aboutsummaryrefslogtreecommitdiffstats
path: root/libavformat/gxfenc.c
blob: e7536a6a7ebe2d40cc3cbcd0019298652d1ecd9e (plain) (blame)
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
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
/*
 * GXF muxer.
 * Copyright (c) 2006 SmartJog S.A., Baptiste Coudurier <baptiste dot coudurier at smartjog dot com>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "libavutil/avassert.h"
#include "libavutil/intfloat.h"
#include "libavutil/opt.h"
#include "libavutil/mathematics.h"
#include "libavutil/timecode.h"
#include "avformat.h"
#include "internal.h"
#include "gxf.h"
#include "audiointerleave.h"

#define GXF_AUDIO_PACKET_SIZE 65536

#define GXF_TIMECODE(c, d, h, m, s, f) \
    ((c) << 30 | (d) << 29 | (h) << 24 | (m) << 16 | (s) << 8 | (f))

typedef struct GXFTimecode{
    int hh;
    int mm;
    int ss;
    int ff;
    int color;
    int drop;
} GXFTimecode;

typedef struct GXFStreamContext {
    AudioInterleaveContext aic;
    uint32_t track_type;
    uint32_t sample_size;
    uint32_t sample_rate;
    uint16_t media_type;
    uint16_t media_info;
    int frame_rate_index;
    int lines_index;
    int fields;
    int iframes;
    int pframes;
    int bframes;
    int p_per_gop;
    int b_per_i_or_p; ///< number of B-frames per I-frame or P-frame
    int first_gop_closed;
    unsigned order;   ///< interleaving order
} GXFStreamContext;

typedef struct GXFContext {
    AVClass *av_class;
    uint32_t nb_fields;
    uint16_t audio_tracks;
    uint16_t mpeg_tracks;
    int64_t creation_time;
    uint32_t umf_start_offset;
    uint32_t umf_track_offset;
    uint32_t umf_media_offset;
    uint32_t umf_length;
    uint16_t umf_track_size;
    uint16_t umf_media_size;
    AVRational time_base;
    int flags;
    GXFStreamContext timecode_track;
    unsigned *flt_entries;    ///< offsets of packets /1024, starts after 2nd video field
    unsigned flt_entries_nb;
    uint64_t *map_offsets;    ///< offset of map packets
    unsigned map_offsets_nb;
    unsigned packet_count;
    GXFTimecode tc;
} GXFContext;

static const struct {
    int height, index;
} gxf_lines_tab[] = {
    { 480,  1 }, /* NTSC */
    { 512,  1 }, /* NTSC + VBI */
    { 576,  2 }, /* PAL */
    { 608,  2 }, /* PAL + VBI */
    { 1080, 4 },
    { 720,  6 },
};

static const AVCodecTag gxf_media_types[] = {
    { AV_CODEC_ID_MJPEG     ,   3 }, /* NTSC */
    { AV_CODEC_ID_MJPEG     ,   4 }, /* PAL */
    { AV_CODEC_ID_PCM_S24LE ,   9 },
    { AV_CODEC_ID_PCM_S16LE ,  10 },
    { AV_CODEC_ID_MPEG2VIDEO,  11 }, /* NTSC */
    { AV_CODEC_ID_MPEG2VIDEO,  12 }, /* PAL */
    { AV_CODEC_ID_DVVIDEO   ,  13 }, /* NTSC */
    { AV_CODEC_ID_DVVIDEO   ,  14 }, /* PAL */
    { AV_CODEC_ID_DVVIDEO   ,  15 }, /* 50M NTSC */
    { AV_CODEC_ID_DVVIDEO   ,  16 }, /* 50M PAL */
    { AV_CODEC_ID_AC3       ,  17 },
    //{ AV_CODEC_ID_NONE,  ,   18 }, /* Non compressed 24 bit audio */
    { AV_CODEC_ID_MPEG2VIDEO,  20 }, /* MPEG HD */
    { AV_CODEC_ID_MPEG1VIDEO,  22 }, /* NTSC */
    { AV_CODEC_ID_MPEG1VIDEO,  23 }, /* PAL */
    { AV_CODEC_ID_NONE,         0 },
};

#define SERVER_PATH "EXT:/PDR/default/"
#define ES_NAME_PATTERN "EXT:/PDR/default/ES."

