aboutsummaryrefslogtreecommitdiffstats
path: root/libavformat/avienc.c
blob: 030c6d3b4627a507e3ded4f75cc3f8d3fdb10738 (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
/*
 * AVI muxer
 * Copyright (c) 2000 Fabrice Bellard
 *
 * 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 "avformat.h"
#include "avi.h"
#include "riff.h"

/*
 * TODO:
 *  - fill all fields if non streamed (nb_frames for example)
 */

typedef struct AVIIentry {
    unsigned int flags, pos, len;
} AVIIentry;

#define AVI_INDEX_CLUSTER_SIZE 16384

typedef struct AVIIndex {
    int64_t     indx_start;
    int         entry;
    int         ents_allocated;
    AVIIentry** cluster;
} AVIIndex;

typedef struct {
    int64_t riff_start, movi_list, odml_list;
    int64_t frames_hdr_all;
    int riff_id;
} AVIContext;

typedef struct  {
    int64_t frames_hdr_strm;
    int audio_strm_length;
    int packet_count;
    int entry;

    AVIIndex indexes;
} AVIStream ;

static inline AVIIentry* avi_get_ientry(AVIIndex* idx, int ent_id)
{
    int cl = ent_id / AVI_INDEX_CLUSTER_SIZE;
    int id = ent_id % AVI_INDEX_CLUSTER_SIZE;
    return &idx->cluster[cl][id];
}

static int64_t avi_start_new_riff(AVFormatContext *s, ByteIOContext *pb,
                                  const char* riff_tag, const char* list_tag)
{
    AVIContext *avi= s->priv_data;
    int64_t loff;
    int i;

    avi->riff_id++;
    for (i=0; i<s->nb_streams; i++){
        AVIStream *avist= s->streams[i]->priv_data;
        avist->indexes.entry = 0;
    }

    avi->riff_start = ff_start_tag(pb, "RIFF");
    put_tag(pb, riff_tag);
    loff = ff_start_tag(pb, "LIST");
    put_tag(pb, list_tag);
    return loff;
}

static char* avi_stream2fourcc(char* tag, int index, enum CodecType type)
{
    tag[0] = '0';
    tag[1] = '0' + index;
    if (type == CODEC_TYPE_VIDEO) {
        tag[2] = 'd';
        tag[3] = 'c';
    } else if (type == CODEC_TYPE_SUBTITLE) {
        // note: this is not an official code
        tag[2] = 's';
        tag[3] = 'b';
    } else {
        tag[2] = 'w';
        tag[3] = 'b';
    }
    tag[4] = '\0';
    return tag;
}

static void avi_write_info_tag(ByteIOContext *pb, const char *tag, const char *str)
{
    int len = strlen(str);
    if (len > 0) {
        len++;
        put_tag(pb, tag);
        put_le32(pb, len);
        put_strz(pb, str);
        if (len & 1)
            put_byte(pb, 0);
    }
}

static void avi_write_info_tag2(AVFormatContext *s, AVStream *st, const char *fourcc, const char *key1, const char *key2)
{
    AVMetadataTag *tag;
    if(st){
        tag= av_metadata_get(st->metadata, key1, NULL, 0);
        if(!tag && key2)
            tag= av_metadata_get(st->metadata, key2, NULL, 0);
    }else{
        tag= av_metadata_get(s->metadata, key1, NULL, 0);
    if(!tag && key2)
        tag= av_metadata_get(s->metadata, key2, NULL, 0);
    }
    if(tag)
        avi_write_info_tag(s->pb, fourcc, tag->value);
}

static int avi_write_counters(AVFormatContext* s, int riff_id)
{
    ByteIOContext *pb = s->pb;
    AVIContext *avi = s->priv_data;
    int n, au_byterate, au_ssize, au_scale, nb_frames = 0;
    int64_t file_size;
    AVCodecContext* stream;

    file_size = url_ftell(pb);
    for(n = 0; n < s->nb_streams; n++) {
        AVIStream *avist= s->streams[n]->priv_data;

