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 "libavutil/intreadwrite.h"
00023 #include "libavutil/mathematics.h"
00024 #include "libavutil/bswap.h"
00025 #include "libavutil/dict.h"
00026 #include "libavutil/avstring.h"
00027 #include "avformat.h"
00028 #include "internal.h"
00029 #include "avi.h"
00030 #include "dv.h"
00031 #include "riff.h"
00032 
00033 #undef NDEBUG
00034 #include <assert.h>
00035 
00036 typedef struct AVIStream {
00037     int64_t frame_offset; /* current frame (video) or byte (audio) counter
00038                          (used to compute the pts) */
00039     int remaining;
00040     int packet_size;
00041 
00042     int scale;
00043     int rate;
00044     int sample_size; /* size of one sample (or packet) (in the rate/scale sense) in bytes */
00045 
00046     int64_t cum_len; /* temporary storage (used during seek) */
00047 
00048     int prefix;                       
00049     int prefix_count;
00050     uint32_t pal[256];
00051     int has_pal;
00052     int dshow_block_align;            
00053 
00054     AVFormatContext *sub_ctx;
00055     AVPacket sub_pkt;
00056     uint8_t *sub_buffer;
00057 } AVIStream;
00058 
00059 typedef struct {
00060     int64_t  riff_end;
00061     int64_t  movi_end;
00062     int64_t  fsize;
00063     int64_t movi_list;
00064     int64_t last_pkt_pos;
00065     int index_loaded;
00066     int is_odml;
00067     int non_interleaved;
00068     int stream_index;
00069     DVDemuxContext* dv_demux;
00070     int odml_depth;
00071 #define MAX_ODML_DEPTH 1000
00072 } AVIContext;
00073 
00074 static const char avi_headers[][8] = {
00075     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', ' ' },
00076     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 'X' },
00077     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 0x19},
00078     { 'O', 'N', '2', ' ',    'O', 'N', '2', 'f' },
00079     { 'R', 'I', 'F', 'F',    'A', 'M', 'V', ' ' },
00080     { 0 }
00081 };
00082 
00083 static const AVMetadataConv avi_metadata_conv[] = {
00084     { "strn", "title" },
00085     { 0 },
00086 };
00087 
00088 static int avi_load_index(AVFormatContext *s);
00089 static int guess_ni_flag(AVFormatContext *s);
00090 
00091 #define print_tag(str, tag, size)                       \
00092     av_dlog(NULL, "%s: tag=%c%c%c%c size=0x%x\n",       \
00093            str, tag & 0xff,                             \
00094            (tag >> 8) & 0xff,                           \
00095            (tag >> 16) & 0xff,                          \
00096            (tag >> 24) & 0xff,                          \
00097            size)
00098 
00099 static inline int get_duration(AVIStream *ast, int len){
00100     if(ast->sample_size){
00101         return len;
00102     }else if (ast->dshow_block_align){
00103         return (len + ast->dshow_block_align - 1)/ast->dshow_block_align;
00104     }else
00105         return 1;
00106 }
00107 
00108 static int get_riff(AVFormatContext *s, AVIOContext *pb)
00109 {
00110     AVIContext *avi = s->priv_data;
00111     char header[8];
00112     int i;
00113 
00114     /* check RIFF header */
00115     avio_read(pb, header, 4);
00116     avi->riff_end = avio_rl32(pb);  /* RIFF chunk size */
00117     avi->riff_end += avio_tell(pb); /* RIFF chunk end */
00118     avio_read(pb, header+4, 4);
00119 
00120     for(i=0; avi_headers[i][0]; i++)
00121         if(!memcmp(header, avi_headers[i], 8))
00122             break;
00123     if(!avi_headers[i][0])
00124         return -1;
00125 
00126     if(header[7] == 0x19)
00127         av_log(s, AV_LOG_INFO, "This file has been generated by a totally broken muxer.\n");
00128 
00129     return 0;
00130 }
00131 
00132 static int read_braindead_odml_indx(AVFormatContext *s, int frame_num){
00133     AVIContext *avi = s->priv_data;
00134     AVIOContext *pb = s->pb;
00135     int longs_pre_entry= avio_rl16(pb);
00136     int index_sub_type = avio_r8(pb);
00137     int index_type     = avio_r8(pb);
00138     int entries_in_use = avio_rl32(pb);
00139     int chunk_id       = avio_rl32(pb);
00140     int64_t base       = avio_rl64(pb);
00141     int stream_id= 10*((chunk_id&0xFF) - '0') + (((chunk_id>>8)&0xFF) - '0');
00142     AVStream *st;
00143     AVIStream *ast;
00144     int i;
00145     int64_t last_pos= -1;
00146     int64_t filesize= avio_size(s->pb);
00147 
00148     av_dlog(s, "longs_pre_entry:%d index_type:%d entries_in_use:%d chunk_id:%X base:%16"PRIX64"\n",
00149             longs_pre_entry,index_type, entries_in_use, chunk_id, base);
00150 
00151     if(stream_id >= s->nb_streams || stream_id < 0)
00152         return -1;
00153     st= s->streams[stream_id];
00154     ast = st->priv_data;
00155 
00156     if(index_sub_type)
00157         return -1;
00158 
00159     avio_rl32(pb);
00160 
00161     if(index_type && longs_pre_entry != 2)
00162         return -1;
00163     if(index_type>1)
00164         return -1;
00165 
00166     if(filesize > 0 && base >= filesize){
00167         av_log(s, AV_LOG_ERROR, "ODML index invalid\n");
00168         if(base>>32 == (base & 0xFFFFFFFF) && (base & 0xFFFFFFFF) < filesize && filesize <= 0xFFFFFFFF)
00169             base &= 0xFFFFFFFF;
00170         else
00171             return -1;
00172     }
00173 
00174     for(i=0; i<entries_in_use; i++){
00175         if(index_type){
00176             int64_t pos= avio_rl32(pb) + base - 8;
00177             int len    = avio_rl32(pb);
00178             int key= len >= 0;
00179             len &= 0x7FFFFFFF;
00180 
00181             av_dlog(s, "pos:%"PRId64", len:%X\n", pos, len);
00182 
00183             if(pb->eof_reached)
00184                 return -1;
00185 
00186             if(last_pos == pos || pos == base - 8)
00187                 avi->non_interleaved= 1;
00188             if(last_pos != pos && (len || !ast->sample_size))
00189                 av_add_index_entry(st, pos, ast->cum_len, len, 0, key ? AVINDEX_KEYFRAME : 0);
00190 
00191             ast->cum_len += get_duration(ast, len);
00192             last_pos= pos;
00193         }else{
00194             int64_t offset, pos;
00195             int duration;
00196             offset = avio_rl64(pb);
00197             avio_rl32(pb);       /* size */
00198             duration = avio_rl32(pb);
00199 
00200             if(pb->eof_reached)
00201                 return -1;
00202 
00203             pos = avio_tell(pb);
00204 
00205             if(avi->odml_depth > MAX_ODML_DEPTH){
00206                 av_log(s, AV_LOG_ERROR, "Too deeply nested ODML indexes\n");
00207                 return -1;
00208             }
00209 
00210             avio_seek(pb, offset+8, SEEK_SET);
00211             avi->odml_depth++;