static int gxf_find_lines_index(AVStream *st)
{
    GXFStreamContext *sc = st->priv_data;
    int i;

    for (i = 0; i < 6; ++i) {
        if (st->codecpar->height == gxf_lines_tab[i].height) {
            sc->lines_index = gxf_lines_tab[i].index;
            return 0;
        }
    }
    return -1;
}

static void gxf_write_padding(AVIOContext *pb, int64_t to_pad)
{
    for (; to_pad > 0; to_pad--) {
        avio_w8(pb, 0);
    }
}

static int64_t updatePacketSize(AVIOContext *pb, int64_t pos)
{
    int64_t curpos;
    int size;

    size = avio_tell(pb) - pos;
    if (size % 4) {
        gxf_write_padding(pb, 4 - size % 4);
        size = avio_tell(pb) - pos;
    }
    curpos = avio_tell(pb);
    avio_seek(pb, pos + 6, SEEK_SET);
    avio_wb32(pb, size);
    avio_seek(pb, curpos, SEEK_SET);
    return curpos - pos;
}

static int64_t updateSize(AVIOContext *pb, int64_t pos)
{
    int64_t curpos;

    curpos = avio_tell(pb);
    avio_seek(pb, pos, SEEK_SET);
    avio_wb16(pb, curpos - pos - 2);
    avio_seek(pb, curpos, SEEK_SET);
    return curpos - pos;
}

static void gxf_write_packet_header(AVIOContext *pb, GXFPktType type)
{
    avio_wb32(pb, 0);  /* packet leader for synchro */
    avio_w8(pb, 1);
    avio_w8(pb, type); /* map packet */
    avio_wb32(pb, 0);  /* size */
    avio_wb32(pb, 0);  /* reserved */
    avio_w8(pb, 0xE1); /* trailer 1 */
    avio_w8(pb, 0xE2); /* trailer 2 */
}

static int gxf_write_mpeg_auxiliary(AVIOContext *pb, AVStream *st)
{
    GXFStreamContext *sc = st->priv_data;
    char buffer[1024];
    int size, starting_line;

    if (sc->iframes) {
        sc->p_per_gop = sc->pframes / sc->iframes;
        if (sc->pframes % sc->iframes)
            sc->p_per_gop++;
        if (sc->pframes) {
            sc->b_per_i_or_p = sc->bframes / sc->pframes;
            if (sc->bframes % sc->pframes)
                sc->b_per_i_or_p++;
        }
        if (sc->p_per_gop > 9)
            sc->p_per_gop = 9; /* ensure value won't take more than one char */
        if (sc->b_per_i_or_p > 9)
            sc->b_per_i_or_p = 9; /* ensure value won't take more than one char */
    }
    if (st->codecpar->height == 512 || st->codecpar->height == 608)
        starting_line = 7; // VBI
    else if (st->codecpar->height == 480)
        starting_line = 20;
    else
        starting_line = 23; // default PAL

    size = snprintf(buffer, sizeof(buffer), "Ver 1\nBr %.6f\nIpg 1\nPpi %d\nBpiop %d\n"
                    "Pix 0\nCf %d\nCg %d\nSl %d\nnl16 %d\nVi 1\nf1 1\n",
                    (float)st->codecpar->bit_rate, sc->p_per_gop, sc->b_per_i_or_p,
                    st->codecpar->format == AV_PIX_FMT_YUV422P ? 2 : 1, sc->first_gop_closed == 1,
                    starting_line, (st->codecpar->height + 15) / 16);
    av_assert0(size < sizeof(buffer));
    avio_w8(pb, TRACK_MPG_AUX);
    avio_w8(pb, size + 1);
    avio_write(pb, (uint8_t *)buffer, size + 1);
    return size + 3;
}

static int gxf_write_dv_auxiliary(AVIOContext *pb, AVStream *st)
{
    int64_t track_aux_data = 0;

    avio_w8(pb, TRACK_AUX);
    avio_w8(pb, 8);
    if (st->codecpar->format == AV_PIX_FMT_YUV420P)
        track_aux_data |= 0x01;     /* marks stream as DVCAM instead of DVPRO */
    track_aux_data |= 0x40000000;   /* aux data is valid */
    avio_wl64(pb, track_aux_data);
    return 8;
}

static int gxf_write_timecode_auxiliary(AVIOContext *pb, GXFContext *gxf)
{
    uint32_t timecode = GXF_TIMECODE(gxf->tc.color, gxf->tc.drop,
                                     gxf->tc.hh, gxf->tc.mm,
                                     gxf->tc.ss, gxf->tc.ff);

    avio_w8(pb, TRACK_AUX);
    avio_w8(pb, 8);
    avio_wl32(pb, timecode);
    /* reserved */
    avio_wl32(pb, 0);
    return 8;
}

static int gxf_write_track_description(AVFormatContext *s, GXFStreamContext *sc, int index)
{
    GXFContext *gxf = s->priv_data;
    AVIOContext *pb = s->pb;
    int64_t pos;

