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1
/*
2
 * MPEG1/2 demuxer
3
 * Copyright (c) 2000, 2001, 2002 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 "avformat.h"
23
#include "mpeg.h"
24

    
25
//#define DEBUG_SEEK
26

    
27
#undef NDEBUG
28
#include <assert.h>
29

    
30
/*********************************************/
31
/* demux code */
32

    
33
#define MAX_SYNC_SIZE 100000
34

    
35
static int cdxa_probe(AVProbeData *p)
36
{
37
    /* check file header */
38
    if (p->buf[0] == 'R' && p->buf[1] == 'I' &&
39
        p->buf[2] == 'F' && p->buf[3] == 'F' &&
40
        p->buf[8] == 'C' && p->buf[9] == 'D' &&
41
        p->buf[10] == 'X' && p->buf[11] == 'A')
42
        return AVPROBE_SCORE_MAX;
43
    else
44
        return 0;
45
}
46

    
47
static int check_pes(uint8_t *p, uint8_t *end){
48
    int pes1;
49
    int pes2=      (p[3] & 0xC0) == 0x80
50
                && (p[4] & 0xC0) != 0x40
51
                &&((p[4] & 0xC0) == 0x00 || (p[4]&0xC0)>>2 == (p[6]&0xF0));
52

    
53
    for(p+=3; p<end && *p == 0xFF; p++);
54
    if((*p&0xC0) == 0x40) p+=2;
55
    if((*p&0xF0) == 0x20){
56
        pes1= p[0]&p[2]&p[4]&1;
57
        p+=5;
58
    }else if((*p&0xF0) == 0x30){
59
        pes1= p[0]&p[2]&p[4]&p[5]&p[7]&p[9]&1;
60
        p+=10;
61
    }else
62
        pes1 = *p == 0x0F;
63

    
64
    return pes1||pes2;
65
}
66

    
67
static int mpegps_probe(AVProbeData *p)
68
{
69
    uint32_t code= -1;
70
    int sys=0, pspack=0, priv1=0, vid=0, audio=0, invalid=0;
71
    int i;
72
    int score=0;
73

    
74
    score = cdxa_probe(p);
75
    if (score > 0) return score;
76

    
77
    /* Search for MPEG stream */
78
    for(i=0; i<p->buf_size; i++){
79
        code = (code<<8) + p->buf[i];
80
        if ((code & 0xffffff00) == 0x100) {
81
            int pes= check_pes(p->buf+i, p->buf+p->buf_size);
82

    
83
            if(code == SYSTEM_HEADER_START_CODE) sys++;
84
            else if(code == PRIVATE_STREAM_1)    priv1++;
85
            else if(code == PACK_START_CODE)     pspack++;
86
            else if((code & 0xf0) == VIDEO_ID && pes) vid++;
87
            else if((code & 0xe0) == AUDIO_ID && pes) audio++;
88

    
89
            else if((code & 0xf0) == VIDEO_ID && !pes) invalid++;
90
            else if((code & 0xe0) == AUDIO_ID && !pes) invalid++;
91
        }
92
    }
93

    
94
    if(vid+audio > invalid)     /* invalid VDR files nd short PES streams */
95
        score= AVPROBE_SCORE_MAX/4;
96

    
97
//av_log(NULL, AV_LOG_ERROR, "%d %d %d %d %d len:%d\n", sys, priv1, pspack,vid, audio, p->buf_size);
98
    if(sys>invalid && sys*9 <= pspack*10)
99
        return AVPROBE_SCORE_MAX/2+2; // +1 for .mpg
100
    if(priv1 + vid + audio > invalid && (priv1+vid+audio)*9 <= pspack*10)
101
        return AVPROBE_SCORE_MAX/2+2; // +1 for .mpg
102
    if((!!vid ^ !!audio) && (audio+vid > 1) && !sys && !pspack && p->buf_size>2048) /* PES stream */
103
        return AVPROBE_SCORE_MAX/2+2;
104

    
105
    //02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1
106
    return score;
107
}
108

    
109

    
110
typedef struct MpegDemuxContext {
111
    int32_t header_state;
112
    unsigned char psm_es_type[256];
113
    int sofdec;
114
} MpegDemuxContext;
115

    
116
static int mpegps_read_header(AVFormatContext *s,
117
                              AVFormatParameters *ap)
118
{
119
    MpegDemuxContext *m = s->priv_data;
120
    const char *sofdec = "Sofdec";
121
    int v, i = 0;
122

