100l (forgoten seeking functions)
[libav.git] / libavformat / avidec.c
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 //#define DEBUG
24 //#define DEBUG_SEEK
25
26 typedef struct AVIIndexEntry {
27 unsigned int flags;
28 unsigned int pos;
29 unsigned int cum_len; /* sum of all lengths before this packet */
30 } AVIIndexEntry;
31
32 typedef struct AVIStream {
33 AVIIndexEntry *index_entries;
34 int nb_index_entries;
35 int index_entries_allocated_size;
36 int frame_offset; /* current frame (video) or byte (audio) counter
37 (used to compute the pts) */
38 int scale;
39 int rate;
40 int sample_size; /* audio only data */
41 int start;
42
43 int new_frame_offset; /* temporary storage (used during seek) */
44 int cum_len; /* temporary storage (used during seek) */
45
46 int prefix; ///< normally 'd'<<8 + 'c' or 'w'<<8 + 'b'
47 int prefix_count;
48 } AVIStream;
49
50 typedef struct {
51 int64_t riff_end;
52 int64_t movi_end;
53 offset_t movi_list;
54 int index_loaded;
55 int is_odml;
56 DVDemuxContext* dv_demux;
57 } AVIContext;
58
59 static int avi_load_index(AVFormatContext *s);
60
61 #ifdef DEBUG
62 static void print_tag(const char *str, unsigned int tag, int size)
63 {
64 printf("%s: tag=%c%c%c%c size=0x%x\n",
65 str, tag & 0xff,
66 (tag >> 8) & 0xff,
67 (tag >> 16) & 0xff,
68 (tag >> 24) & 0xff,
69 size);
70 }
71 #endif
72
73 static int get_riff(AVIContext *avi, ByteIOContext *pb)
74 {
75 uint32_t tag;
76 /* check RIFF header */
77 tag = get_le32(pb);
78
79 if (tag != MKTAG('R', 'I', 'F', 'F'))
80 return -1;
81 avi->riff_end = get_le32(pb); /* RIFF chunk size */
82 avi->riff_end += url_ftell(pb); /* RIFF chunk end */
83 tag = get_le32(pb);
84 if (tag != MKTAG('A', 'V', 'I', ' ') && tag != MKTAG('A', 'V', 'I', 'X'))
85 return -1;
86
87 return 0;
88 }
89
90 static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
91 {
92 AVIContext *avi = s->priv_data;
93 ByteIOContext *pb = &s->pb;
94 uint32_t tag, tag1, handler;
95 int codec_type, stream_index, frame_period, bit_rate, scale, rate;
96 unsigned int size, nb_frames;
97 int i, n;
98 AVStream *st;
99 AVIStream *ast;
100 int xan_video = 0; /* hack to support Xan A/V */
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 switch(tag1) {
168 case MKTAG('i', 'a', 'v', 's'):
169 case MKTAG('i', 'v', 'a', 's'):
170 /*
171 * After some consideration -- I don't think we
172 * have to support anything but DV in a type1 AVIs.
