summaryrefslogtreecommitdiffstats
path: root/libavformat/oggdec.c
blob: a099eb382e28c493ecc99265a529a3c28586de5a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
/*
 * Ogg bitstream support
 * Luca Barbato <lu_zero@gentoo.org>
 * Based on tcvp implementation
 */

/*
    Copyright (C) 2005  Michael Ahlberg, Måns Rullgård

    Permission is hereby granted, free of charge, to any person
    obtaining a copy of this software and associated documentation
    files (the "Software"), to deal in the Software without
    restriction, including without limitation the rights to use, copy,
    modify, merge, publish, distribute, sublicense, and/or sell copies
    of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be
    included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
 */

#include <stdio.h>
#include "libavutil/avassert.h"
#include "libavutil/intreadwrite.h"
#include "oggdec.h"
#include "avformat.h"
#include "internal.h"
#include "vorbiscomment.h"

#define MAX_PAGE_SIZE 65307
#define DECODER_BUFFER_SIZE MAX_PAGE_SIZE

static const struct ogg_codec * const ogg_codecs[] = {
    &ff_skeleton_codec,
    &ff_dirac_codec,
    &ff_speex_codec,
    &ff_vorbis_codec,
    &ff_theora_codec,
    &ff_flac_codec,
    &ff_celt_codec,
    &ff_opus_codec,
    &ff_old_dirac_codec,
    &ff_old_flac_codec,
    &ff_ogm_video_codec,
    &ff_ogm_audio_codec,
    &ff_ogm_text_codec,
    &ff_ogm_old_codec,
    NULL
};

static int64_t ogg_calc_pts(AVFormatContext *s, int idx, int64_t *dts);
static int ogg_new_stream(AVFormatContext *s, uint32_t serial);

//FIXME We could avoid some structure duplication
static int ogg_save(AVFormatContext *s)
{
    struct ogg *ogg = s->priv_data;
    struct ogg_state *ost =
        av_malloc(sizeof(*ost) + (ogg->nstreams - 1) * sizeof(*ogg->streams));
    int i;
    ost->pos      = avio_tell(s->pb);
    ost->curidx   = ogg->curidx;
    ost->next     = ogg->state;
    ost->nstreams = ogg->nstreams;
    memcpy(ost->streams, ogg->streams, ogg->nstreams * sizeof(*ogg->streams));

    for (i = 0; i < ogg->nstreams; i++) {
        struct ogg_stream *os = ogg->streams + i;
        os->buf = av_mallocz(os->bufsize + FF_INPUT_BUFFER_PADDING_SIZE);
        memcpy(os->buf, ost->streams[i].buf, os->bufpos);
    }

    ogg->state = ost;

    return 0;
}

static int ogg_restore(AVFormatContext *s, int discard)
{
    struct ogg *ogg = s->priv_data;
    AVIOContext *bc = s->pb;
    struct ogg_state *ost = ogg->state;
    int i, err;

    if (!ost)
        return 0;

    ogg->state = ost->next;

    if (!discard) {

        for (i = 0; i < ogg->nstreams; i++)
            av_freep(&ogg->streams[i].buf);

        avio_seek(bc, ost->pos, SEEK_SET);
        ogg->page_pos = -1;
        ogg->curidx   = ost->curidx;
        ogg->nstreams = ost->nstreams;
        if ((err = av_reallocp_array(&ogg->streams, ogg->nstreams,
                                     sizeof(*ogg->streams))) < 0) {
            ogg->nstreams = 0;
            return err;
        } else
            memcpy(ogg->streams, ost->streams,
                   ost->nstreams * sizeof(*ogg->streams));
    }

    av_free(ost);

    return 0;
}

static int ogg_reset(AVFormatContext *s)
{
    struct ogg *ogg = s->priv_data;
    int i;
    int64_t start_pos = avio_tell(s->pb);