    
123
    m->header_state = 0xff;
124
    s->ctx_flags |= AVFMTCTX_NOHEADER;
125

    
126
    m->sofdec = -1;
127
    do {
128
        v = get_byte(s->pb);
129
        m->header_state = m->header_state << 8 | v;
130
        m->sofdec++;
131
    } while (v == sofdec[i] && i++ < 6);
132

    
133
    /* no need to do more */
134
    return 0;
135
}
136

    
137
static int64_t get_pts(ByteIOContext *pb, int c)
138
{
139
    int64_t pts;
140
    int val;
141

    
142
    if (c < 0)
143
        c = get_byte(pb);
144
    pts = (int64_t)((c >> 1) & 0x07) << 30;
145
    val = get_be16(pb);
146
    pts |= (int64_t)(val >> 1) << 15;
147
    val = get_be16(pb);
148
    pts |= (int64_t)(val >> 1);
149
    return pts;
150
}
151

    
152
static int find_next_start_code(ByteIOContext *pb, int *size_ptr,
153
                                int32_t *header_state)
154
{
155
    unsigned int state, v;
156
    int val, n;
157

    
158
    state = *header_state;
159
    n = *size_ptr;
160
    while (n > 0) {
161
        if (url_feof(pb))
162
            break;
163
        v = get_byte(pb);
164
        n--;
165
        if (state == 0x000001) {
166
            state = ((state << 8) | v) & 0xffffff;
167
            val = state;
168
            goto found;
169
        }
170
        state = ((state << 8) | v) & 0xffffff;
171
    }
172
    val = -1;
173
 found:
174
    *header_state = state;
175
    *size_ptr = n;
176
    return val;
177
}
178

    
179
#if 0 /* unused, remove? */
180
/* XXX: optimize */
181
static int find_prev_start_code(ByteIOContext *pb, int *size_ptr)
182
{
183
    int64_t pos, pos_start;
184
    int max_size, start_code;
185

186
    max_size = *size_ptr;
187
    pos_start = url_ftell(pb);
188

189
    /* in order to go faster, we fill the buffer */
190
    pos = pos_start - 16386;
191
    if (pos < 0)
192
        pos = 0;
193
    url_fseek(pb, pos, SEEK_SET);
194
    get_byte(pb);
195

196
    pos = pos_start;
197
    for(;;) {
198
        pos--;
199
        if (pos < 0 || (pos_start - pos) >= max_size) {
200
            start_code = -1;
201
            goto the_end;
202
        }
203
        url_fseek(pb, pos, SEEK_SET);
204
        start_code = get_be32(pb);
205
        if ((start_code & 0xffffff00) == 0x100)
206
            break;
207
    }
208
 the_end:
209
    *size_ptr = pos_start - pos;
210
    return start_code;
211
}
212
#endif
213

    
214
/**
215
 * Extracts stream types from a program stream map
216
 * According to ISO/IEC 13818-1 ('MPEG-2 Systems') table 2-35
217
 *
218
 * @return number of bytes occupied by PSM in the bitstream
219
 */
220
static long mpegps_psm_parse(MpegDemuxContext *m, ByteIOContext *pb)
221
{
222
    int psm_length, ps_info_length, es_map_length;
223

    
224
    psm_length = get_be16(pb);
225
    get_byte(pb);
226
    get_byte(pb);
227
    ps_info_length = get_be16(pb);
228

    
229
    /* skip program_stream_info */
230
    url_fskip(pb, ps_info_length);
231
    es_map_length = get_be16(pb);
232

    
233
    /* at least one es available? */
234
    while (es_map_length >= 4){
235
        unsigned char type = get_byte(pb);
236
        unsigned char es_id = get_byte(pb);
237
        uint16_t es_info_length = get_be16(pb);
238
        /* remember mapping from stream id to stream type */
239
        m->psm_es_type[es_id] = type;
240
        /* skip program_stream_info */
241
        url_fskip(pb, es_info_length);
242
        es_map_length -= 4 + es_info_length;
243
    }
244
    get_be32(pb); /* crc32 */
245
    return 2 + psm_length;
246
}
247

    
248
/* read the next PES header. Return its position in ppos
249
   (if not NULL), and its start code, pts and dts.
250
 */
251
static int mpegps_read_pes_header(AVFormatContext *s,
252
                                  int64_t *ppos, int *pstart_code,
253
                                  int64_t *ppts, int64_t *pdts)
254
{
255
    MpegDemuxContext *m = s->priv_data;
256
    int len, size, startcode, c, flags, header_len;
257
    int pes_ext, ext2_len, id_ext, skip;
258
    int64_t pts, dts;
259
    int64_t last_sync= url_ftell(s->pb);
260

