a56f17abf335bbbdfae02cec018aeb55bb80ae66
[libav.git] / libavformat / mpeg.c
1 /*
2 * MPEG1/2 demuxer
3 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include "avformat.h"
23 #include "internal.h"
24 #include "mpeg.h"
25
26 #undef NDEBUG
27 #include <assert.h>
28
29 /*********************************************/
30 /* demux code */
31
32 #define MAX_SYNC_SIZE 100000
33
34 static int check_pes(uint8_t *p, uint8_t *end){
35 int pes1;
36 int pes2= (p[3] & 0xC0) == 0x80
37 && (p[4] & 0xC0) != 0x40
38 &&((p[4] & 0xC0) == 0x00 || (p[4]&0xC0)>>2 == (p[6]&0xF0));
39
40 for(p+=3; p<end && *p == 0xFF; p++);
41 if((*p&0xC0) == 0x40) p+=2;
42 if((*p&0xF0) == 0x20){
43 pes1= p[0]&p[2]&p[4]&1;
44 }else if((*p&0xF0) == 0x30){
45 pes1= p[0]&p[2]&p[4]&p[5]&p[7]&p[9]&1;
46 }else
47 pes1 = *p == 0x0F;
48
49 return pes1||pes2;
50 }
51
52 static int check_pack_header(const uint8_t *buf) {
53 return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20;
54 }
55
56 static int mpegps_probe(AVProbeData *p)
57 {
58 uint32_t code= -1;
59 int sys=0, pspack=0, priv1=0, vid=0, audio=0, invalid=0;
60 int i;
61 int score=0;
62
63 for(i=0; i<p->buf_size; i++){
64 code = (code<<8) + p->buf[i];
65 if ((code & 0xffffff00) == 0x100) {
66 int len= p->buf[i+1] << 8 | p->buf[i+2];
67 int pes= check_pes(p->buf+i, p->buf+p->buf_size);
68 int pack = check_pack_header(p->buf+i);
69
70 if(code == SYSTEM_HEADER_START_CODE) sys++;
71 else if(code == PACK_START_CODE && pack) pspack++;
72 else if((code & 0xf0) == VIDEO_ID && pes) vid++;
73 // skip pes payload to avoid start code emulation for private
74 // and audio streams
75 else if((code & 0xe0) == AUDIO_ID && pes) {audio++; i+=len;}
76 else if(code == PRIVATE_STREAM_1 && pes) {priv1++; i+=len;}
77
78 else if((code & 0xf0) == VIDEO_ID && !pes) invalid++;
79 else if((code & 0xe0) == AUDIO_ID && !pes) invalid++;
80 else if(code == PRIVATE_STREAM_1 && !pes) invalid++;
81 }
82 }
83
84 if(vid+audio > invalid) /* invalid VDR files nd short PES streams */
85 score= AVPROBE_SCORE_MAX/4;
86
87 //av_log(NULL, AV_LOG_ERROR, "%d %d %d %d %d %d len:%d\n", sys, priv1, pspack,vid, audio, invalid, p->buf_size);
88 if(sys>invalid && sys*9 <= pspack*10)
89 return pspack > 2 ? AVPROBE_SCORE_MAX/2+2 : AVPROBE_SCORE_MAX/4; // +1 for .mpg
90 if(pspack > invalid && (priv1+vid+audio)*10 >= pspack*9)
91 return pspack > 2 ? AVPROBE_SCORE_MAX/2+2 : AVPROBE_SCORE_MAX/4; // +1 for .mpg
92 if((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys && !pspack && p->buf_size>2048 && vid + audio > invalid) /* PES stream */
93 return (audio > 12 || vid > 3) ? AVPROBE_SCORE_MAX/2+2 : AVPROBE_SCORE_MAX/4;
94
95 //02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1
96 //mp3_misidentified_2.mp3 has sys:0 priv1:0 pspack:0 vid:0 audio:6
97 return score;
98 }
99
100
101 typedef struct MpegDemuxContext {
102 int32_t header_state;
103 unsigned char psm_es_type[256];
104 int sofdec;
105 } MpegDemuxContext;
106
107 static int mpegps_read_header(AVFormatContext *s)
108 {
109 MpegDemuxContext *m = s->priv_data;
110 const char *sofdec = "Sofdec";
111 int v, i = 0;
112
113 m->header_state = 0xff;
114 s->ctx_flags |= AVFMTCTX_NOHEADER;
115
116 m->sofdec = -1;
117 do {
118 v = avio_r8(s->pb);
119 m->header_state = m->header_state << 8 | v;
120 m->sofdec++;
121 } while (v == sofdec[i] && i++ < 6);
