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ffmpeg / libavformat / avidec.c @ 34f633df

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1
/*
2
 * AVI decoder.
3
 * Copyright (c) 2001 Fabrice Bellard.
4
 *
5
 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
7
 * License as published by the Free Software Foundation; either
8
 * version 2 of the License, or (at your option) any later version.
9
 *
10
 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
15
 * You should have received a copy of the GNU Lesser General Public
16
 * License along with this library; if not, write to the Free Software
17
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18
 */
19
#include "avformat.h"
20
#include "avi.h"
21
#include "dv.h"
22

    
23
#undef NDEBUG
24
#include <assert.h>
25

    
26
//#define DEBUG
27
//#define DEBUG_SEEK
28

    
29
typedef struct AVIStream {
30
    int64_t frame_offset; /* current frame (video) or byte (audio) counter
31
                         (used to compute the pts) */
32
    int remaining;
33
    int packet_size;
34

    
35
    int scale;
36
    int rate;    
37
    int sample_size; /* audio only data */
38
    int start;
39
    
40
    int cum_len; /* temporary storage (used during seek) */
41
    
42
    int prefix;                       ///< normally 'd'<<8 + 'c' or 'w'<<8 + 'b'
43
    int prefix_count;
44
} AVIStream;
45

    
46
typedef struct {
47
    int64_t  riff_end;
48
    int64_t  movi_end;
49
    offset_t movi_list;
50
    int index_loaded;
51
    int is_odml;
52
    int non_interleaved;
53
    int stream_index;
54
    DVDemuxContext* dv_demux;
55
} AVIContext;
56

    
57
static int avi_load_index(AVFormatContext *s);
58

    
59
#ifdef DEBUG
60
static void print_tag(const char *str, unsigned int tag, int size)
61
{
62
    printf("%s: tag=%c%c%c%c size=0x%x\n",
63
           str, tag & 0xff,
64
           (tag >> 8) & 0xff,
65
           (tag >> 16) & 0xff,
66
           (tag >> 24) & 0xff,
67
           size);
68
}
69
#endif
70

    
71
static int get_riff(AVIContext *avi, ByteIOContext *pb)
72
{
73
    uint32_t tag; 
74
    /* check RIFF header */
75
    tag = get_le32(pb);
76

    
77
    if (tag != MKTAG('R', 'I', 'F', 'F'))
78
        return -1;
79
    avi->riff_end = get_le32(pb);   /* RIFF chunk size */
80
    avi->riff_end += url_ftell(pb); /* RIFF chunk end */
81
    tag = get_le32(pb);
82
    if (tag != MKTAG('A', 'V', 'I', ' ') && tag != MKTAG('A', 'V', 'I', 'X'))
83
        return -1;
84
    
85
    return 0;
86
}
87

    
88
static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
89
{
90
    AVIContext *avi = s->priv_data;
91
    ByteIOContext *pb = &s->pb;
92
    uint32_t tag, tag1, handler;
93
    int codec_type, stream_index, frame_period, bit_rate;
94
    unsigned int size, nb_frames;
95
    int i, n;
96
    AVStream *st;
97
    AVIStream *ast;
98
    int xan_video = 0;  /* hack to support Xan A/V */
99

    
100
    avi->stream_index= -1;
101
    
102
    if (get_riff(avi, pb) < 0)
103
        return -1;
104

    
105
    /* first list tag */
106
    stream_index = -1;
107
    codec_type = -1;
108
    frame_period = 0;
109
    for(;;) {
110
        if (url_feof(pb))
111
            goto fail;
112
        tag = get_le32(pb);
113
        size = get_le32(pb);
114
#ifdef DEBUG
115
        print_tag("tag", tag, size);
116
#endif
117