    /* track description section */
    avio_w8(pb, sc->media_type + 0x80);
    avio_w8(pb, index + 0xC0);

    pos = avio_tell(pb);
    avio_wb16(pb, 0); /* size */

    /* media file name */
    avio_w8(pb, TRACK_NAME);
    avio_w8(pb, strlen(ES_NAME_PATTERN) + 3);
    avio_write(pb, ES_NAME_PATTERN, sizeof(ES_NAME_PATTERN) - 1);
    avio_wb16(pb, sc->media_info);
    avio_w8(pb, 0);

    switch (sc->track_type) {
        case 3:     /* timecode */
            gxf_write_timecode_auxiliary(pb, gxf);
            break;
        case 4:     /* MPEG2 */
        case 9:     /* MPEG1 */
            gxf_write_mpeg_auxiliary(pb, s->streams[index]);
            break;
        case 5:     /* DV25 */
        case 6:     /* DV50 */
            gxf_write_dv_auxiliary(pb, s->streams[index]);
            break;
        default:
            avio_w8(pb, TRACK_AUX);
            avio_w8(pb, 8);
            avio_wl64(pb, 0);
    }

    /* file system version */
    avio_w8(pb, TRACK_VER);
    avio_w8(pb, 4);
    avio_wb32(pb, 0);

    /* frame rate */
    avio_w8(pb, TRACK_FPS);
    avio_w8(pb, 4);
    avio_wb32(pb, sc->frame_rate_index);

    /* lines per frame */
    avio_w8(pb, TRACK_LINES);
    avio_w8(pb, 4);
    avio_wb32(pb, sc->lines_index);

    /* fields per frame */
    avio_w8(pb, TRACK_FPF);
    avio_w8(pb, 4);
    avio_wb32(pb, sc->fields);

    return updateSize(pb, pos);
}

static int gxf_write_material_data_section(AVFormatContext *s)
{
    GXFContext *gxf = s->priv_data;
    AVIOContext *pb = s->pb;
    int64_t pos;
    int len;
    const char *filename = strrchr(s->url, '/');

    pos = avio_tell(pb);
    avio_wb16(pb, 0); /* size */

    /* name */
    if (filename)
        filename++;
    else
        filename = s->url;
    len = strlen(filename);

    avio_w8(pb, MAT_NAME);
    avio_w8(pb, strlen(SERVER_PATH) + len + 1);
    avio_write(pb, SERVER_PATH, sizeof(SERVER_PATH) - 1);
    avio_write(pb, filename, len);
    avio_w8(pb, 0);

    /* first field */
    avio_w8(pb, MAT_FIRST_FIELD);
    avio_w8(pb, 4);
    avio_wb32(pb, 0);

    /* last field */
    avio_w8(pb, MAT_LAST_FIELD);
    avio_w8(pb, 4);
    avio_wb32(pb, gxf->nb_fields);

    /* reserved */
    avio_w8(pb, MAT_MARK_IN);
    avio_w8(pb, 4);
    avio_wb32(pb, 0);

    avio_w8(pb, MAT_MARK_OUT);
    avio_w8(pb, 4);
    avio_wb32(pb, gxf->nb_fields);

    /* estimated size */
    avio_w8(pb, MAT_SIZE);
    avio_w8(pb, 4);
    avio_wb32(pb, avio_size(pb) / 1024);

    return updateSize(pb, pos);
}

static int gxf_write_track_description_section(AVFormatContext *s)
{
    GXFContext *gxf = s->priv_data;
    AVIOContext *pb = s->pb;
    int64_t pos;
    int i;

    pos = avio_tell(pb);
    avio_wb16(pb, 0); /* size */
    for (i = 0; i < s->nb_streams; ++i)
        gxf_write_track_description(s, s->streams[i]->priv_data, i);

    gxf_write_track_description(s, &gxf->timecode_track, s->nb_streams);

    return updateSize(pb, pos);
}

static int gxf_write_map_packet(AVFormatContext *s, int rewrite)
{
    GXFContext *gxf = s->priv_data;
    AVIOContext *pb = s->pb;
    int64_t pos = avio_tell(pb);

    if (!rewrite) {
        if (!(gxf->map_offsets_nb % 30)) {
            int err;
            if ((err = av_reallocp_array(&gxf->map_offsets,
                                         gxf->map_offsets_nb + 30,
                                         sizeof(*gxf->map_offsets))) < 0) {
                gxf->map_offsets_nb = 0;
                av_log(s, AV_LOG_ERROR, "could not realloc map offsets\n");
                return err;
            }
        }
        gxf->map_offsets[gxf->map_offsets_nb++] = pos; // do not increment here
    }

    gxf_write_packet_header(pb, PKT_MAP);