    for (i = 0; i < ogg->nstreams; i++) {
        struct ogg_stream *os = ogg->streams + i;
        os->bufpos     = 0;
        os->pstart     = 0;
        os->psize      = 0;
        os->granule    = -1;
        os->lastpts    = AV_NOPTS_VALUE;
        os->lastdts    = AV_NOPTS_VALUE;
        os->sync_pos   = -1;
        os->page_pos   = 0;
        os->nsegs      = 0;
        os->segp       = 0;
        os->incomplete = 0;
        os->got_data = 0;
        if (start_pos <= s->data_offset) {
            os->lastpts = 0;
        }
    }

    ogg->page_pos = -1;
    ogg->curidx = -1;

    return 0;
}

static const struct ogg_codec *ogg_find_codec(uint8_t *buf, int size)
{
    int i;

    for (i = 0; ogg_codecs[i]; i++)
        if (size >= ogg_codecs[i]->magicsize &&
            !memcmp(buf, ogg_codecs[i]->magic, ogg_codecs[i]->magicsize))
            return ogg_codecs[i];

    return NULL;
}

/**
 * Replace the current stream with a new one. This is a typical webradio
 * situation where a new audio stream spawn (identified with a new serial) and
 * must replace the previous one (track switch).
 */
static int ogg_replace_stream(AVFormatContext *s, uint32_t serial, int nsegs)
{
    struct ogg *ogg = s->priv_data;
    struct ogg_stream *os;
    const struct ogg_codec *codec;
    int i = 0;

    if (s->pb->seekable) {
        uint8_t magic[8];
        int64_t pos = avio_tell(s->pb);
        avio_skip(s->pb, nsegs);
        avio_read(s->pb, magic, sizeof(magic));
        avio_seek(s->pb, pos, SEEK_SET);
        codec = ogg_find_codec(magic, sizeof(magic));
        if (!codec) {
            av_log(s, AV_LOG_ERROR, "Cannot identify new stream\n");
            return AVERROR_INVALIDDATA;
        }
        for (i = 0; i < ogg->nstreams; i++) {
            if (ogg->streams[i].codec == codec)
                break;
        }
        if (i >= ogg->nstreams)
            return ogg_new_stream(s, serial);
    } else if (ogg->nstreams != 1) {
        avpriv_report_missing_feature(s, "Changing stream parameters in multistream ogg");
        return AVERROR_PATCHWELCOME;
    }

    os = &ogg->streams[i];

    os->serial  = serial;
    return i;

#if 0
    buf     = os->buf;
    bufsize = os->bufsize;
    codec   = os->codec;

    if (!ogg->state || ogg->state->streams[i].private != os->private)
        av_freep(&ogg->streams[i].private);

    /* Set Ogg stream settings similar to what is done in ogg_new_stream(). We
     * also re-use the ogg_stream allocated buffer */
    memset(os, 0, sizeof(*os));
    os->serial  = serial;
    os->bufsize = bufsize;
    os->buf     = buf;
    os->header  = -1;
    os->codec   = codec;

    return i;
#endif
}

static int ogg_new_stream(AVFormatContext *s, uint32_t serial)
{
    struct ogg *ogg = s->priv_data;
    int idx         = ogg->nstreams;
    AVStream *st;
    struct ogg_stream *os;
    size_t size;

    if (ogg->state) {
        av_log(s, AV_LOG_ERROR, "New streams are not supposed to be added "
               "in between Ogg context save/restore operations.\n");
        return AVERROR_BUG;
    }

    /* Allocate and init a new Ogg Stream */
    if (av_size_mult(ogg->nstreams + 1, sizeof(*ogg->streams), &size) < 0 ||
        !(os = av_realloc(ogg->streams, size)))
        return AVERROR(ENOMEM);
    ogg->streams = os;
    os           = ogg->streams + idx;
    memset(os, 0, sizeof(*os));
    os->serial        = serial;
    os->bufsize       = DECODER_BUFFER_SIZE;
    os->buf           = av_malloc(os->bufsize + FF_INPUT_BUFFER_PADDING_SIZE);
    os->header        = -1;
    os->start_granule = OGG_NOGRANULE_VALUE;
    if (!os->buf)
        return AVERROR(ENOMEM);

