Libav 0.7.1
libavformat/avidec.c
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00001 /*
00002  * AVI demuxer
00003  * Copyright (c) 2001 Fabrice Bellard
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * Libav is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include <strings.h>
00023 #include "libavutil/intreadwrite.h"
00024 #include "libavutil/bswap.h"
00025 #include "libavutil/dict.h"
00026 #include "avformat.h"
00027 #include "avi.h"
00028 #include "dv.h"
00029 #include "riff.h"
00030 
00031 #undef NDEBUG
00032 #include <assert.h>
00033 
00034 typedef struct AVIStream {
00035     int64_t frame_offset; /* current frame (video) or byte (audio) counter
00036                          (used to compute the pts) */
00037     int remaining;
00038     int packet_size;
00039 
00040     int scale;
00041     int rate;
00042     int sample_size; /* size of one sample (or packet) (in the rate/scale sense) in bytes */
00043 
00044     int64_t cum_len; /* temporary storage (used during seek) */
00045 
00046     int prefix;                       
00047     int prefix_count;
00048     uint32_t pal[256];
00049     int has_pal;
00050     int dshow_block_align;            
00051 
00052     AVFormatContext *sub_ctx;
00053     AVPacket sub_pkt;
00054     uint8_t *sub_buffer;
00055 } AVIStream;
00056 
00057 typedef struct {
00058     int64_t  riff_end;
00059     int64_t  movi_end;
00060     int64_t  fsize;
00061     int64_t movi_list;
00062     int64_t last_pkt_pos;
00063     int index_loaded;
00064     int is_odml;
00065     int non_interleaved;
00066     int stream_index;
00067     DVDemuxContext* dv_demux;
00068     int odml_depth;
00069 #define MAX_ODML_DEPTH 1000
00070 } AVIContext;
00071 
00072 static const char avi_headers[][8] = {
00073     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', ' ' },
00074     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 'X' },
00075     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 0x19},
00076     { 'O', 'N', '2', ' ',    'O', 'N', '2', 'f' },
00077     { 'R', 'I', 'F', 'F',    'A', 'M', 'V', ' ' },
00078     { 0 }
00079 };
00080 
00081 static int avi_load_index(AVFormatContext *s);
00082 static int guess_ni_flag(AVFormatContext *s);
00083 
00084 #define print_tag(str, tag, size)                       \
00085     av_dlog(NULL, "%s: tag=%c%c%c%c size=0x%x\n",       \
00086            str, tag & 0xff,                             \
00087            (tag >> 8) & 0xff,                           \
00088            (tag >> 16) & 0xff,                          \
00089            (tag >> 24) & 0xff,                          \
00090            size)
00091 
00092 static inline int get_duration(AVIStream *ast, int len){
00093     if(ast->sample_size){
00094         return len;
00095     }else if (ast->dshow_block_align){
00096         return (len + ast->dshow_block_align - 1)/ast->dshow_block_align;
00097     }else
00098         return 1;
00099 }
00100 
00101 static int get_riff(AVFormatContext *s, AVIOContext *pb)
00102 {
00103     AVIContext *avi = s->priv_data;
00104     char header[8];
00105     int i;
00106 
00107     /* check RIFF header */
00108     avio_read(pb, header, 4);
00109     avi->riff_end = avio_rl32(pb);  /* RIFF chunk size */
00110     avi->riff_end += avio_tell(pb); /* RIFF chunk end */
00111     avio_read(pb, header+4, 4);
00112 
00113     for(i=0; avi_headers[i][0]; i++)
00114         if(!memcmp(header, avi_headers[i], 8))
00115             break;
00116     if(!avi_headers[i][0])
00117         return -1;
00118 
00119     if(header[7] == 0x19)
00120         av_log(s, AV_LOG_INFO, "This file has been generated by a totally broken muxer.\n");
00121 
00122     return 0;
00123 }
00124 
00125 static int read_braindead_odml_indx(AVFormatContext *s, int frame_num){
00126     AVIContext *avi = s->priv_data;
00127     AVIOContext *pb = s->pb;
00128     int longs_pre_entry= avio_rl16(pb);
00129     int index_sub_type = avio_r8(pb);
00130     int index_type     = avio_r8(pb);
00131     int entries_in_use = avio_rl32(pb);
00132     int chunk_id       = avio_rl32(pb);
00133     int64_t base       = avio_rl64(pb);
00134     int stream_id= 10*((chunk_id&0xFF) - '0') + (((chunk_id>>8)&0xFF) - '0');
00135     AVStream *st;
00136     AVIStream *ast;
00137     int i;
00138     int64_t last_pos= -1;
00139     int64_t filesize= avio_size(s->pb);
00140 
00141     av_dlog(s, "longs_pre_entry:%d index_type:%d entries_in_use:%d chunk_id:%X base:%16"PRIX64"\n",
00142             longs_pre_entry,index_type, entries_in_use, chunk_id, base);
00143 
00144     if(stream_id >= s->nb_streams || stream_id < 0)
00145         return -1;
00146     st= s->streams[stream_id];
00147     ast = st->priv_data;
00148 
00149     if(index_sub_type)
00150         return -1;
00151 
00152     avio_rl32(pb);
00153 
00154     if(index_type && longs_pre_entry != 2)
00155         return -1;
00156     if(index_type>1)
00157         return -1;
00158 
00159     if(filesize > 0 && base >= filesize){
00160         av_log(s, AV_LOG_ERROR, "ODML index invalid\n");
00161         if(base>>32 == (base & 0xFFFFFFFF) && (base & 0xFFFFFFFF) < filesize && filesize <= 0xFFFFFFFF)
00162             base &= 0xFFFFFFFF;
00163         else
00164             return -1;
00165     }
00166 
00167     for(i=0; i<entries_in_use; i++){
00168         if(index_type){
00169             int64_t pos= avio_rl32(pb) + base - 8;
00170             int len    = avio_rl32(pb);
00171             int key= len >= 0;
00172             len &= 0x7FFFFFFF;
00173 
00174             av_dlog(s, "pos:%"PRId64", len:%X\n", pos, len);
00175 
00176             if(pb->eof_reached)
00177                 return -1;
00178 
00179             if(last_pos == pos || pos == base - 8)
00180                 avi->non_interleaved= 1;
00181             if(last_pos != pos && (len || !ast->sample_size))
00182                 av_add_index_entry(st, pos, ast->cum_len, len, 0, key ? AVINDEX_KEYFRAME : 0);
00183 
00184             ast->cum_len += get_duration(ast, len);
00185             last_pos= pos;
00186         }else{
00187             int64_t offset, pos;
00188             int duration;
00189             offset = avio_rl64(pb);
00190             avio_rl32(pb);       /* size */
00191             duration = avio_rl32(pb);
00192 
00193             if(pb->eof_reached)
00194                 return -1;
00195 
00196             pos = avio_tell(pb);
00197 
00198             if(avi->odml_depth > MAX_ODML_DEPTH){
00199                 av_log(s, AV_LOG_ERROR, "Too deeply nested ODML indexes\n");
00200                 return -1;
00201             }
00202 
00203             avio_seek(pb, offset+8, SEEK_SET);
00204             avi->odml_depth++;
00205             read_braindead_odml_indx(s, frame_num);
00206             avi->odml_depth--;