    /* preamble */
    avio_w8(pb, 0xE0); /* version */
    avio_w8(pb, 0xFF); /* reserved */

    gxf_write_material_data_section(s);
    gxf_write_track_description_section(s);

    return updatePacketSize(pb, pos);
}

static int gxf_write_flt_packet(AVFormatContext *s)
{
    GXFContext *gxf = s->priv_data;
    AVIOContext *pb = s->pb;
    int64_t pos = avio_tell(pb);
    int fields_per_flt = (gxf->nb_fields+1) / 1000 + 1;
    int flt_entries = gxf->nb_fields / fields_per_flt;
    int i = 0;

    gxf_write_packet_header(pb, PKT_FLT);

    avio_wl32(pb, fields_per_flt); /* number of fields */
    avio_wl32(pb, flt_entries); /* number of active flt entries */

    if (gxf->flt_entries) {
        for (i = 0; i < flt_entries; i++)
            avio_wl32(pb, gxf->flt_entries[(i*fields_per_flt)>>1]);
    }

    for (; i < 1000; i++)
        avio_wl32(pb, 0);

    return updatePacketSize(pb, pos);
}

static int gxf_write_umf_material_description(AVFormatContext *s)
{
    GXFContext *gxf = s->priv_data;
    AVIOContext *pb = s->pb;
    int timecode_base = gxf->time_base.den == 60000 ? 60 : 50;
    int64_t timestamp = 0;
    uint64_t nb_fields;
    uint32_t timecode_in; // timecode at mark in
    uint32_t timecode_out; // timecode at mark out

    ff_parse_creation_time_metadata(s, &timestamp, 1);

    timecode_in = GXF_TIMECODE(gxf->tc.color, gxf->tc.drop,
                               gxf->tc.hh, gxf->tc.mm,
                               gxf->tc.ss, gxf->tc.ff);

    nb_fields = gxf->nb_fields +
                gxf->tc.hh * (timecode_base * 3600) +
                gxf->tc.mm * (timecode_base * 60)   +
                gxf->tc.ss * timecode_base          +
                gxf->tc.ff;

    timecode_out = GXF_TIMECODE(gxf->tc.color, gxf->tc.drop,
                                nb_fields / (timecode_base * 3600) % 24,
                                nb_fields / (timecode_base * 60)   % 60,
                                nb_fields /  timecode_base % 60,
                                nb_fields %  timecode_base);

    avio_wl32(pb, gxf->flags);
    avio_wl32(pb, gxf->nb_fields); /* length of the longest track */
    avio_wl32(pb, gxf->nb_fields); /* length of the shortest track */
    avio_wl32(pb, 0); /* mark in */
    avio_wl32(pb, gxf->nb_fields); /* mark out */
    avio_wl32(pb, timecode_in); /* timecode mark in */
    avio_wl32(pb, timecode_out); /* timecode mark out */
    avio_wl64(pb, timestamp); /* modification time */
    avio_wl64(pb, timestamp); /* creation time */
    avio_wl16(pb, 0); /* reserved */
    avio_wl16(pb, 0); /* reserved */
    avio_wl16(pb, gxf->audio_tracks);
    avio_wl16(pb, 1); /* timecode track count */
    avio_wl16(pb, 0); /* reserved */
    avio_wl16(pb, gxf->mpeg_tracks);
    return 48;
}

static int gxf_write_umf_payload(AVFormatContext *s)
{
    GXFContext *gxf = s->priv_data;
    AVIOContext *pb = s->pb;

    avio_wl32(pb, gxf->umf_length); /* total length of the umf data */
    avio_wl32(pb, 3); /* version */
    avio_wl32(pb, s->nb_streams+1);
    avio_wl32(pb, gxf->umf_track_offset); /* umf track section offset */
    avio_wl32(pb, gxf->umf_track_size);
    avio_wl32(pb, s->nb_streams+1);
    avio_wl32(pb, gxf->umf_media_offset);
    avio_wl32(pb, gxf->umf_media_size);
    avio_wl32(pb, gxf->umf_length); /* user data offset */
    avio_wl32(pb, 0); /* user data size */
    avio_wl32(pb, 0); /* reserved */
    avio_wl32(pb, 0); /* reserved */
    return 48;
}

static int gxf_write_umf_track_description(AVFormatContext *s)
{
    AVIOContext *pb = s->pb;
    GXFContext *gxf = s->priv_data;
    int64_t pos = avio_tell(pb);
    int i;

    gxf->umf_track_offset = pos - gxf->umf_start_offset;
    for (i = 0; i < s->nb_streams; ++i) {
        GXFStreamContext *sc = s->streams[i]->priv_data;
        avio_wl16(pb, sc->media_info);
        avio_wl16(pb, 1);
    }

    avio_wl16(pb, gxf->timecode_track.media_info);
    avio_wl16(pb, 1);

    return avio_tell(pb) - pos;
}

static int gxf_write_umf_media_mpeg(AVIOContext *pb, AVStream *st)
{
    GXFStreamContext *sc = st->priv_data;

    if (st->codecpar->format == AV_PIX_FMT_YUV422P)
        avio_wl32(pb, 2);
    else
        avio_wl32(pb, 1); /* default to 420 */
    avio_wl32(pb, sc->first_gop_closed == 1); /* closed = 1, open = 0, unknown = 255 */
    avio_wl32(pb, 3); /* top = 1, bottom = 2, frame = 3, unknown = 0 */
    avio_wl32(pb, 1); /* I picture per GOP */
    avio_wl32(pb, sc->p_per_gop);
    avio_wl32(pb, sc->b_per_i_or_p);
    if (st->codecpar->codec_id == AV_CODEC_ID_MPEG2VIDEO)
        avio_wl32(pb, 2);
    else if (st->codecpar->codec_id == AV_CODEC_ID_MPEG1VIDEO)
        avio_wl32(pb, 1);
    else
        avio_wl32(pb, 0);
    avio_wl32(pb, 0); /* reserved */
    return 32;
}