        assert(avist->frames_hdr_strm);
        stream = s->streams[n]->codec;
        url_fseek(pb, avist->frames_hdr_strm, SEEK_SET);
        ff_parse_specific_params(stream, &au_byterate, &au_ssize, &au_scale);
        if(au_ssize == 0) {
            put_le32(pb, avist->packet_count);
        } else {
            put_le32(pb, avist->audio_strm_length / au_ssize);
        }
        if(stream->codec_type == CODEC_TYPE_VIDEO)
            nb_frames = FFMAX(nb_frames, avist->packet_count);
    }
    if(riff_id == 1) {
        assert(avi->frames_hdr_all);
        url_fseek(pb, avi->frames_hdr_all, SEEK_SET);
        put_le32(pb, nb_frames);
    }
    url_fseek(pb, file_size, SEEK_SET);

    return 0;
}

static int avi_write_header(AVFormatContext *s)
{
    AVIContext *avi = s->priv_data;
    ByteIOContext *pb = s->pb;
    int bitrate, n, i, nb_frames, au_byterate, au_ssize, au_scale;
    AVCodecContext *stream, *video_enc;
    int64_t list1, list2, strh, strf;

    for(n=0;n<s->nb_streams;n++) {
        s->streams[n]->priv_data= av_mallocz(sizeof(AVIStream));
        if(!s->streams[n]->priv_data)
            return AVERROR(ENOMEM);
    }

    /* header list */
    avi->riff_id = 0;
    list1 = avi_start_new_riff(s, pb, "AVI ", "hdrl");

    /* avi header */
    put_tag(pb, "avih");
    put_le32(pb, 14 * 4);
    bitrate = 0;

    video_enc = NULL;
    for(n=0;n<s->nb_streams;n++) {
        stream = s->streams[n]->codec;
        bitrate += stream->bit_rate;
        if (stream->codec_type == CODEC_TYPE_VIDEO)
            video_enc = stream;
    }

    nb_frames = 0;

    if(video_enc){
        put_le32(pb, (uint32_t)(INT64_C(1000000) * video_enc->time_base.num / video_enc->time_base.den));
    } else {
        put_le32(pb, 0);
    }
    put_le32(pb, bitrate / 8); /* XXX: not quite exact */
    put_le32(pb, 0); /* padding */
    if (url_is_streamed(pb))
        put_le32(pb, AVIF_TRUSTCKTYPE | AVIF_ISINTERLEAVED); /* flags */
    else
        put_le32(pb, AVIF_TRUSTCKTYPE | AVIF_HASINDEX | AVIF_ISINTERLEAVED); /* flags */
    avi->frames_hdr_all = url_ftell(pb); /* remember this offset to fill later */
    put_le32(pb, nb_frames); /* nb frames, filled later */
    put_le32(pb, 0); /* initial frame */
    put_le32(pb, s->nb_streams); /* nb streams */
    put_le32(pb, 1024 * 1024); /* suggested buffer size */
    if(video_enc){
        put_le32(pb, video_enc->width);
        put_le32(pb, video_enc->height);
    } else {
        put_le32(pb, 0);
        put_le32(pb, 0);
    }
    put_le32(pb, 0); /* reserved */
    put_le32(pb, 0); /* reserved */
    put_le32(pb, 0); /* reserved */
    put_le32(pb, 0); /* reserved */

    /* stream list */
    for(i=0;i<n;i++) {
        AVIStream *avist= s->streams[i]->priv_data;
        list2 = ff_start_tag(pb, "LIST");
        put_tag(pb, "strl");

        stream = s->streams[i]->codec;

        /* stream generic header */
        strh = ff_start_tag(pb, "strh");
        switch(stream->codec_type) {
        case CODEC_TYPE_SUBTITLE:
            // XSUB subtitles behave like video tracks, other subtitles
            // are not (yet) supported.
            if (stream->codec_id != CODEC_ID_XSUB) break;
        case CODEC_TYPE_VIDEO: put_tag(pb, "vids"); break;
        case CODEC_TYPE_AUDIO: put_tag(pb, "auds"); break;
//        case CODEC_TYPE_TEXT : put_tag(pb, "txts"); break;
        case CODEC_TYPE_DATA : put_tag(pb, "dats"); break;
        }
        if(stream->codec_type == CODEC_TYPE_VIDEO ||
           stream->codec_id == CODEC_ID_XSUB)
            put_le32(pb, stream->codec_tag);
        else
            put_le32(pb, 1);
        put_le32(pb, 0); /* flags */
        put_le16(pb, 0); /* priority */
        put_le16(pb, 0); /* language */
        put_le32(pb, 0); /* initial frame */

