FFmpeg: libavformat/aacdec.c Source File

FFmpeg
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)
74  return AVPROBE_SCORE_EXTENSION;
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 
83  static int adts_aac_resync(AVFormatContext *s)
84 {
85  uint16_t state;
86  int64_t start_pos = avio_tell(s->pb);
87 
88  // skip data until an ADTS frame is found
89  state = avio_r8(s->pb);
90  while (!avio_feof(s->pb) &&
91  (avio_tell(s->pb) - start_pos) < s->probesize) {
92  state = (state << 8) | avio_r8(s->pb);
93  if ((state >> 4) != 0xFFF)
94  continue;
95  avio_seek(s->pb, -2, SEEK_CUR);
96  break;
97  }
98  if (s->pb->eof_reached)
99  return AVERROR_EOF;
100  if ((state >> 4) != 0xFFF)
101  return AVERROR_INVALIDDATA;
102 
103  return 0;
104 }
105 
106  static int adts_aac_read_header(AVFormatContext *s)
107 {
108  AVStream *st;
109  int ret;
110 
111  st = avformat_new_stream(s, NULL);
112  if (!st)
113  return AVERROR(ENOMEM);
114 
115  st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
116  st->codecpar->codec_id = s->iformat->raw_codec_id;
117  ffstream(st)->need_parsing = AVSTREAM_PARSE_FULL_RAW;
118 
119  ff_id3v1_read(s);
120  if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) &&
121  !av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
122  int64_t cur = avio_tell(s->pb);
123  ff_ape_parse_tag(s);
124  avio_seek(s->pb, cur, SEEK_SET);
125  }
126 
127  ret = adts_aac_resync(s);
128  if (ret < 0)
129  return ret;
130 
131  // LCM of all possible ADTS sample rates
132  avpriv_set_pts_info(st, 64, 1, 28224000);
133 
134  return 0;
135 }
136 
137  static int handle_id3(AVFormatContext *s, AVPacket *pkt)
138 {
139  AVDictionary *metadata = NULL;
140  FFIOContext pb;
141  ID3v2ExtraMeta *id3v2_extra_meta;
142  int ret;
143 
144  ret = av_append_packet(s->pb, pkt, ff_id3v2_tag_len(pkt->data) - pkt->size);
145  if (ret < 0) {
146  return ret;
147  }
148 
149  ffio_init_context(&pb, pkt->data, pkt->size, 0, NULL, NULL, NULL, NULL);
150  ff_id3v2_read_dict(&pb.pub, &metadata, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta);
151  if ((ret = ff_id3v2_parse_priv_dict(&metadata, id3v2_extra_meta)) < 0)
152  goto error;
153 
154  if (metadata) {
155  if ((ret = av_dict_copy(&s->metadata, metadata, 0)) < 0)
156  goto error;
157  s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
158  }
159 
160 error:
161  av_packet_unref(pkt);
162  ff_id3v2_free_extra_meta(&id3v2_extra_meta);
163  av_dict_free(&metadata);
164 
165  return ret;
166 }
167 
168  static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt)
169 {
170  int ret, fsize;
171 
172 retry:
173  ret = av_get_packet(s->pb, pkt, ADTS_HEADER_SIZE);
174  if (ret < 0)
175  return ret;
176 
177  if (ret < ADTS_HEADER_SIZE) {
178  return AVERROR(EIO);
179  }
180 
181  if ((AV_RB16(pkt->data) >> 4) != 0xfff) {
182  // Parse all the ID3 headers between frames
183  int append = ID3v2_HEADER_SIZE - ADTS_HEADER_SIZE;
184 
185  av_assert2(append > 0);
186  ret = av_append_packet(s->pb, pkt, append);
187  if (ret != append) {
188  return AVERROR(EIO);
189  }
190  if (!ff_id3v2_match(pkt->data, ID3v2_DEFAULT_MAGIC)) {
191  av_packet_unref(pkt);
192  ret = adts_aac_resync(s);
193  } else
194  ret = handle_id3(s, pkt);
195  if (ret < 0)
196  return ret;
197 
198  goto retry;
199  }
200 
201  fsize = (AV_RB32(pkt->data + 3) >> 13) & 0x1FFF;
202  if (fsize < ADTS_HEADER_SIZE) {
203  return AVERROR_INVALIDDATA;
204  }
205 
206  ret = av_append_packet(s->pb, pkt, fsize - pkt->size);
207 
208  return ret;
209 }
210 
211  const AVInputFormat ff_aac_demuxer = {
212  .name = "aac",
213  .long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
214  .read_probe = adts_aac_probe,
215  .read_header = adts_aac_read_header,
216  .read_packet = adts_aac_read_packet,
217  .flags = AVFMT_GENERIC_INDEX,
218  .extensions = "aac",
219  .mime_type = "audio/aac,audio/aacp,audio/x-aac",
220  .raw_codec_id = AV_CODEC_ID_AAC,
221 };
error
static void error(const char *err)
Definition: target_bsf_fuzzer.c:31
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:424
AVERROR
Filter the word "frame" indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:768
append
static uint8_t * append(uint8_t *buf, const uint8_t *src, int size)
Definition: mjpeg2jpeg_bsf.c:59
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
id3v2.h
apetag.h
AVPacket::data
uint8_t * data
Definition: packet.h:373
ff_id3v1_read
void ff_id3v1_read(AVFormatContext *s)
Read an ID3v1 tag.
