3 * Copyright (c) 2001 Fabrice Bellard.
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.
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.
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
30 typedef struct AVIStream {
31 int64_t frame_offset; /* current frame (video) or byte (audio) counter
32 (used to compute the pts) */
38 int sample_size; /* size of one sample (or packet) (in the rate/scale sense) in bytes */
40 int64_t cum_len; /* temporary storage (used during seek) */
42 int prefix; ///< normally 'd'<<8 + 'c' or 'w'<<8 + 'b'
54 DVDemuxContext* dv_demux;
57 static int avi_load_index(AVFormatContext *s);
58 static int guess_ni_flag(AVFormatContext *s);
61 static void print_tag(const char *str, unsigned int tag, int size)
63 printf("%s: tag=%c%c%c%c size=0x%x\n",
72 static int get_riff(AVIContext *avi, ByteIOContext *pb)
75 /* check RIFF header */
78 if (tag != MKTAG('R', 'I', 'F', 'F'))
80 avi->riff_end = get_le32(pb); /* RIFF chunk size */
81 avi->riff_end += url_ftell(pb); /* RIFF chunk end */
83 if (tag != MKTAG('A', 'V', 'I', ' ') && tag != MKTAG('A', 'V', 'I', 'X'))
89 static int read_braindead_odml_indx(AVFormatContext *s, int frame_num){
90 AVIContext *avi = s->priv_data;
91 ByteIOContext *pb = &s->pb;
92 int longs_pre_entry= get_le16(pb);
93 int index_sub_type = get_byte(pb);
94 int index_type = get_byte(pb);
95 int entries_in_use = get_le32(pb);
96 int chunk_id = get_le32(pb);
97 int64_t base = get_le64(pb);
98 int stream_id= 10*((chunk_id&0xFF) - '0') + (((chunk_id>>8)&0xFF) - '0');
102 int64_t last_pos= -1;
104 // av_log(s, AV_LOG_ERROR, "longs_pre_entry:%d index_type:%d entries_in_use:%d chunk_id:%X base:%Ld\n",
105 // longs_pre_entry,index_type, entries_in_use, chunk_id, base);
107 if(stream_id > s->nb_streams || stream_id < 0)
109 st= s->streams[stream_id];
117 if(index_type && longs_pre_entry != 2)
122 for(i=0; i<entries_in_use; i++){
124 int64_t pos= get_le32(pb) + base - 8;
125 int len = get_le32(pb);
129 //av_log(s, AV_LOG_ERROR, "pos:%Ld, len:%X\n", pos, len);
130 if(last_pos == pos || pos == base - 8)
131 avi->non_interleaved= 1;
133 av_add_index_entry(st, pos, ast->cum_len, len, 0, key ? AVINDEX_KEYFRAME : 0);
136 ast->cum_len += len / ast->sample_size;
143 offset = get_le64(pb);
144 get_le32(pb); /* size */
145 duration = get_le32(pb);
148 url_fseek(pb, offset+8, SEEK_SET);
149 read_braindead_odml_indx(s, frame_num);
150 frame_num += duration;
152 url_fseek(pb, pos, SEEK_SET);
158 static void clean_index(AVFormatContext *s){
161 for(i=0; i<s->nb_streams; i++){
162 AVStream *st = s->streams[i];
163 AVIStream *ast = st->priv_data;
164 int n= st->nb_index_entries;
165 int max= ast->sample_size;
166 int64_t pos, size, ts;
168 if(n != 1 || ast->sample_size==0)
171 while(max < 1024) max+=max;
173 pos= st->index_entries[0].pos;
174 size= st->index_entries[0].size;
175 ts= st->index_entries[0].timestamp;
177 for(j=0; j<size; j+=max){
178 av_add_index_entry(st, pos+j, ts + j/ast->sample_size, FFMIN(max, size-j), 0, AVINDEX_KEYFRAME);
183 static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