static int gxf_write_umf_media_timecode(AVIOContext *pb, int drop)
{
    avio_wl32(pb, drop); /* drop frame */
    avio_wl32(pb, 0); /* reserved */
    avio_wl32(pb, 0); /* reserved */
    avio_wl32(pb, 0); /* reserved */
    avio_wl32(pb, 0); /* reserved */
    avio_wl32(pb, 0); /* reserved */
    avio_wl32(pb, 0); /* reserved */
    avio_wl32(pb, 0); /* reserved */
    return 32;
}

static int gxf_write_umf_media_dv(AVIOContext *pb, GXFStreamContext *sc, AVStream *st)
{
    int dv_umf_data = 0;

    if (st->codecpar->format == AV_PIX_FMT_YUV420P)
        dv_umf_data |= 0x20; /* marks as DVCAM instead of DVPRO */
    avio_wl32(pb, dv_umf_data);
    avio_wl32(pb, 0);
    avio_wl32(pb, 0);
    avio_wl32(pb, 0);
    avio_wl32(pb, 0);
    avio_wl32(pb, 0);
    avio_wl32(pb, 0);
    avio_wl32(pb, 0);
    return 32;
}

static int gxf_write_umf_media_audio(AVIOContext *pb, GXFStreamContext *sc)
{
    avio_wl64(pb, av_double2int(1)); /* sound level to begin to */
    avio_wl64(pb, av_double2int(1)); /* sound level to begin to */
    avio_wl32(pb, 0); /* number of fields over which to ramp up sound level */
    avio_wl32(pb, 0); /* number of fields over which to ramp down sound level */
    avio_wl32(pb, 0); /* reserved */
    avio_wl32(pb, 0); /* reserved */
    return 32;
}

static int gxf_write_umf_media_description(AVFormatContext *s)
{
    GXFContext *gxf = s->priv_data;
    AVIOContext *pb = s->pb;
    int64_t pos;
    int i, j;

    pos = avio_tell(pb);
    gxf->umf_media_offset = pos - gxf->umf_start_offset;
    for (i = 0; i <= s->nb_streams; ++i) {
        GXFStreamContext *sc;
        int64_t startpos, curpos;

        if (i == s->nb_streams)
            sc = &gxf->timecode_track;
        else
            sc = s->streams[i]->priv_data;

        startpos = avio_tell(pb);
        avio_wl16(pb, 0); /* length */
        avio_wl16(pb, sc->media_info);
        avio_wl16(pb, 0); /* reserved */
        avio_wl16(pb, 0); /* reserved */
        avio_wl32(pb, gxf->nb_fields);
        avio_wl32(pb, 0); /* attributes rw, ro */
        avio_wl32(pb, 0); /* mark in */
        avio_wl32(pb, gxf->nb_fields); /* mark out */
        avio_write(pb, ES_NAME_PATTERN, strlen(ES_NAME_PATTERN));
        avio_wb16(pb, sc->media_info);
        for (j = strlen(ES_NAME_PATTERN)+2; j < 88; j++)
            avio_w8(pb, 0);
        avio_wl32(pb, sc->track_type);
        avio_wl32(pb, sc->sample_rate);
        avio_wl32(pb, sc->sample_size);
        avio_wl32(pb, 0); /* reserved */

        if (sc == &gxf->timecode_track)
            gxf_write_umf_media_timecode(pb, gxf->tc.drop);
        else {
            AVStream *st = s->streams[i];
            switch (st->codecpar->codec_id) {
            case AV_CODEC_ID_MPEG1VIDEO:
            case AV_CODEC_ID_MPEG2VIDEO:
                gxf_write_umf_media_mpeg(pb, st);
                break;
            case AV_CODEC_ID_PCM_S16LE:
                gxf_write_umf_media_audio(pb, sc);
                break;
            case AV_CODEC_ID_DVVIDEO:
                gxf_write_umf_media_dv(pb, sc, st);
                break;
            }
        }

        curpos = avio_tell(pb);
        avio_seek(pb, startpos, SEEK_SET);
        avio_wl16(pb, curpos - startpos);
        avio_seek(pb, curpos, SEEK_SET);
    }
    return avio_tell(pb) - pos;
}

static int gxf_write_umf_packet(AVFormatContext *s)
{
    GXFContext *gxf = s->priv_data;
    AVIOContext *pb = s->pb;
    int64_t pos = avio_tell(pb);

    gxf_write_packet_header(pb, PKT_UMF);