    /* Create the associated AVStream */
    st = avformat_new_stream(s, NULL);
    if (!st) {
        av_freep(&os->buf);
        return AVERROR(ENOMEM);
    }
    st->id = idx;
    avpriv_set_pts_info(st, 64, 1, 1000000);

    ogg->nstreams++;
    return idx;
}

static int ogg_new_buf(struct ogg *ogg, int idx)
{
    struct ogg_stream *os = ogg->streams + idx;
    uint8_t *nb = av_malloc(os->bufsize + FF_INPUT_BUFFER_PADDING_SIZE);
    int size = os->bufpos - os->pstart;

    if (os->buf) {
        memcpy(nb, os->buf + os->pstart, size);
        av_free(os->buf);
    }

    os->buf    = nb;
    os->bufpos = size;
    os->pstart = 0;

    return 0;
}

static int data_packets_seen(const struct ogg *ogg)
{
    int i;

    for (i = 0; i < ogg->nstreams; i++)
        if (ogg->streams[i].got_data)
            return 1;
    return 0;
}

static int ogg_read_page(AVFormatContext *s, int *sid)
{
    AVIOContext *bc = s->pb;
    struct ogg *ogg = s->priv_data;
    struct ogg_stream *os;
    int ret, i = 0;
    int flags, nsegs;
    uint64_t gp;
    uint32_t serial;
    int size, idx;
    uint8_t sync[4];
    int sp = 0;

    ret = avio_read(bc, sync, 4);
    if (ret < 4)
        return ret < 0 ? ret : AVERROR_EOF;

    do {
        int c;

        if (sync[sp & 3] == 'O' &&
            sync[(sp + 1) & 3] == 'g' &&
            sync[(sp + 2) & 3] == 'g' && sync[(sp + 3) & 3] == 'S')
            break;

        if(!i && bc->seekable && ogg->page_pos > 0) {
            memset(sync, 0, 4);
            avio_seek(bc, ogg->page_pos+4, SEEK_SET);
            ogg->page_pos = -1;
        }

        c = avio_r8(bc);

        if (url_feof(bc))
            return AVERROR_EOF;

        sync[sp++ & 3] = c;
    } while (i++ < MAX_PAGE_SIZE);

    if (i >= MAX_PAGE_SIZE) {
        av_log(s, AV_LOG_INFO, "cannot find sync word\n");
        return AVERROR_INVALIDDATA;
    }

    if (avio_r8(bc) != 0) {      /* version */
        av_log (s, AV_LOG_ERROR, "ogg page, unsupported version\n");
        return AVERROR_INVALIDDATA;
    }

    flags  = avio_r8(bc);
    gp     = avio_rl64(bc);
    serial = avio_rl32(bc);
    avio_skip(bc, 8); /* seq, crc */
    nsegs  = avio_r8(bc);

    idx = ogg_find_stream(ogg, serial);
    if (idx < 0) {
        if (data_packets_seen(ogg))
            idx = ogg_replace_stream(s, serial, nsegs);
        else
            idx = ogg_new_stream(s, serial);

        if (idx < 0) {
            av_log(s, AV_LOG_ERROR, "failed to create or replace stream\n");
            return idx;
        }
    }

    os = ogg->streams + idx;
    ogg->page_pos =
    os->page_pos = avio_tell(bc) - 27;

    if (os->psize > 0)
        ogg_new_buf(ogg, idx);

    ret = avio_read(bc, os->segments, nsegs);
    if (ret < nsegs)
        return ret < 0 ? ret : AVERROR_EOF;

    os->nsegs = nsegs;
    os->segp  = 0;

    size = 0;
    for (i = 0; i < nsegs; i++)
        size += os->segments[i];

    if (!(flags & OGG_FLAG_BOS))
        os->got_data = 1;