    
118
        switch(tag) {
119
        case MKTAG('L', 'I', 'S', 'T'):
120
            /* ignored, except when start of video packets */
121
            tag1 = get_le32(pb);
122
#ifdef DEBUG
123
            print_tag("list", tag1, 0);
124
#endif
125
            if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
126
                avi->movi_list = url_ftell(pb) - 4;
127
                if(size) avi->movi_end = avi->movi_list + size;
128
                else     avi->movi_end = url_filesize(url_fileno(pb));
129
#ifdef DEBUG
130
                printf("movi end=%Lx\n", avi->movi_end);
131
#endif
132
                goto end_of_header;
133
            }
134
            break;
135
        case MKTAG('d', 'm', 'l', 'h'):
136
            avi->is_odml = 1;
137
            url_fskip(pb, size + (size & 1));
138
            break;
139
        case MKTAG('a', 'v', 'i', 'h'):
140
            /* avi header */
141
            /* using frame_period is bad idea */
142
            frame_period = get_le32(pb);
143
            bit_rate = get_le32(pb) * 8;
144
            url_fskip(pb, 4 * 4);
145
            n = get_le32(pb);
146
            for(i=0;i<n;i++) {
147
                AVIStream *ast;
148
                st = av_new_stream(s, i);
149
                if (!st)
150
                    goto fail;
151

    
152
                ast = av_mallocz(sizeof(AVIStream));
153
                if (!ast)
154
                    goto fail;
155
                st->priv_data = ast;
156
            }
157
            url_fskip(pb, size - 7 * 4);
158
            break;
159
        case MKTAG('s', 't', 'r', 'h'):
160
            /* stream header */
161
            stream_index++;
162
            tag1 = get_le32(pb);
163
            handler = get_le32(pb); /* codec tag */
164
#ifdef DEBUG
165
        print_tag("strh", tag1, -1);
166
#endif
167
            if(tag1 == MKTAG('i', 'a', 'v', 's') || tag1 == MKTAG('i', 'v', 'a', 's')){
168
                /* 
169
                 * After some consideration -- I don't think we 
170
                 * have to support anything but DV in a type1 AVIs.
171
                 */
172
                if (s->nb_streams != 1)
173
                    goto fail;
174
                
175
                if (handler != MKTAG('d', 'v', 's', 'd') &&
176
                    handler != MKTAG('d', 'v', 'h', 'd') &&
177
                    handler != MKTAG('d', 'v', 's', 'l'))
178
                   goto fail;
179
                
180
                ast = s->streams[0]->priv_data;
181
                av_freep(&s->streams[0]->codec.extradata);
182
                av_freep(&s->streams[0]);
183
                s->nb_streams = 0;
184
                avi->dv_demux = dv_init_demux(s);
185
                if (!avi->dv_demux)
186
                    goto fail;
187
                s->streams[0]->priv_data = ast;
188
                url_fskip(pb, 3 * 4);
189
                ast->scale = get_le32(pb);
190
                ast->rate = get_le32(pb);
191
                stream_index = s->nb_streams - 1;
192
                url_fskip(pb, size - 7*4);
193
                break;
194
            }
195

    
196
            if (stream_index >= s->nb_streams) {
197
                url_fskip(pb, size - 8);
198
                break;
199
            } 
200
            st = s->streams[stream_index];
201
            ast = st->priv_data;
202
            st->codec.stream_codec_tag= handler;
203

    
204
            get_le32(pb); /* flags */
205
            get_le16(pb); /* priority */
206
            get_le16(pb); /* language */
207
            get_le32(pb); /* initial frame */
208
            ast->scale = get_le32(pb);
209
            ast->rate = get_le32(pb);
210
            if(ast->scale && ast->rate){
211
            }else if(frame_period){
212
                ast->rate = 1000000;
213
                ast->scale = frame_period;
214
            }else{
215
                ast->rate = 25;
216
                ast->scale = 1;
217
            }
218
            av_set_pts_info(st, 64, ast->scale, ast->rate);
219
                    
220
            ast->start= get_le32(pb); /* start */
221
            nb_frames = get_le32(pb);
222