        ff_parse_specific_params(stream, &au_byterate, &au_ssize, &au_scale);

        put_le32(pb, au_scale); /* scale */
        put_le32(pb, au_byterate); /* rate */
        av_set_pts_info(s->streams[i], 64, au_scale, au_byterate);

        put_le32(pb, 0); /* start */
        avist->frames_hdr_strm = url_ftell(pb); /* remember this offset to fill later */
        if (url_is_streamed(pb))
            put_le32(pb, AVI_MAX_RIFF_SIZE); /* FIXME: this may be broken, but who cares */
        else
            put_le32(pb, 0); /* length, XXX: filled later */

        /* suggested buffer size */ //FIXME set at the end to largest chunk
        if(stream->codec_type == CODEC_TYPE_VIDEO)
            put_le32(pb, 1024 * 1024);
        else if(stream->codec_type == CODEC_TYPE_AUDIO)
            put_le32(pb, 12 * 1024);
        else
            put_le32(pb, 0);
        put_le32(pb, -1); /* quality */
        put_le32(pb, au_ssize); /* sample size */
        put_le32(pb, 0);
        put_le16(pb, stream->width);
        put_le16(pb, stream->height);
        ff_end_tag(pb, strh);

      if(stream->codec_type != CODEC_TYPE_DATA){
        strf = ff_start_tag(pb, "strf");
        switch(stream->codec_type) {
        case CODEC_TYPE_SUBTITLE:
            // XSUB subtitles behave like video tracks, other subtitles
            // are not (yet) supported.
            if (stream->codec_id != CODEC_ID_XSUB) break;
        case CODEC_TYPE_VIDEO:
            ff_put_bmp_header(pb, stream, ff_codec_bmp_tags, 0);
            break;
        case CODEC_TYPE_AUDIO:
            if (ff_put_wav_header(pb, stream) < 0) {
                return -1;
            }
            break;
        default:
            return -1;
        }
        ff_end_tag(pb, strf);
        avi_write_info_tag2(s, s->streams[i], "strn", "Title", "Description");
      }

        if (!url_is_streamed(pb)) {
            unsigned char tag[5];
            int j;

            /* Starting to lay out AVI OpenDML master index.
             * We want to make it JUNK entry for now, since we'd
             * like to get away without making AVI an OpenDML one
             * for compatibility reasons.
             */
            avist->indexes.entry = avist->indexes.ents_allocated = 0;
            avist->indexes.indx_start = ff_start_tag(pb, "JUNK");
            put_le16(pb, 4);        /* wLongsPerEntry */
            put_byte(pb, 0);        /* bIndexSubType (0 == frame index) */
            put_byte(pb, 0);        /* bIndexType (0 == AVI_INDEX_OF_INDEXES) */
            put_le32(pb, 0);        /* nEntriesInUse (will fill out later on) */
            put_tag(pb, avi_stream2fourcc(&tag[0], i, stream->codec_type));
                                    /* dwChunkId */
            put_le64(pb, 0);        /* dwReserved[3]
            put_le32(pb, 0);           Must be 0.    */
            for (j=0; j < AVI_MASTER_INDEX_SIZE * 2; j++)
                 put_le64(pb, 0);
            ff_end_tag(pb, avist->indexes.indx_start);
        }

        if(   stream->codec_type == CODEC_TYPE_VIDEO
           && s->streams[i]->sample_aspect_ratio.num>0
           && s->streams[i]->sample_aspect_ratio.den>0){
            int vprp= ff_start_tag(pb, "vprp");
            AVRational dar = av_mul_q(s->streams[i]->sample_aspect_ratio,
                                      (AVRational){stream->width, stream->height});
            int num, den;
            av_reduce(&num, &den, dar.num, dar.den, 0xFFFF);

