int whence))
Definition: aviobuf.c:81
static int adts_aac_resync(AVFormatContext *s)
Definition: aacdec.c:83
struct AVInputFormat * iformat
The input container format.
Definition: avformat.h:1363
void ff_id3v2_read_dict(AVIOContext *pb, AVDictionary **metadata, const char *magic, ID3v2ExtraMeta **extra_meta)
Read an ID3v2 tag into specified dictionary and retrieve supported extra metadata.
Definition: id3v2.c:1114
int eof_reached
true if eof reached
Definition: avio.h:239
int ff_id3v2_tag_len(const uint8_t *buf)
Get the length of an ID3v2 tag.
Definition: id3v2.c:155
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:647
#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
Codec parameters associated with this stream.
Definition: avformat.h:1021
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:358
static int64_t fsize(FILE *f)
Definition: audiomatch.c:28
This structure stores compressed data.
Definition: avcodec.h:1422