122
123 m->sofdec = (m->sofdec == 6) ? 1 : 0;
124
125 /* no need to do more */
126 return 0;
127 }
128
129 static int64_t get_pts(AVIOContext *pb, int c)
130 {
131 uint8_t buf[5];
132
133 buf[0] = c<0 ? avio_r8(pb) : c;
134 avio_read(pb, buf+1, 4);
135
136 return ff_parse_pes_pts(buf);
137 }
138
139 static int find_next_start_code(AVIOContext *pb, int *size_ptr,
140 int32_t *header_state)
141 {
142 unsigned int state, v;
143 int val, n;
144
145 state = *header_state;
146 n = *size_ptr;
147 while (n > 0) {
148 if (pb->eof_reached)
149 break;
150 v = avio_r8(pb);
151 n--;
152 if (state == 0x000001) {
153 state = ((state << 8) | v) & 0xffffff;
154 val = state;
155 goto found;
156 }
157 state = ((state << 8) | v) & 0xffffff;
158 }
159 val = -1;
160 found:
161 *header_state = state;
162 *size_ptr = n;
163 return val;
164 }
165
166 /**
167 * Extract stream types from a program stream map
168 * According to ISO/IEC 13818-1 ('MPEG-2 Systems') table 2-35
169 *
170 * @return number of bytes occupied by PSM in the bitstream
171 */
172 static long mpegps_psm_parse(MpegDemuxContext *m, AVIOContext *pb)
173 {
174 int psm_length, ps_info_length, es_map_length;
175
176 psm_length = avio_rb16(pb);
177 avio_r8(pb);
178 avio_r8(pb);
179 ps_info_length = avio_rb16(pb);
180
181 /* skip program_stream_info */
182 avio_skip(pb, ps_info_length);
183 es_map_length = avio_rb16(pb);
184
185 /* at least one es available? */
186 while (es_map_length >= 4){
187 unsigned char type = avio_r8(pb);
188 unsigned char es_id = avio_r8(pb);
189 uint16_t es_info_length = avio_rb16(pb);
190 /* remember mapping from stream id to stream type */
191 m->psm_es_type[es_id] = type;
192 /* skip program_stream_info */
193 avio_skip(pb, es_info_length);
194 es_map_length -= 4 + es_info_length;
195 }
196 avio_rb32(pb); /* crc32 */
197 return 2 + psm_length;
198 }
199
200 /* read the next PES header. Return its position in ppos
201 (if not NULL), and its start code, pts and dts.
202 */
203 static int mpegps_read_pes_header(AVFormatContext *s,
204 int64_t *ppos, int *pstart_code,
205 int64_t *ppts, int64_t *pdts)
206 {
207 MpegDemuxContext *m = s->priv_data;
208 int len, size, startcode, c, flags, header_len;
209 int pes_ext, ext2_len, id_ext, skip;
210 int64_t pts, dts;
211 int64_t last_sync= avio_tell(s->pb);
212
213 error_redo:
214 avio_seek(s->pb, last_sync, SEEK_SET);
215 redo:
216 /* next start code (should be immediately after) */
217 m->header_state = 0xff;
218 size = MAX_SYNC_SIZE;
219 startcode = find_next_start_code(s->pb, &size, &m->header_state);
220 last_sync = avio_tell(s->pb);
221 //printf("startcode=%x pos=0x%"PRIx64"\n", startcode, avio_tell(s->pb));
222 if (startcode < 0){
223 if(s->pb->eof_reached)
224 return AVERROR_EOF;
225 //FIXME we should remember header_state
226 return AVERROR(EAGAIN);
227 }
228
229 if (startcode == PACK_START_CODE)
230 goto redo;
231 if (startcode == SYSTEM_HEADER_START_CODE)
232 goto redo;
233 if (startcode == PADDING_STREAM) {
234 avio_skip(s->pb, avio_rb16(s->pb));
235 goto redo;
236 }
237 if (startcode == PRIVATE_STREAM_2) {
238 len = avio_rb16(s->pb);
239 if (!m->sofdec) {
240 while (len-- >= 6) {
241 if (avio_r8(s->pb) == 'S') {
242 uint8_t buf[5];
243 avio_read(s->pb, buf, sizeof(buf));
244 m->sofdec = !memcmp(buf, "ofdec", 5);