173 */
174 if (s->nb_streams != 1)
175 goto fail;
176
177 if (handler != MKTAG('d', 'v', 's', 'd') &&
178 handler != MKTAG('d', 'v', 'h', 'd') &&
179 handler != MKTAG('d', 'v', 's', 'l'))
180 goto fail;
181
182 ast = s->streams[0]->priv_data;
183 av_freep(&s->streams[0]->codec.extradata);
184 av_freep(&s->streams[0]);
185 s->nb_streams = 0;
186 avi->dv_demux = dv_init_demux(s);
187 if (!avi->dv_demux)
188 goto fail;
189 s->streams[0]->priv_data = ast;
190 url_fskip(pb, 3 * 4);
191 ast->scale = get_le32(pb);
192 ast->rate = get_le32(pb);
193 stream_index = s->nb_streams - 1;
194 url_fskip(pb, size - 7*4);
195 break;
196 case MKTAG('v', 'i', 'd', 's'):
197 codec_type = CODEC_TYPE_VIDEO;
198
199 if (stream_index >= s->nb_streams) {
200 url_fskip(pb, size - 8);
201 break;
202 }
203
204 st = s->streams[stream_index];
205 ast = st->priv_data;
206 st->codec.stream_codec_tag= handler;
207
208 get_le32(pb); /* flags */
209 get_le16(pb); /* priority */
210 get_le16(pb); /* language */
211 get_le32(pb); /* XXX: initial frame ? */
212 scale = get_le32(pb); /* scale */
213 rate = get_le32(pb); /* rate */
214
215 if(scale && rate){
216 }else if(frame_period){
217 rate = 1000000;
218 scale = frame_period;
219 }else{
220 rate = 25;
221 scale = 1;
222 }
223 ast->rate = rate;
224 ast->scale = scale;
225 av_set_pts_info(st, 64, scale, rate);
226 st->codec.frame_rate = rate;
227 st->codec.frame_rate_base = scale;
228 get_le32(pb); /* start */
229 nb_frames = get_le32(pb);
230 st->start_time = 0;
231 st->duration = av_rescale(nb_frames,
232 st->codec.frame_rate_base * AV_TIME_BASE,
233 st->codec.frame_rate);
234 url_fskip(pb, size - 9 * 4);
235 break;
236 case MKTAG('a', 'u', 'd', 's'):
237 {
238 unsigned int length;
239
240 codec_type = CODEC_TYPE_AUDIO;
241
242 if (stream_index >= s->nb_streams) {
243 url_fskip(pb, size - 8);
244 break;
245 }
246 st = s->streams[stream_index];
247 ast = st->priv_data;
248
249 get_le32(pb); /* flags */
250 get_le16(pb); /* priority */
251 get_le16(pb); /* language */
252 get_le32(pb); /* initial frame */
253 ast->scale = get_le32(pb); /* scale */
254 ast->rate = get_le32(pb);
255 av_set_pts_info(st, 64, ast->scale, ast->rate);
256 ast->start= get_le32(pb); /* start */
257 length = get_le32(pb); /* length, in samples or bytes */
258 get_le32(pb); /* buffer size */
259 get_le32(pb); /* quality */
260 ast->sample_size = get_le32(pb); /* sample ssize */
261 //av_log(NULL, AV_LOG_DEBUG, "%d %d %d %d\n", ast->scale, ast->rate, ast->sample_size, ast->start);
262 st->start_time = 0;
263 if (ast->rate != 0)
264 st->duration = (int64_t)length * AV_TIME_BASE / ast->rate;
265 url_fskip(pb, size - 12 * 4);
266 }
267 break;
268 case MKTAG('t', 'x', 't', 's'):
269 //FIXME
270 codec_type = CODEC_TYPE_DATA; //CODEC_TYPE_SUB ? FIXME
271 url_fskip(pb, size - 8);
272 break;
273 case MKTAG('p', 'a', 'd', 's'):
274 codec_type = CODEC_TYPE_UNKNOWN;
275 url_fskip(pb, size - 8);
276 stream_index--;
277 break;
278 default:
279 av_log(s, AV_LOG_ERROR, "unknown stream type %X\n", tag1);
280 goto fail;
281 }
282 break;
283 case MKTAG('s', 't', 'r', 'f'):
284 /* stream header */
285 if (stream_index >= s->nb_streams || avi->dv_demux) {
286 url_fskip(pb, size);
287 } else {