    
261
 error_redo:
262
        url_fseek(s->pb, last_sync, SEEK_SET);
263
 redo:
264
        /* next start code (should be immediately after) */
265
        m->header_state = 0xff;
266
        size = MAX_SYNC_SIZE;
267
        startcode = find_next_start_code(s->pb, &size, &m->header_state);
268
        last_sync = url_ftell(s->pb);
269
    //printf("startcode=%x pos=0x%"PRIx64"\n", startcode, url_ftell(s->pb));
270
    if (startcode < 0)
271
        return AVERROR(EIO);
272
    if (startcode == PACK_START_CODE)
273
        goto redo;
274
    if (startcode == SYSTEM_HEADER_START_CODE)
275
        goto redo;
276
    if (startcode == PADDING_STREAM) {
277
        url_fskip(s->pb, get_be16(s->pb));
278
        goto redo;
279
    }
280
    if (startcode == PRIVATE_STREAM_2) {
281
        len = get_be16(s->pb);
282
        if (!m->sofdec) {
283
            while (len-- >= 6) {
284
                if (get_byte(s->pb) == 'S') {
285
                    uint8_t buf[5];
286
                    get_buffer(s->pb, buf, sizeof(buf));
287
                    m->sofdec = !memcmp(buf, "ofdec", 5);
288
                    len -= sizeof(buf);
289
                    break;
290
                }
291
            }
292
            m->sofdec -= !m->sofdec;
293
        }
294
        url_fskip(s->pb, len);
295
        goto redo;
296
    }
297
    if (startcode == PROGRAM_STREAM_MAP) {
298
        mpegps_psm_parse(m, s->pb);
299
        goto redo;
300
    }
301

    
302
    /* find matching stream */
303
    if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
304
          (startcode >= 0x1e0 && startcode <= 0x1ef) ||
305
          (startcode == 0x1bd) || (startcode == 0x1fd)))
306
        goto redo;
307
    if (ppos) {
308
        *ppos = url_ftell(s->pb) - 4;
309
    }
310
    len = get_be16(s->pb);
311
    pts =
312
    dts = AV_NOPTS_VALUE;
313
    /* stuffing */
314
    for(;;) {
315
        if (len < 1)
316
            goto error_redo;
317
        c = get_byte(s->pb);
318
        len--;
319
        /* XXX: for mpeg1, should test only bit 7 */
320
        if (c != 0xff)
321
            break;
322
    }
323
    if ((c & 0xc0) == 0x40) {
324
        /* buffer scale & size */
325
        get_byte(s->pb);
326
        c = get_byte(s->pb);
327
        len -= 2;
328
    }
329
    if ((c & 0xe0) == 0x20) {
330
        dts = pts = get_pts(s->pb, c);
331
        len -= 4;
332
        if (c & 0x10){
333
            dts = get_pts(s->pb, -1);
334
            len -= 5;
335
        }
336
    } else if ((c & 0xc0) == 0x80) {
337
        /* mpeg 2 PES */
338
#if 0 /* some streams have this field set for no apparent reason */
339
        if ((c & 0x30) != 0) {
340
            /* Encrypted multiplex not handled */
341
            goto redo;
342
        }
343
#endif
344
        flags = get_byte(s->pb);
345
        header_len = get_byte(s->pb);
346
        len -= 2;
347
        if (header_len > len)
348
            goto error_redo;
349
        len -= header_len;
350
        if (flags & 0x80) {
351
            dts = pts = get_pts(s->pb, -1);
352
            header_len -= 5;
353
            if (flags & 0x40) {
354
                dts = get_pts(s->pb, -1);
355
                header_len -= 5;
356
            }
357
        }
358
        if (flags & 0x01) { /* PES extension */
359
            pes_ext = get_byte(s->pb);
360
            header_len--;
361
            if (pes_ext & 0x40) { /* pack header - should be zero in PS */
362
                goto error_redo;
363
            }
364
            /* Skip PES private data, program packet sequence counter and P-STD buffer */
365
            skip = (pes_ext >> 4) & 0xb;
366
            skip += skip & 0x9;
367
            url_fskip(s->pb, skip);
368
            header_len -= skip;
369

    
370
            if (pes_ext & 0x01) { /* PES extension 2 */
371
                ext2_len = get_byte(s->pb);
372
                header_len--;
373
                if ((ext2_len & 0x7f) > 0) {
374
                    id_ext = get_byte(s->pb);
375
                    if ((id_ext & 0x80) == 0)
376
                        startcode = ((startcode & 0xff) << 8) | id_ext;
377
                    header_len--;
378
                }
379
            }
380
        }
381
        if(header_len < 0)
382
            goto error_redo;
383
        url_fskip(s->pb, header_len);
384
    }
385
    else if( c!= 0xf )
386
        goto redo;
387

