FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavformat/mp3dec.c
Date: 2024-11-20 23:03:26
Exec Total Coverage
Lines: 267 308 86.7%
Functions: 10 10 100.0%
Branches: 171 242 70.7%
Line Branch Exec Source
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/intreadwrite.h"
24 #include "libavutil/dict.h"
25 #include "libavutil/mathematics.h"
26 #include "avformat.h"
27 #include "internal.h"
28 #include "avio_internal.h"
29 #include "demux.h"
30 #include "id3v2.h"
31 #include "id3v1.h"
32 #include "replaygain.h"
33
34 #include "libavcodec/codec_id.h"
35 #include "libavcodec/mpegaudio.h"
36 #include "libavcodec/mpegaudiodecheader.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
46 typedef struct {
47 AVClass *class;
48 int64_t filesize;
49 int xing_toc;
50 int start_pad;
51 int end_pad;
52 int usetoc;
53 unsigned frames; /* Total number of frames in file */
54 unsigned header_filesize; /* Total number of bytes in the stream */
55 int is_cbr;
56 } MP3DecContext;
57
58 enum CheckRet {
59 CHECK_WRONG_HEADER = -1,
60 CHECK_SEEK_FAILED = -2,
61 };
62
63 static int check(AVIOContext *pb, int64_t pos, uint32_t *header);
64
65 /* mp3 read */
66
67 7186 static int mp3_read_probe(const AVProbeData *p)
68 {
69 7186 int max_frames, first_frames = 0;
70 7186 int whole_used = 0;
71 int frames, ret;
72 int framesizes, max_framesizes;
73 uint32_t header;
74 const uint8_t *buf, *buf0, *buf2, *buf3, *end;
75
76 7186 buf0 = p->buf;
77 7186 end = p->buf + p->buf_size - sizeof(uint32_t);
78
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 118207 while (buf0 < end && !*buf0)
79 111021 buf0++;
80
81 7186 max_frames = 0;
82 7186 max_framesizes = 0;
83 7186 buf = buf0;
84
85
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 348851118 for (; buf < end; buf = buf2+1) {
86 348843932 buf2 = buf;
87
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 348911717 for (framesizes = frames = 0; buf2 < end; frames++) {
88 MPADecodeHeader h;
89 348911716 int header_emu = 0;
90 int available;
91
92 348911716 header = AV_RB32(buf2);
93 348911716 ret = avpriv_mpegaudio_decode_header(&h, header);
94
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 348911716 if (ret != 0)
95 348843931 break;
96
97 69913 available = FFMIN(h.frame_size, end - buf2);
98
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 27260711 for (buf3 = buf2 + 4; buf3 < buf2 + available; buf3++) {
99 27190798 uint32_t next_sync = AV_RB32(buf3);
100 27190798 header_emu += (next_sync & MP3_MASK) == (header & MP3_MASK);
101 }
102
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 69913 if (header_emu > 2)
103 1159 break;
104 68754 framesizes += h.frame_size;
105
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 68754 if (available < h.frame_size) {
106 969 frames++;
107 969 break;
108 }
109 67785 buf2 += h.frame_size;
110 }
111 348843932 max_frames = FFMAX(max_frames, frames);
112 348843932 max_framesizes = FFMAX(max_framesizes, framesizes);
113
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 348843932 if (buf == buf0) {
114 7186 first_frames= frames;
115
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 7186 if (buf2 == end + sizeof(uint32_t))
116 ✗ whole_used = 1;
117 }
118 }
119 // keep this in sync with ac3 probe, both need to avoid
120 // issues with MPEG-files!
