FFmpeg  2.8.17
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Modules Pages
mp3dec.c
Go to the documentation of this file.
1 /*
2  * MP3 demuxer
3  * Copyright (c) 2003 Fabrice Bellard
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/opt.h"
23 #include "libavutil/avstring.h"
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/crc.h"
26 #include "libavutil/dict.h"
27 #include "libavutil/mathematics.h"
28 #include "avformat.h"
29 #include "internal.h"
30 #include "avio_internal.h"
31 #include "id3v2.h"
32 #include "id3v1.h"
33 #include "replaygain.h"
34 
35 #include "libavcodec/avcodec.h"
37 
38 #define XING_FLAG_FRAMES 0x01
39 #define XING_FLAG_SIZE 0x02
40 #define XING_FLAG_TOC 0x04
41 #define XING_FLAC_QSCALE 0x08
42 
43 #define XING_TOC_COUNT 100
44 
45 #define SAME_HEADER_MASK \
46  (0xffe00000 | (3 << 17) | (3 << 10) | (3 << 19))
47 
48 typedef struct {
49  AVClass *class;
50  int64_t filesize;
51  int xing_toc;
52  int start_pad;
53  int end_pad;
54  int usetoc;
55  unsigned frames; /* Total number of frames in file */
56  unsigned header_filesize; /* Total number of bytes in the stream */
57  int is_cbr;
59 
60 static int check(AVIOContext *pb, int64_t pos, uint32_t *header);
61 
62 /* mp3 read */
63 
65 {
66  int max_frames, first_frames = 0;
67  int fsize, frames;
68  uint32_t header;
69  const uint8_t *buf, *buf0, *buf2, *end;
71 
72  if (!avctx)
73  return AVERROR(ENOMEM);
74 
75  buf0 = p->buf;
76  end = p->buf + p->buf_size - sizeof(uint32_t);
77  while(buf0 < end && !*buf0)
78  buf0++;
79 
80  max_frames = 0;
81  buf = buf0;
82 
83  for(; buf < end; buf= buf2+1) {
84  buf2 = buf;
85  if(ff_mpa_check_header(AV_RB32(buf2)))
86  continue;
87 
88  for(frames = 0; buf2 < end; frames++) {
89  int dummy;
90  header = AV_RB32(buf2);
91  fsize = avpriv_mpa_decode_header(avctx, header,
92  &dummy, &dummy, &dummy, &dummy);
93  if(fsize < 0)
94  break;
95  buf2 += fsize;
96  }
97  max_frames = FFMAX(max_frames, frames);
98  if(buf == buf0)
99  first_frames= frames;
100  }
101  avcodec_free_context(&avctx);
102  // keep this in sync with ac3 probe, both need to avoid
103  // issues with MPEG-files!
104  if (first_frames>=7) return AVPROBE_SCORE_EXTENSION + 1;
105  else if(max_frames>200)return AVPROBE_SCORE_EXTENSION;
106  else if(max_frames>=4 && max_frames >= p->buf_size/10000) return AVPROBE_SCORE_EXTENSION / 2;
107  else if(ff_id3v2_match(buf0, ID3v2_DEFAULT_MAGIC) && 2*ff_id3v2_tag_len(buf0) >= p->buf_size)
109  else if(max_frames>=1 && max_frames >= p->buf_size/10000) return 1;
110  else return 0;
111 //mpegps_mp3_unrecognized_format.mpg has max_frames=3
112 }
113 
114 static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration)
115 {
116  int i;
117  MP3DecContext *mp3 = s->priv_data;
118  int fill_index = mp3->usetoc == 1 && duration > 0;
119 
120  if (!filesize &&
121  !(filesize = avio_size(s->pb))) {
122  av_log(s, AV_LOG_WARNING, "Cannot determine file size, skipping TOC table.\n");
123  fill_index = 0;
124  }
125 
126  for (i = 0; i < XING_TOC_COUNT; i++) {