00212             read_braindead_odml_indx(s, frame_num);
00213             avi->odml_depth--;
00214             frame_num += duration;
00215 
00216             avio_seek(pb, pos, SEEK_SET);
00217         }
00218     }
00219     avi->index_loaded=1;
00220     return 0;
00221 }
00222 
00223 static void clean_index(AVFormatContext *s){
00224     int i;
00225     int64_t j;
00226 
00227     for(i=0; i<s->nb_streams; i++){
00228         AVStream *st = s->streams[i];
00229         AVIStream *ast = st->priv_data;
00230         int n= st->nb_index_entries;
00231         int max= ast->sample_size;
00232         int64_t pos, size, ts;
00233 
00234         if(n != 1 || ast->sample_size==0)
00235             continue;
00236 
00237         while(max < 1024) max+=max;
00238 
00239         pos= st->index_entries[0].pos;
00240         size= st->index_entries[0].size;
00241         ts= st->index_entries[0].timestamp;
00242 
00243         for(j=0; j<size; j+=max){
00244             av_add_index_entry(st, pos+j, ts+j, FFMIN(max, size-j), 0, AVINDEX_KEYFRAME);
00245         }
00246     }
00247 }
00248 
00249 static int avi_read_tag(AVFormatContext *s, AVStream *st, uint32_t tag, uint32_t size)
00250 {
00251     AVIOContext *pb = s->pb;
00252     char key[5] = {0}, *value;
00253 
00254     size += (size & 1);
00255 
00256     if (size == UINT_MAX)
00257         return -1;
00258     value = av_malloc(size+1);
00259     if (!value)
00260         return -1;
00261     avio_read(pb, value, size);
00262     value[size]=0;
00263 
00264     AV_WL32(key, tag);
00265 
00266     return av_dict_set(st ? &st->metadata : &s->metadata, key, value,
00267                             AV_DICT_DONT_STRDUP_VAL);
00268 }
00269 
00270 static const char months[12][4] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
00271                                     "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
00272 
00273 static void avi_metadata_creation_time(AVDictionary **metadata, char *date)
00274 {
00275     char month[4], time[9], buffer[64];
00276     int i, day, year;
00277     /* parse standard AVI date format (ie. "Mon Mar 10 15:04:43 2003") */
00278     if (sscanf(date, "%*3s%*[ ]%3s%*[ ]%2d%*[ ]%8s%*[ ]%4d",
00279                month, &day, time, &year) == 4) {
00280         for (i=0; i<12; i++)
00281             if (!av_strcasecmp(month, months[i])) {
00282                 snprintf(buffer, sizeof(buffer), "%.4d-%.2d-%.2d %s",
00283                          year, i+1, day, time);
00284                 av_dict_set(metadata, "creation_time", buffer, 0);
00285             }
00286     } else if (date[4] == '/' && date[7] == '/') {
00287         date[4] = date[7] = '-';
00288         av_dict_set(metadata, "creation_time", date, 0);
00289     }
00290 }
00291 
00292 static void avi_read_nikon(AVFormatContext *s, uint64_t end)
00293 {
00294     while (avio_tell(s->pb) < end) {
00295         uint32_t tag  = avio_rl32(s->pb);
00296         uint32_t size = avio_rl32(s->pb);
00297         switch (tag) {
00298         case MKTAG('n', 'c', 't', 'g'): {  /* Nikon Tags */
00299             uint64_t tag_end = avio_tell(s->pb) + size;
00300             while (avio_tell(s->pb) < tag_end) {
00301                 uint16_t tag  = avio_rl16(s->pb);
00302                 uint16_t size = avio_rl16(s->pb);
00303                 const char *name = NULL;
00304                 char buffer[64] = {0};
00305                 size -= avio_read(s->pb, buffer,
00306                                    FFMIN(size, sizeof(buffer)-1));
00307                 switch (tag) {
00308                 case 0x03:  name = "maker";  break;
00309                 case 0x04:  name = "model";  break;
00310                 case 0x13:  name = "creation_time";
00311                     if (buffer[4] == ':' && buffer[7] == ':')
00312                         buffer[4] = buffer[7] = '-';
00313                     break;
00314                 }
00315                 if (name)
00316                     av_dict_set(&s->metadata, name, buffer, 0);
00317                 avio_skip(s->pb, size);
00318             }
00319             break;
00320         }
00321         default:
00322             avio_skip(s->pb, size);
00323             break;
00324         }
00325     }
00326 }
00327 
00328 static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
00329 {
00330     AVIContext *avi = s->priv_data;
00331     AVIOContext *pb = s->pb;
00332     unsigned int tag, tag1, handler;
00333     int codec_type, stream_index, frame_period;
00334     unsigned int size;
00335     int i;
00336     AVStream *st;
00337     AVIStream *ast = NULL;
00338     int avih_width=0, avih_height=0;
00339     int amv_file_format=0;
00340     uint64_t list_end = 0;
00341     int ret;
00342 
00343     avi->stream_index= -1;
00344 
00345     if (get_riff(s, pb) < 0)
00346         return -1;
00347 
00348     avi->fsize = avio_size(pb);
00349     if(avi->fsize<=0)
00350         avi->fsize= avi->riff_end == 8 ? INT64_MAX : avi->riff_end;
00351 
00352     /* first list tag */
00353     stream_index = -1;
00354     codec_type = -1;
00355     frame_period = 0;
00356     for(;;) {
00357         if (pb->eof_reached)
00358             goto fail;
00359         tag = avio_rl32(pb);
00360         size = avio_rl32(pb);
00361 
00362         print_tag("tag", tag, size);
00363 
00364         switch(tag) {
00365         case MKTAG('L', 'I', 'S', 'T'):
00366             list_end = avio_tell(pb) + size;
00367             /* Ignored, except at start of video packets. */
00368             tag1 = avio_rl32(pb);
00369 
00370             print_tag("list", tag1, 0);
00371 
00372             if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
00373                 avi->movi_list = avio_tell(pb) - 4;
00374                 if(size) avi->movi_end = avi->movi_list + size + (size & 1);
00375                 else     avi->movi_end = avio_size(pb);
00376                 av_dlog(NULL, "movi end=%"PRIx64"\n", avi->movi_end);
00377                 goto end_of_header;
00378             }
00379             else if (tag1 == MKTAG('I', 'N', 'F', 'O'))
00380                 ff_read_riff_info(s, size - 4);
00381             else if (tag1 == MKTAG('n', 'c', 'd', 't'))
00382                 avi_read_nikon(s, list_end);
00383 
00384             break;
00385         case MKTAG('I', 'D', 'I', 'T'): {
00386             unsigned char date[64] = {0};
00387             size += (size & 1);
00388             size -= avio_read(pb, date, FFMIN(size, sizeof(date)-1));
00389             avio_skip(pb, size);
00390             avi_metadata_creation_time(&s->metadata, date);
00391             break;
00392         }
00393         case MKTAG('d', 'm', 'l', 'h'):
00394             avi->is_odml = 1;