00207             frame_num += duration;
00208 
00209             avio_seek(pb, pos, SEEK_SET);
00210         }
00211     }
00212     avi->index_loaded=1;
00213     return 0;
00214 }
00215 
00216 static void clean_index(AVFormatContext *s){
00217     int i;
00218     int64_t j;
00219 
00220     for(i=0; i<s->nb_streams; i++){
00221         AVStream *st = s->streams[i];
00222         AVIStream *ast = st->priv_data;
00223         int n= st->nb_index_entries;
00224         int max= ast->sample_size;
00225         int64_t pos, size, ts;
00226 
00227         if(n != 1 || ast->sample_size==0)
00228             continue;
00229 
00230         while(max < 1024) max+=max;
00231 
00232         pos= st->index_entries[0].pos;
00233         size= st->index_entries[0].size;
00234         ts= st->index_entries[0].timestamp;
00235 
00236         for(j=0; j<size; j+=max){
00237             av_add_index_entry(st, pos+j, ts+j, FFMIN(max, size-j), 0, AVINDEX_KEYFRAME);
00238         }
00239     }
00240 }
00241 
00242 static int avi_read_tag(AVFormatContext *s, AVStream *st, uint32_t tag, uint32_t size)
00243 {
00244     AVIOContext *pb = s->pb;
00245     char key[5] = {0}, *value;
00246 
00247     size += (size & 1);
00248 
00249     if (size == UINT_MAX)
00250         return -1;
00251     value = av_malloc(size+1);
00252     if (!value)
00253         return -1;
00254     avio_read(pb, value, size);
00255     value[size]=0;
00256 
00257     AV_WL32(key, tag);
00258 
00259     return av_dict_set(st ? &st->metadata : &s->metadata, key, value,
00260                             AV_DICT_DONT_STRDUP_VAL);
00261 }
00262 
00263 static void avi_read_info(AVFormatContext *s, uint64_t end)
00264 {
00265     while (avio_tell(s->pb) < end) {
00266         uint32_t tag  = avio_rl32(s->pb);
00267         uint32_t size = avio_rl32(s->pb);
00268         avi_read_tag(s, NULL, tag, size);
00269     }
00270 }
00271 
00272 static const char months[12][4] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
00273                                     "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
00274 
00275 static void avi_metadata_creation_time(AVDictionary **metadata, char *date)
00276 {
00277     char month[4], time[9], buffer[64];
00278     int i, day, year;
00279     /* parse standard AVI date format (ie. "Mon Mar 10 15:04:43 2003") */
00280     if (sscanf(date, "%*3s%*[ ]%3s%*[ ]%2d%*[ ]%8s%*[ ]%4d",
00281                month, &day, time, &year) == 4) {
00282         for (i=0; i<12; i++)
00283             if (!strcasecmp(month, months[i])) {
00284                 snprintf(buffer, sizeof(buffer), "%.4d-%.2d-%.2d %s",
00285                          year, i+1, day, time);
00286                 av_dict_set(metadata, "creation_time", buffer, 0);
00287             }
00288     } else if (date[4] == '/' && date[7] == '/') {
00289         date[4] = date[7] = '-';
00290         av_dict_set(metadata, "creation_time", date, 0);
00291     }
00292 }
00293 
00294 static void avi_read_nikon(AVFormatContext *s, uint64_t end)
00295 {
00296     while (avio_tell(s->pb) < end) {
00297         uint32_t tag  = avio_rl32(s->pb);
00298         uint32_t size = avio_rl32(s->pb);
00299         switch (tag) {
00300         case MKTAG('n', 'c', 't', 'g'): {  /* Nikon Tags */
00301             uint64_t tag_end = avio_tell(s->pb) + size;
00302             while (avio_tell(s->pb) < tag_end) {
00303                 uint16_t tag  = avio_rl16(s->pb);
00304                 uint16_t size = avio_rl16(s->pb);
00305                 const char *name = NULL;
00306                 char buffer[64] = {0};
00307                 size -= avio_read(s->pb, buffer,
00308                                    FFMIN(size, sizeof(buffer)-1));
00309                 switch (tag) {
00310                 case 0x03:  name = "maker";  break;
00311                 case 0x04:  name = "model";  break;
00312                 case 0x13:  name = "creation_time";
00313                     if (buffer[4] == ':' && buffer[7] == ':')
00314                         buffer[4] = buffer[7] = '-';
00315                     break;
00316                 }
00317                 if (name)
00318                     av_dict_set(&s->metadata, name, buffer, 0);
00319                 avio_skip(s->pb, size);
00320             }
00321             break;
00322         }
00323         default:
00324             avio_skip(s->pb, size);
00325             break;
00326         }
00327     }
00328 }
00329 
00330 static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
00331 {
00332     AVIContext *avi = s->priv_data;
00333     AVIOContext *pb = s->pb;
00334     unsigned int tag, tag1, handler;
00335     int codec_type, stream_index, frame_period;
00336     unsigned int size;
00337     int i;
00338     AVStream *st;
00339     AVIStream *ast = NULL;
00340     int avih_width=0, avih_height=0;
00341     int amv_file_format=0;
00342     uint64_t list_end = 0;
00343     int ret;
00344 
00345     avi->stream_index= -1;
00346 
00347     if (get_riff(s, pb) < 0)
00348         return -1;
00349 
00350     avi->fsize = avio_size(pb);
00351     if(avi->fsize<=0)
00352         avi->fsize= avi->riff_end == 8 ? INT64_MAX : avi->riff_end;
00353 
00354     /* first list tag */
00355     stream_index = -1;
00356     codec_type = -1;
00357     frame_period = 0;
00358     for(;;) {
00359         if (pb->eof_reached)
00360             goto fail;
00361         tag = avio_rl32(pb);
00362         size = avio_rl32(pb);
00363 
00364         print_tag("tag", tag, size);
00365 
00366         switch(tag) {
00367         case MKTAG('L', 'I', 'S', 'T'):
00368             list_end = avio_tell(pb) + size;
00369             /* Ignored, except at start of video packets. */
00370             tag1 = avio_rl32(pb);
00371 
00372             print_tag("list", tag1, 0);
00373 
00374             if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
00375                 avi->movi_list = avio_tell(pb) - 4;
00376                 if(size) avi->movi_end = avi->movi_list + size + (size & 1);
00377                 else     avi->movi_end = avio_size(pb);
00378                 av_dlog(NULL, "movi end=%"PRIx64"\n", avi->movi_end);
00379                 goto end_of_header;
00380             }
00381             else if (tag1 == MKTAG('I', 'N', 'F', 'O'))
00382                 avi_read_info(s, list_end);
00383             else if (tag1 == MKTAG('n', 'c', 'd', 't'))
00384                 avi_read_nikon(s, list_end);
00385 
00386             break;
00387         case MKTAG('I', 'D', 'I', 'T'): {
00388             unsigned char date[64] = {0};
00389             size += (size & 1);
00390             size -= avio_read(pb, date, FFMIN(size, sizeof(date)-1));
00391             avio_skip(pb, size);