288 st = s->streams[stream_index];
289 switch(codec_type) {
290 case CODEC_TYPE_VIDEO:
291 get_le32(pb); /* size */
292 st->codec.width = get_le32(pb);
293 st->codec.height = get_le32(pb);
294 get_le16(pb); /* panes */
295 st->codec.bits_per_sample= get_le16(pb); /* depth */
296 tag1 = get_le32(pb);
297 get_le32(pb); /* ImageSize */
298 get_le32(pb); /* XPelsPerMeter */
299 get_le32(pb); /* YPelsPerMeter */
300 get_le32(pb); /* ClrUsed */
301 get_le32(pb); /* ClrImportant */
302
303 st->codec.extradata_size= size - 10*4;
304 st->codec.extradata= av_malloc(st->codec.extradata_size);
305 get_buffer(pb, st->codec.extradata, st->codec.extradata_size);
306
307 if(st->codec.extradata_size & 1) //FIXME check if the encoder really did this correctly
308 get_byte(pb);
309
310 /* Extract palette from extradata if bpp <= 8 */
311 /* This code assumes that extradata contains only palette */
312 /* This is true for all paletted codecs implemented in ffmpeg */
313 if (st->codec.extradata_size && (st->codec.bits_per_sample <= 8)) {
314 st->codec.palctrl = av_mallocz(sizeof(AVPaletteControl));
315 #ifdef WORDS_BIGENDIAN
316 for (i = 0; i < FFMIN(st->codec.extradata_size, AVPALETTE_SIZE)/4; i++)
317 st->codec.palctrl->palette[i] = bswap_32(((uint32_t*)st->codec.extradata)[i]);
318 #else
319 memcpy(st->codec.palctrl->palette, st->codec.extradata,
320 FFMIN(st->codec.extradata_size, AVPALETTE_SIZE));
321 #endif
322 st->codec.palctrl->palette_changed = 1;
323 }
324
325 #ifdef DEBUG
326 print_tag("video", tag1, 0);
327 #endif
328 st->codec.codec_type = CODEC_TYPE_VIDEO;
329 st->codec.codec_tag = tag1;
330 st->codec.codec_id = codec_get_id(codec_bmp_tags, tag1);
331 if (st->codec.codec_id == CODEC_ID_XAN_WC4)
332 xan_video = 1;
333 // url_fskip(pb, size - 5 * 4);
334 break;
335 case CODEC_TYPE_AUDIO:
336 get_wav_header(pb, &st->codec, size);
337 if (size%2) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
338 url_fskip(pb, 1);
339 /* special case time: To support Xan DPCM, hardcode
340 * the format if Xxan is the video codec */
341 st->need_parsing = 1;
342 /* force parsing as several audio frames can be in
343 one packet */
344 if (xan_video)
345 st->codec.codec_id = CODEC_ID_XAN_DPCM;
346 break;
347 default:
348 st->codec.codec_type = CODEC_TYPE_DATA;
349 st->codec.codec_id= CODEC_ID_NONE;
350 st->codec.codec_tag= 0;
351 url_fskip(pb, size);
352 break;
353 }
354 }
355 break;
356 default:
357 /* skip tag */
358 size += (size & 1);
359 url_fskip(pb, size);
360 break;
361 }
362 }
363 end_of_header:
364 /* check stream number */
365 if (stream_index != s->nb_streams - 1) {
366 fail:
367 for(i=0;i<s->nb_streams;i++) {
368 av_freep(&s->streams[i]->codec.extradata);
369 av_freep(&s->streams[i]);
370 }
371 return -1;
372 }
373
374 assert(!avi->index_loaded);
375 avi_load_index(s);
376 avi->index_loaded = 1;
377
378 return 0;
379 }
380
381 static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
382 {
383 AVIContext *avi = s->priv_data;
384 ByteIOContext *pb = &s->pb;
385 int n, d[8], size;
386 offset_t i;
387 void* dstr;
388
389 memset(d, -1, sizeof(int)*8);
390
391 if (avi->dv_demux) {
392 size = dv_get_packet(avi->dv_demux, pkt);
393 if (size >= 0)
394 return size;
395 }
396
397 for(i=url_ftell(pb); !url_feof(pb); i++) {