    /* preamble */
    avio_w8(pb, 3); /* first and last (only) packet */
    avio_wb32(pb, gxf->umf_length); /* data length */

    gxf->umf_start_offset = avio_tell(pb);
    gxf_write_umf_payload(s);
    gxf_write_umf_material_description(s);
    gxf->umf_track_size = gxf_write_umf_track_description(s);
    gxf->umf_media_size = gxf_write_umf_media_description(s);
    gxf->umf_length = avio_tell(pb) - gxf->umf_start_offset;
    return updatePacketSize(pb, pos);
}

static const int GXF_samples_per_frame = 32768;

static void gxf_init_timecode_track(GXFStreamContext *sc, GXFStreamContext *vsc)
{
    if (!vsc)
        return;

    sc->media_type = vsc->sample_rate == 60 ? 7 : 8;
    sc->sample_rate = vsc->sample_rate;
    sc->media_info = ('T'<<8) | '0';
    sc->track_type = 3;
    sc->frame_rate_index = vsc->frame_rate_index;
    sc->lines_index = vsc->lines_index;
    sc->sample_size = 16;
    sc->fields = vsc->fields;
}

static int gxf_init_timecode(AVFormatContext *s, GXFTimecode *tc, const char *tcstr, int fields)
{
    char c;

    if (sscanf(tcstr, "%d:%d:%d%c%d", &tc->hh, &tc->mm, &tc->ss, &c, &tc->ff) != 5) {
        av_log(s, AV_LOG_ERROR, "unable to parse timecode, "
                                "syntax: hh:mm:ss[:;.]ff\n");
        return -1;
    }

    tc->color = 0;
    tc->drop = c != ':';

    if (fields == 2)
        tc->ff = tc->ff * 2;

    return 0;
}

static int gxf_write_header(AVFormatContext *s)
{
    AVIOContext *pb = s->pb;
    GXFContext *gxf = s->priv_data;
    GXFStreamContext *vsc = NULL;
    uint8_t tracks[255] = {0};
    int i, media_info = 0;
    int ret;
    AVDictionaryEntry *tcr = av_dict_get(s->metadata, "timecode", NULL, 0);

    if (!(pb->seekable & AVIO_SEEKABLE_NORMAL)) {
        av_log(s, AV_LOG_ERROR, "gxf muxer does not support streamed output, patch welcome\n");
        return -1;
    }

    gxf->flags |= 0x00080000; /* material is simple clip */
    for (i = 0; i < s->nb_streams; ++i) {
        AVStream *st = s->streams[i];
        GXFStreamContext *sc = av_mallocz(sizeof(*sc));
        if (!sc)
            return AVERROR(ENOMEM);
        st->priv_data = sc;

        sc->media_type = ff_codec_get_tag(gxf_media_types, st->codecpar->codec_id);
        if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
            if (st->codecpar->codec_id != AV_CODEC_ID_PCM_S16LE) {
                av_log(s, AV_LOG_ERROR, "only 16 BIT PCM LE allowed for now\n");
                return -1;
            }
            if (st->codecpar->sample_rate != 48000) {
                av_log(s, AV_LOG_ERROR, "only 48000hz sampling rate is allowed\n");
                return -1;
            }
            if (st->codecpar->channels != 1) {
                av_log(s, AV_LOG_ERROR, "only mono tracks are allowed\n");
                return -1;
            }
            sc->track_type = 2;
            sc->sample_rate = st->codecpar->sample_rate;
            avpriv_set_pts_info(st, 64, 1, sc->sample_rate);
            sc->sample_size = 16;
            sc->frame_rate_index = -2;
            sc->lines_index = -2;
            sc->fields = -2;
            gxf->audio_tracks++;
            gxf->flags |= 0x04000000; /* audio is 16 bit pcm */
            media_info = 'A';
        } else if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
            if (i != 0) {
                av_log(s, AV_LOG_ERROR, "video stream must be the first track\n");
                return -1;
            }
            /* FIXME check from time_base ? */
            if (st->codecpar->height == 480 || st->codecpar->height == 512) { /* NTSC or NTSC+VBI */
                sc->frame_rate_index = 5;
                sc->sample_rate = 60;
                gxf->flags |= 0x00000080;
                gxf->time_base = (AVRational){ 1001, 60000 };
            } else if (st->codecpar->height == 576 || st->codecpar->height == 608) { /* PAL or PAL+VBI */
                sc->frame_rate_index = 6;
                sc->media_type++;
                sc->sample_rate = 50;
                gxf->flags |= 0x00000040;
                gxf->time_base = (AVRational){ 1, 50 };
            } else {
                av_log(s, AV_LOG_ERROR, "unsupported video resolution, "
                       "gxf muxer only accepts PAL or NTSC resolutions currently\n");
                return -1;
            }
            if (!tcr)
                tcr = av_dict_get(st->metadata, "timecode", NULL, 0);
            avpriv_set_pts_info(st, 64, gxf->time_base.num, gxf->time_base.den);
            if (gxf_find_lines_index(st) < 0)
                sc->lines_index = -1;
            sc->sample_size = st->codecpar->bit_rate;
            sc->fields = 2; /* interlaced */