00392             avi_metadata_creation_time(&s->metadata, date);
00393             break;
00394         }
00395         case MKTAG('d', 'm', 'l', 'h'):
00396             avi->is_odml = 1;
00397             avio_skip(pb, size + (size & 1));
00398             break;
00399         case MKTAG('a', 'm', 'v', 'h'):
00400             amv_file_format=1;
00401         case MKTAG('a', 'v', 'i', 'h'):
00402             /* AVI header */
00403             /* using frame_period is bad idea */
00404             frame_period = avio_rl32(pb);
00405             avio_skip(pb, 4);
00406             avio_rl32(pb);
00407             avi->non_interleaved |= avio_rl32(pb) & AVIF_MUSTUSEINDEX;
00408 
00409             avio_skip(pb, 2 * 4);
00410             avio_rl32(pb);
00411             avio_rl32(pb);
00412             avih_width=avio_rl32(pb);
00413             avih_height=avio_rl32(pb);
00414 
00415             avio_skip(pb, size - 10 * 4);
00416             break;
00417         case MKTAG('s', 't', 'r', 'h'):
00418             /* stream header */
00419 
00420             tag1 = avio_rl32(pb);
00421             handler = avio_rl32(pb); /* codec tag */
00422 
00423             if(tag1 == MKTAG('p', 'a', 'd', 's')){
00424                 avio_skip(pb, size - 8);
00425                 break;
00426             }else{
00427                 stream_index++;
00428                 st = av_new_stream(s, stream_index);
00429                 if (!st)
00430                     goto fail;
00431 
00432                 ast = av_mallocz(sizeof(AVIStream));
00433                 if (!ast)
00434                     goto fail;
00435                 st->priv_data = ast;
00436             }
00437             if(amv_file_format)
00438                 tag1 = stream_index ? MKTAG('a','u','d','s') : MKTAG('v','i','d','s');
00439 
00440             print_tag("strh", tag1, -1);
00441 
00442             if(tag1 == MKTAG('i', 'a', 'v', 's') || tag1 == MKTAG('i', 'v', 'a', 's')){
00443                 int64_t dv_dur;
00444 
00445                 /*
00446                  * After some consideration -- I don't think we
00447                  * have to support anything but DV in type1 AVIs.
00448                  */
00449                 if (s->nb_streams != 1)
00450                     goto fail;
00451 
00452                 if (handler != MKTAG('d', 'v', 's', 'd') &&
00453                     handler != MKTAG('d', 'v', 'h', 'd') &&
00454                     handler != MKTAG('d', 'v', 's', 'l'))
00455                    goto fail;
00456 
00457                 ast = s->streams[0]->priv_data;
00458                 av_freep(&s->streams[0]->codec->extradata);
00459                 av_freep(&s->streams[0]->codec);
00460                 av_freep(&s->streams[0]);
00461                 s->nb_streams = 0;
00462                 if (CONFIG_DV_DEMUXER) {
00463                     avi->dv_demux = dv_init_demux(s);
00464                     if (!avi->dv_demux)
00465                         goto fail;
00466                 }
00467                 s->streams[0]->priv_data = ast;
00468                 avio_skip(pb, 3 * 4);
00469                 ast->scale = avio_rl32(pb);
00470                 ast->rate = avio_rl32(pb);
00471                 avio_skip(pb, 4);  /* start time */
00472 
00473                 dv_dur = avio_rl32(pb);
00474                 if (ast->scale > 0 && ast->rate > 0 && dv_dur > 0) {
00475                     dv_dur *= AV_TIME_BASE;
00476                     s->duration = av_rescale(dv_dur, ast->scale, ast->rate);
00477                 }
00478                 /*
00479                  * else, leave duration alone; timing estimation in utils.c
00480                  *      will make a guess based on bitrate.
00481                  */
00482 
00483                 stream_index = s->nb_streams - 1;
00484                 avio_skip(pb, size - 9*4);
00485                 break;
00486             }
00487 
00488             assert(stream_index < s->nb_streams);
00489             st->codec->stream_codec_tag= handler;
00490 
00491             avio_rl32(pb); /* flags */
00492             avio_rl16(pb); /* priority */
00493             avio_rl16(pb); /* language */
00494             avio_rl32(pb); /* initial frame */
00495             ast->scale = avio_rl32(pb);
00496             ast->rate = avio_rl32(pb);
00497             if(!(ast->scale && ast->rate)){
00498                 av_log(s, AV_LOG_WARNING, "scale/rate is %u/%u which is invalid. (This file has been generated by broken software.)\n", ast->scale, ast->rate);
00499                 if(frame_period){
00500                     ast->rate = 1000000;
00501                     ast->scale = frame_period;
00502                 }else{
00503                     ast->rate = 25;
00504                     ast->scale = 1;
00505                 }
00506             }
00507             av_set_pts_info(st, 64, ast->scale, ast->rate);
00508 
00509             ast->cum_len=avio_rl32(pb); /* start */
00510             st->nb_frames = avio_rl32(pb);
00511 
00512             st->start_time = 0;
00513             avio_rl32(pb); /* buffer size */
00514             avio_rl32(pb); /* quality */
00515             ast->sample_size = avio_rl32(pb); /* sample ssize */
00516             ast->cum_len *= FFMAX(1, ast->sample_size);
00517 //            av_log(s, AV_LOG_DEBUG, "%d %d %d %d\n", ast->rate, ast->scale, ast->start, ast->sample_size);
00518 
00519             switch(tag1) {
00520             case MKTAG('v', 'i', 'd', 's'):
00521                 codec_type = AVMEDIA_TYPE_VIDEO;
00522 
00523                 ast->sample_size = 0;
00524                 break;
00525             case MKTAG('a', 'u', 'd', 's'):
00526                 codec_type = AVMEDIA_TYPE_AUDIO;
00527                 break;
00528             case MKTAG('t', 'x', 't', 's'):
00529                 codec_type = AVMEDIA_TYPE_SUBTITLE;
00530                 break;
00531             case MKTAG('d', 'a', 't', 's'):
00532                 codec_type = AVMEDIA_TYPE_DATA;
00533                 break;
00534             default:
00535                 av_log(s, AV_LOG_ERROR, "unknown stream type %X\n", tag1);
00536                 goto fail;
00537             }
00538             if(ast->sample_size == 0)
00539                 st->duration = st->nb_frames;
00540             ast->frame_offset= ast->cum_len;
00541             avio_skip(pb, size - 12 * 4);
00542             break;
00543         case MKTAG('s', 't', 'r', 'f'):
00544             /* stream header */
00545             if (stream_index >= (unsigned)s->nb_streams || avi->dv_demux) {
00546                 avio_skip(pb, size);
00547             } else {
00548                 uint64_t cur_pos = avio_tell(pb);
00549                 if (cur_pos < list_end)
00550                     size = FFMIN(size, list_end - cur_pos);