00395             avio_skip(pb, size + (size & 1));
00396             break;
00397         case MKTAG('a', 'm', 'v', 'h'):
00398             amv_file_format=1;
00399         case MKTAG('a', 'v', 'i', 'h'):
00400             /* AVI header */
00401             /* using frame_period is bad idea */
00402             frame_period = avio_rl32(pb);
00403             avio_skip(pb, 4);
00404             avio_rl32(pb);
00405             avi->non_interleaved |= avio_rl32(pb) & AVIF_MUSTUSEINDEX;
00406 
00407             avio_skip(pb, 2 * 4);
00408             avio_rl32(pb);
00409             avio_rl32(pb);
00410             avih_width=avio_rl32(pb);
00411             avih_height=avio_rl32(pb);
00412 
00413             avio_skip(pb, size - 10 * 4);
00414             break;
00415         case MKTAG('s', 't', 'r', 'h'):
00416             /* stream header */
00417 
00418             tag1 = avio_rl32(pb);
00419             handler = avio_rl32(pb); /* codec tag */
00420 
00421             if(tag1 == MKTAG('p', 'a', 'd', 's')){
00422                 avio_skip(pb, size - 8);
00423                 break;
00424             }else{
00425                 stream_index++;
00426                 st = avformat_new_stream(s, NULL);
00427                 if (!st)
00428                     goto fail;
00429 
00430                 st->id = stream_index;
00431                 ast = av_mallocz(sizeof(AVIStream));
00432                 if (!ast)
00433                     goto fail;
00434                 st->priv_data = ast;
00435             }
00436             if(amv_file_format)
00437                 tag1 = stream_index ? MKTAG('a','u','d','s') : MKTAG('v','i','d','s');
00438 
00439             print_tag("strh", tag1, -1);
00440 
00441             if(tag1 == MKTAG('i', 'a', 'v', 's') || tag1 == MKTAG('i', 'v', 'a', 's')){
00442                 int64_t dv_dur;
00443 
00444                 /*
00445                  * After some consideration -- I don't think we
00446                  * have to support anything but DV in type1 AVIs.
00447                  */
00448                 if (s->nb_streams != 1)
00449                     goto fail;
00450 
00451                 if (handler != MKTAG('d', 'v', 's', 'd') &&
00452                     handler != MKTAG('d', 'v', 'h', 'd') &&
00453                     handler != MKTAG('d', 'v', 's', 'l'))
00454                    goto fail;
00455 
00456                 ast = s->streams[0]->priv_data;
00457                 av_freep(&s->streams[0]->codec->extradata);
00458                 av_freep(&s->streams[0]->codec);
00459                 av_freep(&s->streams[0]);
00460                 s->nb_streams = 0;
00461                 if (CONFIG_DV_DEMUXER) {
00462                     avi->dv_demux = avpriv_dv_init_demux(s);
00463                     if (!avi->dv_demux)
00464                         goto fail;
00465                 }
00466                 s->streams[0]->priv_data = ast;
00467                 avio_skip(pb, 3 * 4);
00468                 ast->scale = avio_rl32(pb);
00469                 ast->rate = avio_rl32(pb);
00470                 avio_skip(pb, 4);  /* start time */
00471 
00472                 dv_dur = avio_rl32(pb);
00473                 if (ast->scale > 0 && ast->rate > 0 && dv_dur > 0) {
00474                     dv_dur *= AV_TIME_BASE;
00475                     s->duration = av_rescale(dv_dur, ast->scale, ast->rate);
00476                 }
00477                 /*
00478                  * else, leave duration alone; timing estimation in utils.c
00479                  *      will make a guess based on bitrate.
00480                  */
00481 
00482                 stream_index = s->nb_streams - 1;
00483                 avio_skip(pb, size - 9*4);
00484                 break;
00485             }
00486 
00487             assert(stream_index < s->nb_streams);
00488             st->codec->stream_codec_tag= handler;
00489 
00490             avio_rl32(pb); /* flags */
00491             avio_rl16(pb); /* priority */
00492             avio_rl16(pb); /* language */
00493             avio_rl32(pb); /* initial frame */
00494             ast->scale = avio_rl32(pb);
00495             ast->rate = avio_rl32(pb);
00496             if(!(ast->scale && ast->rate)){
00497                 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);
00498                 if(frame_period){
00499                     ast->rate = 1000000;
00500                     ast->scale = frame_period;
00501                 }else{
00502                     ast->rate = 25;
00503                     ast->scale = 1;
00504                 }
00505             }
00506             avpriv_set_pts_info(st, 64, ast->scale, ast->rate);
00507 
00508             ast->cum_len=avio_rl32(pb); /* start */
00509             st->nb_frames = avio_rl32(pb);
00510 
00511             st->start_time = 0;
00512             avio_rl32(pb); /* buffer size */
00513             avio_rl32(pb); /* quality */
00514             ast->sample_size = avio_rl32(pb); /* sample ssize */
00515             ast->cum_len *= FFMAX(1, ast->sample_size);
00516 //            av_log(s, AV_LOG_DEBUG, "%d %d %d %d\n", ast->rate, ast->scale, ast->start, ast->sample_size);
00517 
00518             switch(tag1) {
00519             case MKTAG('v', 'i', 'd', 's'):
00520                 codec_type = AVMEDIA_TYPE_VIDEO;
00521 
00522                 ast->sample_size = 0;
00523                 break;
00524             case MKTAG('a', 'u', 'd', 's'):
00525                 codec_type = AVMEDIA_TYPE_AUDIO;
00526                 break;
00527             case MKTAG('t', 'x', 't', 's'):
00528                 codec_type = AVMEDIA_TYPE_SUBTITLE;
00529                 break;
00530             case MKTAG('d', 'a', 't', 's'):
00531                 codec_type = AVMEDIA_TYPE_DATA;
00532                 break;
00533             default:
00534                 av_log(s, AV_LOG_ERROR, "unknown stream type %X\n", tag1);
00535                 goto fail;
00536             }
00537             if(ast->sample_size == 0)
00538                 st->duration = st->nb_frames;
00539             ast->frame_offset= ast->cum_len;
00540             avio_skip(pb, size - 12 * 4);
00541             break;
00542         case MKTAG('s', 't', 'r', 'f'):
00543             /* stream header */
00544             if (stream_index >= (unsigned)s->nb_streams || avi->dv_demux) {
00545                 avio_skip(pb, size);
00546             } else {
00547                 uint64_t cur_pos = avio_tell(pb);
00548                 if (cur_pos < list_end)
00549                     size = FFMIN(size, list_end - cur_pos);
00550                 st = s->streams[stream_index];
00551                 switch(codec_type) {