121
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 7186 if (first_frames>=7) return AVPROBE_SCORE_EXTENSION + 1;
122
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 7157 else if (max_frames>200 && p->buf_size < 2*max_framesizes)return AVPROBE_SCORE_EXTENSION;
123
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 7157 else if (max_frames>=4 && p->buf_size < 2*max_framesizes) return AVPROBE_SCORE_EXTENSION / 2;
124
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 7150 else if (ff_id3v2_match(buf0, ID3v2_DEFAULT_MAGIC) && 2*ff_id3v2_tag_len(buf0) >= p->buf_size)
125
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 21 return p->buf_size < PROBE_BUF_MAX ? AVPROBE_SCORE_EXTENSION / 4 : AVPROBE_SCORE_EXTENSION - 2;
126
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 7129 else if (first_frames > 1 && whole_used) return 5;
127
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 7129 else if (max_frames>=1 && p->buf_size < 10*max_framesizes) return 1;
128 5926 else return 0;
129 //mpegps_mp3_unrecognized_format.mpg has max_frames=3
130 }
131
132 17 static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration)
133 {
134 int i;
135 17 MP3DecContext *mp3 = s->priv_data;
136 17 int fast_seek = s->flags & AVFMT_FLAG_FAST_SEEK;
137
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 17 int fill_index = (mp3->usetoc || fast_seek) && duration > 0;
138
139
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 17 if (!filesize &&
140 ✗ (filesize = avio_size(s->pb)) <= 0) {
141 ✗ av_log(s, AV_LOG_WARNING, "Cannot determine file size, skipping TOC table.\n");
142 ✗ fill_index = 0;
143 ✗ filesize = 0;
144 }
145
146
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 1717 for (i = 0; i < XING_TOC_COUNT; i++) {
147 1700 uint8_t b = avio_r8(s->pb);
148
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 1700 if (fill_index)
149 100 av_add_index_entry(s->streams[0],
150 av_rescale(b, filesize, 256),
151 av_rescale(i, duration, XING_TOC_COUNT),
152 0, 0, AVINDEX_KEYFRAME);
153 }
154
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 17 if (fill_index)
155 1 mp3->xing_toc = 1;
156 17 }
157
158 28 static void mp3_parse_info_tag(AVFormatContext *s, AVStream *st,
159 MPADecodeHeader *c, uint32_t spf)
160 {
161 #define LAST_BITS(k, n) ((k) & ((1 << (n)) - 1))
162 #define MIDDLE_BITS(k, m, n) LAST_BITS((k) >> (m), ((n) - (m) + 1))
163
164 28 FFStream *const sti = ffstream(st);
165 uint16_t crc;
166 uint32_t v;
167
168 char version[10];
169
170 28 uint32_t peak = 0;
171 28 int32_t r_gain = INT32_MIN, a_gain = INT32_MIN;
172
173 28 MP3DecContext *mp3 = s->priv_data;
174 static const int64_t xing_offtbl[2][2] = {{32, 17}, {17,9}};
175 28 uint64_t fsize = avio_size(s->pb);
176 28 int64_t pos = avio_tell(s->pb);
177
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 28 fsize = fsize >= pos ? fsize - pos : 0;
178
179 /* Check for Xing / Info tag */
180 28 avio_skip(s->pb, xing_offtbl[c->lsf == 1][c->nb_channels == 1]);
181 28 v = avio_rb32(s->pb);
182 28 mp3->is_cbr = v == MKBETAG('I', 'n', 'f', 'o');
183
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 28 if (v != MKBETAG('X', 'i', 'n', 'g') && !mp3->is_cbr)
184 10 return;
185
186 18 v = avio_rb32(s->pb);
187
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 18 if (v & XING_FLAG_FRAMES)
188 18 mp3->frames = avio_rb32(s->pb);
189
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 18 if (v & XING_FLAG_SIZE)
190 17 mp3->header_filesize = avio_rb32(s->pb);
191
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 18 if (fsize && mp3->header_filesize) {
192 uint64_t min, delta;
193 17 min = FFMIN(fsize, mp3->header_filesize);
194 17 delta = FFMAX(fsize, mp3->header_filesize) - min;
195
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 17 if (fsize > mp3->header_filesize && delta > min >> 4) {
196 ✗ mp3->frames = 0;
197 ✗ av_log(s, AV_LOG_WARNING,
198 "invalid concatenated file detected - using bitrate for duration\n");