00551                 st = s->streams[stream_index];
00552                 switch(codec_type) {
00553                 case AVMEDIA_TYPE_VIDEO:
00554                     if(amv_file_format){
00555                         st->codec->width=avih_width;
00556                         st->codec->height=avih_height;
00557                         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00558                         st->codec->codec_id = CODEC_ID_AMV;
00559                         avio_skip(pb, size);
00560                         break;
00561                     }
00562                     tag1 = ff_get_bmp_header(pb, st);
00563 
00564                     if (tag1 == MKTAG('D', 'X', 'S', 'B') || tag1 == MKTAG('D','X','S','A')) {
00565                         st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
00566                         st->codec->codec_tag = tag1;
00567                         st->codec->codec_id = CODEC_ID_XSUB;
00568                         break;
00569                     }
00570 
00571                     if(size > 10*4 && size<(1<<30)){
00572                         st->codec->extradata_size= size - 10*4;
00573                         st->codec->extradata= av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00574                         if (!st->codec->extradata) {
00575                             st->codec->extradata_size= 0;
00576                             return AVERROR(ENOMEM);
00577                         }
00578                         avio_read(pb, st->codec->extradata, st->codec->extradata_size);
00579                     }
00580 
00581                     if(st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly
00582                         avio_r8(pb);
00583 
00584                     /* Extract palette from extradata if bpp <= 8. */
00585                     /* This code assumes that extradata contains only palette. */
00586                     /* This is true for all paletted codecs implemented in Libav. */
00587                     if (st->codec->extradata_size && (st->codec->bits_per_coded_sample <= 8)) {
00588                         int pal_size = (1 << st->codec->bits_per_coded_sample) << 2;
00589                         const uint8_t *pal_src;
00590 
00591                         pal_size = FFMIN(pal_size, st->codec->extradata_size);
00592                         pal_src = st->codec->extradata + st->codec->extradata_size - pal_size;
00593 #if HAVE_BIGENDIAN
00594                         for (i = 0; i < pal_size/4; i++)
00595                             ast->pal[i] = av_bswap32(((uint32_t*)pal_src)[i]);
00596 #else
00597                         memcpy(ast->pal, pal_src, pal_size);
00598 #endif
00599                         ast->has_pal = 1;
00600                     }
00601 
00602                     print_tag("video", tag1, 0);
00603 
00604                     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00605                     st->codec->codec_tag = tag1;
00606                     st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, tag1);
00607                     st->need_parsing = AVSTREAM_PARSE_HEADERS; // This is needed to get the pict type which is necessary for generating correct pts.
00608                     // Support "Resolution 1:1" for Avid AVI Codec
00609                     if(tag1 == MKTAG('A', 'V', 'R', 'n') &&
00610                        st->codec->extradata_size >= 31 &&
00611                        !memcmp(&st->codec->extradata[28], "1:1", 3))
00612                         st->codec->codec_id = CODEC_ID_RAWVIDEO;
00613 
00614                     if(st->codec->codec_tag==0 && st->codec->height > 0 && st->codec->extradata_size < 1U<<30){
00615                         st->codec->extradata_size+= 9;
00616                         st->codec->extradata= av_realloc(st->codec->extradata, st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00617                         if(st->codec->extradata)
00618                             memcpy(st->codec->extradata + st->codec->extradata_size - 9, "BottomUp", 9);
00619                     }
00620                     st->codec->height= FFABS(st->codec->height);
00621 
00622 //                    avio_skip(pb, size - 5 * 4);
00623                     break;
00624                 case AVMEDIA_TYPE_AUDIO:
00625                     ret = ff_get_wav_header(pb, st->codec, size);
00626                     if (ret < 0)
00627                         return ret;
00628                     ast->dshow_block_align= st->codec->block_align;
00629                     if(ast->sample_size && st->codec->block_align && ast->sample_size != st->codec->block_align){
00630                         av_log(s, AV_LOG_WARNING, "sample size (%d) != block align (%d)\n", ast->sample_size, st->codec->block_align);
00631                         ast->sample_size= st->codec->block_align;
00632                     }
00633                     if (size&1) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
00634                         avio_skip(pb, 1);
00635                     /* Force parsing as several audio frames can be in
00636                      * one packet and timestamps refer to packet start. */
00637                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;
00638                     /* ADTS header is in extradata, AAC without header must be
00639                      * stored as exact frames. Parser not needed and it will
00640                      * fail. */
00641                     if (st->codec->codec_id == CODEC_ID_AAC && st->codec->extradata_size)
00642                         st->need_parsing = AVSTREAM_PARSE_NONE;
00643                     /* AVI files with Xan DPCM audio (wrongly) declare PCM
00644                      * audio in the header but have Axan as stream_code_tag. */
00645                     if (st->codec->stream_codec_tag == AV_RL32("Axan")){
00646                         st->codec->codec_id  = CODEC_ID_XAN_DPCM;
00647                         st->codec->codec_tag = 0;
00648                     }
00649                     if (amv_file_format){
00650                         st->codec->codec_id  = CODEC_ID_ADPCM_IMA_AMV;
00651                         ast->dshow_block_align = 0;
00652                     }
00653                     break;
00654                 case AVMEDIA_TYPE_SUBTITLE:
00655                     st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
00656                     st->codec->codec_id   = CODEC_ID_PROBE;
00657                     break;
00658                 default:
00659                     st->codec->codec_type = AVMEDIA_TYPE_DATA;
00660                     st->codec->codec_id= CODEC_ID_NONE;
00661                     st->codec->codec_tag= 0;
00662                     avio_skip(pb, size);