127  uint8_t b = avio_r8(s->pb);
128  if (fill_index)
130  av_rescale(b, filesize, 256),
131  av_rescale(i, duration, XING_TOC_COUNT),
132  0, 0, AVINDEX_KEYFRAME);
133  }
134  if (fill_index)
135  mp3->xing_toc = 1;
136 }
137 
139  MPADecodeHeader *c, uint32_t spf)
140 {
141 #define LAST_BITS(k, n) ((k) & ((1 << (n)) - 1))
142 #define MIDDLE_BITS(k, m, n) LAST_BITS((k) >> (m), ((n) - (m)))
143 
144  uint16_t crc;
145  uint32_t v;
146 
147  char version[10];
148 
149  uint32_t peak = 0;
150  int32_t r_gain = INT32_MIN, a_gain = INT32_MIN;
151 
152  MP3DecContext *mp3 = s->priv_data;
153  static const int64_t xing_offtbl[2][2] = {{32, 17}, {17,9}};
154  uint64_t fsize = avio_size(s->pb);
155  fsize = fsize >= avio_tell(s->pb) ? fsize - avio_tell(s->pb) : 0;
156 
157  /* Check for Xing / Info tag */
158  avio_skip(s->pb, xing_offtbl[c->lsf == 1][c->nb_channels == 1]);
159  v = avio_rb32(s->pb);
160  mp3->is_cbr = v == MKBETAG('I', 'n', 'f', 'o');
161  if (v != MKBETAG('X', 'i', 'n', 'g') && !mp3->is_cbr)
162  return;
163 
164  v = avio_rb32(s->pb);
165  if (v & XING_FLAG_FRAMES)
166  mp3->frames = avio_rb32(s->pb);
167  if (v & XING_FLAG_SIZE)
168  mp3->header_filesize = avio_rb32(s->pb);
169  if (fsize && mp3->header_filesize) {
170  uint64_t min, delta;
171  min = FFMIN(fsize, mp3->header_filesize);
172  delta = FFMAX(fsize, mp3->header_filesize) - min;
173  if (fsize > mp3->header_filesize && delta > min >> 4) {
174  mp3->frames = 0;
176  "invalid concatenated file detected - using bitrate for duration\n");
177  } else if (delta > min >> 4) {
179  "filesize and duration do not match (growing file?)\n");
180  }
181  }
182  if (v & XING_FLAG_TOC)
184  (AVRational){spf, c->sample_rate},
185  st->time_base));
186  /* VBR quality */
187  if (v & XING_FLAC_QSCALE)
188  avio_rb32(s->pb);
189 
190  /* Encoder short version string */
191  memset(version, 0, sizeof(version));
192  avio_read(s->pb, version, 9);
193 
194  /* Info Tag revision + VBR method */
195  avio_r8(s->pb);
196 
197  /* Lowpass filter value */
198  avio_r8(s->pb);
199 
200  /* ReplayGain peak */
201  v = avio_rb32(s->pb);
202  peak = av_rescale(v, 100000, 1 << 23);
203 
204  /* Radio ReplayGain */
205  v = avio_rb16(s->pb);
206 
207  if (MIDDLE_BITS(v, 13, 15) == 1) {
208  r_gain = MIDDLE_BITS(v, 0, 8) * 10000;
209 
210  if (v & (1 << 9))
211  r_gain *= -1;
212  }
213 
214  /* Audiophile ReplayGain */
215  v = avio_rb16(s->pb);
216 
217  if (MIDDLE_BITS(v, 13, 15) == 2) {
218  a_gain = MIDDLE_BITS(v, 0, 8) * 10000;
219 
220  if (v & (1 << 9))
221  a_gain *= -1;
222  }
223 
224  /* Encoding flags + ATH Type */
225  avio_r8(s->pb);
226 
227  /* if ABR {specified bitrate} else {minimal bitrate} */
228  avio_r8(s->pb);
229 
230  /* Encoder delays */
231  v= avio_rb24(s->pb);
232  if(AV_RB32(version) == MKBETAG('L', 'A', 'M', 'E')
233  || AV_RB32(version) == MKBETAG('L', 'a', 'v', 'f')
234  || AV_RB32(version) == MKBETAG('L', 'a', 'v', 'c')
235  ) {
236 
237  mp3->start_pad = v>>12;
238  mp3-> end_pad = v&4095;