185 AVIContext *avi = s->priv_data;
186 ByteIOContext *pb = &s->pb;
187 uint32_t tag, tag1, handler;
188 int codec_type, stream_index, frame_period, bit_rate;
189 unsigned int size, nb_frames;
192 AVIStream *ast = NULL;
193 int xan_video = 0; /* hack to support Xan A/V */
195 avi->stream_index= -1;
197 if (get_riff(avi, pb) < 0)
210 print_tag("tag", tag, size);
214 case MKTAG('L', 'I', 'S', 'T'):
215 /* ignored, except when start of video packets */
218 print_tag("list", tag1, 0);
220 if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
221 avi->movi_list = url_ftell(pb) - 4;
222 if(size) avi->movi_end = avi->movi_list + size;
223 else avi->movi_end = url_fsize(pb);
225 printf("movi end=%Lx\n", avi->movi_end);
230 case MKTAG('d', 'm', 'l', 'h'):
232 url_fskip(pb, size + (size & 1));
234 case MKTAG('a', 'v', 'i', 'h'):
236 /* using frame_period is bad idea */
237 frame_period = get_le32(pb);
238 bit_rate = get_le32(pb) * 8;
240 avi->non_interleaved |= get_le32(pb) & AVIF_MUSTUSEINDEX;
242 url_fskip(pb, 2 * 4);
246 st = av_new_stream(s, i);
250 ast = av_mallocz(sizeof(AVIStream));
255 url_fskip(pb, size - 7 * 4);
257 case MKTAG('s', 't', 'r', 'h'):
261 handler = get_le32(pb); /* codec tag */
263 print_tag("strh", tag1, -1);
265 if(tag1 == MKTAG('i', 'a', 'v', 's') || tag1 == MKTAG('i', 'v', 'a', 's')){
267 * After some consideration -- I don't think we
268 * have to support anything but DV in a type1 AVIs.
270 if (s->nb_streams != 1)
273 if (handler != MKTAG('d', 'v', 's', 'd') &&
274 handler != MKTAG('d', 'v', 'h', 'd') &&
275 handler != MKTAG('d', 'v', 's', 'l'))
278 ast = s->streams[0]->priv_data;
279 av_freep(&s->streams[0]->codec->extradata);
280 av_freep(&s->streams[0]);
282 avi->dv_demux = dv_init_demux(s);
285 s->streams[0]->priv_data = ast;
286 url_fskip(pb, 3 * 4);
287 ast->scale = get_le32(pb);
288 ast->rate = get_le32(pb);
289 stream_index = s->nb_streams - 1;
290 url_fskip(pb, size - 7*4);
294 if (stream_index >= s->nb_streams) {
295 url_fskip(pb, size - 8);
296 /* ignore padding stream */
297 if (tag1 == MKTAG('p', 'a', 'd', 's'))
301 st = s->streams[stream_index];
303 st->codec->stream_codec_tag= handler;
305 get_le32(pb); /* flags */
306 get_le16(pb); /* priority */
307 get_le16(pb); /* language */
308 get_le32(pb); /* initial frame */
309 ast->scale = get_le32(pb);
310 ast->rate = get_le32(pb);
311 if(ast->scale && ast->rate){
312 }else if(frame_period){
314 ast->scale = frame_period;
319 av_set_pts_info(st, 64, ast->scale, ast->rate);
321 ast->cum_len=get_le32(pb); /* start */
322 nb_frames = get_le32(pb);
325 st->duration = nb_frames;
326 get_le32(pb); /* buffer size */
327 get_le32(pb); /* quality */
328 ast->sample_size = get_le32(pb); /* sample ssize */
329 // av_log(NULL, AV_LOG_DEBUG, "%d %d %d %d\n", ast->rate, ast->scale, ast->start, ast->sample_size);
332 case MKTAG('v', 'i', 'd', 's'):
333 codec_type = CODEC_TYPE_VIDEO;
335 ast->sample_size = 0;
337 case MKTAG('a', 'u', 'd', 's'):
338 codec_type = CODEC_TYPE_AUDIO;
340 case MKTAG('t', 'x', 't', 's'):