00552                 case AVMEDIA_TYPE_VIDEO:
00553                     if(amv_file_format){
00554                         st->codec->width=avih_width;
00555                         st->codec->height=avih_height;
00556                         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00557                         st->codec->codec_id = CODEC_ID_AMV;
00558                         avio_skip(pb, size);
00559                         break;
00560                     }
00561                     tag1 = ff_get_bmp_header(pb, st);
00562 
00563                     if (tag1 == MKTAG('D', 'X', 'S', 'B') || tag1 == MKTAG('D','X','S','A')) {
00564                         st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
00565                         st->codec->codec_tag = tag1;
00566                         st->codec->codec_id = CODEC_ID_XSUB;
00567                         break;
00568                     }
00569 
00570                     if(size > 10*4 && size<(1<<30)){
00571                         st->codec->extradata_size= size - 10*4;
00572                         st->codec->extradata= av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00573                         if (!st->codec->extradata) {
00574                             st->codec->extradata_size= 0;
00575                             return AVERROR(ENOMEM);
00576                         }
00577                         avio_read(pb, st->codec->extradata, st->codec->extradata_size);
00578                     }
00579 
00580                     if(st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly
00581                         avio_r8(pb);
00582 
00583                     /* Extract palette from extradata if bpp <= 8. */
00584                     /* This code assumes that extradata contains only palette. */
00585                     /* This is true for all paletted codecs implemented in Libav. */
00586                     if (st->codec->extradata_size && (st->codec->bits_per_coded_sample <= 8)) {
00587                         int pal_size = (1 << st->codec->bits_per_coded_sample) << 2;
00588                         const uint8_t *pal_src;
00589 
00590                         pal_size = FFMIN(pal_size, st->codec->extradata_size);
00591                         pal_src = st->codec->extradata + st->codec->extradata_size - pal_size;
00592 #if HAVE_BIGENDIAN
00593                         for (i = 0; i < pal_size/4; i++)
00594                             ast->pal[i] = av_bswap32(((uint32_t*)pal_src)[i]);
00595 #else
00596                         memcpy(ast->pal, pal_src, pal_size);
00597 #endif
00598                         ast->has_pal = 1;
00599                     }
00600 
00601                     print_tag("video", tag1, 0);
00602 
00603                     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00604                     st->codec->codec_tag = tag1;
00605                     st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, tag1);
00606                     st->need_parsing = AVSTREAM_PARSE_HEADERS; // This is needed to get the pict type which is necessary for generating correct pts.
00607                     // Support "Resolution 1:1" for Avid AVI Codec
00608                     if(tag1 == MKTAG('A', 'V', 'R', 'n') &&
00609                        st->codec->extradata_size >= 31 &&
00610                        !memcmp(&st->codec->extradata[28], "1:1", 3))
00611                         st->codec->codec_id = CODEC_ID_RAWVIDEO;
00612 
00613                     if(st->codec->codec_tag==0 && st->codec->height > 0 && st->codec->extradata_size < 1U<<30){
00614                         st->codec->extradata_size+= 9;
00615                         st->codec->extradata= av_realloc(st->codec->extradata, st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00616                         if(st->codec->extradata)
00617                             memcpy(st->codec->extradata + st->codec->extradata_size - 9, "BottomUp", 9);
00618                     }
00619                     st->codec->height= FFABS(st->codec->height);
00620 
00621 //                    avio_skip(pb, size - 5 * 4);
00622                     break;
00623                 case AVMEDIA_TYPE_AUDIO:
00624                     ret = ff_get_wav_header(pb, st->codec, size);
00625                     if (ret < 0)
00626                         return ret;
00627                     ast->dshow_block_align= st->codec->block_align;
00628                     if(ast->sample_size && st->codec->block_align && ast->sample_size != st->codec->block_align){
00629                         av_log(s, AV_LOG_WARNING, "sample size (%d) != block align (%d)\n", ast->sample_size, st->codec->block_align);
00630                         ast->sample_size= st->codec->block_align;
00631                     }
00632                     if (size&1) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
00633                         avio_skip(pb, 1);
00634                     /* Force parsing as several audio frames can be in
00635                      * one packet and timestamps refer to packet start. */
00636                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;
00637                     /* ADTS header is in extradata, AAC without header must be
00638                      * stored as exact frames. Parser not needed and it will
00639                      * fail. */
00640                     if (st->codec->codec_id == CODEC_ID_AAC && st->codec->extradata_size)
00641                         st->need_parsing = AVSTREAM_PARSE_NONE;
00642                     /* AVI files with Xan DPCM audio (wrongly) declare PCM
00643                      * audio in the header but have Axan as stream_code_tag. */
00644                     if (st->codec->stream_codec_tag == AV_RL32("Axan")){
00645                         st->codec->codec_id  = CODEC_ID_XAN_DPCM;
00646                         st->codec->codec_tag = 0;
00647                     }
00648                     if (amv_file_format){
00649                         st->codec->codec_id  = CODEC_ID_ADPCM_IMA_AMV;
00650                         ast->dshow_block_align = 0;
00651                     }
00652                     break;
00653                 case AVMEDIA_TYPE_SUBTITLE:
00654                     st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
00655                     st->codec->codec_id   = CODEC_ID_PROBE;
00656                     break;
00657                 default:
00658                     st->codec->codec_type = AVMEDIA_TYPE_DATA;
00659                     st->codec->codec_id= CODEC_ID_NONE;
00660                     st->codec->codec_tag= 0;
00661                     avio_skip(pb, size);
00662                     break;