239  st->start_skip_samples = mp3->start_pad + 528 + 1;
240  if (mp3->frames) {
241  st->first_discard_sample = -mp3->end_pad + 528 + 1 + mp3->frames * (int64_t)spf;
242  st->last_discard_sample = mp3->frames * (int64_t)spf;
243  }
244  if (!st->start_time)
246  (AVRational){1, c->sample_rate},
247  st->time_base);
248  av_log(s, AV_LOG_DEBUG, "pad %d %d\n", mp3->start_pad, mp3-> end_pad);
249  }
250 
251  /* Misc */
252  avio_r8(s->pb);
253 
254  /* MP3 gain */
255  avio_r8(s->pb);
256 
257  /* Preset and surround info */
258  avio_rb16(s->pb);
259 
260  /* Music length */
261  avio_rb32(s->pb);
262 
263  /* Music CRC */
264  avio_rb16(s->pb);
265 
266  /* Info Tag CRC */
267  crc = ffio_get_checksum(s->pb);
268  v = avio_rb16(s->pb);
269 
270  if (v == crc) {
271  ff_replaygain_export_raw(st, r_gain, peak, a_gain, 0);
272  av_dict_set(&st->metadata, "encoder", version, 0);
273  }
274 }
275 
276 static void mp3_parse_vbri_tag(AVFormatContext *s, AVStream *st, int64_t base)
277 {
278  uint32_t v;
279  MP3DecContext *mp3 = s->priv_data;
280 
281  /* Check for VBRI tag (always 32 bytes after end of mpegaudio header) */
282  avio_seek(s->pb, base + 4 + 32, SEEK_SET);
283  v = avio_rb32(s->pb);
284  if (v == MKBETAG('V', 'B', 'R', 'I')) {
285  /* Check tag version */
286  if (avio_rb16(s->pb) == 1) {
287  /* skip delay and quality */
288  avio_skip(s->pb, 4);
289  mp3->header_filesize = avio_rb32(s->pb);
290  mp3->frames = avio_rb32(s->pb);
291  }
292  }
293 }
294 
295 /**
296  * Try to find Xing/Info/VBRI tags and compute duration from info therein
297  */
298 static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
299 {
300  uint32_t v, spf;
302  int vbrtag_size = 0;
303  MP3DecContext *mp3 = s->priv_data;
304 
306 
307  v = avio_rb32(s->pb);
308  if(ff_mpa_check_header(v) < 0)
309  return -1;
310 
311  if (avpriv_mpegaudio_decode_header(&c, v) == 0)
312  vbrtag_size = c.frame_size;
313  if(c.layer != 3)
314  return -1;
315 
316  spf = c.lsf ? 576 : 1152; /* Samples per frame, layer 3 */
317 
318  mp3->frames = 0;
319  mp3->header_filesize = 0;
320 
321  mp3_parse_info_tag(s, st, &c, spf);
322  mp3_parse_vbri_tag(s, st, base);
323 
324  if (!mp3->frames && !mp3->header_filesize)
325  return -1;
326 
327  /* Skip the vbr tag frame */
328  avio_seek(s->pb, base + vbrtag_size, SEEK_SET);
329 
330  if (mp3->frames)
331  st->duration = av_rescale_q(mp3->frames, (AVRational){spf, c.sample_rate},
332  st->time_base);
333  if (mp3->header_filesize && mp3->frames && !mp3->is_cbr)
334  st->codec->bit_rate = av_rescale(mp3->header_filesize, 8 * c.sample_rate, mp3->frames * (int64_t)spf);
335 
336  return 0;
337 }
338 
340 {
341  MP3DecContext *mp3 = s->priv_data;
342  AVStream *st;
343  int64_t off;
344  int ret;
345  int i;
346 
347  if (mp3->usetoc < 0)
348  mp3->usetoc = (s->flags & AVFMT_FLAG_FAST_SEEK) ? 0 : 2;
349 
350  st = avformat_new_stream(s, NULL);
351  if (!st)
352  return AVERROR(ENOMEM);
353 
357  st->start_time = 0;
358 
359  // lcm of all mp3 sample rates
360  avpriv_set_pts_info(st, 64, 1, 14112000);
361 