    if (flags & OGG_FLAG_CONT || os->incomplete) {
        if (!os->psize) {
            // If this is the very first segment we started
            // playback in the middle of a continuation packet.
            // Discard it since we missed the start of it.
            while (os->segp < os->nsegs) {
                int seg = os->segments[os->segp++];
                os->pstart += seg;
                if (seg < 255)
                    break;
            }
            os->sync_pos = os->page_pos;
        }
    } else {
        os->psize    = 0;
        os->sync_pos = os->page_pos;
    }

    if (os->bufsize - os->bufpos < size) {
        uint8_t *nb = av_malloc((os->bufsize *= 2) + FF_INPUT_BUFFER_PADDING_SIZE);
        if (!nb)
            return AVERROR(ENOMEM);
        memcpy(nb, os->buf, os->bufpos);
        av_free(os->buf);
        os->buf = nb;
    }

    ret = avio_read(bc, os->buf + os->bufpos, size);
    if (ret < size)
        return ret < 0 ? ret : AVERROR_EOF;

    os->bufpos += size;
    os->granule = gp;
    os->flags   = flags;

    memset(os->buf + os->bufpos, 0, FF_INPUT_BUFFER_PADDING_SIZE);
    if (sid)
        *sid = idx;

    return 0;
}

/**
 * @brief find the next Ogg packet
 * @param *sid is set to the stream for the packet or -1 if there is
 *             no matching stream, in that case assume all other return
 *             values to be uninitialized.
 * @return negative value on error or EOF.
 */
static int ogg_packet(AVFormatContext *s, int *sid, int *dstart, int *dsize,
                      int64_t *fpos)
{
    struct ogg *ogg = s->priv_data;
    int idx, i, ret;
    struct ogg_stream *os;
    int complete = 0;
    int segp     = 0, psize = 0;

    av_dlog(s, "ogg_packet: curidx=%i\n", ogg->curidx);
    if (sid)
        *sid = -1;

    do {
        idx = ogg->curidx;

        while (idx < 0) {
            ret = ogg_read_page(s, &idx);
            if (ret < 0)
                return ret;
        }

        os = ogg->streams + idx;

        av_dlog(s, "ogg_packet: idx=%d pstart=%d psize=%d segp=%d nsegs=%d\n",
                idx, os->pstart, os->psize, os->segp, os->nsegs);

        if (!os->codec) {
            if (os->header < 0) {
                os->codec = ogg_find_codec(os->buf, os->bufpos);
                if (!os->codec) {
                    av_log(s, AV_LOG_WARNING, "Codec not found\n");
                    os->header = 0;
                    return 0;
                }
            } else {
                return 0;
            }
        }

        segp  = os->segp;
        psize = os->psize;

        while (os->segp < os->nsegs) {
            int ss = os->segments[os->segp++];
            os->psize += ss;
            if (ss < 255) {
                complete = 1;
                break;
            }
        }

        if (!complete && os->segp == os->nsegs) {
            ogg->curidx    = -1;
            // Do not set incomplete for empty packets.
            // Together with the code in ogg_read_page
            // that discards all continuation of empty packets
            // we would get an infinite loop.
            os->incomplete = !!os->psize;
        }
    } while (!complete);


    if (os->granule == -1)
        av_log(s, AV_LOG_WARNING,
               "Page at %"PRId64" is missing granule\n",
               os->page_pos);

    ogg->curidx    = idx;
    os->incomplete = 0;

    if (os->header) {
        os->header = os->codec->header(s, idx);
        if (!os->header) {
            os->segp  = segp;
            os->psize = psize;

            // We have reached the first non-header packet in this stream.
            // Unfortunately more header packets may still follow for others,
            // but if we continue with header parsing we may lose data packets.
            ogg->headers = 1;

            // Update the header state for all streams and
            // compute the data_offset.
            if (!s->data_offset)
                s->data_offset = os->sync_pos;

            for (i = 0; i < ogg->nstreams; i++) {
                struct ogg_stream *cur_os = ogg->streams + i;