    
223
            st->start_time = 0;
224
            st->duration = nb_frames;
225
            get_le32(pb); /* buffer size */
226
            get_le32(pb); /* quality */
227
            ast->sample_size = get_le32(pb); /* sample ssize */
228
//            av_log(NULL, AV_LOG_DEBUG, "%d %d %d %d\n", ast->rate, ast->scale, ast->start, ast->sample_size);
229

    
230
            switch(tag1) {
231
            case MKTAG('v', 'i', 'd', 's'):
232
                codec_type = CODEC_TYPE_VIDEO;
233

    
234
                ast->sample_size = 0;
235
                break;
236
            case MKTAG('a', 'u', 'd', 's'):
237
                codec_type = CODEC_TYPE_AUDIO;
238
                break;
239
            case MKTAG('t', 'x', 't', 's'):
240
                //FIXME 
241
                codec_type = CODEC_TYPE_DATA; //CODEC_TYPE_SUB ?  FIXME
242
                break;
243
            case MKTAG('p', 'a', 'd', 's'):
244
                codec_type = CODEC_TYPE_UNKNOWN;
245
                stream_index--;
246
                break;
247
            default:
248
                av_log(s, AV_LOG_ERROR, "unknown stream type %X\n", tag1);
249
                goto fail;
250
            }
251
            url_fskip(pb, size - 12 * 4);
252
            break;
253
        case MKTAG('s', 't', 'r', 'f'):
254
            /* stream header */
255
            if (stream_index >= s->nb_streams || avi->dv_demux) {
256
                url_fskip(pb, size);
257
            } else {
258
                st = s->streams[stream_index];
259
                switch(codec_type) {
260
                case CODEC_TYPE_VIDEO:
261
                    get_le32(pb); /* size */
262
                    st->codec.width = get_le32(pb);
263
                    st->codec.height = get_le32(pb);
264
                    get_le16(pb); /* panes */
265
                    st->codec.bits_per_sample= get_le16(pb); /* depth */
266
                    tag1 = get_le32(pb);
267
                    get_le32(pb); /* ImageSize */
268
                    get_le32(pb); /* XPelsPerMeter */
269
                    get_le32(pb); /* YPelsPerMeter */
270
                    get_le32(pb); /* ClrUsed */
271
                    get_le32(pb); /* ClrImportant */
272

    
273
                 if(size > 10*4 && size<(1<<30)){
274
                    st->codec.extradata_size= size - 10*4;
275
                    st->codec.extradata= av_malloc(st->codec.extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
276
                    get_buffer(pb, st->codec.extradata, st->codec.extradata_size);
277
                 }
278
                    
279
                    if(st->codec.extradata_size & 1) //FIXME check if the encoder really did this correctly
280
                        get_byte(pb);
281

    
282
                    /* Extract palette from extradata if bpp <= 8 */
283
                    /* This code assumes that extradata contains only palette */
284
                    /* This is true for all paletted codecs implemented in ffmpeg */
285
                    if (st->codec.extradata_size && (st->codec.bits_per_sample <= 8)) {
286
                        st->codec.palctrl = av_mallocz(sizeof(AVPaletteControl));
287
#ifdef WORDS_BIGENDIAN
288
                        for (i = 0; i < FFMIN(st->codec.extradata_size, AVPALETTE_SIZE)/4; i++)
289
                            st->codec.palctrl->palette[i] = bswap_32(((uint32_t*)st->codec.extradata)[i]);
290
#else
291
                        memcpy(st->codec.palctrl->palette, st->codec.extradata,
292
                               FFMIN(st->codec.extradata_size, AVPALETTE_SIZE));
293
#endif
294
                        st->codec.palctrl->palette_changed = 1;
295
                    }
296