362  s->pb->maxsize = -1;
363  off = avio_tell(s->pb);
364 
366  ff_id3v1_read(s);
367 
368  if(s->pb->seekable)
369  mp3->filesize = avio_size(s->pb);
370 
371  if (mp3_parse_vbr_tags(s, st, off) < 0)
372  avio_seek(s->pb, off, SEEK_SET);
373 
374  ret = ff_replaygain_export(st, s->metadata);
375  if (ret < 0)
376  return ret;
377 
378  off = avio_tell(s->pb);
379  for (i = 0; i < 64 * 1024; i++) {
380  uint32_t header, header2;
381  int frame_size;
382  if (!(i&1023))
383  ffio_ensure_seekback(s->pb, i + 1024 + 4);
384  frame_size = check(s->pb, off + i, &header);
385  if (frame_size > 0) {
386  avio_seek(s->pb, off, SEEK_SET);
387  ffio_ensure_seekback(s->pb, i + 1024 + frame_size + 4);
388  if (check(s->pb, off + i + frame_size, &header2) >= 0 &&
389  (header & SAME_HEADER_MASK) == (header2 & SAME_HEADER_MASK))
390  {
391  av_log(s, AV_LOG_INFO, "Skipping %d bytes of junk at %"PRId64".\n", i, off);
392  avio_seek(s->pb, off + i, SEEK_SET);
393  break;
394  }
395  }
396  avio_seek(s->pb, off, SEEK_SET);
397  }
398 
399  // the seek index is relative to the end of the xing vbr headers
400  for (i = 0; i < st->nb_index_entries; i++)
401  st->index_entries[i].pos += avio_tell(s->pb);
402 
403  /* the parameters will be extracted from the compressed bitstream */
404  return 0;
405 }
406 
407 #define MP3_PACKET_SIZE 1024
408 
410 {
411  MP3DecContext *mp3 = s->priv_data;
412  int ret, size;
413  int64_t pos;
414 
415  size= MP3_PACKET_SIZE;
416  pos = avio_tell(s->pb);
417  if(mp3->filesize > ID3v1_TAG_SIZE && pos < mp3->filesize)
418  size= FFMIN(size, mp3->filesize - pos);
419 
420  ret= av_get_packet(s->pb, pkt, size);
421  if (ret <= 0) {
422  if(ret<0)
423  return ret;
424  return AVERROR_EOF;
425  }
426 
427  pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
428  pkt->stream_index = 0;
429 
430  return ret;
431 }
432 
433 #define SEEK_WINDOW 4096
434 
435 static int check(AVIOContext *pb, int64_t pos, uint32_t *ret_header)
436 {
437  int64_t ret = avio_seek(pb, pos, SEEK_SET);
438  unsigned header;
439  MPADecodeHeader sd;
440  if (ret < 0)
441  return ret;
442 
443  header = avio_rb32(pb);
444  if (ff_mpa_check_header(header) < 0)
445  return -1;
446  if (avpriv_mpegaudio_decode_header(&sd, header) == 1)
447  return -1;
448 
449  if (ret_header)
450  *ret_header = header;
451  return sd.frame_size;
452 }
453 
454 static int64_t mp3_sync(AVFormatContext *s, int64_t target_pos, int flags)
455 {
456  int dir = (flags&AVSEEK_FLAG_BACKWARD) ? -1 : 1;
457  int64_t best_pos;
458  int best_score, i, j;
459  int64_t ret;
460 
461  avio_seek(s->pb, FFMAX(target_pos - SEEK_WINDOW, 0), SEEK_SET);
462  ret = avio_seek(s->pb, target_pos, SEEK_SET);
463  if (ret < 0)
464  return ret;
465 
466 #define MIN_VALID 3
467  best_pos = target_pos;
468  best_score = 999;
469  for(i=0; i<SEEK_WINDOW; i++) {
470  int64_t pos = target_pos + (dir > 0 ? i - SEEK_WINDOW/4 : -i);
471  int64_t candidate = -1;
472  int score = 999;
473 
474  if (pos < 0)
475  continue;
476 
477  for(j=0; j<MIN_VALID; j++) {