00663                     break;
00664                 }
00665             }
00666             break;
00667         case MKTAG('i', 'n', 'd', 'x'):
00668             i= avio_tell(pb);
00669             if(pb->seekable && !(s->flags & AVFMT_FLAG_IGNIDX)){
00670                 read_braindead_odml_indx(s, 0);
00671             }
00672             avio_seek(pb, i+size, SEEK_SET);
00673             break;
00674         case MKTAG('v', 'p', 'r', 'p'):
00675             if(stream_index < (unsigned)s->nb_streams && size > 9*4){
00676                 AVRational active, active_aspect;
00677 
00678                 st = s->streams[stream_index];
00679                 avio_rl32(pb);
00680                 avio_rl32(pb);
00681                 avio_rl32(pb);
00682                 avio_rl32(pb);
00683                 avio_rl32(pb);
00684 
00685                 active_aspect.den= avio_rl16(pb);
00686                 active_aspect.num= avio_rl16(pb);
00687                 active.num       = avio_rl32(pb);
00688                 active.den       = avio_rl32(pb);
00689                 avio_rl32(pb); //nbFieldsPerFrame
00690 
00691                 if(active_aspect.num && active_aspect.den && active.num && active.den){
00692                     st->sample_aspect_ratio= av_div_q(active_aspect, active);
00693 //av_log(s, AV_LOG_ERROR, "vprp %d/%d %d/%d\n", active_aspect.num, active_aspect.den, active.num, active.den);
00694                 }
00695                 size -= 9*4;
00696             }
00697             avio_skip(pb, size);
00698             break;
00699         case MKTAG('s', 't', 'r', 'n'):
00700             if(s->nb_streams){
00701                 avi_read_tag(s, s->streams[s->nb_streams-1], tag, size);
00702                 break;
00703             }
00704         default:
00705             if(size > 1000000){
00706                 av_log(s, AV_LOG_ERROR, "Something went wrong during header parsing, "
00707                                         "I will ignore it and try to continue anyway.\n");
00708                 avi->movi_list = avio_tell(pb) - 4;
00709                 avi->movi_end  = avio_size(pb);
00710                 goto end_of_header;
00711             }
00712             /* skip tag */
00713             size += (size & 1);
00714             avio_skip(pb, size);
00715             break;
00716         }
00717     }
00718  end_of_header:
00719     /* check stream number */
00720     if (stream_index != s->nb_streams - 1) {
00721     fail:
00722         return -1;
00723     }
00724 
00725     if(!avi->index_loaded && pb->seekable)
00726         avi_load_index(s);
00727     avi->index_loaded = 1;
00728     avi->non_interleaved |= guess_ni_flag(s);
00729     for(i=0; i<s->nb_streams; i++){
00730         AVStream *st = s->streams[i];
00731         if(st->nb_index_entries)
00732             break;
00733     }
00734     if(i==s->nb_streams && avi->non_interleaved) {
00735         av_log(s, AV_LOG_WARNING, "non-interleaved AVI without index, switching to interleaved\n");
00736         avi->non_interleaved=0;
00737     }
00738 
00739     if(avi->non_interleaved) {
00740         av_log(s, AV_LOG_INFO, "non-interleaved AVI\n");
00741         clean_index(s);
00742     }
00743 
00744     ff_metadata_conv_ctx(s, NULL, ff_avi_metadata_conv);
00745 
00746     return 0;
00747 }
00748 
00749 static int read_gab2_sub(AVStream *st, AVPacket *pkt) {
00750     if (!strcmp(pkt->data, "GAB2") && AV_RL16(pkt->data+5) == 2) {
00751         uint8_t desc[256];
00752         int score = AVPROBE_SCORE_MAX / 2, ret;
00753         AVIStream *ast = st->priv_data;
00754         AVInputFormat *sub_demuxer;
00755         AVRational time_base;
00756         AVIOContext *pb = avio_alloc_context( pkt->data + 7,
00757                                               pkt->size - 7,
00758                                               0, NULL, NULL, NULL, NULL);
00759         AVProbeData pd;
00760         unsigned int desc_len = avio_rl32(pb);
00761 
00762         if (desc_len > pb->buf_end - pb->buf_ptr)
00763             goto error;
00764 
00765         ret = avio_get_str16le(pb, desc_len, desc, sizeof(desc));
00766         avio_skip(pb, desc_len - ret);
00767         if (*desc)
00768             av_dict_set(&st->metadata, "title", desc, 0);
00769 
00770         avio_rl16(pb);   /* flags? */
00771         avio_rl32(pb);   /* data size */
00772 
00773         pd = (AVProbeData) { .buf = pb->buf_ptr, .buf_size = pb->buf_end - pb->buf_ptr };
00774         if (!(sub_demuxer = av_probe_input_format2(&pd, 1, &score)))
00775             goto error;
00776 
00777         if (!(ast->sub_ctx = avformat_alloc_context()))
00778             goto error;
00779 
00780         ast->sub_ctx->pb      = pb;
00781         if (!avformat_open_input(&ast->sub_ctx, "", sub_demuxer, NULL)) {
00782             av_read_packet(ast->sub_ctx, &ast->sub_pkt);
00783             *st->codec = *ast->sub_ctx->streams[0]->codec;
00784             ast->sub_ctx->streams[0]->codec->extradata = NULL;
00785             time_base = ast->sub_ctx->streams[0]->time_base;
00786             av_set_pts_info(st, 64, time_base.num, time_base.den);
00787         }
00788         ast->sub_buffer = pkt->data;
00789         memset(pkt, 0, sizeof(*pkt));
00790         return 1;
00791 error:
00792         av_freep(&pb);
00793     }
00794     return 0;
00795 }
00796 
00797 static AVStream *get_subtitle_pkt(AVFormatContext *s, AVStream *next_st,
00798                                   AVPacket *pkt)
00799 {
00800     AVIStream *ast, *next_ast = next_st->priv_data;
00801     int64_t ts, next_ts, ts_min = INT64_MAX;
00802     AVStream *st, *sub_st = NULL;
00803     int i;
00804 
00805     next_ts = av_rescale_q(next_ast->frame_offset, next_st->time_base,
00806                            AV_TIME_BASE_Q);
00807 
00808     for (i=0; i<s->nb_streams; i++) {
00809         st  = s->streams[i];
00810         ast = st->priv_data;
00811         if (st->discard < AVDISCARD_ALL && ast && ast->sub_pkt.data) {
00812             ts = av_rescale_q(ast->sub_pkt.dts, st->time_base, AV_TIME_BASE_Q);
00813             if (ts <= next_ts && ts < ts_min) {
00814                 ts_min = ts;
00815                 sub_st = st;
00816             }
00817         }
00818     }
00819 
00820     if (sub_st) {
00821         ast = sub_st->priv_data;
00822         *pkt = ast->sub_pkt;
00823         pkt->stream_index = sub_st->index;
00824         if (av_read_packet(ast->sub_ctx, &ast->sub_pkt) < 0)
00825             ast->sub_pkt.data = NULL;
00826     }
00827     return sub_st;
00828 }
00829 
00830 static int get_stream_idx(int *d){
00831     if(    d[0] >= '0' && d[0] <= '9'
00832         && d[1] >= '0' && d[1] <= '9'){
00833         return (d[0] - '0') * 10 + (d[1] - '0');
00834     }else{