    
297
#ifdef DEBUG
298
                    print_tag("video", tag1, 0);
299
#endif
300
                    st->codec.codec_type = CODEC_TYPE_VIDEO;
301
                    st->codec.codec_tag = tag1;
302
                    st->codec.codec_id = codec_get_id(codec_bmp_tags, tag1);
303
                    if (st->codec.codec_id == CODEC_ID_XAN_WC4)
304
                        xan_video = 1;
305
//                    url_fskip(pb, size - 5 * 4);
306
                    break;
307
                case CODEC_TYPE_AUDIO:
308
                    get_wav_header(pb, &st->codec, size);
309
                    if (size%2) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
310
                        url_fskip(pb, 1);
311
                    /* special case time: To support Xan DPCM, hardcode
312
                     * the format if Xxan is the video codec */
313
                    st->need_parsing = 1;
314
                    /* force parsing as several audio frames can be in
315
                       one packet */
316
                    if (xan_video)
317
                        st->codec.codec_id = CODEC_ID_XAN_DPCM;
318
                    break;
319
                default:
320
                    st->codec.codec_type = CODEC_TYPE_DATA;
321
                    st->codec.codec_id= CODEC_ID_NONE;
322
                    st->codec.codec_tag= 0;
323
                    url_fskip(pb, size);
324
                    break;
325
                }
326
            }
327
            break;
328
        default:
329
            /* skip tag */
330
            size += (size & 1);
331
            url_fskip(pb, size);
332
            break;
333
        }
334
    }
335
 end_of_header:
336
    /* check stream number */
337
    if (stream_index != s->nb_streams - 1) {
338
    fail:
339
        for(i=0;i<s->nb_streams;i++) {
340
            av_freep(&s->streams[i]->codec.extradata);
341
            av_freep(&s->streams[i]);
342
        }
343
        return -1;
344
    }
345

    
346
    assert(!avi->index_loaded);
347
    avi_load_index(s);
348
    avi->index_loaded = 1;
349
 
350
    return 0;
351
}
352

    
353
static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
354
{
355
    AVIContext *avi = s->priv_data;
356
    ByteIOContext *pb = &s->pb;
357
    int n, d[8], size;
358
    offset_t i, sync;
359
    void* dstr;
360
   
361
    if (avi->dv_demux) {
362
        size = dv_get_packet(avi->dv_demux, pkt);
363
        if (size >= 0)
364
            return size;
365
    }
366
    
367
    if(avi->non_interleaved){
368
        int best_stream_index;
369
        AVStream *best_st= NULL;
370
        AVIStream *best_ast;
371
        int64_t best_ts= INT64_MAX;
372
        int i;
373
        
374
        for(i=0; i<s->nb_streams; i++){
375
            AVStream *st = s->streams[i];
376
            AVIStream *ast = st->priv_data;
377
            int64_t ts= ast->frame_offset;
378

    
379
            if(ast->sample_size)
380
                ts /= ast->sample_size;
381
            ts= av_rescale(ts, AV_TIME_BASE * (int64_t)st->time_base.num, st->time_base.den);
382

    
383
//            av_log(NULL, AV_LOG_DEBUG, "%Ld %d/%d %Ld\n", ts, st->time_base.num, st->time_base.den, ast->frame_offset);
384
            if(ts < best_ts){
385
                best_ts= ts;
386
                best_st= st;
387
                best_stream_index= i;
388
            }
389
        }
390
        best_ast = best_st->priv_data;
391
        best_ts= av_rescale(best_ts, best_st->time_base.den, AV_TIME_BASE * (int64_t)best_st->time_base.num); //FIXME a little ugly
392
        if(best_ast->remaining)
393
            i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
394
        else
395
            i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
396

    
397
//        av_log(NULL, AV_LOG_DEBUG, "%d\n", i);
398
        if(i>=0){
399
            int64_t pos= best_st->index_entries[i].pos;
400
            pos += avi->movi_list + best_ast->packet_size - best_ast->remaining;
401
            url_fseek(&s->pb, pos, SEEK_SET);
402
//        av_log(NULL, AV_LOG_DEBUG, "pos=%Ld\n", pos);
403
            