342 codec_type = CODEC_TYPE_DATA; //CODEC_TYPE_SUB ? FIXME
344 case MKTAG('p', 'a', 'd', 's'):
345 codec_type = CODEC_TYPE_UNKNOWN;
349 av_log(s, AV_LOG_ERROR, "unknown stream type %X\n", tag1);
352 ast->frame_offset= ast->cum_len * FFMAX(ast->sample_size, 1);
353 url_fskip(pb, size - 12 * 4);
355 case MKTAG('s', 't', 'r', 'f'):
357 if (stream_index >= s->nb_streams || avi->dv_demux) {
360 st = s->streams[stream_index];
362 case CODEC_TYPE_VIDEO:
363 get_le32(pb); /* size */
364 st->codec->width = get_le32(pb);
365 st->codec->height = get_le32(pb);
366 get_le16(pb); /* panes */
367 st->codec->bits_per_sample= get_le16(pb); /* depth */
369 get_le32(pb); /* ImageSize */
370 get_le32(pb); /* XPelsPerMeter */
371 get_le32(pb); /* YPelsPerMeter */
372 get_le32(pb); /* ClrUsed */
373 get_le32(pb); /* ClrImportant */
375 if(size > 10*4 && size<(1<<30)){
376 st->codec->extradata_size= size - 10*4;
377 st->codec->extradata= av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
378 get_buffer(pb, st->codec->extradata, st->codec->extradata_size);
381 if(st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly
384 /* Extract palette from extradata if bpp <= 8 */
385 /* This code assumes that extradata contains only palette */
386 /* This is true for all paletted codecs implemented in ffmpeg */
387 if (st->codec->extradata_size && (st->codec->bits_per_sample <= 8)) {
388 st->codec->palctrl = av_mallocz(sizeof(AVPaletteControl));
389 #ifdef WORDS_BIGENDIAN
390 for (i = 0; i < FFMIN(st->codec->extradata_size, AVPALETTE_SIZE)/4; i++)
391 st->codec->palctrl->palette[i] = bswap_32(((uint32_t*)st->codec->extradata)[i]);
393 memcpy(st->codec->palctrl->palette, st->codec->extradata,
394 FFMIN(st->codec->extradata_size, AVPALETTE_SIZE));
396 st->codec->palctrl->palette_changed = 1;
400 print_tag("video", tag1, 0);
402 st->codec->codec_type = CODEC_TYPE_VIDEO;
403 st->codec->codec_tag = tag1;
404 st->codec->codec_id = codec_get_id(codec_bmp_tags, tag1);
405 if (st->codec->codec_id == CODEC_ID_XAN_WC4)
407 st->need_parsing = 2; //only parse headers dont do slower repacketization, this is needed to get the pict type which is needed for generating correct pts
408 // url_fskip(pb, size - 5 * 4);
410 case CODEC_TYPE_AUDIO:
411 get_wav_header(pb, st->codec, size);
412 if(ast->sample_size && st->codec->block_align && ast->sample_size % st->codec->block_align)
413 av_log(s, AV_LOG_DEBUG, "invalid sample size or block align detected\n");
414 if (size%2) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
416 /* special case time: To support Xan DPCM, hardcode
417 * the format if Xxan is the video codec */
418 st->need_parsing = 1;
419 /* force parsing as several audio frames can be in
422 st->codec->codec_id = CODEC_ID_XAN_DPCM;
425 st->codec->codec_type = CODEC_TYPE_DATA;
426 st->codec->codec_id= CODEC_ID_NONE;
427 st->codec->codec_tag= 0;
433 case MKTAG('i', 'n', 'd', 'x'):
435 if(!url_is_streamed(pb)){
436 read_braindead_odml_indx(s, 0);
439 url_fseek(pb, i+size, SEEK_SET);
449 /* check stream number */
450 if (stream_index != s->nb_streams - 1) {