            vsc = sc;

            switch (st->codecpar->codec_id) {
            case AV_CODEC_ID_MJPEG:
                sc->track_type = 1;
                gxf->flags |= 0x00004000;
                media_info = 'J';
                break;
            case AV_CODEC_ID_MPEG1VIDEO:
                sc->track_type = 9;
                gxf->mpeg_tracks++;
                media_info = 'L';
                break;
            case AV_CODEC_ID_MPEG2VIDEO:
                sc->first_gop_closed = -1;
                sc->track_type = 4;
                gxf->mpeg_tracks++;
                gxf->flags |= 0x00008000;
                media_info = 'M';
                break;
            case AV_CODEC_ID_DVVIDEO:
                if (st->codecpar->format == AV_PIX_FMT_YUV422P) {
                    sc->media_type += 2;
                    sc->track_type = 6;
                    gxf->flags |= 0x00002000;
                    media_info = 'E';
                } else {
                    sc->track_type = 5;
                    gxf->flags |= 0x00001000;
                    media_info = 'D';
                }
                break;
            default:
                av_log(s, AV_LOG_ERROR, "video codec not supported\n");
                return -1;
            }
        }
        /* FIXME first 10 audio tracks are 0 to 9 next 22 are A to V */
        sc->media_info = media_info<<8 | ('0'+tracks[media_info]++);
        sc->order = s->nb_streams - st->index;
    }

    if (ff_audio_interleave_init(s, GXF_samples_per_frame, (AVRational){ 1, 48000 }) < 0)
        return -1;

    if (tcr && vsc)
        gxf_init_timecode(s, &gxf->tc, tcr->value, vsc->fields);

    gxf_init_timecode_track(&gxf->timecode_track, vsc);
    gxf->flags |= 0x200000; // time code track is non-drop frame

    if ((ret = gxf_write_map_packet(s, 0)) < 0)
        return ret;
    gxf_write_flt_packet(s);
    gxf_write_umf_packet(s);

    gxf->packet_count = 3;

    return 0;
}

static int gxf_write_eos_packet(AVIOContext *pb)
{
    int64_t pos = avio_tell(pb);

    gxf_write_packet_header(pb, PKT_EOS);
    return updatePacketSize(pb, pos);
}

static int gxf_write_trailer(AVFormatContext *s)
{
    GXFContext *gxf = s->priv_data;
    AVIOContext *pb = s->pb;
    int64_t end;
    int i;
    int ret;

    gxf_write_eos_packet(pb);
    end = avio_tell(pb);
    avio_seek(pb, 0, SEEK_SET);
    /* overwrite map, flt and umf packets with new values */
    if ((ret = gxf_write_map_packet(s, 1)) < 0)
        return ret;
    gxf_write_flt_packet(s);
    gxf_write_umf_packet(s);
    /* update duration in all map packets */
    for (i = 1; i < gxf->map_offsets_nb; i++) {
        avio_seek(pb, gxf->map_offsets[i], SEEK_SET);
        if ((ret = gxf_write_map_packet(s, 1)) < 0)
            return ret;
    }

    avio_seek(pb, end, SEEK_SET);

    return 0;
}

static void gxf_deinit(AVFormatContext *s)
{
    GXFContext *gxf = s->priv_data;

    ff_audio_interleave_close(s);

    av_freep(&gxf->flt_entries);
    av_freep(&gxf->map_offsets);
}

static int gxf_parse_mpeg_frame(GXFStreamContext *sc, const uint8_t *buf, int size)
{
    uint32_t c=-1;
    int i;
    for(i=0; i<size-4 && c!=0x100; i++){
        c = (c<<8) + buf[i];
        if(c == 0x1B8 && sc->first_gop_closed == -1) /* GOP start code */
            sc->first_gop_closed= (buf[i+4]>>6)&1;
    }
    return (buf[i+1]>>3)&7;
}

static int gxf_write_media_preamble(AVFormatContext *s, AVPacket *pkt, int size)
{
    GXFContext *gxf = s->priv_data;
    AVIOContext *pb = s->pb;
    AVStream *st = s->streams[pkt->stream_index];
    GXFStreamContext *sc = st->priv_data;
    unsigned field_nb;
    /* If the video is frame-encoded, the frame numbers shall be represented by
     * even field numbers.
     * see SMPTE360M-2004  6.4.2.1.3 Media field number */
    if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
        field_nb = gxf->nb_fields;
    } else {
        field_nb = av_rescale_rnd(pkt->dts, gxf->time_base.den,
                                  (int64_t)48000*gxf->time_base.num, AV_ROUND_UP);
    }