404
            if(best_ast->remaining)
405
                avi->stream_index= best_stream_index;
406
            else
407
                avi->stream_index= -1;
408
        }
409
    }
410
    
411
resync:
412
    if(avi->stream_index >= 0){
413
        AVStream *st= s->streams[ avi->stream_index ];
414
        AVIStream *ast= st->priv_data;
415
        int size;
416
        
417
        if(ast->sample_size == 0)
418
            size= INT_MAX;
419
        else if(ast->sample_size < 32) 
420
            size= 64*ast->sample_size;
421
        else
422
            size= ast->sample_size;
423

    
424
        if(size > ast->remaining)
425
            size= ast->remaining;
426
        av_new_packet(pkt, size);
427
        get_buffer(pb, pkt->data, size);
428
        
429
        if (avi->dv_demux) {
430
            dstr = pkt->destruct;
431
            size = dv_produce_packet(avi->dv_demux, pkt,
432
                                    pkt->data, pkt->size);
433
            pkt->destruct = dstr;
434
            pkt->flags |= PKT_FLAG_KEY;
435
        } else {
436
            /* XXX: how to handle B frames in avi ? */
437
            pkt->dts = ast->frame_offset;
438
//                pkt->dts += ast->start;
439
            if(ast->sample_size)
440
                pkt->dts /= ast->sample_size;
441
//av_log(NULL, AV_LOG_DEBUG, "dts:%Ld offset:%d %d/%d smpl_siz:%d base:%d st:%d size:%d\n", pkt->dts, ast->frame_offset, ast->scale, ast->rate, ast->sample_size, AV_TIME_BASE, n, size);
442
            pkt->stream_index = avi->stream_index;
443

    
444
            if (st->codec.codec_type == CODEC_TYPE_VIDEO) {
445
                if(st->index_entries){
446
                    AVIndexEntry *e;
447
                    int index;
448

    
449
                    index= av_index_search_timestamp(st, pkt->dts, 0);
450
                    e= &st->index_entries[index];
451
                    
452
                    if(index >= 0 && e->timestamp == ast->frame_offset){
453
                        if (e->flags & AVINDEX_KEYFRAME)
454
                            pkt->flags |= PKT_FLAG_KEY;
455
                    }
456
                } else {
457
                    /* if no index, better to say that all frames
458
                        are key frames */
459
                    pkt->flags |= PKT_FLAG_KEY;
460
                }
461
            } else {
462
                pkt->flags |= PKT_FLAG_KEY; 
463
            }
464
            if(ast->sample_size)
465
                ast->frame_offset += pkt->size;
466
            else
467
                ast->frame_offset++;
468
        }
469
        ast->remaining -= size;
470
        if(!ast->remaining){
471
            avi->stream_index= -1;
472
            ast->packet_size= 0;
473
            if (size & 1) {
474
                get_byte(pb);
475
                size++;
476
            }
477
        }
478

    
479
        return size;
480
    }
481

    
482
    memset(d, -1, sizeof(int)*8);
483
    for(i=sync=url_ftell(pb); !url_feof(pb); i++) {
484
        int j;
485

    
486
        if (i >= avi->movi_end) {
487
            if (avi->is_odml) {
488
                url_fskip(pb, avi->riff_end - i);
489
                avi->riff_end = avi->movi_end = url_filesize(url_fileno(pb));
490
            } else
491
                break;
492
        }
493

    
494
        for(j=0; j<7; j++)
495
            d[j]= d[j+1];
496
        d[7]= get_byte(pb);
497
        
498
        size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
499
        
500
        if(    d[2] >= '0' && d[2] <= '9'
501
            && d[3] >= '0' && d[3] <= '9'){
502
            n= (d[2] - '0') * 10 + (d[3] - '0');
503
        }else{
504
            n= 100; //invalid stream id
505
        }
506
//av_log(NULL, AV_LOG_DEBUG, "%X %X %X %X %X %X %X %X %lld %d %d\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);
507
        if(i + size > avi->movi_end || d[0]<0)
508
            continue;
509
        