00663                 }
00664             }
00665             break;
00666         case MKTAG('i', 'n', 'd', 'x'):
00667             i= avio_tell(pb);
00668             if(pb->seekable && !(s->flags & AVFMT_FLAG_IGNIDX) &&
00669                read_braindead_odml_indx(s, 0) < 0 &&
00670                (s->error_recognition & AV_EF_EXPLODE))
00671                 goto fail;
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                 if (s->error_recognition & AV_EF_EXPLODE)
00709                     goto fail;
00710                 avi->movi_list = avio_tell(pb) - 4;
00711                 avi->movi_end  = avio_size(pb);
00712                 goto end_of_header;
00713             }
00714             /* skip tag */
00715             size += (size & 1);
00716             avio_skip(pb, size);
00717             break;
00718         }
00719     }
00720  end_of_header:
00721     /* check stream number */
00722     if (stream_index != s->nb_streams - 1) {
00723     fail:
00724         return -1;
00725     }
00726 
00727     if(!avi->index_loaded && pb->seekable)
00728         avi_load_index(s);
00729     avi->index_loaded = 1;
00730     avi->non_interleaved |= guess_ni_flag(s);
00731     for(i=0; i<s->nb_streams; i++){
00732         AVStream *st = s->streams[i];
00733         if(st->nb_index_entries)
00734             break;
00735     }
00736     if(i==s->nb_streams && avi->non_interleaved) {
00737         av_log(s, AV_LOG_WARNING, "non-interleaved AVI without index, switching to interleaved\n");
00738         avi->non_interleaved=0;
00739     }
00740 
00741     if(avi->non_interleaved) {
00742         av_log(s, AV_LOG_INFO, "non-interleaved AVI\n");
00743         clean_index(s);
00744     }
00745 
00746     ff_metadata_conv_ctx(s, NULL, avi_metadata_conv);
00747     ff_metadata_conv_ctx(s, NULL, ff_riff_info_conv);
00748 
00749     return 0;
00750 }
00751 
00752 static int read_gab2_sub(AVStream *st, AVPacket *pkt)
00753 {
00754     if (pkt->size >= 7 &&
00755         !strcmp(pkt->data, "GAB2") && AV_RL16(pkt->data + 5) == 2) {
00756         uint8_t desc[256];
00757         int score = AVPROBE_SCORE_MAX / 2, ret;
00758         AVIStream *ast = st->priv_data;
00759         AVInputFormat *sub_demuxer;
00760         AVRational time_base;
00761         AVIOContext *pb = avio_alloc_context( pkt->data + 7,
00762                                               pkt->size - 7,
00763                                               0, NULL, NULL, NULL, NULL);
00764         AVProbeData pd;
00765         unsigned int desc_len = avio_rl32(pb);
00766 
00767         if (desc_len > pb->buf_end - pb->buf_ptr)
00768             goto error;
00769 
00770         ret = avio_get_str16le(pb, desc_len, desc, sizeof(desc));
00771         avio_skip(pb, desc_len - ret);
00772         if (*desc)
00773             av_dict_set(&st->metadata, "title", desc, 0);
00774 
00775         avio_rl16(pb);   /* flags? */
00776         avio_rl32(pb);   /* data size */
00777 
00778         pd = (AVProbeData) { .buf = pb->buf_ptr, .buf_size = pb->buf_end - pb->buf_ptr };
00779         if (!(sub_demuxer = av_probe_input_format2(&pd, 1, &score)))
00780             goto error;
00781 
00782         if (!(ast->sub_ctx = avformat_alloc_context()))
00783             goto error;
00784 
00785         ast->sub_ctx->pb      = pb;
00786         if (!avformat_open_input(&ast->sub_ctx, "", sub_demuxer, NULL)) {
00787             av_read_packet(ast->sub_ctx, &ast->sub_pkt);
00788             *st->codec = *ast->sub_ctx->streams[0]->codec;
00789             ast->sub_ctx->streams[0]->codec->extradata = NULL;
00790             time_base = ast->sub_ctx->streams[0]->time_base;
00791             avpriv_set_pts_info(st, 64, time_base.num, time_base.den);
00792         }
00793         ast->sub_buffer = pkt->data;
00794         memset(pkt, 0, sizeof(*pkt));
00795         return 1;
00796 error:
00797         av_freep(&pb);
00798     }
00799     return 0;
00800 }
00801 
00802 static AVStream *get_subtitle_pkt(AVFormatContext *s, AVStream *next_st,
00803                                   AVPacket *pkt)
00804 {
00805     AVIStream *ast, *next_ast = next_st->priv_data;
00806     int64_t ts, next_ts, ts_min = INT64_MAX;
00807     AVStream *st, *sub_st = NULL;
00808     int i;
00809 
00810     next_ts = av_rescale_q(next_ast->frame_offset, next_st->time_base,
00811                            AV_TIME_BASE_Q);
00812 
00813     for (i=0; i<s->nb_streams; i++) {
00814         st  = s->streams[i];
00815         ast = st->priv_data;
00816         if (st->discard < AVDISCARD_ALL && ast && ast->sub_pkt.data) {
00817             ts = av_rescale_q(ast->sub_pkt.dts, st->time_base, AV_TIME_BASE_Q);
00818             if (ts <= next_ts && ts < ts_min) {
00819                 ts_min = ts;
00820                 sub_st = st;
00821             }
00822         }
00823     }
00824 
00825     if (sub_st) {
00826         ast = sub_st->priv_data;
00827         *pkt = ast->sub_pkt;
00828         pkt->stream_index = sub_st->index;
00829         if (av_read_packet(ast->sub_ctx, &ast->sub_pkt) < 0)
00830             ast->sub_pkt.data = NULL;
00831     }
00832     return sub_st;
00833 }
00834 
00835 static int get_stream_idx(int *d){
00836     if(    d[0] >= '0' && d[0] <= '9'
00837         && d[1] >= '0' && d[1] <= '9'){
00838         return (d[0] - '0') * 10 + (d[1] - '0');
00839     }else{
00840         return 100; //invalid stream ID
00841     }
00842 }
00843 
00844 static int avi_sync(AVFormatContext *s, int exit_early)
00845 {
00846     AVIContext *avi = s->priv_data;
00847     AVIOContext *pb = s->pb;
00848     int n;
00849     unsigned int d[8];
00850     unsigned int size;
00851     int64_t i, sync;
00852 
00853 start_sync:
00854     memset(d, -1, sizeof(d));
00855     for(i=sync=avio_tell(pb); !pb->eof_reached; i++) {
00856         int j;
00857 
00858         for(j=0; j<7; j++)
00859             d[j]= d[j+1];
00860         d[7]= avio_r8(pb);
00861 
00862         size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
00863 
00864         n= get_stream_idx(d+2);
00865 //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);
00866         if(i + (uint64_t)size > avi->fsize || d[0] > 127)
00867             continue;
00868 
00869         //parse ix##
00870         if(  (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
00871         //parse JUNK
00872            ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')
00873            ||(d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')){
00874             avio_skip(pb, size);
00875 //av_log(s, AV_LOG_DEBUG, "SKIP\n");
00876             goto start_sync;
00877         }
00878 
00879         //parse stray LIST