398 int j;
399
400 if (i >= avi->movi_end) {
401 if (avi->is_odml) {
402 url_fskip(pb, avi->riff_end - i);
403 avi->riff_end = avi->movi_end = url_filesize(url_fileno(pb));
404 } else
405 break;
406 }
407
408 for(j=0; j<7; j++)
409 d[j]= d[j+1];
410 d[7]= get_byte(pb);
411
412 size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
413
414 if( d[2] >= '0' && d[2] <= '9'
415 && d[3] >= '0' && d[3] <= '9'){
416 n= (d[2] - '0') * 10 + (d[3] - '0');
417 }else{
418 n= 100; //invalid stream id
419 }
420 //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);
421 if(i + size > avi->movi_end || d[0]<0)
422 continue;
423
424 //parse ix##
425 if( (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
426 //parse JUNK
427 ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')){
428 url_fskip(pb, size);
429 i+= size;
430 memset(d, -1, sizeof(int)*8);
431 //av_log(NULL, AV_LOG_DEBUG, "SKIP\n");
432 continue;
433 }
434
435 if( d[0] >= '0' && d[0] <= '9'
436 && d[1] >= '0' && d[1] <= '9'){
437 n= (d[0] - '0') * 10 + (d[1] - '0');
438 }else{
439 n= 100; //invalid stream id
440 }
441
442 //parse ##dc/##wb
443 if(n < s->nb_streams){
444 AVStream *st;
445 AVIStream *ast;
446 st = s->streams[n];
447 ast = st->priv_data;
448
449 if( (ast->prefix_count<5 && d[2]<128 && d[3]<128) ||
450 d[2]*256+d[3] == ast->prefix /*||
451 (d[2] == 'd' && d[3] == 'c') ||
452 (d[2] == 'w' && d[3] == 'b')*/) {
453
454 //av_log(NULL, AV_LOG_DEBUG, "OK\n");
455 if(d[2]*256+d[3] == ast->prefix)
456 ast->prefix_count++;
457 else{
458 ast->prefix= d[2]*256+d[3];
459 ast->prefix_count= 0;
460 }
461
462 av_new_packet(pkt, size);
463 get_buffer(pb, pkt->data, size);
464 if (size & 1) {
465 get_byte(pb);
466 size++;
467 }
468
469 if (avi->dv_demux) {
470 dstr = pkt->destruct;
471 size = dv_produce_packet(avi->dv_demux, pkt,
472 pkt->data, pkt->size);
473 pkt->destruct = dstr;
474 pkt->flags |= PKT_FLAG_KEY;
475 } else {
476 /* XXX: how to handle B frames in avi ? */
477 pkt->dts = ast->frame_offset;
478 // pkt->dts += ast->start;
479 if(ast->sample_size)
480 pkt->dts /= ast->sample_size;
481 //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);
482 pkt->stream_index = n;
483 /* FIXME: We really should read index for that */
484 if (st->codec.codec_type == CODEC_TYPE_VIDEO) {
485 if (ast->frame_offset < ast->nb_index_entries) {
486 if (ast->index_entries[ast->frame_offset].flags & AVIIF_INDEX)
487 pkt->flags |= PKT_FLAG_KEY;
488 } else {
489 /* if no index, better to say that all frames
490 are key frames */
491 pkt->flags |= PKT_FLAG_KEY;
492 }
493 } else {
494 pkt->flags |= PKT_FLAG_KEY;
495 }
496 if(ast->sample_size)
497 ast->frame_offset += pkt->size;
498 else
499 ast->frame_offset++;
500 }
501 return size;
502 }
503 }
504 /* palette changed chunk */
505 if ( d[0] >= '0' && d[0] <= '9'
506 && d[1] >= '0' && d[1] <= '9'
507 && ((d[2] == 'p' && d[3] == 'c'))
508 && n < s->nb_streams && i + size <= avi->movi_end) {
509
510 AVStream *st;
511 int first, clr, flags, k, p;
512
513 st = s->streams[n];
514
515 first = get_byte(pb);
516 clr = get_byte(pb);
517 flags = get_le16(pb);
518 p = 4;
519 for (k = first; k < clr + first; k++) {
520 int r, g, b;
521 r = get_byte(pb);
522 g = get_byte(pb);
523 b = get_byte(pb);