                // if we have a partial non-header packet, its start is
                // obviously at or after the data start
                if (cur_os->incomplete)
                    s->data_offset = FFMIN(s->data_offset, cur_os->sync_pos);
            }
        } else {
            os->nb_header++;
            os->pstart += os->psize;
            os->psize   = 0;
        }
    } else {
        os->pflags    = 0;
        os->pduration = 0;
        if (os->codec && os->codec->packet)
            os->codec->packet(s, idx);
        if (sid)
            *sid = idx;
        if (dstart)
            *dstart = os->pstart;
        if (dsize)
            *dsize = os->psize;
        if (fpos)
            *fpos = os->sync_pos;
        os->pstart  += os->psize;
        os->psize    = 0;
        if(os->pstart == os->bufpos)
            os->bufpos = os->pstart = 0;
        os->sync_pos = os->page_pos;
    }

    // determine whether there are more complete packets in this page
    // if not, the page's granule will apply to this packet
    os->page_end = 1;
    for (i = os->segp; i < os->nsegs; i++)
        if (os->segments[i] < 255) {
            os->page_end = 0;
            break;
        }

    if (os->segp == os->nsegs)
        ogg->curidx = -1;

    return 0;
}

static int ogg_get_length(AVFormatContext *s)
{
    struct ogg *ogg = s->priv_data;
    int i;
    int64_t size, end;
    int streams_left=0;

    if (!s->pb->seekable)
        return 0;

// already set
    if (s->duration != AV_NOPTS_VALUE)
        return 0;

    size = avio_size(s->pb);
    if (size < 0)
        return 0;
    end = size > MAX_PAGE_SIZE ? size - MAX_PAGE_SIZE : 0;

    ogg_save(s);
    avio_seek(s->pb, end, SEEK_SET);
    ogg->page_pos = -1;

    while (!ogg_read_page(s, &i)) {
        if (ogg->streams[i].granule != -1 && ogg->streams[i].granule != 0 &&
            ogg->streams[i].codec) {
            s->streams[i]->duration =
                ogg_gptopts(s, i, ogg->streams[i].granule, NULL);
            if (s->streams[i]->start_time != AV_NOPTS_VALUE) {
                s->streams[i]->duration -= s->streams[i]->start_time;
                streams_left-= (ogg->streams[i].got_start==-1);
                ogg->streams[i].got_start= 1;
            } else if(!ogg->streams[i].got_start) {
                ogg->streams[i].got_start= -1;
                streams_left++;
            }
        }
    }

    ogg_restore(s, 0);

    ogg_save (s);
    avio_seek (s->pb, s->data_offset, SEEK_SET);
    ogg_reset(s);
    while (streams_left > 0 && !ogg_packet(s, &i, NULL, NULL, NULL)) {
        int64_t pts;
        if (i < 0) continue;
        pts = ogg_calc_pts(s, i, NULL);
        if (pts != AV_NOPTS_VALUE && s->streams[i]->start_time == AV_NOPTS_VALUE && !ogg->streams[i].got_start) {
            s->streams[i]->duration -= pts;
            ogg->streams[i].got_start= 1;
            streams_left--;
        }else if(s->streams[i]->start_time != AV_NOPTS_VALUE && !ogg->streams[i].got_start) {
            ogg->streams[i].got_start= 1;
            streams_left--;
        }
    }
    ogg_restore (s, 0);

    return 0;
}

static int ogg_read_close(AVFormatContext *s)
{
    struct ogg *ogg = s->priv_data;
    int i;

    for (i = 0; i < ogg->nstreams; i++) {
        av_freep(&ogg->streams[i].buf);
        if (ogg->streams[i].codec &&
            ogg->streams[i].codec->cleanup) {
            ogg->streams[i].codec->cleanup(s, i);
        }
        av_freep(&ogg->streams[i].private);
    }
    av_freep(&ogg->streams);
    return 0;
}

static int ogg_read_header(AVFormatContext *s)
{
    struct ogg *ogg = s->priv_data;
    int ret, i;

    ogg->curidx = -1;