452 for(i=0;i<s->nb_streams;i++) {
453 av_freep(&s->streams[i]->codec->extradata);
454 av_freep(&s->streams[i]);
459 if(!avi->index_loaded && !url_is_streamed(pb))
461 avi->index_loaded = 1;
462 avi->non_interleaved |= guess_ni_flag(s);
463 if(avi->non_interleaved)
469 static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
471 AVIContext *avi = s->priv_data;
472 ByteIOContext *pb = &s->pb;
478 size = dv_get_packet(avi->dv_demux, pkt);
483 if(avi->non_interleaved){
484 int best_stream_index = 0;
485 AVStream *best_st= NULL;
487 int64_t best_ts= INT64_MAX;
490 for(i=0; i<s->nb_streams; i++){
491 AVStream *st = s->streams[i];
492 AVIStream *ast = st->priv_data;
493 int64_t ts= ast->frame_offset;
496 ts /= ast->sample_size;
497 ts= av_rescale(ts, AV_TIME_BASE * (int64_t)st->time_base.num, st->time_base.den);
499 // av_log(NULL, AV_LOG_DEBUG, "%Ld %d/%d %Ld\n", ts, st->time_base.num, st->time_base.den, ast->frame_offset);
503 best_stream_index= i;
506 best_ast = best_st->priv_data;
507 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
508 if(best_ast->remaining)
509 i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
511 i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
513 // av_log(NULL, AV_LOG_DEBUG, "%d\n", i);
515 int64_t pos= best_st->index_entries[i].pos;
516 pos += best_ast->packet_size - best_ast->remaining;
517 url_fseek(&s->pb, pos + 8, SEEK_SET);
518 // av_log(NULL, AV_LOG_DEBUG, "pos=%Ld\n", pos);
520 assert(best_ast->remaining <= best_ast->packet_size);
522 avi->stream_index= best_stream_index;
523 if(!best_ast->remaining)
524 best_ast->packet_size=
525 best_ast->remaining= best_st->index_entries[i].size;
530 if(avi->stream_index >= 0){
531 AVStream *st= s->streams[ avi->stream_index ];
532 AVIStream *ast= st->priv_data;
535 if(ast->sample_size <= 1) // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM
537 else if(ast->sample_size < 32)
538 size= 64*ast->sample_size;
540 size= ast->sample_size;
542 if(size > ast->remaining)
543 size= ast->remaining;
544 av_get_packet(pb, pkt, size);
547 dstr = pkt->destruct;
548 size = dv_produce_packet(avi->dv_demux, pkt,
549 pkt->data, pkt->size);
550 pkt->destruct = dstr;
551 pkt->flags |= PKT_FLAG_KEY;
553 /* XXX: how to handle B frames in avi ? */
554 pkt->dts = ast->frame_offset;
555 // pkt->dts += ast->start;
557 pkt->dts /= ast->sample_size;
558 //av_log(NULL, AV_LOG_DEBUG, "dts:%Ld offset:%Ld %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, avi->stream_index, size);
559 pkt->stream_index = avi->stream_index;
561 if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
562 if(st->index_entries){
566 index= av_index_search_timestamp(st, pkt->dts, 0);
567 e= &st->index_entries[index];
569 if(index >= 0 && e->timestamp == ast->frame_offset){
570 if (e->flags & AVINDEX_KEYFRAME)
571 pkt->flags |= PKT_FLAG_KEY;
574 /* if no index, better to say that all frames
576 pkt->flags |= PKT_FLAG_KEY;
579 pkt->flags |= PKT_FLAG_KEY;
582 ast->frame_offset += pkt->size;
586 ast->remaining -= size;
588 avi->stream_index= -1;
599 memset(d, -1, sizeof(int)*8);