524 get_byte(pb);
525 st->codec.palctrl->palette[k] = b + (g << 8) + (r << 16);
526 }
527 st->codec.palctrl->palette_changed = 1;
528 }
529
530 }
531
532 return -1;
533 }
534
535 /* XXX: we make the implicit supposition that the position are sorted
536 for each stream */
537 static int avi_read_idx1(AVFormatContext *s, int size)
538 {
539 ByteIOContext *pb = &s->pb;
540 int nb_index_entries, i;
541 AVStream *st;
542 AVIStream *ast;
543 AVIIndexEntry *ie, *entries;
544 unsigned int index, tag, flags, pos, len;
545
546 nb_index_entries = size / 16;
547 if (nb_index_entries <= 0)
548 return -1;
549
550 /* read the entries and sort them in each stream component */
551 for(i = 0; i < nb_index_entries; i++) {
552 tag = get_le32(pb);
553 flags = get_le32(pb);
554 pos = get_le32(pb);
555 len = get_le32(pb);
556 #if defined(DEBUG_SEEK) && 0
557 printf("%d: tag=0x%x flags=0x%x pos=0x%x len=%d\n",
558 i, tag, flags, pos, len);
559 #endif
560 index = ((tag & 0xff) - '0') * 10;
561 index += ((tag >> 8) & 0xff) - '0';
562 if (index >= s->nb_streams)
563 continue;
564 st = s->streams[index];
565 ast = st->priv_data;
566
567 entries = av_fast_realloc(ast->index_entries,
568 &ast->index_entries_allocated_size,
569 (ast->nb_index_entries + 1) *
570 sizeof(AVIIndexEntry));
571 if (entries) {
572 ast->index_entries = entries;
573 ie = &entries[ast->nb_index_entries++];
574 ie->flags = flags;
575 ie->pos = pos;
576 ie->cum_len = ast->cum_len;
577 ast->cum_len += len;
578 }
579 }
580 return 0;
581 }
582
583 static int avi_load_index(AVFormatContext *s)
584 {
585 AVIContext *avi = s->priv_data;
586 ByteIOContext *pb = &s->pb;
587 uint32_t tag, size;
588 offset_t pos= url_ftell(pb);
589
590 url_fseek(pb, avi->movi_end, SEEK_SET);
591 #ifdef DEBUG_SEEK
592 printf("movi_end=0x%llx\n", avi->movi_end);
593 #endif
594 for(;;) {
595 if (url_feof(pb))
596 break;
597 tag = get_le32(pb);
598 size = get_le32(pb);
599 #ifdef DEBUG_SEEK
600 printf("tag=%c%c%c%c size=0x%x\n",
601 tag & 0xff,
602 (tag >> 8) & 0xff,
603 (tag >> 16) & 0xff,
604 (tag >> 24) & 0xff,
605 size);
606 #endif
607 switch(tag) {
608 case MKTAG('i', 'd', 'x', '1'):
609 if (avi_read_idx1(s, size) < 0)
610 goto skip;
611 else
612 goto the_end;
613 break;
614 default:
615 skip:
616 size += (size & 1);
617 url_fskip(pb, size);
618 break;
619 }
620 }
621 the_end:
622 url_fseek(pb, pos, SEEK_SET);
623 return 0;
624 }
625
626 /* return the index entry whose position is immediately >= 'wanted_pos' */
627 static int locate_frame_in_index(AVIIndexEntry *entries,
628 int nb_entries, int wanted_pos)
629 {
630 int a, b, m, pos;
631
632 a = 0;
633 b = nb_entries - 1;
634 while (a <= b) {
635 m = (a + b) >> 1;
636 pos = entries[m].pos;
637 if (pos == wanted_pos)
638 goto found;
639 else if (pos > wanted_pos) {
640 b = m - 1;
641 } else {
642 a = m + 1;
643 }
644 }
645 m = a;
646 if (m > 0)
647 m--;
648 found:
649 return m;
650 }
651
652 static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
653 {
654 AVIContext *avi = s->priv_data;
655 AVStream *st;
656 AVIStream *ast;
657 int frame_number, i;
658 int64_t pos;
659
660 if (!avi->index_loaded) {
661 /* we only load the index on demand */
662 avi_load_index(s);
663 avi->index_loaded = 1;
664 }
