FFmpeg  4.4
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 
34 static int adts_aac_probe(const AVProbeData *p)
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 
114  st->codecpar->codec_id = s->iformat->raw_codec_id;
116 
117  ff_id3v1_read(s);
118  if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) &&
119  !av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
120  int64_t cur = avio_tell(s->pb);
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 
143  if (ret < 0) {
144  return ret;
145  }
146 
147  ffio_init_context(&ioctx, pkt->data, pkt->size, 0, NULL, NULL, NULL, NULL);
148  ff_id3v2_read_dict(&ioctx, &metadata, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta);
149  if ((ret = ff_id3v2_parse_priv_dict(&metadata, id3v2_extra_meta)) < 0)
150  goto error;
151 
152  if (metadata) {
153  if ((ret = av_dict_copy(&s->metadata, metadata, 0)) < 0)
154  goto error;
155  s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
156  }
157 
158 error:
160  ff_id3v2_free_extra_meta(&id3v2_extra_meta);
161  av_dict_free(&metadata);
162 
163  return ret;
164 }
165 
167 {
168  int ret, fsize;
169 
170 retry:
171  ret = av_get_packet(s->pb, pkt, ADTS_HEADER_SIZE);
172  if (ret < 0)
173  return ret;
174 
175  if (ret < ADTS_HEADER_SIZE) {
176  return AVERROR(EIO);
177  }
178 
179  if ((AV_RB16(pkt->data) >> 4) != 0xfff) {
180  // Parse all the ID3 headers between frames
182 
183  av_assert2(append > 0);
184  ret = av_append_packet(s->pb, pkt, append);
185  if (ret != append) {
186  return AVERROR(EIO);
187  }
190  ret = adts_aac_resync(s);
191  } else
192  ret = handle_id3(s, pkt);
193  if (ret < 0)
194  return ret;
195 
196  goto retry;
197  }
198 
199  fsize = (AV_RB32(pkt->data + 3) >> 13) & 0x1FFF;
200  if (fsize < ADTS_HEADER_SIZE) {
201  return AVERROR_INVALIDDATA;
202  }
203 
204  ret = av_append_packet(s->pb, pkt, fsize - pkt->size);
205 
206  return ret;
207 }
208 
210  .name = "aac",
211  .long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
212  .read_probe = adts_aac_probe,
213  .read_header = adts_aac_read_header,
214  .read_packet = adts_aac_read_packet,
215  .flags = AVFMT_GENERIC_INDEX,
216  .extensions = "aac",
217  .mime_type = "audio/aac,audio/aacp,audio/x-aac",
218  .raw_codec_id = AV_CODEC_ID_AAC,
219 };
int64_t ff_ape_parse_tag(AVFormatContext *s)
Read and parse an APE tag.
Definition: apetag.c:118
uint8_t
static int64_t fsize(FILE *f)
Definition: audiomatch.c:29
simple assert() macros that are a bit more flexible than ISO C assert().
#define av_assert2(cond)
assert() equivalent, that does lie in speed critical code.
Definition: avassert.h:64
Main libavformat public API header.
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:326
#define AVFMT_EVENT_FLAG_METADATA_UPDATED
Definition: avformat.h:1562
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:451
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
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:463
@ AVSTREAM_PARSE_FULL_RAW
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:798
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:253
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:40
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:364
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:624
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:88
#define AV_RB32
Definition: intreadwrite.h:130
#define AV_RB16
Definition: intreadwrite.h:53
#define s(width, name)
Definition: cbs_vp9.c:257
static struct @321 state
#define FFMIN(a, b)
Definition: common.h:105
#define FFMAX(a, b)
Definition: common.h:103
#define NULL
Definition: coverity.c:32
@ AV_CODEC_ID_AAC
Definition: codec_id.h:426
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:634
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4505
void av_dict_free(AVDictionary **pm)
Free all the memory allocated for an AVDictionary struct and all keys and values.
Definition: dict.c:203
#define AV_DICT_IGNORE_SUFFIX
Return first entry in a dictionary whose first part corresponds to the search key,...
Definition: dict.h:70
int av_dict_copy(AVDictionary **dst, const AVDictionary *src, int flags)
Copy entries from one AVDictionary struct into another.
Definition: dict.c:217
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
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define AVERROR_EOF
End of file.
Definition: error.h:55
#define AVERROR(e)
Definition: error.h:43
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
void ff_id3v1_read(AVFormatContext *s)
Read an ID3v1 tag.
Definition: id3v1.c:279
int ff_id3v2_tag_len(const uint8_t *buf)
Get the length of an ID3v2 tag.
Definition: id3v2.c:156
int ff_id3v2_match(const uint8_t *buf, const char *magic)
Detect ID3v2 Header.
Definition: id3v2.c:143
void ff_id3v2_free_extra_meta(ID3v2ExtraMeta **extra_meta)
Free memory allocated parsing special (non-text) metadata.
Definition: id3v2.c:1122
int ff_id3v2_parse_priv_dict(AVDictionary **metadata, ID3v2ExtraMeta *extra_meta)
Parse PRIV tags into a dictionary.
Definition: id3v2.c:1229
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:1110
#define ID3v2_DEFAULT_MAGIC
Default magic bytes for ID3v2 header: "ID3".
Definition: id3v2.h:35
#define ID3v2_HEADER_SIZE
Definition: id3v2.h:30
static int handle_id3(AVFormatContext *s, AVPacket *pkt)
Definition: aacdec.c:135
static int adts_aac_probe(const AVProbeData *p)
Definition: aacdec.c:34
#define ADTS_HEADER_SIZE
Definition: aacdec.c:32
static int adts_aac_read_header(AVFormatContext *s)
Definition: aacdec.c:104
static int adts_aac_resync(AVFormatContext *s)
Definition: aacdec.c:83
static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: aacdec.c:166
AVInputFormat ff_aac_demuxer
Definition: aacdec.c:209
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:4941
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
static uint8_t * append(uint8_t *buf, const uint8_t *src, int size)
static const uint8_t header[24]
Definition: sdr2.c:67
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
Format I/O context.
Definition: avformat.h:1232
Bytestream IO Context.
Definition: avio.h:161
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
This structure stores compressed data.
Definition: packet.h:346
int size
Definition: packet.h:370
uint8_t * data
Definition: packet.h:369
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
Stream structure.
Definition: avformat.h:873
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
enum AVStreamParseType need_parsing
Definition: avformat.h:1081
static void error(const char *err)
AVPacket * pkt
Definition: movenc.c:59
int frames
Definition: movenc.c:66