245 len -= sizeof(buf);
246 break;
247 }
248 }
249 m->sofdec -= !m->sofdec;
250 }
251 avio_skip(s->pb, len);
252 goto redo;
253 }
254 if (startcode == PROGRAM_STREAM_MAP) {
255 mpegps_psm_parse(m, s->pb);
256 goto redo;
257 }
258
259 /* find matching stream */
260 if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
261 (startcode >= 0x1e0 && startcode <= 0x1ef) ||
262 (startcode == 0x1bd) || (startcode == 0x1fd)))
263 goto redo;
264 if (ppos) {
265 *ppos = avio_tell(s->pb) - 4;
266 }
267 len = avio_rb16(s->pb);
268 pts =
269 dts = AV_NOPTS_VALUE;
270 /* stuffing */
271 for(;;) {
272 if (len < 1)
273 goto error_redo;
274 c = avio_r8(s->pb);
275 len--;
276 /* XXX: for mpeg1, should test only bit 7 */
277 if (c != 0xff)
278 break;
279 }
280 if ((c & 0xc0) == 0x40) {
281 /* buffer scale & size */
282 avio_r8(s->pb);
283 c = avio_r8(s->pb);
284 len -= 2;
285 }
286 if ((c & 0xe0) == 0x20) {
287 dts = pts = get_pts(s->pb, c);
288 len -= 4;
289 if (c & 0x10){
290 dts = get_pts(s->pb, -1);
291 len -= 5;
292 }
293 } else if ((c & 0xc0) == 0x80) {
294 /* mpeg 2 PES */
295 flags = avio_r8(s->pb);
296 header_len = avio_r8(s->pb);
297 len -= 2;
298 if (header_len > len)
299 goto error_redo;
300 len -= header_len;
301 if (flags & 0x80) {
302 dts = pts = get_pts(s->pb, -1);
303 header_len -= 5;
304 if (flags & 0x40) {
305 dts = get_pts(s->pb, -1);
306 header_len -= 5;
307 }
308 }
309 if (flags & 0x3f && header_len == 0){
310 flags &= 0xC0;
311 av_log(s, AV_LOG_WARNING, "Further flags set but no bytes left\n");
312 }
313 if (flags & 0x01) { /* PES extension */
314 pes_ext = avio_r8(s->pb);
315 header_len--;
316 /* Skip PES private data, program packet sequence counter and P-STD buffer */
317 skip = (pes_ext >> 4) & 0xb;
318 skip += skip & 0x9;
319 if (pes_ext & 0x40 || skip > header_len){
320 av_log(s, AV_LOG_WARNING, "pes_ext %X is invalid\n", pes_ext);
321 pes_ext=skip=0;
322 }
323 avio_skip(s->pb, skip);
324 header_len -= skip;
325
326 if (pes_ext & 0x01) { /* PES extension 2 */
327 ext2_len = avio_r8(s->pb);
328 header_len--;
329 if ((ext2_len & 0x7f) > 0) {
330 id_ext = avio_r8(s->pb);
331 if ((id_ext & 0x80) == 0)
332 startcode = ((startcode & 0xff) << 8) | id_ext;
333 header_len--;
334 }
335 }
336 }
337 if(header_len < 0)
338 goto error_redo;
339 avio_skip(s->pb, header_len);
340 }
341 else if( c!= 0xf )
342 goto redo;
343
344 if (startcode == PRIVATE_STREAM_1 && !m->psm_es_type[startcode & 0xff]) {
345 startcode = avio_r8(s->pb);
346 len--;
347 if (startcode >= 0x80 && startcode <= 0xcf) {
348 /* audio: skip header */
349 avio_r8(s->pb);
350 avio_r8(s->pb);
351 avio_r8(s->pb);
352 len -= 3;
353 if (startcode >= 0xb0 && startcode <= 0xbf) {
354 /* MLP/TrueHD audio has a 4-byte header */
355 avio_r8(s->pb);
356 len--;
357 }
358 }
359 }
360 if(len<0)
361 goto error_redo;
362 if(dts != AV_NOPTS_VALUE && ppos){
363 int i;
364 for(i=0; i<s->nb_streams; i++){
365 if(startcode == s->streams[i]->id &&
366 s->pb->seekable /* index useless on streams anyway */) {
367 ff_reduce_index(s, i);
368 av_add_index_entry(s->streams[i], *ppos, dts, 0, 0, AVINDEX_KEYFRAME /* FIXME keyframe? */);
369 }
370 }
371 }
372
373 *pstart_code = startcode;
374 *ppts = pts;
375 *pdts = dts;
376 return len;
377 }
378
379 static int mpegps_read_packet(AVFormatContext *s,
380 AVPacket *pkt)