Definition: id3v1.c:278
AV_DICT_IGNORE_SUFFIX
#define AV_DICT_IGNORE_SUFFIX
Return first entry in a dictionary whose first part corresponds to the search key,...
Definition: dict.h:68
adts_aac_read_packet
static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: aacdec.c:168
AVDictionary
Definition: dict.c:30
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:450
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
id3v1.h
FFIOContext
Definition: avio_internal.h:29
ff_ape_parse_tag
int64_t ff_ape_parse_tag(AVFormatContext *s)
Read and parse an APE tag.
Definition: apetag.c:108
ffstream
static av_always_inline FFStream * ffstream(AVStream *st)
Definition: internal.h:432
frames
if it could not because there are no more frames
Definition: filter_design.txt:266
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:504
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:476
ADTS_HEADER_SIZE
#define ADTS_HEADER_SIZE
Definition: aacdec.c:32
avassert.h
pkt
AVPacket * pkt
Definition: movenc.c:59
AVInputFormat
Definition: avformat.h:650
adts_aac_read_header
static int adts_aac_read_header(AVFormatContext *s)
Definition: aacdec.c:106
ID3v2ExtraMeta
Definition: id3v2.h:84
av_dict_get
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
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:655
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:449
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
fsize
static int64_t fsize(FILE *f)
Definition: audiomatch.c:29
FFStream::need_parsing
enum AVStreamParseType need_parsing
Definition: internal.h:405
AVFormatContext
Format I/O context.
Definition: avformat.h:1200
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1095
NULL
#define NULL
Definition: coverity.c:32
adts_aac_probe
static int adts_aac_probe(const AVProbeData *p)
Definition: aacdec.c:34
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:447
ID3v2_HEADER_SIZE
#define ID3v2_HEADER_SIZE
Definition: id3v2.h:30
AVPROBE_SCORE_EXTENSION
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:457
ff_aac_demuxer
const AVInputFormat ff_aac_demuxer
Definition: aacdec.c:211
AV_CODEC_ID_AAC
@ AV_CODEC_ID_AAC
Definition: codec_id.h:425
state
static struct @320 state
AVPacket::size
int size
Definition: packet.h:374
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
FFIOContext::pub
AVIOContext pub
Definition: avio_internal.h:30
ID3v2_DEFAULT_MAGIC
#define ID3v2_DEFAULT_MAGIC
Default magic bytes for ID3v2 header: "ID3".
Definition: id3v2.h:35
AV_RB32
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:96
header
static const uint8_t header[24]
Definition: sdr2.c:67
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:632
av_dict_free
void av_dict_free(AVDictionary **pm)
Free all the memory allocated for an AVDictionary struct and all keys and values.
Definition: dict.c:203
av_assert2
#define av_assert2(cond)
assert() equivalent, that does lie in speed critical code.
Definition: avassert.h:64
avio_internal.h
ffio_init_context
void ffio_init_context(FFIOContext *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
ff_id3v2_read_dict
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:1129
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
av_get_packet
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:197
ff_id3v2_tag_len
int ff_id3v2_tag_len(const uint8_t *buf)
Get the length of an ID3v2 tag.
Definition: id3v2.c:156
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:935
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:260
av_append_packet
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:213
handle_id3
static int handle_id3(AVFormatContext *s, AVPacket *pkt)
Definition: aacdec.c:137
avformat.h
adts_aac_resync
static int adts_aac_resync(AVFormatContext *s)
Definition: aacdec.c:83
AVIO_SEEKABLE_NORMAL
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:40
AVSTREAM_PARSE_FULL_RAW
@ AVSTREAM_PARSE_FULL_RAW
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:796
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, 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:1196
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:350
av_dict_copy
int av_dict_copy(AVDictionary **dst, const AVDictionary *src, int flags)
Copy entries from one AVDictionary struct into another.
Definition: dict.c:217
ff_id3v2_free_extra_meta
void ff_id3v2_free_extra_meta(ID3v2ExtraMeta **extra_meta)
Free memory allocated parsing special (non-text) metadata.
Definition: id3v2.c:1141
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
ff_id3v2_parse_priv_dict
int ff_id3v2_parse_priv_dict(AVDictionary **metadata, ID3v2ExtraMeta *extra_meta)
Parse PRIV tags into a dictionary.
Definition: id3v2.c:1213
AVFMT_EVENT_FLAG_METADATA_UPDATED
#define AVFMT_EVENT_FLAG_METADATA_UPDATED
Definition: avformat.h:1517
ff_id3v2_match
int ff_id3v2_match(const uint8_t *buf, const char *magic)
Detect ID3v2 Header.
Definition: id3v2.c:143
AV_RB16
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:98
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:375
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