478  ret = check(s->pb, pos, NULL);
479  if(ret < 0)
480  break;
481  if ((target_pos - pos)*dir <= 0 && abs(MIN_VALID/2-j) < score) {
482  candidate = pos;
483  score = abs(MIN_VALID/2-j);
484  }
485  pos += ret;
486  }
487  if (best_score > score && j == MIN_VALID) {
488  best_pos = candidate;
489  best_score = score;
490  if(score == 0)
491  break;
492  }
493  }
494 
495  return avio_seek(s->pb, best_pos, SEEK_SET);
496 }
497 
498 static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
499  int flags)
500 {
501  MP3DecContext *mp3 = s->priv_data;
502  AVIndexEntry *ie, ie1;
503  AVStream *st = s->streams[0];
504  int64_t ret = av_index_search_timestamp(st, timestamp, flags);
505  int64_t best_pos;
506 
507  if (mp3->usetoc == 2)
508  return -1; // generic index code
509 
510  if ( mp3->is_cbr
511  && (mp3->usetoc == 0 || !mp3->xing_toc)
512  && st->duration > 0
513  && mp3->header_filesize > s->internal->data_offset
514  && mp3->frames) {
515  ie = &ie1;
516  timestamp = av_clip64(timestamp, 0, st->duration);
517  ie->timestamp = timestamp;
518  ie->pos = av_rescale(timestamp, mp3->header_filesize, st->duration) + s->internal->data_offset;
519  } else if (mp3->xing_toc) {
520  if (ret < 0)
521  return ret;
522 
523  ie = &st->index_entries[ret];
524  } else {
525  return -1;
526  }
527 
528  best_pos = mp3_sync(s, ie->pos, flags);
529  if (best_pos < 0)
530  return best_pos;
531 
532  if (mp3->is_cbr && ie == &ie1) {
533  int frame_duration = av_rescale(st->duration, 1, mp3->frames);
534  ie1.timestamp = frame_duration * av_rescale(best_pos - s->internal->data_offset, mp3->frames, mp3->header_filesize);
535  }
536 
537  ff_update_cur_dts(s, st, ie->timestamp);
538  return 0;
539 }
540 
541 static const AVOption options[] = {
542  { "usetoc", "use table of contents", offsetof(MP3DecContext, usetoc), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 2, AV_OPT_FLAG_DECODING_PARAM},
543  { NULL },
544 };
545 
546 static const AVClass demuxer_class = {
547  .class_name = "mp3",
548  .item_name = av_default_item_name,
549  .option = options,
550  .version = LIBAVUTIL_VERSION_INT,
551  .category = AV_CLASS_CATEGORY_DEMUXER,
552 };
553 
555  .name = "mp3",
556  .long_name = NULL_IF_CONFIG_SMALL("MP2/3 (MPEG audio layer 2/3)"),
557  .read_probe = mp3_read_probe,
558  .read_header = mp3_read_header,
559  .read_packet = mp3_read_packet,
560  .read_seek = mp3_seek,
561  .priv_data_size = sizeof(MP3DecContext),
563  .extensions = "mp2,mp3,m2a,mpa", /* XXX: use probe */
564  .priv_class = &demuxer_class,
565 };
#define AVSEEK_FLAG_BACKWARD
Definition: avformat.h:2296
#define NULL
Definition: coverity.c:32
float v
const char * s
Definition: avisynth_c.h:631
Bytestream IO Context.
Definition: avio.h:111
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:284
AVOption.
Definition: opt.h:255
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
Definition: utils.c:1749
int64_t start_skip_samples
If not 0, the number of samples that should be skipped from the start of the stream (the samples are ...