            put_le32(pb, 0); //video format  = unknown
            put_le32(pb, 0); //video standard= unknown
            put_le32(pb, lrintf(1.0/av_q2d(stream->time_base)));
            put_le32(pb, stream->width );
            put_le32(pb, stream->height);
            put_le16(pb, den);
            put_le16(pb, num);
            put_le32(pb, stream->width );
            put_le32(pb, stream->height);
            put_le32(pb, 1); //progressive FIXME

            put_le32(pb, stream->height);
            put_le32(pb, stream->width );
            put_le32(pb, stream->height);
            put_le32(pb, stream->width );
            put_le32(pb, 0);
            put_le32(pb, 0);

            put_le32(pb, 0);
            put_le32(pb, 0);
            ff_end_tag(pb, vprp);
        }

        ff_end_tag(pb, list2);
    }

    if (!url_is_streamed(pb)) {
        /* AVI could become an OpenDML one, if it grows beyond 2Gb range */
        avi->odml_list = ff_start_tag(pb, "JUNK");
        put_tag(pb, "odml");
        put_tag(pb, "dmlh");
        put_le32(pb, 248);
        for (i = 0; i < 248; i+= 4)
             put_le32(pb, 0);
        ff_end_tag(pb, avi->odml_list);
    }

    ff_end_tag(pb, list1);

    list2 = ff_start_tag(pb, "LIST");
    put_tag(pb, "INFO");
    avi_write_info_tag2(s, NULL, "INAM", "Title", NULL);
    avi_write_info_tag2(s, NULL, "IART", "Artist", "Author");
    avi_write_info_tag2(s, NULL, "ICOP", "Copyright", NULL);
    avi_write_info_tag2(s, NULL, "ICMT", "Comment", NULL);
    avi_write_info_tag2(s, NULL, "IPRD", "Album", NULL);
    avi_write_info_tag2(s, NULL, "IGNR", "Genre", NULL);
    avi_write_info_tag2(s, NULL, "IPRT", "Track", NULL);
    if(!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT))
        avi_write_info_tag(pb, "ISFT", LIBAVFORMAT_IDENT);
    ff_end_tag(pb, list2);

    /* some padding for easier tag editing */
    list2 = ff_start_tag(pb, "JUNK");
    for (i = 0; i < 1016; i += 4)
        put_le32(pb, 0);
    ff_end_tag(pb, list2);

    avi->movi_list = ff_start_tag(pb, "LIST");
    put_tag(pb, "movi");

    put_flush_packet(pb);

    return 0;
}

static int avi_write_ix(AVFormatContext *s)
{
    ByteIOContext *pb = s->pb;
    AVIContext *avi = s->priv_data;
    char tag[5];
    char ix_tag[] = "ix00";
    int i, j;

    assert(!url_is_streamed(pb));

    if (avi->riff_id > AVI_MASTER_INDEX_SIZE)
        return -1;

    for (i=0;i<s->nb_streams;i++) {
        AVIStream *avist= s->streams[i]->priv_data;
         int64_t ix, pos;

         avi_stream2fourcc(&tag[0], i, s->streams[i]->codec->codec_type);
         ix_tag[3] = '0' + i;

         /* Writing AVI OpenDML leaf index chunk */
         ix = url_ftell(pb);
         put_tag(pb, &ix_tag[0]);     /* ix?? */
         put_le32(pb, avist->indexes.entry * 8 + 24);
                                      /* chunk size */
         put_le16(pb, 2);             /* wLongsPerEntry */
         put_byte(pb, 0);             /* bIndexSubType (0 == frame index) */
         put_byte(pb, 1);             /* bIndexType (1 == AVI_INDEX_OF_CHUNKS) */
         put_le32(pb, avist->indexes.entry);
                                      /* nEntriesInUse */
         put_tag(pb, &tag[0]);        /* dwChunkId */
         put_le64(pb, avi->movi_list);/* qwBaseOffset */
         put_le32(pb, 0);             /* dwReserved_3 (must be 0) */

         for (j=0; j<avist->indexes.entry; j++) {
             AVIIentry* ie = avi_get_ientry(&avist->indexes, j);
             put_le32(pb, ie->pos + 8);
             put_le32(pb, ((uint32_t)ie->len & ~0x80000000) |
                          (ie->flags & 0x10 ? 0 : 0x80000000));
         }
         put_flush_packet(pb);
         pos = url_ftell(pb);