600 for(i=sync=url_ftell(pb); !url_feof(pb); i++) {
603 if (i >= avi->movi_end) {
605 url_fskip(pb, avi->riff_end - i);
606 avi->riff_end = avi->movi_end = url_fsize(pb);
615 size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
617 if( d[2] >= '0' && d[2] <= '9'
618 && d[3] >= '0' && d[3] <= '9'){
619 n= (d[2] - '0') * 10 + (d[3] - '0');
621 n= 100; //invalid stream id
623 //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);
624 if(i + size > avi->movi_end || d[0]<0)
628 if( (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
630 ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')){
632 //av_log(NULL, AV_LOG_DEBUG, "SKIP\n");
636 if( d[0] >= '0' && d[0] <= '9'
637 && d[1] >= '0' && d[1] <= '9'){
638 n= (d[0] - '0') * 10 + (d[1] - '0');
640 n= 100; //invalid stream id
644 if(n < s->nb_streams){
650 if( (st->discard >= AVDISCARD_DEFAULT && size==0)
651 /*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & PKT_FLAG_KEY))*/ //FIXME needs a little reordering
652 || st->discard >= AVDISCARD_ALL){
653 if(ast->sample_size) ast->frame_offset += pkt->size;
654 else ast->frame_offset++;
659 if( ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||
660 d[2]*256+d[3] == ast->prefix /*||
661 (d[2] == 'd' && d[3] == 'c') ||
662 (d[2] == 'w' && d[3] == 'b')*/) {
664 //av_log(NULL, AV_LOG_DEBUG, "OK\n");
665 if(d[2]*256+d[3] == ast->prefix)
668 ast->prefix= d[2]*256+d[3];
669 ast->prefix_count= 0;
672 avi->stream_index= n;
673 ast->packet_size= size + 8;
674 ast->remaining= size;
678 /* palette changed chunk */
679 if ( d[0] >= '0' && d[0] <= '9'
680 && d[1] >= '0' && d[1] <= '9'
681 && ((d[2] == 'p' && d[3] == 'c'))
682 && n < s->nb_streams && i + size <= avi->movi_end) {
685 int first, clr, flags, k, p;
689 first = get_byte(pb);
691 if(!clr) /* all 256 colors used */
693 flags = get_le16(pb);
695 for (k = first; k < clr + first; k++) {
701 st->codec->palctrl->palette[k] = b + (g << 8) + (r << 16);
703 st->codec->palctrl->palette_changed = 1;
712 /* XXX: we make the implicit supposition that the position are sorted
714 static int avi_read_idx1(AVFormatContext *s, int size)
716 AVIContext *avi = s->priv_data;
717 ByteIOContext *pb = &s->pb;
718 int nb_index_entries, i;
721 unsigned int index, tag, flags, pos, len;
722 unsigned last_pos= -1;
724 nb_index_entries = size / 16;
725 if (nb_index_entries <= 0)
728 /* read the entries and sort them in each stream component */
729 for(i = 0; i < nb_index_entries; i++) {
731 flags = get_le32(pb);
734 #if defined(DEBUG_SEEK)
735 av_log(NULL, AV_LOG_DEBUG, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
736 i, tag, flags, pos, len);
738 if(i==0 && pos > avi->movi_list)
739 avi->movi_list= 0; //FIXME better check
740 pos += avi->movi_list;
742 index = ((tag & 0xff) - '0') * 10;
743 index += ((tag >> 8) & 0xff) - '0';
744 if (index >= s->nb_streams)
746 st = s->streams[index];
749 #if defined(DEBUG_SEEK)
750 av_log(NULL, AV_LOG_DEBUG, "%d cum_len=%d\n", len, ast->cum_len);
753 avi->non_interleaved= 1;
755 av_add_index_entry(st, pos, ast->cum_len, len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