Definition: avformat.h:1111
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
#define LIBAVUTIL_VERSION_INT
Definition: version.h:62
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:4098
int64_t pos
Definition: avformat.h:796
int64_t data_offset
offset of the first packet
Definition: internal.h:80
int64_t first_discard_sample
If not 0, the first audio sample that should be discarded from the stream.
Definition: avformat.h:1119
void ff_id3v1_read(AVFormatContext *s)
Read an ID3v1 tag.
Definition: id3v1.c:235
const char * b
Definition: vf_curves.c:109
#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:204
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: avformat.h:1057
AVFormatInternal * internal
An opaque field for libavformat internal usage.
Definition: avformat.h:1710
static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration)
Definition: mp3dec.c:114
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:279
int version
Definition: avisynth_c.h:629
static AVPacket pkt
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:679
#define PROBE_BUF_MAX
Definition: internal.h:32
int64_t maxsize
max filesize, used to limit allocations This field is internal to libavformat and access from outside...
Definition: avio.h:166
unsigned frames
Definition: mp3dec.c:55
Format I/O context.
Definition: avformat.h:1285
void ff_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp)
Update cur_dts of all streams based on the given timestamp and AVStream.
Definition: utils.c:1663
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
Public dictionary API.
static int mp3_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mp3dec.c:409
uint8_t
int usetoc
Definition: mp3dec.c:54
#define XING_FLAG_SIZE
Definition: mp3dec.c:39
float delta
AVOptions.
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:694
static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: mp3dec.c:498
#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:1046
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:3761
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1353
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
int flags
Flags modifying the (de)muxer behaviour.
Definition: avformat.h:1396
int avpriv_mpegaudio_decode_header(MPADecodeHeader *s, uint32_t header)
static const uint8_t xing_offtbl[2][2]
Definition: mp3enc.c:124
#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:244
ptrdiff_t size
Definition: opengl_enc.c:101
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:390
static const uint8_t header[24]
Definition: sdr2.c:67
static int64_t duration
Definition: ffplay.c:326
int ff_replaygain_export(AVStream *st, AVDictionary *metadata)
Parse replaygain tags and export them as per-stream side data.
Definition: replaygain.c:91
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:790
#define av_log(a,...)
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:542
int64_t filesize
Definition: mp3dec.c:50
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:147
#define AVINDEX_KEYFRAME
Definition: avformat.h:803
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1497
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:1850
av_default_item_name
#define AVERROR(e)
Definition: error.h:43
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
Definition: avformat.h:797
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:178
static int mp3_read_header(AVFormatContext *s)
Definition: mp3dec.c:339
#define SAME_HEADER_MASK
Definition: mp3dec.c:45
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
preferred ID for decoding MPEG audio layer 1, 2 or 3
Definition: avcodec.h:425
static int ff_mpa_check_header(uint32_t header)
#define FFMAX(a, b)
Definition: common.h:90
Libavcodec external API header.
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1439
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:533
int avpriv_mpa_decode_header(AVCodecContext *avctx, uint32_t head, int *sample_rate, int *channels, int *frame_size, int *bit_rate)
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:873
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:463
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:462
#define SEEK_WINDOW
Definition: mp3dec.c:433
void ffio_init_checksum(AVIOContext *s, unsigned long(*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), unsigned long checksum)
Definition: aviobuf.c:521
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:160
int bit_rate
the average bitrate
Definition: avcodec.h:1577
unsigned int avio_rb24(AVIOContext *s)
Definition: aviobuf.c:687
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
Definition: mathematics.c:134
#define MP3_PACKET_SIZE
Definition: mp3dec.c:407
#define FFMIN(a, b)
Definition: common.h:92
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
Definition: options.c:149
static int check(AVIOContext *pb, int64_t pos, uint32_t *header)
Definition: mp3dec.c:435
int end_pad
Definition: mp3dec.c:53
static void mp3_parse_info_tag(AVFormatContext *s, AVStream *st, MPADecodeHeader *c, uint32_t spf)
Definition: mp3dec.c:138
int32_t
static int64_t mp3_sync(AVFormatContext *s, int64_t target_pos, int flags)
Definition: mp3dec.c:454
int xing_toc
Definition: mp3dec.c:51
AVDictionary * metadata
Definition: avformat.h:928
unsigned long ff_crcA001_update(unsigned long checksum, const uint8_t *buf, unsigned int len)
Definition: aviobuf.c:507
static void mp3_parse_vbri_tag(AVFormatContext *s, AVStream *st, int64_t base)
Definition: mp3dec.c:276
#define MIN_VALID
Stream structure.