199
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 17 } else if (delta > min >> 4) {
200 ✗ av_log(s, AV_LOG_WARNING,
201 "filesize and duration do not match (growing file?)\n");
202 }
203 }
204
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 18 if (v & XING_FLAG_TOC)
205 17 read_xing_toc(s, mp3->header_filesize, av_rescale_q(mp3->frames,
206 17 (AVRational){spf, c->sample_rate},
207 st->time_base));
208 /* VBR quality */
209
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 18 if (v & XING_FLAC_QSCALE)
210 15 avio_rb32(s->pb);
211
212 /* Encoder short version string */
213 18 memset(version, 0, sizeof(version));
214 18 avio_read(s->pb, version, 9);
215
216 /* Info Tag revision + VBR method */
217 18 avio_r8(s->pb);
218
219 /* Lowpass filter value */
220 18 avio_r8(s->pb);
221
222 /* ReplayGain peak */
223 18 v = avio_rb32(s->pb);
224 18 peak = av_rescale(v, 100000, 1 << 23);
225
226 /* Radio ReplayGain */
227 18 v = avio_rb16(s->pb);
228
229
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 18 if (MIDDLE_BITS(v, 13, 15) == 1) {
230 ✗ r_gain = MIDDLE_BITS(v, 0, 8) * 10000;
231
232 ✗ if (v & (1 << 9))
233 ✗ r_gain *= -1;
234 }
235
236 /* Audiophile ReplayGain */
237 18 v = avio_rb16(s->pb);
238
239
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 18 if (MIDDLE_BITS(v, 13, 15) == 2) {
240 ✗ a_gain = MIDDLE_BITS(v, 0, 8) * 10000;
241
242 ✗ if (v & (1 << 9))
243 ✗ a_gain *= -1;
244 }
245
246 /* Encoding flags + ATH Type */
247 18 avio_r8(s->pb);
248
249 /* if ABR {specified bitrate} else {minimal bitrate} */
250 18 avio_r8(s->pb);
251
252 /* Encoder delays */
253 18 v = avio_rb24(s->pb);
254
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 18 if (AV_RB32(version) == MKBETAG('L', 'A', 'M', 'E')
255
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 8 || AV_RB32(version) == MKBETAG('L', 'a', 'v', 'f')
256
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 1 || AV_RB32(version) == MKBETAG('L', 'a', 'v', 'c')
257 ) {
258
259 17 mp3->start_pad = v>>12;
260 17 mp3-> end_pad = v&4095;
261 17 sti->start_skip_samples = mp3->start_pad + 528 + 1;
262
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 17 if (mp3->frames) {
263 17 sti->first_discard_sample = -mp3->end_pad + 528 + 1 + mp3->frames * (int64_t)spf;
264 17 sti->last_discard_sample = mp3->frames * (int64_t)spf;
265 }
266
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 17 if (!st->start_time)
267 17 st->start_time = av_rescale_q(sti->start_skip_samples,
268 17 (AVRational){1, c->sample_rate},
269 st->time_base);
270 17 av_log(s, AV_LOG_DEBUG, "pad %d %d\n", mp3->start_pad, mp3-> end_pad);
271 }
272
273 /* Misc */
274 18 avio_r8(s->pb);
275
276 /* MP3 gain */
277 18 avio_r8(s->pb);
278
279 /* Preset and surround info */
280 18 avio_rb16(s->pb);
281
282 /* Music length */
283 18 avio_rb32(s->pb);
284
285 /* Music CRC */
286 18 avio_rb16(s->pb);
287
288 /* Info Tag CRC */
289 18 crc = ffio_get_checksum(s->pb);
290 18 v = avio_rb16(s->pb);
291
292
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 18 if (v == crc) {
293 12 ff_replaygain_export_raw(st, r_gain, peak, a_gain, 0);
294 12 av_dict_set(&st->metadata, "encoder", version, 0);
295 }
296 }
297
298 28 static void mp3_parse_vbri_tag(AVFormatContext *s, AVStream *st, int64_t base)
299 {
300 uint32_t v;
301 28 MP3DecContext *mp3 = s->priv_data;
302
303 /* Check for VBRI tag (always 32 bytes after end of mpegaudio header) */
304 28 avio_seek(s->pb, base + 4 + 32, SEEK_SET);
305 28 v = avio_rb32(s->pb);
306
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 28 if (v == MKBETAG('V', 'B', 'R', 'I')) {
307 /* Check tag version */
308 ✗ if (avio_rb16(s->pb) == 1) {
309 /* skip delay and quality */
310 ✗ avio_skip(s->pb, 4);
311 ✗ mp3->header_filesize = avio_rb32(s->pb);
312 ✗ mp3->frames = avio_rb32(s->pb);
313 }
314 }
315 28 }
316
317 /**
318 * Try to find Xing/Info/VBRI tags and compute duration from info therein