757 ast->cum_len += len / ast->sample_size;
765 static int guess_ni_flag(AVFormatContext *s){
767 int64_t last_start=0;
768 int64_t first_end= INT64_MAX;
770 for(i=0; i<s->nb_streams; i++){
771 AVStream *st = s->streams[i];
772 int n= st->nb_index_entries;
777 if(st->index_entries[0].pos > last_start)
778 last_start= st->index_entries[0].pos;
779 if(st->index_entries[n-1].pos < first_end)
780 first_end= st->index_entries[n-1].pos;
782 return last_start > first_end;
785 static int avi_load_index(AVFormatContext *s)
787 AVIContext *avi = s->priv_data;
788 ByteIOContext *pb = &s->pb;
790 offset_t pos= url_ftell(pb);
792 url_fseek(pb, avi->movi_end, SEEK_SET);
794 printf("movi_end=0x%llx\n", avi->movi_end);
802 printf("tag=%c%c%c%c size=0x%x\n",
810 case MKTAG('i', 'd', 'x', '1'):
811 if (avi_read_idx1(s, size) < 0)
824 url_fseek(pb, pos, SEEK_SET);
828 static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
830 AVIContext *avi = s->priv_data;
835 if (!avi->index_loaded) {
836 /* we only load the index on demand */
838 avi->index_loaded = 1;
840 assert(stream_index>= 0);
842 st = s->streams[stream_index];
843 index= av_index_search_timestamp(st, timestamp, flags);
847 /* find the position */
848 pos = st->index_entries[index].pos;
849 timestamp = st->index_entries[index].timestamp;
851 // av_log(NULL, AV_LOG_DEBUG, "XX %Ld %d %Ld\n", timestamp, index, st->index_entries[index].timestamp);
853 for(i = 0; i < s->nb_streams; i++) {
854 AVStream *st2 = s->streams[i];
855 AVIStream *ast2 = st2->priv_data;
860 if (st2->nb_index_entries <= 0)
863 // assert(st2->codec->block_align);
864 assert(st2->time_base.den == ast2->rate);
865 assert(st2->time_base.num == ast2->scale);
866 index = av_index_search_timestamp(
868 av_rescale(timestamp, st2->time_base.den*(int64_t)st->time_base.num, st->time_base.den * (int64_t)st2->time_base.num),
869 flags | AVSEEK_FLAG_BACKWARD);
873 if(!avi->non_interleaved){
874 while(index>0 && st2->index_entries[index].pos > pos)
876 while(index+1 < st2->nb_index_entries && st2->index_entries[index].pos < pos)
880 // av_log(NULL, AV_LOG_DEBUG, "%Ld %d %Ld\n", timestamp, index, st2->index_entries[index].timestamp);
881 /* extract the current frame number */
882 ast2->frame_offset = st2->index_entries[index].timestamp;
883 if(ast2->sample_size)
884 ast2->frame_offset *=ast2->sample_size;
888 dv_flush_audio_packets(avi->dv_demux);
890 url_fseek(&s->pb, pos, SEEK_SET);
891 avi->stream_index= -1;
895 static int avi_read_close(AVFormatContext *s)
898 AVIContext *avi = s->priv_data;
900 for(i=0;i<s->nb_streams;i++) {
901 AVStream *st = s->streams[i];
902 AVIStream *ast = st->priv_data;
904 av_free(st->codec->palctrl);
908 av_free(avi->dv_demux);
913 static int avi_probe(AVProbeData *p)
915 /* check file header */
916 if (p->buf_size <= 32)
918 if (p->buf[0] == 'R' && p->buf[1] == 'I' &&
919 p->buf[2] == 'F' && p->buf[3] == 'F' &&
920 p->buf[8] == 'A' && p->buf[9] == 'V' &&
921 p->buf[10] == 'I' && p->buf[11] == ' ')
922 return AVPROBE_SCORE_MAX;
927 AVInputFormat avi_demuxer = {