665 if (stream_index < 0) {
666 for(i = 0; i < s->nb_streams; i++) {
667 st = s->streams[i];
668 if (st->codec.codec_type == CODEC_TYPE_VIDEO)
669 goto found;
670 }
671 return -1;
672 found:
673 stream_index = i;
674 }
675
676 st = s->streams[stream_index];
677 if (st->codec.codec_type != CODEC_TYPE_VIDEO)
678 return -1;
679 ast = st->priv_data;
680 /* compute the frame number */
681 frame_number = timestamp;
682 #ifdef DEBUG_SEEK
683 printf("timestamp=%0.3f nb_indexes=%d frame_number=%d\n",
684 (double)timestamp / AV_TIME_BASE,
685 ast->nb_index_entries, frame_number);
686 #endif
687 /* find a closest key frame before */
688 if (frame_number >= ast->nb_index_entries)
689 return -1;
690 while (frame_number >= 0 &&
691 !(ast->index_entries[frame_number].flags & AVIIF_INDEX))
692 frame_number--;
693 if (frame_number < 0)
694 return -1;
695 ast->new_frame_offset = frame_number;
696
697 /* find the position */
698 pos = ast->index_entries[frame_number].pos;
699
700 #ifdef DEBUG_SEEK
701 printf("key_frame_number=%d pos=0x%llx\n",
702 frame_number, pos);
703 #endif
704
705 /* update the frame counters for all the other stream by looking
706 at the positions just after the one found */
707 for(i = 0; i < s->nb_streams; i++) {
708 int j;
709 if (i != stream_index) {
710 st = s->streams[i];
711 ast = st->priv_data;
712 if (ast->nb_index_entries <= 0)
713 return -1;
714 j = locate_frame_in_index(ast->index_entries,
715 ast->nb_index_entries,
716 pos);
717 /* get next frame */
718 if ((j + 1) < ast->nb_index_entries)
719 j++;
720 /* extract the current frame number */
721 if (ast->sample_size==0)
722 ast->new_frame_offset = j;
723 else
724 ast->new_frame_offset = ast->index_entries[j].cum_len;
725 }
726 }
727
728 /* everything is OK now. We can update the frame offsets */
729 for(i = 0; i < s->nb_streams; i++) {
730 st = s->streams[i];
731 ast = st->priv_data;
732 ast->frame_offset = ast->new_frame_offset;
733 #ifdef DEBUG_SEEK
734 printf("%d: frame_offset=%d\n", i,
735 ast->frame_offset);
736 #endif
737 }
738 /* do the seek */
739 pos += avi->movi_list;
740 url_fseek(&s->pb, pos, SEEK_SET);
741 return 0;
742 }
743
744 static int avi_read_close(AVFormatContext *s)
745 {
746 int i;
747 AVIContext *avi = s->priv_data;
748
749 for(i=0;i<s->nb_streams;i++) {
750 AVStream *st = s->streams[i];
751 AVIStream *ast = st->priv_data;
752 if(ast){
753 av_free(ast->index_entries);
754 av_free(ast);
755 }
756 av_free(st->codec.extradata);
757 av_free(st->codec.palctrl);
758 }
759
760 if (avi->dv_demux)
761 av_free(avi->dv_demux);
762
763 return 0;
764 }
765
766 static int avi_probe(AVProbeData *p)
767 {
768 /* check file header */
769 if (p->buf_size <= 32)
770 return 0;
771 if (p->buf[0] == 'R' && p->buf[1] == 'I' &&
772 p->buf[2] == 'F' && p->buf[3] == 'F' &&
773 p->buf[8] == 'A' && p->buf[9] == 'V' &&
774 p->buf[10] == 'I' && p->buf[11] == ' ')
775 return AVPROBE_SCORE_MAX;
776 else
777 return 0;
778 }
779
780 static AVInputFormat avi_iformat = {
781 "avi",
782 "avi format",
783 sizeof(AVIContext),
784 avi_probe,
785 avi_read_header,
786 avi_read_packet,
787 avi_read_close,
788 avi_read_seek,
789 };
790
791 int avidec_init(void)
792 {
793 av_register_input_format(&avi_iformat);
794 return 0;
795 }