319 */
320 32 static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
321 {
322 uint32_t v, spf;
323 MPADecodeHeader c;
324 32 int vbrtag_size = 0;
325 32 MP3DecContext *mp3 = s->priv_data;
326 int ret;
327
328 32 ffio_init_checksum(s->pb, ff_crcA001_update, 0);
329
330 32 v = avio_rb32(s->pb);
331
332 32 ret = avpriv_mpegaudio_decode_header(&c, v);
333
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 32 if (ret < 0)
334 1 return ret;
335
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 31 else if (ret == 0)
336 31 vbrtag_size = c.frame_size;
337
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 31 if (c.layer != 3)
338 3 return -1;
339
340
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 28 spf = c.lsf ? 576 : 1152; /* Samples per frame, layer 3 */
341
342 28 mp3->frames = 0;
343 28 mp3->header_filesize = 0;
344
345 28 mp3_parse_info_tag(s, st, &c, spf);
346 28 mp3_parse_vbri_tag(s, st, base);
347
348
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 28 if (!mp3->frames && !mp3->header_filesize)
349 10 return -1;
350
351 /* Skip the vbr tag frame */
352 18 avio_seek(s->pb, base + vbrtag_size, SEEK_SET);
353
354
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 18 if (mp3->frames)
355 18 st->duration = av_rescale_q(mp3->frames, (AVRational){spf, c.sample_rate},
356 st->time_base);
357
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 18 if (mp3->header_filesize && mp3->frames && !mp3->is_cbr)
358 1 st->codecpar->bit_rate = av_rescale(mp3->header_filesize, 8 * c.sample_rate, mp3->frames * (int64_t)spf);
359
360 18 return 0;
361 }
362
363 32 static int mp3_read_header(AVFormatContext *s)
364 {
365 32 FFFormatContext *const si = ffformatcontext(s);
366 32 MP3DecContext *mp3 = s->priv_data;
367 AVStream *st;
368 FFStream *sti;
369 int64_t off;
370 int ret;
371 int i;
372
373 32 s->metadata = si->id3v2_meta;
374 32 si->id3v2_meta = NULL;
375
376 32 st = avformat_new_stream(s, NULL);
377
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 32 if (!st)
378 ✗ return AVERROR(ENOMEM);
379 32 sti = ffstream(st);
380
381 32 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
382 32 st->codecpar->codec_id = AV_CODEC_ID_MP3;
383 32 sti->need_parsing = AVSTREAM_PARSE_FULL_RAW;
384 32 st->start_time = 0;
385
386 // lcm of all mp3 sample rates
387 32 avpriv_set_pts_info(st, 64, 1, 14112000);
388
389 32 ffiocontext(s->pb)->maxsize = -1;
390 32 off = avio_tell(s->pb);
391
392
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 32 if (!av_dict_count(s->metadata))
393 13 ff_id3v1_read(s);
394
395
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 32 if (s->pb->seekable & AVIO_SEEKABLE_NORMAL)
396 32 mp3->filesize = avio_size(s->pb);
397
398
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 32 if (mp3_parse_vbr_tags(s, st, off) < 0)
399 14 avio_seek(s->pb, off, SEEK_SET);
400
401 32 ret = ff_replaygain_export(st, s->metadata);
402
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 32 if (ret < 0)
403 ✗ return ret;
404
405 32 ret = ffio_ensure_seekback(s->pb, 64 * 1024 + MPA_MAX_CODED_FRAME_SIZE + 4);
406
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 32 if (ret < 0)
407 ✗ return ret;
408
409 32 off = avio_tell(s->pb);
410
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 658 for (i = 0; i < 64 * 1024; i++) {
411 uint32_t header, header2;
412 int frame_size;
413 658 frame_size = check(s->pb, off + i, &header);
414
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 658 if (frame_size > 0) {
415 32 ret = check(s->pb, off + i + frame_size, &header2);
416
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 32 if (ret >= 0 && (header & MP3_MASK) == (header2 & MP3_MASK))
417 32 break;
418
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 626 } else if (frame_size == CHECK_SEEK_FAILED) {
419 ✗ av_log(s, AV_LOG_ERROR, "Failed to find two consecutive MPEG audio frames.\n");
420 ✗ return AVERROR_INVALIDDATA;
421 }