Definition: avformat.h:854
static int mp3_read_probe(AVProbeData *p)
Definition: mp3dec.c:64
#define AV_LOG_INFO
Standard information.
Definition: log.h:187
int frame_size
Definition: mxfenc.c:1819
enum AVMediaType codec_type
Definition: avcodec.h:1520
void avcodec_free_context(AVCodecContext **avctx)
Free the codec context and everything associated with it and write NULL to the provided pointer...
Definition: options.c:164
enum AVCodecID codec_id
Definition: avcodec.h:1529
AVIOContext * pb
I/O context.
Definition: avformat.h:1327
main external API structure.
Definition: avcodec.h:1512
#define XING_FLAG_FRAMES
Definition: mp3dec.c:38
void * buf
Definition: avisynth_c.h:553
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:69
int nb_index_entries
Definition: avformat.h:1059
Describe the class of an AVClass context structure.
Definition: log.h:67
static const AVOption options[]
Definition: mp3dec.c:541
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:485
rational number numerator/denominator
Definition: rational.h:43
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:286
#define XING_FLAC_QSCALE
Definition: mp3dec.c:41
unsigned long ffio_get_checksum(AVIOContext *s)
Definition: aviobuf.c:513
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:470
This structure contains the data a format has to probe a file.
Definition: avformat.h:460
static int flags
Definition: cpu.c:47
int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size)
Ensures that the requested seekback buffer size will be available.
Definition: aviobuf.c:814
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:913
MPEG Audio header decoder.
int is_cbr
Definition: mp3dec.c:57
Main libavformat public API header.
unsigned header_filesize
Definition: mp3dec.c:56
static const AVClass demuxer_class
Definition: mp3dec.c:546
int ff_id3v2_match(const uint8_t *buf, const char *magic)
Detect ID3v2 Header.
Definition: id3v2.c:141
int ff_replaygain_export_raw(AVStream *st, int32_t tg, uint32_t tp, int32_t ag, uint32_t ap)
Export already decoded replaygain values as per-stream side data.
Definition: replaygain.c:70
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base...
Definition: avformat.h:906
AVInputFormat ff_mp3_demuxer
Definition: mp3dec.c:554
static double c[64]
#define AV_PKT_FLAG_CORRUPT
The packet content is corrupted.
Definition: avcodec.h:1480
#define MKBETAG(a, b, c, d)
Definition: common.h:342
#define XING_FLAG_TOC
Definition: mp3dec.c:40
#define MIDDLE_BITS(k, m, n)
#define AVFMT_FLAG_FAST_SEEK
Enable fast, but inaccurate seeks for some formats.
Definition: avformat.h:1418
int ff_id3v2_tag_len(const uint8_t *buf)
Get the length of an ID3v2 tag.
Definition: id3v2.c:154
void * priv_data
Format private data.
Definition: avformat.h:1313
#define XING_TOC_COUNT
Definition: mp3dec.c:43
static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
Try to find Xing/Info/VBRI tags and compute duration from info therein.
Definition: mp3dec.c:298
#define ID3v1_TAG_SIZE
Definition: id3v1.h:27
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:640
#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:72
int start_pad
Definition: mp3dec.c:52
int stream_index
Definition: avcodec.h:1435
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avformat.h:896
int dummy
Definition: motion-test.c:64
float min
This structure stores compressed data.
Definition: avcodec.h:1410
int64_t last_discard_sample
The sample after last sample that is intended to be discarded after first_discard_sample.
Definition: avformat.h:1126