00880         if(d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T'){
00881             avio_skip(pb, 4);
00882             goto start_sync;
00883         }
00884 
00885         n = avi->dv_demux ? 0 : get_stream_idx(d);
00886 
00887         if(!((i-avi->last_pkt_pos)&1) && get_stream_idx(d+1) < s->nb_streams)
00888             continue;
00889 
00890         //detect ##ix chunk and skip
00891         if(d[2] == 'i' && d[3] == 'x' && n < s->nb_streams){
00892             avio_skip(pb, size);
00893             goto start_sync;
00894         }
00895 
00896         //parse ##dc/##wb
00897         if(n < s->nb_streams){
00898             AVStream *st;
00899             AVIStream *ast;
00900             st = s->streams[n];
00901             ast = st->priv_data;
00902 
00903             if(s->nb_streams>=2){
00904                 AVStream *st1  = s->streams[1];
00905                 AVIStream *ast1= st1->priv_data;
00906                 //workaround for broken small-file-bug402.avi
00907                 if(   d[2] == 'w' && d[3] == 'b'
00908                    && n==0
00909                    && st ->codec->codec_type == AVMEDIA_TYPE_VIDEO
00910                    && st1->codec->codec_type == AVMEDIA_TYPE_AUDIO
00911                    && ast->prefix == 'd'*256+'c'
00912                    && (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)
00913                   ){
00914                     n=1;
00915                     st = st1;
00916                     ast = ast1;
00917                     av_log(s, AV_LOG_WARNING, "Invalid stream + prefix combination, assuming audio.\n");
00918                 }
00919             }
00920 
00921 
00922             if (!avi->dv_demux &&
00923                 ((st->discard >= AVDISCARD_DEFAULT && size==0) /* ||
00924                 //FIXME needs a little reordering
00925                 (st->discard >= AVDISCARD_NONKEY &&
00926                  !(pkt->flags & AV_PKT_FLAG_KEY)) */
00927                 || st->discard >= AVDISCARD_ALL)) {
00928                 if (!exit_early) {
00929                     ast->frame_offset += get_duration(ast, size);
00930                 }
00931                 avio_skip(pb, size);
00932                 goto start_sync;
00933             }
00934 
00935             if (d[2] == 'p' && d[3] == 'c' && size<=4*256+4) {
00936                 int k = avio_r8(pb);
00937                 int last = (k + avio_r8(pb) - 1) & 0xFF;
00938 
00939                 avio_rl16(pb); //flags
00940 
00941                 for (; k <= last; k++)
00942                     ast->pal[k] = avio_rb32(pb)>>8;// b + (g << 8) + (r << 16);
00943                 ast->has_pal= 1;
00944                 goto start_sync;
00945             } else if(   ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||
00946                          d[2]*256+d[3] == ast->prefix /*||
00947                          (d[2] == 'd' && d[3] == 'c') ||
00948                          (d[2] == 'w' && d[3] == 'b')*/) {
00949 
00950                 if (exit_early)
00951                     return 0;
00952 //av_log(s, AV_LOG_DEBUG, "OK\n");
00953                 if(d[2]*256+d[3] == ast->prefix)
00954                     ast->prefix_count++;
00955                 else{
00956                     ast->prefix= d[2]*256+d[3];
00957                     ast->prefix_count= 0;
00958                 }
00959 
00960                 avi->stream_index= n;
00961                 ast->packet_size= size + 8;
00962                 ast->remaining= size;
00963 
00964                 if(size || !ast->sample_size){
00965                     uint64_t pos= avio_tell(pb) - 8;
00966                     if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){
00967                         av_add_index_entry(st, pos, ast->frame_offset, size, 0, AVINDEX_KEYFRAME);
00968                     }
00969                 }
00970                 return 0;
00971             }
00972         }
00973     }
00974 
00975     return AVERROR_EOF;
00976 }
00977 
00978 static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
00979 {
00980     AVIContext *avi = s->priv_data;
00981     AVIOContext *pb = s->pb;
00982     int err;
00983     void* dstr;
00984 
00985     if (CONFIG_DV_DEMUXER && avi->dv_demux) {
00986         int size = avpriv_dv_get_packet(avi->dv_demux, pkt);
00987         if (size >= 0)
00988             return size;
00989         else
00990             goto resync;
00991     }
00992 
00993     if(avi->non_interleaved){
00994         int best_stream_index = 0;
00995         AVStream *best_st= NULL;
00996         AVIStream *best_ast;
00997         int64_t best_ts= INT64_MAX;
00998         int i;
00999 
01000         for(i=0; i<s->nb_streams; i++){
01001             AVStream *st = s->streams[i];
01002             AVIStream *ast = st->priv_data;
01003             int64_t ts= ast->frame_offset;
01004             int64_t last_ts;
01005 
01006             if(!st->nb_index_entries)
01007                 continue;
01008 
01009             last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;
01010             if(!ast->remaining && ts > last_ts)
01011                 continue;
01012 
01013             ts = av_rescale_q(ts, st->time_base, (AVRational){FFMAX(1, ast->sample_size), AV_TIME_BASE});
01014 
01015 //            av_log(s, AV_LOG_DEBUG, "%"PRId64" %d/%d %"PRId64"\n", ts, st->time_base.num, st->time_base.den, ast->frame_offset);
01016             if(ts < best_ts){
01017                 best_ts= ts;
01018                 best_st= st;
01019                 best_stream_index= i;
01020             }
01021         }
01022         if(!best_st)
01023             return -1;
01024 
01025         best_ast = best_st->priv_data;
01026         best_ts = av_rescale_q(best_ts, (AVRational){FFMAX(1, best_ast->sample_size), AV_TIME_BASE}, best_st->time_base);
01027         if(best_ast->remaining)
01028             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
01029         else{
01030             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
01031             if(i>=0)
01032                 best_ast->frame_offset= best_st->index_entries[i].timestamp;
01033         }
01034 
01035 //        av_log(s, AV_LOG_DEBUG, "%d\n", i);
01036         if(i>=0){
01037             int64_t pos= best_st->index_entries[i].pos;
01038             pos += best_ast->packet_size - best_ast->remaining;
01039             avio_seek(s->pb, pos + 8, SEEK_SET);
01040 //        av_log(s, AV_LOG_DEBUG, "pos=%"PRId64"\n", pos);
01041 
01042             assert(best_ast->remaining <= best_ast->packet_size);
01043 
01044             avi->stream_index= best_stream_index;
01045             if(!best_ast->remaining)
01046                 best_ast->packet_size=