510
        //parse ix##
511
        if(  (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
512
        //parse JUNK
513
           ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')){
514
            url_fskip(pb, size);
515
//av_log(NULL, AV_LOG_DEBUG, "SKIP\n");
516
            goto resync;
517
        }
518

    
519
        if(    d[0] >= '0' && d[0] <= '9'
520
            && d[1] >= '0' && d[1] <= '9'){
521
            n= (d[0] - '0') * 10 + (d[1] - '0');
522
        }else{
523
            n= 100; //invalid stream id
524
        }
525
        
526
        //parse ##dc/##wb
527
        if(n < s->nb_streams){
528
          AVStream *st;
529
          AVIStream *ast;
530
          st = s->streams[n];
531
          ast = st->priv_data;
532
          
533
          if(   (st->discard >= AVDISCARD_DEFAULT && size==0)
534
             /*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & PKT_FLAG_KEY))*/ //FIXME needs a little reordering
535
             || st->discard >= AVDISCARD_ALL){
536
                if(ast->sample_size) ast->frame_offset += pkt->size;
537
                else                 ast->frame_offset++;
538
                url_fskip(pb, size);
539
                goto resync;
540
          }
541

    
542
          if(   ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) || 
543
                d[2]*256+d[3] == ast->prefix /*||
544
                (d[2] == 'd' && d[3] == 'c') || 
545
                (d[2] == 'w' && d[3] == 'b')*/) {
546

    
547
//av_log(NULL, AV_LOG_DEBUG, "OK\n");
548
            if(d[2]*256+d[3] == ast->prefix)
549
                ast->prefix_count++;
550
            else{
551
                ast->prefix= d[2]*256+d[3];
552
                ast->prefix_count= 0;
553
            }
554

    
555
            avi->stream_index= n;
556
            ast->packet_size= size + 8;
557
            ast->remaining= size;
558
            goto resync;
559
          }
560
        }
561
        /* palette changed chunk */
562
        if (   d[0] >= '0' && d[0] <= '9'
563
            && d[1] >= '0' && d[1] <= '9'
564
            && ((d[2] == 'p' && d[3] == 'c'))
565
            && n < s->nb_streams && i + size <= avi->movi_end) {
566

    
567
            AVStream *st;
568
            int first, clr, flags, k, p;
569

    
570
            st = s->streams[n];
571

    
572
            first = get_byte(pb);
573
            clr = get_byte(pb);
574
            if(!clr) /* all 256 colors used */
575
                clr = 256;
576
            flags = get_le16(pb);
577
            p = 4;
578
            for (k = first; k < clr + first; k++) {
579
                int r, g, b;
580
                r = get_byte(pb);
581
                g = get_byte(pb);
582
                b = get_byte(pb);
583
                    get_byte(pb);
584
                st->codec.palctrl->palette[k] = b + (g << 8) + (r << 16);
585
            }
586
            st->codec.palctrl->palette_changed = 1;
587
            goto resync;
588
        }
589

    
590
    }
591

    
592
    return -1;
593
}
594

    
595
/* XXX: we make the implicit supposition that the position are sorted
596
   for each stream */
597
static int avi_read_idx1(AVFormatContext *s, int size)
598
{
599
    AVIContext *avi = s->priv_data;
600
    ByteIOContext *pb = &s->pb;
601
    int nb_index_entries, i;
602
    AVStream *st;
603
    AVIStream *ast;
604
    unsigned int index, tag, flags, pos, len;
605
    unsigned last_pos= -1;
606
    
607
    nb_index_entries = size / 16;
608
    if (nb_index_entries <= 0)
609
        return -1;
610