381 {
382 MpegDemuxContext *m = s->priv_data;
383 AVStream *st;
384 int len, startcode, i, es_type, ret;
385 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
386 enum AVMediaType type;
387 int64_t pts, dts, dummy_pos; //dummy_pos is needed for the index building to work
388 uint8_t av_uninit(dvdaudio_substream_type);
389
390 redo:
391 len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts);
392 if (len < 0)
393 return len;
394
395 if(startcode == 0x1bd) {
396 dvdaudio_substream_type = avio_r8(s->pb);
397 avio_skip(s->pb, 3);
398 len -= 4;
399 }
400
401 /* now find stream */
402 for(i=0;i<s->nb_streams;i++) {
403 st = s->streams[i];
404 if (st->id == startcode)
405 goto found;
406 }
407
408 es_type = m->psm_es_type[startcode & 0xff];
409 if(es_type > 0 && es_type != STREAM_TYPE_PRIVATE_DATA){
410 if(es_type == STREAM_TYPE_VIDEO_MPEG1){
411 codec_id = AV_CODEC_ID_MPEG2VIDEO;
412 type = AVMEDIA_TYPE_VIDEO;
413 } else if(es_type == STREAM_TYPE_VIDEO_MPEG2){
414 codec_id = AV_CODEC_ID_MPEG2VIDEO;
415 type = AVMEDIA_TYPE_VIDEO;
416 } else if(es_type == STREAM_TYPE_AUDIO_MPEG1 ||
417 es_type == STREAM_TYPE_AUDIO_MPEG2){
418 codec_id = AV_CODEC_ID_MP3;
419 type = AVMEDIA_TYPE_AUDIO;
420 } else if(es_type == STREAM_TYPE_AUDIO_AAC){
421 codec_id = AV_CODEC_ID_AAC;
422 type = AVMEDIA_TYPE_AUDIO;
423 } else if(es_type == STREAM_TYPE_VIDEO_MPEG4){
424 codec_id = AV_CODEC_ID_MPEG4;
425 type = AVMEDIA_TYPE_VIDEO;
426 } else if(es_type == STREAM_TYPE_VIDEO_H264){
427 codec_id = AV_CODEC_ID_H264;
428 type = AVMEDIA_TYPE_VIDEO;
429 } else if(es_type == STREAM_TYPE_AUDIO_AC3){
430 codec_id = AV_CODEC_ID_AC3;
431 type = AVMEDIA_TYPE_AUDIO;
432 } else {
433 goto skip;
434 }
435 } else if (startcode >= 0x1e0 && startcode <= 0x1ef) {
436 static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };
437 unsigned char buf[8];
438 avio_read(s->pb, buf, 8);
439 avio_seek(s->pb, -8, SEEK_CUR);
440 if(!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))
441 codec_id = AV_CODEC_ID_CAVS;
442 else
443 codec_id = AV_CODEC_ID_PROBE;
444 type = AVMEDIA_TYPE_VIDEO;
445 } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
446 type = AVMEDIA_TYPE_AUDIO;
447 codec_id = m->sofdec > 0 ? AV_CODEC_ID_ADPCM_ADX : AV_CODEC_ID_MP2;
448 } else if (startcode >= 0x80 && startcode <= 0x87) {
449 type = AVMEDIA_TYPE_AUDIO;
450 codec_id = AV_CODEC_ID_AC3;
451 } else if ( ( startcode >= 0x88 && startcode <= 0x8f)
452 ||( startcode >= 0x98 && startcode <= 0x9f)) {
453 /* 0x90 - 0x97 is reserved for SDDS in DVD specs */
454 type = AVMEDIA_TYPE_AUDIO;
455 codec_id = AV_CODEC_ID_DTS;
456 } else if (startcode >= 0xa0 && startcode <= 0xaf) {
457 type = AVMEDIA_TYPE_AUDIO;
458 /* 16 bit form will be handled as AV_CODEC_ID_PCM_S16BE */
459 codec_id = AV_CODEC_ID_PCM_DVD;
460 } else if (startcode >= 0xb0 && startcode <= 0xbf) {
461 type = AVMEDIA_TYPE_AUDIO;
462 codec_id = AV_CODEC_ID_TRUEHD;
463 } else if (startcode >= 0xc0 && startcode <= 0xcf) {
464 /* Used for both AC-3 and E-AC-3 in EVOB files */
465 type = AVMEDIA_TYPE_AUDIO;
466 codec_id = AV_CODEC_ID_AC3;
467 } else if (startcode >= 0x20 && startcode <= 0x3f) {
468 type = AVMEDIA_TYPE_SUBTITLE;
469 codec_id = AV_CODEC_ID_DVD_SUBTITLE;
470 } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {
471 type = AVMEDIA_TYPE_VIDEO;