01047                 best_ast->remaining= best_st->index_entries[i].size;
01048         }
01049     }
01050 
01051 resync:
01052     if(avi->stream_index >= 0){
01053         AVStream *st= s->streams[ avi->stream_index ];
01054         AVIStream *ast= st->priv_data;
01055         int size, err;
01056 
01057         if(get_subtitle_pkt(s, st, pkt))
01058             return 0;
01059 
01060         if(ast->sample_size <= 1) // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM
01061             size= INT_MAX;
01062         else if(ast->sample_size < 32)
01063             // arbitrary multiplier to avoid tiny packets for raw PCM data
01064             size= 1024*ast->sample_size;
01065         else
01066             size= ast->sample_size;
01067 
01068         if(size > ast->remaining)
01069             size= ast->remaining;
01070         avi->last_pkt_pos= avio_tell(pb);
01071         err= av_get_packet(pb, pkt, size);
01072         if(err<0)
01073             return err;
01074 
01075         if(ast->has_pal && pkt->data && pkt->size<(unsigned)INT_MAX/2){
01076             uint8_t *pal;
01077             pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE);
01078             if(!pal){
01079                 av_log(s, AV_LOG_ERROR, "Failed to allocate data for palette\n");
01080             }else{
01081                 memcpy(pal, ast->pal, AVPALETTE_SIZE);
01082                 ast->has_pal = 0;
01083             }
01084         }
01085 
01086         if (CONFIG_DV_DEMUXER && avi->dv_demux) {
01087             dstr = pkt->destruct;
01088             size = avpriv_dv_produce_packet(avi->dv_demux, pkt,
01089                                     pkt->data, pkt->size);
01090             pkt->destruct = dstr;
01091             pkt->flags |= AV_PKT_FLAG_KEY;
01092             if (size < 0)
01093                 av_free_packet(pkt);
01094         } else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE
01095                    && !st->codec->codec_tag && read_gab2_sub(st, pkt)) {
01096             ast->frame_offset++;
01097             avi->stream_index = -1;
01098             ast->remaining = 0;
01099             goto resync;
01100         } else {
01101             /* XXX: How to handle B-frames in AVI? */
01102             pkt->dts = ast->frame_offset;
01103 //                pkt->dts += ast->start;
01104             if(ast->sample_size)
01105                 pkt->dts /= ast->sample_size;
01106 //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);
01107             pkt->stream_index = avi->stream_index;
01108 
01109             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
01110                 AVIndexEntry *e;
01111                 int index;
01112                 assert(st->index_entries);
01113 
01114                 index= av_index_search_timestamp(st, ast->frame_offset, 0);
01115                 e= &st->index_entries[index];
01116 
01117                 if(index >= 0 && e->timestamp == ast->frame_offset){
01118                     if (e->flags & AVINDEX_KEYFRAME)
01119                         pkt->flags |= AV_PKT_FLAG_KEY;
01120                 }
01121             } else {
01122                 pkt->flags |= AV_PKT_FLAG_KEY;
01123             }
01124             ast->frame_offset += get_duration(ast, pkt->size);
01125         }
01126         ast->remaining -= err;
01127         if(!ast->remaining){
01128             avi->stream_index= -1;
01129             ast->packet_size= 0;
01130         }
01131 
01132         return 0;
01133     }
01134 
01135     if ((err = avi_sync(s, 0)) < 0)
01136         return err;
01137     goto resync;
01138 }
01139 
01140 /* XXX: We make the implicit supposition that the positions are sorted
01141    for each stream. */
01142 static int avi_read_idx1(AVFormatContext *s, int size)
01143 {
01144     AVIContext *avi = s->priv_data;
01145     AVIOContext *pb = s->pb;
01146     int nb_index_entries, i;
01147     AVStream *st;
01148     AVIStream *ast;
01149     unsigned int index, tag, flags, pos, len, first_packet = 1;
01150     unsigned last_pos= -1;
01151     int64_t idx1_pos, first_packet_pos = 0, data_offset = 0;
01152 
01153     nb_index_entries = size / 16;
01154     if (nb_index_entries <= 0)
01155         return -1;
01156 
01157     idx1_pos = avio_tell(pb);
01158     avio_seek(pb, avi->movi_list+4, SEEK_SET);
01159     if (avi_sync(s, 1) == 0) {
01160         first_packet_pos = avio_tell(pb) - 8;
01161     }
01162     avi->stream_index = -1;
01163     avio_seek(pb, idx1_pos, SEEK_SET);
01164 
01165     /* Read the entries and sort them in each stream component. */
01166     for(i = 0; i < nb_index_entries; i++) {
01167         tag = avio_rl32(pb);
01168         flags = avio_rl32(pb);
01169         pos = avio_rl32(pb);
01170         len = avio_rl32(pb);
01171         av_dlog(s, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
01172                 i, tag, flags, pos, len);
01173 
01174         index = ((tag & 0xff) - '0') * 10;
01175         index += ((tag >> 8) & 0xff) - '0';
01176         if (index >= s->nb_streams)
01177             continue;
01178         st = s->streams[index];
01179         ast = st->priv_data;
01180 
01181         if(first_packet && first_packet_pos && len) {
01182             data_offset = first_packet_pos - pos;
01183             first_packet = 0;
01184         }
01185         pos += data_offset;
01186 
01187         av_dlog(s, "%d cum_len=%"PRId64"\n", len, ast->cum_len);
01188 
01189         if(pb->eof_reached)
01190             return -1;
01191 
01192         if(last_pos == pos)
01193             avi->non_interleaved= 1;
01194         else if(len || !ast->sample_size)
01195             av_add_index_entry(st, pos, ast->cum_len, len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
01196         ast->cum_len += get_duration(ast, len);
01197         last_pos= pos;
01198     }
01199     return 0;
01200 }
01201 
01202 static int guess_ni_flag(AVFormatContext *s){
01203     int i;
01204     int64_t last_start=0;
01205     int64_t first_end= INT64_MAX;
01206     int64_t oldpos= avio_tell(s->pb);
01207 
01208     for(i=0; i<s->nb_streams; i++){
01209         AVStream *st = s->streams[i];
01210         int n= st->nb_index_entries;
01211         unsigned int size;
01212 
01213         if(n <= 0)
01214             continue;
01215 
01216         if(n >= 2){
01217             int64_t pos= st->index_entries[0].pos;
01218             avio_seek(s->pb, pos + 4, SEEK_SET);
01219             size= avio_rl32(s->pb);
01220             if(pos + size > st->index_entries[1].pos)
01221                 last_start= INT64_MAX;
01222         }
01223 
01224         if(st->index_entries[0].pos > last_start)