    
611
    /* read the entries and sort them in each stream component */
612
    for(i = 0; i < nb_index_entries; i++) {
613
        tag = get_le32(pb);
614
        flags = get_le32(pb);
615
        pos = get_le32(pb);
616
        len = get_le32(pb);
617
#if defined(DEBUG_SEEK)
618
        av_log(NULL, AV_LOG_DEBUG, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/", 
619
               i, tag, flags, pos, len);
620
#endif
621
        if(i==0 && pos > avi->movi_list)
622
            avi->movi_list= 0; //FIXME better check
623

    
624
        index = ((tag & 0xff) - '0') * 10;
625
        index += ((tag >> 8) & 0xff) - '0';
626
        if (index >= s->nb_streams)
627
            continue;
628
        st = s->streams[index];
629
        ast = st->priv_data;
630
        
631
#if defined(DEBUG_SEEK)
632
        av_log(NULL, AV_LOG_DEBUG, "%d cum_len=%d\n", len, ast->cum_len);
633
#endif
634
        if(last_pos == pos)
635
            avi->non_interleaved= 1;
636
        else
637
            av_add_index_entry(st, pos, ast->cum_len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
638
        if(ast->sample_size)
639
            ast->cum_len += len / ast->sample_size;
640
        else
641
            ast->cum_len ++;
642
        last_pos= pos;
643
    }
644
    return 0;
645
}
646

    
647
static int guess_ni_flag(AVFormatContext *s){
648
    AVIContext *avi = s->priv_data;
649
    int i;
650
    int64_t last_start=0;
651
    int64_t first_end= INT64_MAX;
652
    
653
    for(i=0; i<s->nb_streams; i++){
654
        AVStream *st = s->streams[i];
655
        AVIStream *ast = st->priv_data;
656
        int n= st->nb_index_entries;
657

    
658
        if(n <= 0)
659
            continue;
660

    
661
        if(st->index_entries[0].pos > last_start)
662
            last_start= st->index_entries[0].pos;
663
        if(st->index_entries[n-1].pos < first_end)
664
            first_end= st->index_entries[n-1].pos;
665
    }
666
    return last_start > first_end;
667
}
668

    
669
static int avi_load_index(AVFormatContext *s)
670
{
671
    AVIContext *avi = s->priv_data;
672
    ByteIOContext *pb = &s->pb;
673
    uint32_t tag, size;
674
    offset_t pos= url_ftell(pb);
675
    
676
    url_fseek(pb, avi->movi_end, SEEK_SET);
677
#ifdef DEBUG_SEEK
678
    printf("movi_end=0x%llx\n", avi->movi_end);
679
#endif
680
    for(;;) {
681
        if (url_feof(pb))
682
            break;
683
        tag = get_le32(pb);
684
        size = get_le32(pb);
685
#ifdef DEBUG_SEEK
686
        printf("tag=%c%c%c%c size=0x%x\n",
687
               tag & 0xff,
688
               (tag >> 8) & 0xff,
689
               (tag >> 16) & 0xff,
690
               (tag >> 24) & 0xff,
691
               size);
692
#endif
693
        switch(tag) {
694
        case MKTAG('i', 'd', 'x', '1'):
695
            if (avi_read_idx1(s, size) < 0)
696
                goto skip;
697
            else
698
                goto the_end;
699
            break;
700
        default:
701
        skip:
702
            size += (size & 1);
703
            url_fskip(pb, size);
704
            break;
705
        }
706
    }
707
 the_end:
708
    avi->non_interleaved |= guess_ni_flag(s);
709
    url_fseek(pb, pos, SEEK_SET);
710
    return 0;
711
}
712

    
713
static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
714
{
715
    AVIContext *avi = s->priv_data;
716
    AVStream *st;
717
    int i, index;
718
    int64_t pos;
719

    
720
    if (!avi->index_loaded) {
721
        /* we only load the index on demand */
722
        avi_load_index(s);
723
        avi->index_loaded = 1;
724
    }
725
    assert(stream_index>= 0);
726