422 }
423
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 32 if (i == 64 * 1024) {
424 ✗ off = avio_seek(s->pb, off, SEEK_SET);
425 } else {
426
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 32 av_log(s, i > 0 ? AV_LOG_INFO : AV_LOG_VERBOSE, "Skipping %d bytes of junk at %"PRId64".\n", i, off);
427 32 off = avio_seek(s->pb, off + i, SEEK_SET);
428 }
429
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 32 if (off < 0)
430 ✗ return off;
431
432 // the seek index is relative to the end of the xing vbr headers
433
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 132 for (int i = 0; i < sti->nb_index_entries; i++)
434 100 sti->index_entries[i].pos += off;
435
436 /* the parameters will be extracted from the compressed bitstream */
437 32 return 0;
438 }
439
440 #define MP3_PACKET_SIZE 1024
441
442 3141 static int mp3_read_packet(AVFormatContext *s, AVPacket *pkt)
443 {
444 3141 MP3DecContext *mp3 = s->priv_data;
445 int ret, size;
446 int64_t pos;
447
448 3141 size = MP3_PACKET_SIZE;
449 3141 pos = avio_tell(s->pb);
450
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 3141 if (mp3->filesize > ID3v1_TAG_SIZE && pos < mp3->filesize)
451 3105 size= FFMIN(size, mp3->filesize - pos);
452
453 3141 ret = av_get_packet(s->pb, pkt, size);
454
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 3141 if (ret <= 0) {
455
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 36 if(ret<0)
456 36 return ret;
457 ✗ return AVERROR_EOF;
458 }
459
460 3105 pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
461 3105 pkt->stream_index = 0;
462
463 3105 return ret;
464 }
465
466 #define SEEK_WINDOW 4096
467
468 17660 static int check(AVIOContext *pb, int64_t pos, uint32_t *ret_header)
469 {
470 17660 int64_t ret = avio_seek(pb, pos, SEEK_SET);
471 uint8_t header_buf[4];
472 unsigned header;
473 MPADecodeHeader sd;
474
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 17660 if (ret < 0)
475 ✗ return CHECK_SEEK_FAILED;
476
477 17660 ret = avio_read(pb, &header_buf[0], 4);
478 /* We should always find four bytes for a valid mpa header. */
479
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 17660 if (ret < 4)
480 ✗ return CHECK_SEEK_FAILED;
481
482 17660 header = AV_RB32(&header_buf[0]);
483
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 17660 if (ff_mpa_check_header(header) < 0)
484 17424 return CHECK_WRONG_HEADER;
485
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 236 if (avpriv_mpegaudio_decode_header(&sd, header) == 1)
486 ✗ return CHECK_WRONG_HEADER;
487
488
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 236 if (ret_header)
489 64 *ret_header = header;
490 236 return sd.frame_size;
491 }
492
493 26 static int64_t mp3_sync(AVFormatContext *s, int64_t target_pos, int flags)
494 {
495
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 26 int dir = (flags&AVSEEK_FLAG_BACKWARD) ? -1 : 1;
496 int64_t best_pos;
497 int best_score, i, j;
498 int64_t ret;
499
500 26 avio_seek(s->pb, FFMAX(target_pos - SEEK_WINDOW, 0), SEEK_SET);
501 26 ret = avio_seek(s->pb, target_pos, SEEK_SET);
502
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 26 if (ret < 0)
503 ✗ return ret;
504
505 #define MIN_VALID 3
506 26 best_pos = target_pos;
507 26 best_score = 999;
508
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509
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 16850 int64_t pos = target_pos + (dir > 0 ? i - SEEK_WINDOW/4 : -i);
510 16850 int64_t candidate = -1;
511 16850 int score = 999;
512
513
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 16850 if (pos < 0)
514 ✗ continue;
515
516
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 17022 for (j = 0; j < MIN_VALID; j++) {
517 16970 ret = check(s->pb, pos, NULL);
518
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 16970 if (ret < 0) {
519
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 16798 if (ret == CHECK_WRONG_HEADER) {
520 16798 break;