01225             last_start= st->index_entries[0].pos;
01226         if(st->index_entries[n-1].pos < first_end)
01227             first_end= st->index_entries[n-1].pos;
01228     }
01229     avio_seek(s->pb, oldpos, SEEK_SET);
01230     return last_start > first_end;
01231 }
01232 
01233 static int avi_load_index(AVFormatContext *s)
01234 {
01235     AVIContext *avi = s->priv_data;
01236     AVIOContext *pb = s->pb;
01237     uint32_t tag, size;
01238     int64_t pos= avio_tell(pb);
01239     int ret = -1;
01240 
01241     if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)
01242         goto the_end; // maybe truncated file
01243     av_dlog(s, "movi_end=0x%"PRIx64"\n", avi->movi_end);
01244     for(;;) {
01245         if (pb->eof_reached)
01246             break;
01247         tag = avio_rl32(pb);
01248         size = avio_rl32(pb);
01249         av_dlog(s, "tag=%c%c%c%c size=0x%x\n",
01250                  tag        & 0xff,
01251                 (tag >>  8) & 0xff,
01252                 (tag >> 16) & 0xff,
01253                 (tag >> 24) & 0xff,
01254                 size);
01255 
01256         if (tag == MKTAG('i', 'd', 'x', '1') &&
01257             avi_read_idx1(s, size) >= 0) {
01258             ret = 0;
01259             break;
01260         }
01261 
01262         size += (size & 1);
01263         if (avio_skip(pb, size) < 0)
01264             break; // something is wrong here
01265     }
01266  the_end:
01267     avio_seek(pb, pos, SEEK_SET);
01268     return ret;
01269 }
01270 
01271 static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)
01272 {
01273     AVIStream *ast2 = st2->priv_data;
01274     int64_t ts2 = av_rescale_q(timestamp, st->time_base, st2->time_base);
01275     av_free_packet(&ast2->sub_pkt);
01276     if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||
01277         avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)
01278         av_read_packet(ast2->sub_ctx, &ast2->sub_pkt);
01279 }
01280 
01281 static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
01282 {
01283     AVIContext *avi = s->priv_data;
01284     AVStream *st;
01285     int i, index;
01286     int64_t pos;
01287     AVIStream *ast;
01288 
01289     /* Does not matter which stream is requested dv in avi has the
01290      * stream information in the first video stream.
01291      */
01292     if (avi->dv_demux)
01293         stream_index = 0;
01294 
01295     if (!avi->index_loaded) {
01296         /* we only load the index on demand */
01297         avi_load_index(s);
01298         avi->index_loaded = 1;
01299     }
01300 
01301     st = s->streams[stream_index];
01302     ast= st->priv_data;
01303     index= av_index_search_timestamp(st, timestamp * FFMAX(ast->sample_size, 1), flags);
01304     if(index<0)
01305         return -1;
01306 
01307     /* find the position */
01308     pos = st->index_entries[index].pos;
01309     timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);
01310 
01311 //    av_log(s, AV_LOG_DEBUG, "XX %"PRId64" %d %"PRId64"\n", timestamp, index, st->index_entries[index].timestamp);
01312 
01313     if (CONFIG_DV_DEMUXER && avi->dv_demux) {
01314         /* One and only one real stream for DV in AVI, and it has video  */
01315         /* offsets. Calling with other stream indexes should have failed */
01316         /* the av_index_search_timestamp call above.                     */
01317 
01318         /* Feed the DV video stream version of the timestamp to the */
01319         /* DV demux so it can synthesize correct timestamps.        */
01320         dv_offset_reset(avi->dv_demux, timestamp);
01321 
01322         avio_seek(s->pb, pos, SEEK_SET);
01323         avi->stream_index= -1;
01324         return 0;
01325     }
01326 
01327     for(i = 0; i < s->nb_streams; i++) {
01328         AVStream *st2 = s->streams[i];
01329         AVIStream *ast2 = st2->priv_data;
01330 
01331         ast2->packet_size=
01332         ast2->remaining= 0;
01333 
01334         if (ast2->sub_ctx) {
01335             seek_subtitle(st, st2, timestamp);
01336             continue;
01337         }
01338 
01339         if (st2->nb_index_entries <= 0)
01340             continue;
01341 
01342 //        assert(st2->codec->block_align);
01343         assert((int64_t)st2->time_base.num*ast2->rate == (int64_t)st2->time_base.den*ast2->scale);
01344         index = av_index_search_timestamp(
01345                 st2,
01346                 av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),
01347                 flags | AVSEEK_FLAG_BACKWARD);
01348         if(index<0)
01349             index=0;
01350 
01351         if(!avi->non_interleaved){
01352             while(index>0 && st2->index_entries[index].pos > pos)
01353                 index--;
01354             while(index+1 < st2->nb_index_entries && st2->index_entries[index].pos < pos)
01355                 index++;
01356         }
01357 
01358 //        av_log(s, AV_LOG_DEBUG, "%"PRId64" %d %"PRId64"\n", timestamp, index, st2->index_entries[index].timestamp);
01359         /* extract the current frame number */
01360         ast2->frame_offset = st2->index_entries[index].timestamp;
01361     }
01362 
01363     /* do the seek */
01364     avio_seek(s->pb, pos, SEEK_SET);
01365     avi->stream_index= -1;
01366     return 0;
01367 }
01368 
01369 static int avi_read_close(AVFormatContext *s)
01370 {
01371     int i;
01372     AVIContext *avi = s->priv_data;
01373 
01374     for(i=0;i<s->nb_streams;i++) {
01375         AVStream *st = s->streams[i];
01376         AVIStream *ast = st->priv_data;
01377         if (ast) {
01378             if (ast->sub_ctx) {
01379                 av_freep(&ast->sub_ctx->pb);
01380                 avformat_close_input(&ast->sub_ctx);
01381             }
01382             av_free(ast->sub_buffer);
01383             av_free_packet(&ast->sub_pkt);
01384         }
01385     }
01386 
01387     av_free(avi->dv_demux);
01388 
01389     return 0;
01390 }
01391 
01392 static int avi_probe(AVProbeData *p)
01393 {
01394     int i;
01395 
01396     /* check file header */
01397     for(i=0; avi_headers[i][0]; i++)
01398         if(!memcmp(p->buf  , avi_headers[i]  , 4) &&
01399            !memcmp(p->buf+8, avi_headers[i]+4, 4))
01400             return AVPROBE_SCORE_MAX;
01401 
01402     return 0;
01403 }
01404 
01405 AVInputFormat ff_avi_demuxer = {
01406     .name           = "avi",
01407     .long_name      = NULL_IF_CONFIG_SMALL("AVI format"),
01408     .priv_data_size = sizeof(AVIContext),
01409     .read_probe     = avi_probe,
01410     .read_header    = avi_read_header,
01411     .read_packet    = avi_read_packet,
01412     .read_close     = avi_read_close,
01413     .read_seek      = avi_read_seek,
01414 };