    avio_w8(pb, sc->media_type);
    avio_w8(pb, st->index);
    avio_wb32(pb, field_nb);
    if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
        avio_wb16(pb, 0);
        avio_wb16(pb, size / 2);
    } else if (st->codecpar->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
        int frame_type = gxf_parse_mpeg_frame(sc, pkt->data, pkt->size);
        if (frame_type == AV_PICTURE_TYPE_I) {
            avio_w8(pb, 0x0d);
            sc->iframes++;
        } else if (frame_type == AV_PICTURE_TYPE_B) {
            avio_w8(pb, 0x0f);
            sc->bframes++;
        } else {
            avio_w8(pb, 0x0e);
            sc->pframes++;
        }
        avio_wb24(pb, size);
    } else if (st->codecpar->codec_id == AV_CODEC_ID_DVVIDEO) {
        avio_w8(pb, size / 4096);
        avio_wb24(pb, 0);
    } else
        avio_wb32(pb, size);
    avio_wb32(pb, field_nb);
    avio_w8(pb, 1); /* flags */
    avio_w8(pb, 0); /* reserved */
    return 16;
}

static int gxf_write_packet(AVFormatContext *s, AVPacket *pkt)
{
    GXFContext *gxf = s->priv_data;
    AVIOContext *pb = s->pb;
    AVStream *st = s->streams[pkt->stream_index];
    int64_t pos = avio_tell(pb);
    int padding = 0;
    unsigned packet_start_offset = avio_tell(pb) / 1024;
    int ret;

    gxf_write_packet_header(pb, PKT_MEDIA);
    if (st->codecpar->codec_id == AV_CODEC_ID_MPEG2VIDEO && pkt->size % 4) /* MPEG-2 frames must be padded */
        padding = 4 - pkt->size % 4;
    else if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)
        padding = GXF_AUDIO_PACKET_SIZE - pkt->size;
    gxf_write_media_preamble(s, pkt, pkt->size + padding);
    avio_write(pb, pkt->data, pkt->size);
    gxf_write_padding(pb, padding);

    if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
        if (!(gxf->flt_entries_nb % 500)) {
            int err;
            if ((err = av_reallocp_array(&gxf->flt_entries,
                                         gxf->flt_entries_nb + 500,
                                         sizeof(*gxf->flt_entries))) < 0) {
                gxf->flt_entries_nb = 0;
                gxf->nb_fields = 0;
                av_log(s, AV_LOG_ERROR, "could not reallocate flt entries\n");
                return err;
            }
        }
        gxf->flt_entries[gxf->flt_entries_nb++] = packet_start_offset;
        gxf->nb_fields += 2; // count fields
    }

    updatePacketSize(pb, pos);

    gxf->packet_count++;
    if (gxf->packet_count == 100) {
        if ((ret = gxf_write_map_packet(s, 0)) < 0)
            return ret;
        gxf->packet_count = 0;
    }

    return 0;
}

static int gxf_compare_field_nb(AVFormatContext *s, const AVPacket *next,
                                                    const AVPacket *cur)
{
    GXFContext *gxf = s->priv_data;
    const AVPacket *pkt[2] = { cur, next };
    int i, field_nb[2];
    GXFStreamContext *sc[2];

    for (i = 0; i < 2; i++) {
        AVStream *st = s->streams[pkt[i]->stream_index];
        sc[i] = st->priv_data;
        if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
            field_nb[i] = av_rescale_rnd(pkt[i]->dts, gxf->time_base.den,
                                         (int64_t)48000*gxf->time_base.num, AV_ROUND_UP);
            field_nb[i] &= ~1; // compare against even field number because audio must be before video
        } else
            field_nb[i] = pkt[i]->dts; // dts are field based
    }

    return field_nb[1] > field_nb[0] ||
        (field_nb[1] == field_nb[0] && sc[1]->order > sc[0]->order);
}

static int gxf_interleave_packet(AVFormatContext *s, AVPacket *out, AVPacket *pkt, int flush)
{
    if (pkt && s->streams[pkt->stream_index]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
        pkt->duration = 2; // enforce 2 fields
    return ff_audio_rechunk_interleave(s, out, pkt, flush,
                               ff_interleave_packet_per_dts, gxf_compare_field_nb);
}

AVOutputFormat ff_gxf_muxer = {
    .name              = "gxf",
    .long_name         = NULL_IF_CONFIG_SMALL("GXF (General eXchange Format)"),
    .extensions        = "gxf",
    .priv_data_size    = sizeof(GXFContext),
    .audio_codec       = AV_CODEC_ID_PCM_S16LE,
    .video_codec       = AV_CODEC_ID_MPEG2VIDEO,
    .write_header      = gxf_write_header,
    .write_packet      = gxf_write_packet,
    .write_trailer     = gxf_write_trailer,
    .deinit            = gxf_deinit,
    .interleave_packet = gxf_interleave_packet,
};