00835         return 100; //invalid stream ID
00836     }
00837 }
00838 
00839 static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
00840 {
00841     AVIContext *avi = s->priv_data;
00842     AVIOContext *pb = s->pb;
00843     int n, d[8];
00844     unsigned int size;
00845     int64_t i, sync;
00846     void* dstr;
00847 
00848     if (CONFIG_DV_DEMUXER && avi->dv_demux) {
00849         int size = dv_get_packet(avi->dv_demux, pkt);
00850         if (size >= 0)
00851             return size;
00852     }
00853 
00854     if(avi->non_interleaved){
00855         int best_stream_index = 0;
00856         AVStream *best_st= NULL;
00857         AVIStream *best_ast;
00858         int64_t best_ts= INT64_MAX;
00859         int i;
00860 
00861         for(i=0; i<s->nb_streams; i++){
00862             AVStream *st = s->streams[i];
00863             AVIStream *ast = st->priv_data;
00864             int64_t ts= ast->frame_offset;
00865             int64_t last_ts;
00866 
00867             if(!st->nb_index_entries)
00868                 continue;
00869 
00870             last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;
00871             if(!ast->remaining && ts > last_ts)
00872                 continue;
00873 
00874             ts = av_rescale_q(ts, st->time_base, (AVRational){FFMAX(1, ast->sample_size), AV_TIME_BASE});
00875 
00876 //            av_log(s, AV_LOG_DEBUG, "%"PRId64" %d/%d %"PRId64"\n", ts, st->time_base.num, st->time_base.den, ast->frame_offset);
00877             if(ts < best_ts){
00878                 best_ts= ts;
00879                 best_st= st;
00880                 best_stream_index= i;
00881             }
00882         }
00883         if(!best_st)
00884             return -1;
00885 
00886         best_ast = best_st->priv_data;
00887         best_ts = av_rescale_q(best_ts, (AVRational){FFMAX(1, best_ast->sample_size), AV_TIME_BASE}, best_st->time_base);
00888         if(best_ast->remaining)
00889             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
00890         else{
00891             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
00892             if(i>=0)
00893                 best_ast->frame_offset= best_st->index_entries[i].timestamp;
00894         }
00895 
00896 //        av_log(s, AV_LOG_DEBUG, "%d\n", i);
00897         if(i>=0){
00898             int64_t pos= best_st->index_entries[i].pos;
00899             pos += best_ast->packet_size - best_ast->remaining;
00900             avio_seek(s->pb, pos + 8, SEEK_SET);
00901 //        av_log(s, AV_LOG_DEBUG, "pos=%"PRId64"\n", pos);
00902 
00903             assert(best_ast->remaining <= best_ast->packet_size);
00904 
00905             avi->stream_index= best_stream_index;
00906             if(!best_ast->remaining)
00907                 best_ast->packet_size=
00908                 best_ast->remaining= best_st->index_entries[i].size;
00909         }
00910     }
00911 
00912 resync:
00913     if(avi->stream_index >= 0){
00914         AVStream *st= s->streams[ avi->stream_index ];
00915         AVIStream *ast= st->priv_data;
00916         int size, err;
00917 
00918         if(get_subtitle_pkt(s, st, pkt))
00919             return 0;
00920 
00921         if(ast->sample_size <= 1) // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM
00922             size= INT_MAX;
00923         else if(ast->sample_size < 32)
00924             // arbitrary multiplier to avoid tiny packets for raw PCM data
00925             size= 1024*ast->sample_size;
00926         else
00927             size= ast->sample_size;
00928 
00929         if(size > ast->remaining)
00930             size= ast->remaining;
00931         avi->last_pkt_pos= avio_tell(pb);
00932         err= av_get_packet(pb, pkt, size);
00933         if(err<0)
00934             return err;
00935 
00936         if(ast->has_pal && pkt->data && pkt->size<(unsigned)INT_MAX/2){
00937             uint8_t *pal;
00938             pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE);
00939             if(!pal){
00940                 av_log(s, AV_LOG_ERROR, "Failed to allocate data for palette\n");
00941             }else{
00942                 memcpy(pal, ast->pal, AVPALETTE_SIZE);
00943                 ast->has_pal = 0;
00944             }
00945         }
00946 
00947         if (CONFIG_DV_DEMUXER && avi->dv_demux) {
00948             dstr = pkt->destruct;
00949             size = dv_produce_packet(avi->dv_demux, pkt,
00950                                     pkt->data, pkt->size);
00951             pkt->destruct = dstr;
00952             pkt->flags |= AV_PKT_FLAG_KEY;
00953             if (size < 0)
00954                 av_free_packet(pkt);
00955         } else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE
00956                    && !st->codec->codec_tag && read_gab2_sub(st, pkt)) {
00957             ast->frame_offset++;
00958             avi->stream_index = -1;
00959             ast->remaining = 0;
00960             goto resync;
00961         } else {
00962             /* XXX: How to handle B-frames in AVI? */
00963             pkt->dts = ast->frame_offset;
00964 //                pkt->dts += ast->start;
00965             if(ast->sample_size)
00966                 pkt->dts /= ast->sample_size;
00967 //av_log(s, AV_LOG_DEBUG, "dts:%"PRId64" offset:%"PRId64" %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);
00968             pkt->stream_index = avi->stream_index;
00969 
00970             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
00971                 AVIndexEntry *e;
00972                 int index;
00973                 assert(st->index_entries);
00974 
00975                 index= av_index_search_timestamp(st, ast->frame_offset, 0);
00976                 e= &st->index_entries[index];
00977 
00978                 if(index >= 0 && e->timestamp == ast->frame_offset){
00979                     if (e->flags & AVINDEX_KEYFRAME)
00980                         pkt->flags |= AV_PKT_FLAG_KEY;
00981                 }
00982             } else {
00983                 pkt->flags |= AV_PKT_FLAG_KEY;
00984             }
00985             ast->frame_offset += get_duration(ast, pkt->size);
00986         }
00987         ast->remaining -= size;
00988         if(!ast->remaining){
00989             avi->stream_index= -1;
00990             ast->packet_size= 0;
00991         }
00992 
00993         return size;
00994     }
00995 
00996     memset(d, -1, sizeof(int)*8);
00997     for(i=sync=avio_tell(pb); !pb->eof_reached; i++) {
00998         int j;
00999 
01000         for(j=0; j<7; j++)
01001             d[j]= d[j+1];
01002         d[7]= avio_r8(pb);
01003 
01004         size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
01005 
01006         n= get_stream_idx(d+2);
01007 //av_log(s, AV_LOG_DEBUG, "%X %X %X %X %X %X %X %X %"PRId64" %d %d\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);