    
388
    if (startcode == PRIVATE_STREAM_1 && !m->psm_es_type[startcode & 0xff]) {
389
        startcode = get_byte(s->pb);
390
        len--;
391
        if (startcode >= 0x80 && startcode <= 0xcf) {
392
            /* audio: skip header */
393
            get_byte(s->pb);
394
            get_byte(s->pb);
395
            get_byte(s->pb);
396
            len -= 3;
397
            if (startcode >= 0xb0 && startcode <= 0xbf) {
398
                /* MLP/TrueHD audio has a 4-byte header */
399
                get_byte(s->pb);
400
                len--;
401
            }
402
        }
403
    }
404
    if(len<0)
405
        goto error_redo;
406
    if(dts != AV_NOPTS_VALUE && ppos){
407
        int i;
408
        for(i=0; i<s->nb_streams; i++){
409
            if(startcode == s->streams[i]->id) {
410
                av_add_index_entry(s->streams[i], *ppos, dts, 0, 0, AVINDEX_KEYFRAME /* FIXME keyframe? */);
411
            }
412
        }
413
    }
414

    
415
    *pstart_code = startcode;
416
    *ppts = pts;
417
    *pdts = dts;
418
    return len;
419
}
420

    
421
static int mpegps_read_packet(AVFormatContext *s,
422
                              AVPacket *pkt)
423
{
424
    MpegDemuxContext *m = s->priv_data;
425
    AVStream *st;
426
    int len, startcode, i, type, codec_id = 0, es_type;
427
    int64_t pts, dts, dummy_pos; //dummy_pos is needed for the index building to work
428

    
429
 redo:
430
    len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts);
431
    if (len < 0)
432
        return len;
433

    
434
    /* now find stream */
435
    for(i=0;i<s->nb_streams;i++) {
436
        st = s->streams[i];
437
        if (st->id == startcode)
438
            goto found;
439
    }
440

    
441
    es_type = m->psm_es_type[startcode & 0xff];
442
    if(es_type > 0){
443
        if(es_type == STREAM_TYPE_VIDEO_MPEG1){
444
            codec_id = CODEC_ID_MPEG2VIDEO;
445
            type = CODEC_TYPE_VIDEO;
446
        } else if(es_type == STREAM_TYPE_VIDEO_MPEG2){
447
            codec_id = CODEC_ID_MPEG2VIDEO;
448
            type = CODEC_TYPE_VIDEO;
449
        } else if(es_type == STREAM_TYPE_AUDIO_MPEG1 ||
450
                  es_type == STREAM_TYPE_AUDIO_MPEG2){
451
            codec_id = CODEC_ID_MP3;
452
            type = CODEC_TYPE_AUDIO;
453
        } else if(es_type == STREAM_TYPE_AUDIO_AAC){
454
            codec_id = CODEC_ID_AAC;
455
            type = CODEC_TYPE_AUDIO;
456
        } else if(es_type == STREAM_TYPE_VIDEO_MPEG4){
457
            codec_id = CODEC_ID_MPEG4;
458
            type = CODEC_TYPE_VIDEO;
459
        } else if(es_type == STREAM_TYPE_VIDEO_H264){
460
            codec_id = CODEC_ID_H264;
461
            type = CODEC_TYPE_VIDEO;
462
        } else if(es_type == STREAM_TYPE_AUDIO_AC3){
463
            codec_id = CODEC_ID_AC3;
464
            type = CODEC_TYPE_AUDIO;
465
        } else {
466
            goto skip;
467
        }
468
    } else if (startcode >= 0x1e0 && startcode <= 0x1ef) {
469
        static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };
470
        unsigned char buf[8];
471
        get_buffer(s->pb, buf, 8);
472
        url_fseek(s->pb, -8, SEEK_CUR);
473
        if(!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))
474
            codec_id = CODEC_ID_CAVS;
475
        else
476
            codec_id = CODEC_ID_MPEG2VIDEO;
477
        type = CODEC_TYPE_VIDEO;
478
    } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
479
        type = CODEC_TYPE_AUDIO;
480
        codec_id = m->sofdec > 0 ? CODEC_ID_ADPCM_ADX : CODEC_ID_MP2;
481
    } else if (startcode >= 0x80 && startcode <= 0x87) {
482
        type = CODEC_TYPE_AUDIO;
483
        codec_id = CODEC_ID_AC3;
484
    } else if ((startcode >= 0x88 && startcode <= 0x8f)
485
               ||( startcode >= 0x98 && startcode <= 0x9f)) {
486
        /* 0x90 - 0x97 is reserved for SDDS in DVD specs */
487
        type = CODEC_TYPE_AUDIO;
488
        codec_id = CODEC_ID_DTS;
489
    } else if (startcode >= 0xa0 && startcode <= 0xaf) {
490
        type = CODEC_TYPE_AUDIO;
491
        codec_id = CODEC_ID_PCM_S16BE;
492
    } else if (startcode >= 0xb0 && startcode <= 0xbf) {
493
        type = CODEC_TYPE_AUDIO;
494
        codec_id = CODEC_ID_MLP;
495
    } else if (startcode >= 0xc0 && startcode <= 0xcf) {
496
        /* Used for both AC-3 and E-AC-3 in EVOB files */
497
        type = CODEC_TYPE_AUDIO;
498
        codec_id = CODEC_ID_AC3;
499
    } else if (startcode >= 0x20 && startcode <= 0x3f) {
500
        type = CODEC_TYPE_SUBTITLE;
501
        codec_id = CODEC_ID_DVD_SUBTITLE;
502
    } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {
503
        type = CODEC_TYPE_VIDEO;
504
        codec_id = CODEC_ID_VC1;
505
    } else {
506
    skip:
507
        /* skip packet */
508
        url_fskip(s->pb, len);
509
        goto redo;
510
    }
511
    /* no stream found: add a new stream */
512
    st = av_new_stream(s, startcode);
513
    if (!st)
514
        goto skip;
515
    st->codec->codec_type = type;
516
    st->codec->codec_id = codec_id;
517
    if (codec_id != CODEC_ID_PCM_S16BE)
518
        st->need_parsing = AVSTREAM_PARSE_FULL;
519
 found:
520
    if(st->discard >= AVDISCARD_ALL)
521
        goto skip;
522
    if (startcode >= 0xa0 && startcode <= 0xaf) {
523
        int b1, freq;
524