    //linear headers seek from start
    do {
        ret = ogg_packet(s, NULL, NULL, NULL, NULL);
        if (ret < 0) {
            ogg_read_close(s);
            return ret;
        }
    } while (!ogg->headers);
    av_dlog(s, "found headers\n");

    for (i = 0; i < ogg->nstreams; i++) {
        struct ogg_stream *os = ogg->streams + i;

        if (ogg->streams[i].header < 0) {
            av_log(s, AV_LOG_ERROR, "Header parsing failed for stream %d\n", i);
            ogg->streams[i].codec = NULL;
        } else if (os->codec && os->nb_header < os->codec->nb_header) {
            av_log(s, AV_LOG_WARNING,
                   "Headers mismatch for stream %d: "
                   "expected %d received %d.\n",
                   i, os->codec->nb_header, os->nb_header);
            if (s->error_recognition & AV_EF_EXPLODE)
                return AVERROR_INVALIDDATA;
        }
        if (os->start_granule != OGG_NOGRANULE_VALUE)
            os->lastpts = s->streams[i]->start_time =
                ogg_gptopts(s, i, os->start_granule, NULL);
    }

    //linear granulepos seek from end
    ogg_get_length(s);

    return 0;
}

static int64_t ogg_calc_pts(AVFormatContext *s, int idx, int64_t *dts)
{
    struct ogg *ogg       = s->priv_data;
    struct ogg_stream *os = ogg->streams + idx;
    int64_t pts           = AV_NOPTS_VALUE;

    if (dts)
        *dts = AV_NOPTS_VALUE;

    if (os->lastpts != AV_NOPTS_VALUE) {
        pts         = os->lastpts;
        os->lastpts = AV_NOPTS_VALUE;
    }
    if (os->lastdts != AV_NOPTS_VALUE) {
        if (dts)
            *dts = os->lastdts;
        os->lastdts = AV_NOPTS_VALUE;
    }
    if (os->page_end) {
        if (os->granule != -1LL) {
            if (os->codec && os->codec->granule_is_start)
                pts = ogg_gptopts(s, idx, os->granule, dts);
            else
                os->lastpts = ogg_gptopts(s, idx, os->granule, &os->lastdts);
            os->granule = -1LL;
        }
    }
    return pts;
}

static void ogg_validate_keyframe(AVFormatContext *s, int idx, int pstart, int psize)
{
    struct ogg *ogg = s->priv_data;
    struct ogg_stream *os = ogg->streams + idx;
    if (psize && s->streams[idx]->codec->codec_id == AV_CODEC_ID_THEORA) {
        if (!!(os->pflags & AV_PKT_FLAG_KEY) != !(os->buf[pstart] & 0x40)) {
            os->pflags ^= AV_PKT_FLAG_KEY;
            av_log(s, AV_LOG_WARNING, "Broken file, %skeyframe not correctly marked.\n",
                   (os->pflags & AV_PKT_FLAG_KEY) ? "" : "non-");
        }
    }
}

static int ogg_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    struct ogg *ogg;
    struct ogg_stream *os;
    int idx, ret;
    int pstart, psize;
    int64_t fpos, pts, dts;

    if (s->io_repositioned) {
        ogg_reset(s);
        s->io_repositioned = 0;
    }

    //Get an ogg packet
retry:
    do {
        ret = ogg_packet(s, &idx, &pstart, &psize, &fpos);
        if (ret < 0)
            return ret;
    } while (idx < 0 || !s->streams[idx]);

    ogg = s->priv_data;
    os  = ogg->streams + idx;

    // pflags might not be set until after this
    pts = ogg_calc_pts(s, idx, &dts);
    ogg_validate_keyframe(s, idx, pstart, psize);

    if (os->keyframe_seek && !(os->pflags & AV_PKT_FLAG_KEY))
        goto retry;
    os->keyframe_seek = 0;