521 ✗ } else if (ret == CHECK_SEEK_FAILED) {
522 ✗ av_log(s, AV_LOG_ERROR, "Could not seek to %"PRId64".\n", pos);
523 ✗ return AVERROR(EINVAL);
524 }
525 }
526
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 172 if ((target_pos - pos)*dir <= 0 && FFABS(MIN_VALID/2-j) < score) {
527 68 candidate = pos;
528
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 68 score = FFABS(MIN_VALID/2-j);
529 }
530 172 pos += ret;
531 }
532
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 16850 if (best_score > score && j == MIN_VALID) {
533 48 best_pos = candidate;
534 48 best_score = score;
535
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 48 if(score == 0)
536 26 break;
537 }
538 }
539
540 26 return avio_seek(s->pb, best_pos, SEEK_SET);
541 }
542
543 128 static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
544 int flags)
545 {
546 128 FFFormatContext *const si = ffformatcontext(s);
547 128 MP3DecContext *mp3 = s->priv_data;
548 AVIndexEntry *ie, ie1;
549 128 AVStream *st = s->streams[0];
550 128 FFStream *const sti = ffstream(st);
551 int64_t best_pos;
552 128 int fast_seek = s->flags & AVFMT_FLAG_FAST_SEEK;
553 128 int64_t filesize = mp3->header_filesize;
554
555
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 128 if (filesize <= 0) {
556 48 int64_t size = avio_size(s->pb);
557
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 48 if (size > 0 && size > si->data_offset)
558 48 filesize = size - si->data_offset;
559 }
560
561
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 128 if (mp3->xing_toc && (mp3->usetoc || (fast_seek && !mp3->is_cbr))) {
562 ✗ int64_t ret = av_index_search_timestamp(st, timestamp, flags);
563
564 // NOTE: The MP3 TOC is not a precise lookup table. Accuracy is worse
565 // for bigger files.
566 ✗ av_log(s, AV_LOG_WARNING, "Using MP3 TOC to seek; may be imprecise.\n");
567
568 ✗ if (ret < 0)
569 ✗ return ret;
570
571 ✗ ie = &sti->index_entries[ret];
572
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 128 } else if (fast_seek && st->duration > 0 && filesize > 0) {
573
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 26 if (!mp3->is_cbr)
574 ✗ av_log(s, AV_LOG_WARNING, "Using scaling to seek VBR MP3; may be imprecise.\n");
575
576 26 ie = &ie1;
577 26 timestamp = av_clip64(timestamp, 0, st->duration);
578 26 ie->timestamp = timestamp;
579 26 ie->pos = av_rescale(timestamp, filesize, st->duration) + si->data_offset;
580 } else {
581 102 return -1; // generic index code
582 }
583
584 26 best_pos = mp3_sync(s, ie->pos, flags);
585
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 26 if (best_pos < 0)
586 ✗ return best_pos;
587
588
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 26 if (mp3->is_cbr && ie == &ie1 && mp3->frames && mp3->header_filesize > 0) {
589 26 int frame_duration = av_rescale(st->duration, 1, mp3->frames);
590 26 ie1.timestamp = frame_duration * av_rescale(best_pos - si->data_offset, mp3->frames, mp3->header_filesize);
591 }
592
593 26 avpriv_update_cur_dts(s, st, ie->timestamp);
594 26 return 0;
595 }
596
597 static const AVOption options[] = {
598 { "usetoc", "use table of contents", offsetof(MP3DecContext, usetoc), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM},
599 { NULL },
600 };
601
602 static const AVClass demuxer_class = {
603 .class_name = "mp3",
604 .item_name = av_default_item_name,
605 .option = options,
606 .version = LIBAVUTIL_VERSION_INT,
607 .category = AV_CLASS_CATEGORY_DEMUXER,
608 };
609
610 const FFInputFormat ff_mp3_demuxer = {
611 .p.name = "mp3",
612 .p.long_name = NULL_IF_CONFIG_SMALL("MP2/3 (MPEG audio layer 2/3)"),
613 .p.flags = AVFMT_GENERIC_INDEX,
614 .p.extensions = "mp2,mp3,m2a,mpa", /* XXX: use probe */
615 .p.priv_class = &demuxer_class,
616 .p.mime_type = "audio/mpeg",
617 .read_probe = mp3_read_probe,
618 .read_header = mp3_read_header,
619 .read_packet = mp3_read_packet,
620 .read_seek = mp3_seek,
621 .priv_data_size = sizeof(MP3DecContext),
622 };
623