    
525
        /* for LPCM, we just skip the header and consider it is raw
526
           audio data */
527
        if (len <= 3)
528
            goto skip;
529
        get_byte(s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */
530
        b1 = get_byte(s->pb); /* quant (2), freq(2), reserved(1), channels(3) */
531
        get_byte(s->pb); /* dynamic range control (0x80 = off) */
532
        len -= 3;
533
        freq = (b1 >> 4) & 3;
534
        st->codec->sample_rate = lpcm_freq_tab[freq];
535
        st->codec->channels = 1 + (b1 & 7);
536
        st->codec->bit_rate = st->codec->channels * st->codec->sample_rate * 2;
537
    }
538
    av_new_packet(pkt, len);
539
    get_buffer(s->pb, pkt->data, pkt->size);
540
    pkt->pts = pts;
541
    pkt->dts = dts;
542
    pkt->stream_index = st->index;
543
#if 0
544
    av_log(s, AV_LOG_DEBUG, "%d: pts=%0.3f dts=%0.3f size=%d\n",
545
           pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0, pkt->size);
546
#endif
547

    
548
    return 0;
549
}
550

    
551
static int mpegps_read_close(AVFormatContext *s)
552
{
553
    return 0;
554
}
555

    
556
static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
557
                               int64_t *ppos, int64_t pos_limit)
558
{
559
    int len, startcode;
560
    int64_t pos, pts, dts;
561

    
562
    pos = *ppos;
563
#ifdef DEBUG_SEEK
564
    printf("read_dts: pos=0x%"PRIx64" next=%d -> ", pos, find_next);
565
#endif
566
    url_fseek(s->pb, pos, SEEK_SET);
567
    for(;;) {
568
        len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts);
569
        if (len < 0) {
570
#ifdef DEBUG_SEEK
571
            printf("none (ret=%d)\n", len);
572
#endif
573
            return AV_NOPTS_VALUE;
574
        }
575
        if (startcode == s->streams[stream_index]->id &&
576
            dts != AV_NOPTS_VALUE) {
577
            break;
578
        }
579
        url_fskip(s->pb, len);
580
    }
581
#ifdef DEBUG_SEEK
582
    printf("pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n", pos, dts, dts / 90000.0);
583
#endif
584
    *ppos = pos;
585
    return dts;
586
}
587

    
588
AVInputFormat mpegps_demuxer = {
589
    "mpeg",
590
    "MPEG PS format",
591
    sizeof(MpegDemuxContext),
592
    mpegps_probe,
593
    mpegps_read_header,
594
    mpegps_read_packet,
595
    mpegps_read_close,
596
    NULL, //mpegps_read_seek,
597
    mpegps_read_dts,
598
    .flags = AVFMT_SHOW_IDS,
599
};