         /* Updating one entry in the AVI OpenDML master index */
         url_fseek(pb, avist->indexes.indx_start - 8, SEEK_SET);
         put_tag(pb, "indx");                 /* enabling this entry */
         url_fskip(pb, 8);
         put_le32(pb, avi->riff_id);          /* nEntriesInUse */
         url_fskip(pb, 16*avi->riff_id);
         put_le64(pb, ix);                    /* qwOffset */
         put_le32(pb, pos - ix);              /* dwSize */
         put_le32(pb, avist->indexes.entry); /* dwDuration */

         url_fseek(pb, pos, SEEK_SET);
    }
    return 0;
}

static int avi_write_idx1(AVFormatContext *s)
{
    ByteIOContext *pb = s->pb;
    AVIContext *avi = s->priv_data;
    int64_t idx_chunk;
    int i;
    char tag[5];

    if (!url_is_streamed(pb)) {
        AVIStream *avist;
        AVIIentry* ie = 0, *tie;
        int empty, stream_id = -1;

        idx_chunk = ff_start_tag(pb, "idx1");
        for(i=0; i<s->nb_streams; i++){
            avist= s->streams[i]->priv_data;
            avist->entry=0;
        }

        do {
            empty = 1;
            for (i=0; i<s->nb_streams; i++) {
                avist= s->streams[i]->priv_data;
                 if (avist->indexes.entry <= avist->entry)
                     continue;

                 tie = avi_get_ientry(&avist->indexes, avist->entry);
                 if (empty || tie->pos < ie->pos) {
                     ie = tie;
                     stream_id = i;
                 }
                 empty = 0;
            }
            if (!empty) {
                avist= s->streams[stream_id]->priv_data;
                avi_stream2fourcc(&tag[0], stream_id,
                                  s->streams[stream_id]->codec->codec_type);
                put_tag(pb, &tag[0]);
                put_le32(pb, ie->flags);
                put_le32(pb, ie->pos);
                put_le32(pb, ie->len);
                avist->entry++;
            }
        } while (!empty);
        ff_end_tag(pb, idx_chunk);

        avi_write_counters(s, avi->riff_id);
    }
    return 0;
}

static int avi_write_packet(AVFormatContext *s, AVPacket *pkt)
{
    AVIContext *avi = s->priv_data;
    ByteIOContext *pb = s->pb;
    unsigned char tag[5];
    unsigned int flags=0;
    const int stream_index= pkt->stream_index;
    AVIStream *avist= s->streams[stream_index]->priv_data;
    AVCodecContext *enc= s->streams[stream_index]->codec;
    int size= pkt->size;

//    av_log(s, AV_LOG_DEBUG, "%"PRId64" %d %d\n", pkt->dts, avi->packet_count[stream_index], stream_index);
    while(enc->block_align==0 && pkt->dts != AV_NOPTS_VALUE && pkt->dts > avist->packet_count){
        AVPacket empty_packet;

        av_init_packet(&empty_packet);
        empty_packet.size= 0;
        empty_packet.data= NULL;
        empty_packet.stream_index= stream_index;
        avi_write_packet(s, &empty_packet);
//        av_log(s, AV_LOG_DEBUG, "dup %"PRId64" %d\n", pkt->dts, avi->packet_count[stream_index]);
    }
    avist->packet_count++;