472 codec_id = AV_CODEC_ID_VC1;
473 } else if (startcode == 0x1bd) {
474 // check dvd audio substream type
475 type = AVMEDIA_TYPE_AUDIO;
476 switch(dvdaudio_substream_type & 0xe0) {
477 case 0xa0: codec_id = AV_CODEC_ID_PCM_DVD;
478 break;
479 case 0x80: if((dvdaudio_substream_type & 0xf8) == 0x88)
480 codec_id = AV_CODEC_ID_DTS;
481 else codec_id = AV_CODEC_ID_AC3;
482 break;
483 default: av_log(s, AV_LOG_ERROR, "Unknown 0x1bd sub-stream\n");
484 goto skip;
485 }
486 } else {
487 skip:
488 /* skip packet */
489 avio_skip(s->pb, len);
490 goto redo;
491 }
492 /* no stream found: add a new stream */
493 st = avformat_new_stream(s, NULL);
494 if (!st)
495 goto skip;
496 st->id = startcode;
497 st->codec->codec_type = type;
498 st->codec->codec_id = codec_id;
499 if (codec_id != AV_CODEC_ID_PCM_S16BE)
500 st->need_parsing = AVSTREAM_PARSE_FULL;
501 found:
502 if(st->discard >= AVDISCARD_ALL)
503 goto skip;
504 if ((startcode >= 0xa0 && startcode <= 0xaf) ||
505 (startcode == 0x1bd && ((dvdaudio_substream_type & 0xe0) == 0xa0))) {
506 int b1, freq;
507
508 /* for LPCM, we just skip the header and consider it is raw
509 audio data */
510 if (len <= 3)
511 goto skip;
512 avio_r8(s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */
513 b1 = avio_r8(s->pb); /* quant (2), freq(2), reserved(1), channels(3) */
514 avio_r8(s->pb); /* dynamic range control (0x80 = off) */
515 len -= 3;
516 freq = (b1 >> 4) & 3;
517 st->codec->sample_rate = lpcm_freq_tab[freq];
518 st->codec->channels = 1 + (b1 & 7);
519 st->codec->bits_per_coded_sample = 16 + ((b1 >> 6) & 3) * 4;
520 st->codec->bit_rate = st->codec->channels *
521 st->codec->sample_rate *
522 st->codec->bits_per_coded_sample;
523 if (st->codec->bits_per_coded_sample == 16)
524 st->codec->codec_id = AV_CODEC_ID_PCM_S16BE;
525 else if (st->codec->bits_per_coded_sample == 28)
526 return AVERROR(EINVAL);
527 }
528 ret = av_get_packet(s->pb, pkt, len);
529 pkt->pts = pts;
530 pkt->dts = dts;
531 pkt->pos = dummy_pos;
532 pkt->stream_index = st->index;
533 av_dlog(s, "%d: pts=%0.3f dts=%0.3f size=%d\n",
534 pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0,
535 pkt->size);
536
537 return (ret < 0) ? ret : 0;
538 }
539
540 static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
541 int64_t *ppos, int64_t pos_limit)
542 {
543 int len, startcode;
544 int64_t pos, pts, dts;
545
546 pos = *ppos;
547 if (avio_seek(s->pb, pos, SEEK_SET) < 0)
548 return AV_NOPTS_VALUE;
549
550 for(;;) {
551 len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts);
552 if (len < 0) {
553 av_dlog(s, "none (ret=%d)\n", len);
554 return AV_NOPTS_VALUE;
555 }
556 if (startcode == s->streams[stream_index]->id &&
557 dts != AV_NOPTS_VALUE) {
558 break;
559 }
560 avio_skip(s->pb, len);
561 }
562 av_dlog(s, "pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n",
563 pos, dts, dts / 90000.0);
564 *ppos = pos;
565 return dts;
566 }
567
568 AVInputFormat ff_mpegps_demuxer = {
569 .name = "mpeg",
570 .long_name = NULL_IF_CONFIG_SMALL("MPEG-PS (MPEG-2 Program Stream)"),
571 .priv_data_size = sizeof(MpegDemuxContext),
572 .read_probe = mpegps_probe,
573 .read_header = mpegps_read_header,
574 .read_packet = mpegps_read_packet,
575 .read_timestamp = mpegps_read_dts,
576 .flags = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT,
577 };