01008         if(i + (uint64_t)size > avi->fsize || d[0]<0)
01009             continue;
01010 
01011         //parse ix##
01012         if(  (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
01013         //parse JUNK
01014            ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')
01015            ||(d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')){
01016             avio_skip(pb, size);
01017 //av_log(s, AV_LOG_DEBUG, "SKIP\n");
01018             goto resync;
01019         }
01020 
01021         //parse stray LIST
01022         if(d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T'){
01023             avio_skip(pb, 4);
01024             goto resync;
01025         }
01026 
01027         n= get_stream_idx(d);
01028 
01029         if(!((i-avi->last_pkt_pos)&1) && get_stream_idx(d+1) < s->nb_streams)
01030             continue;
01031 
01032         //detect ##ix chunk and skip
01033         if(d[2] == 'i' && d[3] == 'x' && n < s->nb_streams){
01034             avio_skip(pb, size);
01035             goto resync;
01036         }
01037 
01038         //parse ##dc/##wb
01039         if(n < s->nb_streams){
01040             AVStream *st;
01041             AVIStream *ast;
01042             st = s->streams[n];
01043             ast = st->priv_data;
01044 
01045             if(s->nb_streams>=2){
01046                 AVStream *st1  = s->streams[1];
01047                 AVIStream *ast1= st1->priv_data;
01048                 //workaround for broken small-file-bug402.avi
01049                 if(   d[2] == 'w' && d[3] == 'b'
01050                    && n==0
01051                    && st ->codec->codec_type == AVMEDIA_TYPE_VIDEO
01052                    && st1->codec->codec_type == AVMEDIA_TYPE_AUDIO
01053                    && ast->prefix == 'd'*256+'c'
01054                    && (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)
01055                   ){
01056                     n=1;
01057                     st = st1;
01058                     ast = ast1;
01059                     av_log(s, AV_LOG_WARNING, "Invalid stream + prefix combination, assuming audio.\n");
01060                 }
01061             }
01062 
01063 
01064             if(   (st->discard >= AVDISCARD_DEFAULT && size==0)
01065                /*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & AV_PKT_FLAG_KEY))*/ //FIXME needs a little reordering
01066                || st->discard >= AVDISCARD_ALL){
01067                 ast->frame_offset += get_duration(ast, size);
01068                 avio_skip(pb, size);
01069                 goto resync;
01070             }
01071 
01072             if (d[2] == 'p' && d[3] == 'c' && size<=4*256+4) {
01073                 int k = avio_r8(pb);
01074                 int last = (k + avio_r8(pb) - 1) & 0xFF;
01075 
01076                 avio_rl16(pb); //flags
01077 
01078                 for (; k <= last; k++)
01079                     ast->pal[k] = avio_rb32(pb)>>8;// b + (g << 8) + (r << 16);
01080                 ast->has_pal= 1;
01081                 goto resync;
01082             } else if(   ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||
01083                          d[2]*256+d[3] == ast->prefix /*||
01084                          (d[2] == 'd' && d[3] == 'c') ||
01085                          (d[2] == 'w' && d[3] == 'b')*/) {
01086 
01087 //av_log(s, AV_LOG_DEBUG, "OK\n");
01088                 if(d[2]*256+d[3] == ast->prefix)
01089                     ast->prefix_count++;
01090                 else{
01091                     ast->prefix= d[2]*256+d[3];
01092                     ast->prefix_count= 0;
01093                 }
01094 
01095                 avi->stream_index= n;
01096                 ast->packet_size= size + 8;
01097                 ast->remaining= size;
01098 
01099                 if(size || !ast->sample_size){
01100                     uint64_t pos= avio_tell(pb) - 8;
01101                     if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){
01102                         av_add_index_entry(st, pos, ast->frame_offset, size, 0, AVINDEX_KEYFRAME);
01103                     }
01104                 }
01105                 goto resync;
01106             }
01107         }
01108     }
01109 
01110     return AVERROR_EOF;
01111 }
01112 
01113 /* XXX: We make the implicit supposition that the positions are sorted
01114    for each stream. */
01115 static int avi_read_idx1(AVFormatContext *s, int size)
01116 {
01117     AVIContext *avi = s->priv_data;
01118     AVIOContext *pb = s->pb;
01119     int nb_index_entries, i;
01120     AVStream *st;
01121     AVIStream *ast;
01122     unsigned int index, tag, flags, pos, len;
01123     unsigned last_pos= -1;
01124 
01125     nb_index_entries = size / 16;
01126     if (nb_index_entries <= 0)
01127         return -1;
01128 
01129     /* Read the entries and sort them in each stream component. */
01130     for(i = 0; i < nb_index_entries; i++) {
01131         tag = avio_rl32(pb);
01132         flags = avio_rl32(pb);
01133         pos = avio_rl32(pb);
01134         len = avio_rl32(pb);
01135         av_dlog(s, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
01136                 i, tag, flags, pos, len);
01137         if(i==0 && pos > avi->movi_list)
01138             avi->movi_list= 0; //FIXME better check
01139         pos += avi->movi_list;
01140 
01141         index = ((tag & 0xff) - '0') * 10;
01142         index += ((tag >> 8) & 0xff) - '0';
01143         if (index >= s->nb_streams)
01144             continue;
01145         st = s->streams[index];
01146         ast = st->priv_data;
01147 
01148         av_dlog(s, "%d cum_len=%"PRId64"\n", len, ast->cum_len);
01149 
01150         if(pb->eof_reached)
01151             return -1;
01152 
01153         if(last_pos == pos)
01154             avi->non_interleaved= 1;
01155         else if(len || !ast->sample_size)
01156             av_add_index_entry(st, pos, ast->cum_len, len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
01157         ast->cum_len += get_duration(ast, len);
01158         last_pos= pos;
01159     }
01160     return 0;
01161 }
01162 
01163 static int guess_ni_flag(AVFormatContext *s){
01164     int i;
01165     int64_t last_start=0;
01166     int64_t first_end= INT64_MAX;
01167     int64_t oldpos= avio_tell(s->pb);
01168 
01169     for(i=0; i<s->nb_streams; i++){
01170         AVStream *st = s->streams[i];
01171         int n= st->nb_index_entries;
01172         unsigned int size;
01173 
01174         if(n <= 0)
01175             continue;
01176 
01177         if(n >= 2){
01178             int64_t pos= st->index_entries[0].pos;
01179             avio_seek(s->pb, pos + 4, SEEK_SET);
01180             size= avio_rl32(s->pb);