    // Make sure to put an OpenDML chunk when the file size exceeds the limits
    if (!url_is_streamed(pb) &&
        (url_ftell(pb) - avi->riff_start > AVI_MAX_RIFF_SIZE)) {

        avi_write_ix(s);
        ff_end_tag(pb, avi->movi_list);

        if (avi->riff_id == 1)
            avi_write_idx1(s);

        ff_end_tag(pb, avi->riff_start);
        avi->movi_list = avi_start_new_riff(s, pb, "AVIX", "movi");
    }

    avi_stream2fourcc(&tag[0], stream_index, enc->codec_type);
    if(pkt->flags&PKT_FLAG_KEY)
        flags = 0x10;
    if (enc->codec_type == CODEC_TYPE_AUDIO) {
       avist->audio_strm_length += size;
    }

    if (!url_is_streamed(s->pb)) {
        AVIIndex* idx = &avist->indexes;
        int cl = idx->entry / AVI_INDEX_CLUSTER_SIZE;
        int id = idx->entry % AVI_INDEX_CLUSTER_SIZE;
        if (idx->ents_allocated <= idx->entry) {
            idx->cluster = av_realloc(idx->cluster, (cl+1)*sizeof(void*));
            if (!idx->cluster)
                return -1;
            idx->cluster[cl] = av_malloc(AVI_INDEX_CLUSTER_SIZE*sizeof(AVIIentry));
            if (!idx->cluster[cl])
                return -1;
            idx->ents_allocated += AVI_INDEX_CLUSTER_SIZE;
        }

        idx->cluster[cl][id].flags = flags;
        idx->cluster[cl][id].pos = url_ftell(pb) - avi->movi_list;
        idx->cluster[cl][id].len = size;
        idx->entry++;
    }

    put_buffer(pb, tag, 4);
    put_le32(pb, size);
    put_buffer(pb, pkt->data, size);
    if (size & 1)
        put_byte(pb, 0);

    put_flush_packet(pb);
    return 0;
}

static int avi_write_trailer(AVFormatContext *s)
{
    AVIContext *avi = s->priv_data;
    ByteIOContext *pb = s->pb;
    int res = 0;
    int i, j, n, nb_frames;
    int64_t file_size;

    if (!url_is_streamed(pb)){
        if (avi->riff_id == 1) {
            ff_end_tag(pb, avi->movi_list);
            res = avi_write_idx1(s);
            ff_end_tag(pb, avi->riff_start);
        } else {
            avi_write_ix(s);
            ff_end_tag(pb, avi->movi_list);
            ff_end_tag(pb, avi->riff_start);

            file_size = url_ftell(pb);
            url_fseek(pb, avi->odml_list - 8, SEEK_SET);
            put_tag(pb, "LIST"); /* Making this AVI OpenDML one */
            url_fskip(pb, 16);

            for (n=nb_frames=0;n<s->nb_streams;n++) {
                AVCodecContext *stream = s->streams[n]->codec;
                AVIStream *avist= s->streams[n]->priv_data;

                if (stream->codec_type == CODEC_TYPE_VIDEO) {
                    if (nb_frames < avist->packet_count)
                        nb_frames = avist->packet_count;
                } else {
                    if (stream->codec_id == CODEC_ID_MP2 || stream->codec_id == CODEC_ID_MP3) {
                        nb_frames += avist->packet_count;
                    }
                }
            }
            put_le32(pb, nb_frames);
            url_fseek(pb, file_size, SEEK_SET);

            avi_write_counters(s, avi->riff_id);
        }
    }
    put_flush_packet(pb);

    for (i=0; i<s->nb_streams; i++) {
         AVIStream *avist= s->streams[i]->priv_data;
         for (j=0; j<avist->indexes.ents_allocated/AVI_INDEX_CLUSTER_SIZE; j++)
              av_free(avist->indexes.cluster[j]);
         av_freep(&avist->indexes.cluster);
         avist->indexes.ents_allocated = avist->indexes.entry = 0;
    }

    return res;
}

AVOutputFormat avi_muxer = {
    "avi",
    NULL_IF_CONFIG_SMALL("AVI format"),
    "video/x-msvideo",
    "avi",
    sizeof(AVIContext),
    CODEC_ID_MP2,
    CODEC_ID_MPEG4,
    avi_write_header,
    avi_write_packet,
    avi_write_trailer,
    .codec_tag= (const AVCodecTag* const []){ff_codec_bmp_tags, ff_codec_wav_tags, 0},
    .flags= AVFMT_VARIABLE_FPS,
};