    //Alloc a pkt
    ret = av_new_packet(pkt, psize);
    if (ret < 0)
        return ret;
    pkt->stream_index = idx;
    memcpy(pkt->data, os->buf + pstart, psize);

    pkt->pts      = pts;
    pkt->dts      = dts;
    pkt->flags    = os->pflags;
    pkt->duration = os->pduration;
    pkt->pos      = fpos;

    if (os->end_trimming) {
        uint8_t *side_data = av_packet_new_side_data(pkt,
                                                     AV_PKT_DATA_SKIP_SAMPLES,
                                                     10);
        if(side_data == NULL) {
            av_free_packet(pkt);
            av_free(pkt);
            return AVERROR(ENOMEM);
        }
        AV_WL32(side_data + 4, os->end_trimming);
    }

    return psize;
}

static int64_t ogg_read_timestamp(AVFormatContext *s, int stream_index,
                                  int64_t *pos_arg, int64_t pos_limit)
{
    struct ogg *ogg = s->priv_data;
    AVIOContext *bc = s->pb;
    int64_t pts     = AV_NOPTS_VALUE;
    int64_t keypos  = -1;
    int i;
    int pstart, psize;
    avio_seek(bc, *pos_arg, SEEK_SET);
    ogg_reset(s);

    while (   avio_tell(bc) <= pos_limit
           && !ogg_packet(s, &i, &pstart, &psize, pos_arg)) {
        if (i == stream_index) {
            struct ogg_stream *os = ogg->streams + stream_index;
            pts = ogg_calc_pts(s, i, NULL);
            ogg_validate_keyframe(s, i, pstart, psize);
            if (os->pflags & AV_PKT_FLAG_KEY) {
                keypos = *pos_arg;
            } else if (os->keyframe_seek) {
                // if we had a previous keyframe but no pts for it,
                // return that keyframe with this pts value.
                if (keypos >= 0)
                    *pos_arg = keypos;
                else
                    pts = AV_NOPTS_VALUE;
            }
        }
        if (pts != AV_NOPTS_VALUE)
            break;
    }
    ogg_reset(s);
    return pts;
}

static int ogg_read_seek(AVFormatContext *s, int stream_index,
                         int64_t timestamp, int flags)
{
    struct ogg *ogg       = s->priv_data;
    struct ogg_stream *os = ogg->streams + stream_index;
    int ret;

    av_assert0(stream_index < ogg->nstreams);
    // Ensure everything is reset even when seeking via
    // the generated index.
    ogg_reset(s);

    // Try seeking to a keyframe first. If this fails (very possible),
    // av_seek_frame will fall back to ignoring keyframes
    if (s->streams[stream_index]->codec->codec_type == AVMEDIA_TYPE_VIDEO
        && !(flags & AVSEEK_FLAG_ANY))
        os->keyframe_seek = 1;

    ret = ff_seek_frame_binary(s, stream_index, timestamp, flags);
    os  = ogg->streams + stream_index;
    if (ret < 0)
        os->keyframe_seek = 0;
    return ret;
}

static int ogg_probe(AVProbeData *p)
{
    if (!memcmp("OggS", p->buf, 5) && p->buf[5] <= 0x7)
        return AVPROBE_SCORE_MAX;
    return 0;
}

AVInputFormat ff_ogg_demuxer = {
    .name           = "ogg",
    .long_name      = NULL_IF_CONFIG_SMALL("Ogg"),
    .priv_data_size = sizeof(struct ogg),
    .read_probe     = ogg_probe,
    .read_header    = ogg_read_header,
    .read_packet    = ogg_read_packet,
    .read_close     = ogg_read_close,
    .read_seek      = ogg_read_seek,
    .read_timestamp = ogg_read_timestamp,
    .extensions     = "ogg",
    .flags          = AVFMT_GENERIC_INDEX | AVFMT_TS_DISCONT | AVFMT_NOBINSEARCH,
};
OpenPOWER on IntegriCloud