    
727
    st = s->streams[stream_index];
728
    index= av_index_search_timestamp(st, timestamp, flags);
729
    if(index<0)
730
        return -1;
731
    
732
    /* find the position */
733
    pos = st->index_entries[index].pos;
734
    timestamp = st->index_entries[index].timestamp;
735

    
736
//    av_log(NULL, AV_LOG_DEBUG, "XX %Ld %d %Ld\n", timestamp, index, st->index_entries[index].timestamp);
737

    
738
    for(i = 0; i < s->nb_streams; i++) {
739
        AVStream *st2 = s->streams[i];
740
        AVIStream *ast2 = st2->priv_data;
741

    
742
        ast2->packet_size=
743
        ast2->remaining= 0;
744

    
745
        if (st2->nb_index_entries <= 0)
746
            continue;
747
        
748
//        assert(st2->codec.block_align);
749
        assert(st2->time_base.den == ast2->rate);
750
        assert(st2->time_base.num == ast2->scale);
751
        index = av_index_search_timestamp(
752
                st2, 
753
                av_rescale(timestamp, st2->time_base.den*(int64_t)st->time_base.num, st->time_base.den * (int64_t)st2->time_base.num),
754
                flags | AVSEEK_FLAG_BACKWARD);
755
        if(index<0)
756
            index=0;
757
        
758
        if(!avi->non_interleaved){
759
            while(index>0 && st2->index_entries[index].pos > pos)
760
                index--;
761
            while(index+1 < st2->nb_index_entries && st2->index_entries[index].pos < pos)
762
                index++;
763
        }
764

    
765
//        av_log(NULL, AV_LOG_DEBUG, "%Ld %d %Ld\n", timestamp, index, st2->index_entries[index].timestamp);
766
        /* extract the current frame number */
767
        ast2->frame_offset = st2->index_entries[index].timestamp;
768
        if(ast2->sample_size)
769
            ast2->frame_offset *=ast2->sample_size;
770
    }
771

    
772
    if (avi->dv_demux)
773
        dv_flush_audio_packets(avi->dv_demux);
774
    /* do the seek */
775
    pos += avi->movi_list;
776
    url_fseek(&s->pb, pos, SEEK_SET);
777
    avi->stream_index= -1;
778
    return 0;
779
}
780

    
781
static int avi_read_close(AVFormatContext *s)
782
{
783
    int i;
784
    AVIContext *avi = s->priv_data;
785

    
786
    for(i=0;i<s->nb_streams;i++) {
787
        AVStream *st = s->streams[i];
788
        AVIStream *ast = st->priv_data;
789
        av_free(ast);
790
        av_free(st->codec.extradata);
791
        av_free(st->codec.palctrl);
792
    }
793

    
794
    if (avi->dv_demux)
795
        av_free(avi->dv_demux);
796

    
797
    return 0;
798
}
799

    
800
static int avi_probe(AVProbeData *p)
801
{
802
    /* check file header */
803
    if (p->buf_size <= 32)
804
        return 0;
805
    if (p->buf[0] == 'R' && p->buf[1] == 'I' &&
806
        p->buf[2] == 'F' && p->buf[3] == 'F' &&
807
        p->buf[8] == 'A' && p->buf[9] == 'V' &&
808
        p->buf[10] == 'I' && p->buf[11] == ' ')
809
        return AVPROBE_SCORE_MAX;
810
    else
811
        return 0;
812
}
813

    
814
static AVInputFormat avi_iformat = {
815
    "avi",
816
    "avi format",
817
    sizeof(AVIContext),
818
    avi_probe,
819
    avi_read_header,
820
    avi_read_packet,
821
    avi_read_close,
822
    avi_read_seek,
823
};
824

    
825
int avidec_init(void)
826
{
827
    av_register_input_format(&avi_iformat);
828
    return 0;
829
}