01181             if(pos + size > st->index_entries[1].pos)
01182                 last_start= INT64_MAX;
01183         }
01184 
01185         if(st->index_entries[0].pos > last_start)
01186             last_start= st->index_entries[0].pos;
01187         if(st->index_entries[n-1].pos < first_end)
01188             first_end= st->index_entries[n-1].pos;
01189     }
01190     avio_seek(s->pb, oldpos, SEEK_SET);
01191     return last_start > first_end;
01192 }
01193 
01194 static int avi_load_index(AVFormatContext *s)
01195 {
01196     AVIContext *avi = s->priv_data;
01197     AVIOContext *pb = s->pb;
01198     uint32_t tag, size;
01199     int64_t pos= avio_tell(pb);
01200     int ret = -1;
01201 
01202     if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)
01203         goto the_end; // maybe truncated file
01204     av_dlog(s, "movi_end=0x%"PRIx64"\n", avi->movi_end);
01205     for(;;) {
01206         if (pb->eof_reached)
01207             break;
01208         tag = avio_rl32(pb);
01209         size = avio_rl32(pb);
01210         av_dlog(s, "tag=%c%c%c%c size=0x%x\n",
01211                  tag        & 0xff,
01212                 (tag >>  8) & 0xff,
01213                 (tag >> 16) & 0xff,
01214                 (tag >> 24) & 0xff,
01215                 size);
01216         switch(tag) {
01217         case MKTAG('i', 'd', 'x', '1'):
01218             if (avi_read_idx1(s, size) < 0)
01219                 goto skip;
01220             ret = 0;
01221                 goto the_end;
01222             break;
01223         default:
01224         skip:
01225             size += (size & 1);
01226             if (avio_skip(pb, size) < 0)
01227                 goto the_end; // something is wrong here
01228             break;
01229         }
01230     }
01231  the_end:
01232     avio_seek(pb, pos, SEEK_SET);
01233     return ret;
01234 }
01235 
01236 static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)
01237 {
01238     AVIStream *ast2 = st2->priv_data;
01239     int64_t ts2 = av_rescale_q(timestamp, st->time_base, st2->time_base);
01240     av_free_packet(&ast2->sub_pkt);
01241     if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||
01242         avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)
01243         av_read_packet(ast2->sub_ctx, &ast2->sub_pkt);
01244 }
01245 
01246 static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
01247 {
01248     AVIContext *avi = s->priv_data;
01249     AVStream *st;
01250     int i, index;
01251     int64_t pos;
01252     AVIStream *ast;
01253 
01254     if (!avi->index_loaded) {
01255         /* we only load the index on demand */
01256         avi_load_index(s);
01257         avi->index_loaded = 1;
01258     }
01259     assert(stream_index>= 0);
01260 
01261     st = s->streams[stream_index];
01262     ast= st->priv_data;
01263     index= av_index_search_timestamp(st, timestamp * FFMAX(ast->sample_size, 1), flags);
01264     if(index<0)
01265         return -1;
01266 
01267     /* find the position */
01268     pos = st->index_entries[index].pos;
01269     timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);
01270 
01271 //    av_log(s, AV_LOG_DEBUG, "XX %"PRId64" %d %"PRId64"\n", timestamp, index, st->index_entries[index].timestamp);
01272 
01273     if (CONFIG_DV_DEMUXER && avi->dv_demux) {
01274         /* One and only one real stream for DV in AVI, and it has video  */
01275         /* offsets. Calling with other stream indexes should have failed */
01276         /* the av_index_search_timestamp call above.                     */
01277         assert(stream_index == 0);
01278 
01279         /* Feed the DV video stream version of the timestamp to the */
01280         /* DV demux so it can synthesize correct timestamps.        */
01281         dv_offset_reset(avi->dv_demux, timestamp);
01282 
01283         avio_seek(s->pb, pos, SEEK_SET);
01284         avi->stream_index= -1;
01285         return 0;
01286     }
01287 
01288     for(i = 0; i < s->nb_streams; i++) {
01289         AVStream *st2 = s->streams[i];
01290         AVIStream *ast2 = st2->priv_data;
01291 
01292         ast2->packet_size=
01293         ast2->remaining= 0;
01294 
01295         if (ast2->sub_ctx) {
01296             seek_subtitle(st, st2, timestamp);
01297             continue;
01298         }
01299 
01300         if (st2->nb_index_entries <= 0)
01301             continue;
01302 
01303 //        assert(st2->codec->block_align);
01304         assert((int64_t)st2->time_base.num*ast2->rate == (int64_t)st2->time_base.den*ast2->scale);
01305         index = av_index_search_timestamp(
01306                 st2,
01307                 av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),
01308                 flags | AVSEEK_FLAG_BACKWARD);
01309         if(index<0)
01310             index=0;
01311 
01312         if(!avi->non_interleaved){
01313             while(index>0 && st2->index_entries[index].pos > pos)
01314                 index--;
01315             while(index+1 < st2->nb_index_entries && st2->index_entries[index].pos < pos)
01316                 index++;
01317         }
01318 
01319 //        av_log(s, AV_LOG_DEBUG, "%"PRId64" %d %"PRId64"\n", timestamp, index, st2->index_entries[index].timestamp);
01320         /* extract the current frame number */
01321         ast2->frame_offset = st2->index_entries[index].timestamp;
01322     }
01323 
01324     /* do the seek */
01325     avio_seek(s->pb, pos, SEEK_SET);
01326     avi->stream_index= -1;
01327     return 0;
01328 }
01329 
01330 static int avi_read_close(AVFormatContext *s)
01331 {
01332     int i;
01333     AVIContext *avi = s->priv_data;
01334 
01335     for(i=0;i<s->nb_streams;i++) {
01336         AVStream *st = s->streams[i];
01337         AVIStream *ast = st->priv_data;
01338         if (ast) {
01339             if (ast->sub_ctx) {
01340                 av_freep(&ast->sub_ctx->pb);
01341                 av_close_input_file(ast->sub_ctx);
01342             }
01343             av_free(ast->sub_buffer);
01344             av_free_packet(&ast->sub_pkt);
01345         }
01346     }
01347 
01348     av_free(avi->dv_demux);
01349 
01350     return 0;
01351 }
01352 
01353 static int avi_probe(AVProbeData *p)
01354 {
01355     int i;
01356 
01357     /* check file header */
01358     for(i=0; avi_headers[i][0]; i++)
01359         if(!memcmp(p->buf  , avi_headers[i]  , 4) &&
01360            !memcmp(p->buf+8, avi_headers[i]+4, 4))
01361             return AVPROBE_SCORE_MAX;
01362 
01363     return 0;
01364 }
01365 
01366 AVInputFormat ff_avi_demuxer = {
01367     "avi",
01368     NULL_IF_CONFIG_SMALL("AVI format"),
01369     sizeof(AVIContext),
01370     avi_probe,
01371     avi_read_header,
01372     avi_read_packet,
01373     avi_read_close,
01374     avi_read_seek,
01375 };