FFmpeg: libavformat/avidec.c Source File

00001 /*
00002  * AVI demuxer
00003  * Copyright (c) 2001 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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/opt.h"
00026 #include "libavutil/dict.h"
00027 #include "avformat.h"
00028 #include "avi.h"
00029 #include "dv.h"
00030 #include "riff.h"
00031 
00032 #undef NDEBUG
00033 #include <assert.h>
00034 
00035 typedef struct AVIStream {
00036     int64_t frame_offset; /* current frame (video) or byte (audio) counter
00037                          (used to compute the pts) */
00038     int remaining;
00039     int packet_size;
00040 
00041     int scale;
00042     int rate;
00043     int sample_size; /* size of one sample (or packet) (in the rate/scale sense) in bytes */
00044 
00045     int64_t cum_len; /* temporary storage (used during seek) */
00046 
00047     int prefix;                       
00048     int prefix_count;
00049     uint32_t pal[256];
00050     int has_pal;
00051     int dshow_block_align;            
00052 
00053     AVFormatContext *sub_ctx;
00054     AVPacket sub_pkt;
00055     uint8_t *sub_buffer;
00056 
00057     int64_t seek_pos;
00058 } AVIStream;
00059 
00060 typedef struct {
00061     const AVClass *class;
00062     int64_t  riff_end;
00063     int64_t  movi_end;
00064     int64_t  fsize;
00065     int64_t movi_list;
00066     int64_t last_pkt_pos;
00067     int index_loaded;
00068     int is_odml;
00069     int non_interleaved;
00070     int stream_index;
00071     DVDemuxContext* dv_demux;
00072     int odml_depth;
00073     int use_odml;
00074 #define MAX_ODML_DEPTH 1000
00075 } AVIContext;
00076 
00077 
00078 static const AVOption options[] = {
00079     { "use_odml", "use odml index", offsetof(AVIContext, use_odml), FF_OPT_TYPE_INT, 1, -1, 1, AV_OPT_FLAG_DECODING_PARAM},
00080     { NULL },
00081 };
00082 
00083 static const AVClass demuxer_class = {
00084     "AVI demuxer",
00085     av_default_item_name,
00086     options,
00087     LIBAVUTIL_VERSION_INT,
00088 };
00089 
00090 
00091 static const char avi_headers[][8] = {
00092     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', ' ' },
00093     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 'X' },
00094     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 0x19},
00095     { 'O', 'N', '2', ' ',    'O', 'N', '2', 'f' },
00096     { 'R', 'I', 'F', 'F',    'A', 'M', 'V', ' ' },
00097     { 0 }
00098 };
00099 
00100 static int avi_load_index(AVFormatContext *s);
00101 static int guess_ni_flag(AVFormatContext *s);
00102 
00103 #define print_tag(str, tag, size)                       \
00104     av_dlog(NULL, "%s: tag=%c%c%c%c size=0x%x\n",       \
00105            str, tag & 0xff,                             \
00106            (tag >> 8) & 0xff,                           \
00107            (tag >> 16) & 0xff,                          \
00108            (tag >> 24) & 0xff,                          \
00109            size)
00110 
00111 static inline int get_duration(AVIStream *ast, int len){
00112     if(ast->sample_size){
00113         return len;
00114     }else if (ast->dshow_block_align){
00115         return (len + ast->dshow_block_align - 1)/ast->dshow_block_align;
00116     }else
00117         return 1;
00118 }
00119 
00120 static int get_riff(AVFormatContext *s, AVIOContext *pb)
00121 {
00122     AVIContext *avi = s->priv_data;
00123     char header[8];
00124     int i;
00125 
00126     /* check RIFF header */
00127     avio_read(pb, header, 4);
00128     avi->riff_end = avio_rl32(pb);  /* RIFF chunk size */
00129     avi->riff_end += avio_tell(pb); /* RIFF chunk end */
00130     avio_read(pb, header+4, 4);
00131 
00132     for(i=0; avi_headers[i][0]; i++)
00133         if(!memcmp(header, avi_headers[i], 8))
00134             break;
00135     if(!avi_headers[i][0])
00136         return -1;
00137 
00138     if(header[7] == 0x19)
00139         av_log(s, AV_LOG_INFO, "This file has been generated by a totally broken muxer.\n");
00140 
00141     return 0;
00142 }
00143 
00144 static int read_braindead_odml_indx(AVFormatContext *s, int frame_num){
00145     AVIContext *avi = s->priv_data;
00146     AVIOContext *pb = s->pb;
00147     int longs_pre_entry= avio_rl16(pb);
00148     int index_sub_type = avio_r8(pb);
00149     int index_type     = avio_r8(pb);
00150     int entries_in_use = avio_rl32(pb);
00151     int chunk_id       = avio_rl32(pb);
00152     int64_t base       = avio_rl64(pb);
00153     int stream_id= 10*((chunk_id&0xFF) - '0') + (((chunk_id>>8)&0xFF) - '0');
00154     AVStream *st;
00155     AVIStream *ast;
00156     int i;
00157     int64_t last_pos= -1;
00158     int64_t filesize= avio_size(s->pb);
00159 
00160     av_dlog(s, "longs_pre_entry:%d index_type:%d entries_in_use:%d chunk_id:%X base:%16"PRIX64"\n",
00161             longs_pre_entry,index_type, entries_in_use, chunk_id, base);
00162 
00163     if(stream_id >= s->nb_streams || stream_id < 0)
00164         return -1;
00165     st= s->streams[stream_id];
00166     ast = st->priv_data;
00167 
00168     if(index_sub_type)
00169         return -1;
00170 
00171     avio_rl32(pb);
00172 
00173     if(index_type && longs_pre_entry != 2)
00174         return -1;
00175     if(index_type>1)
00176         return -1;
00177 
00178     if(filesize > 0 && base >= filesize){
00179         av_log(s, AV_LOG_ERROR, "ODML index invalid\n");
00180         if(base>>32 == (base & 0xFFFFFFFF) && (base & 0xFFFFFFFF) < filesize && filesize <= 0xFFFFFFFF)
00181             base &= 0xFFFFFFFF;
00182         else
00183             return -1;
00184     }
00185 
00186     for(i=0; i<entries_in_use; i++){
00187         if(index_type){
00188             int64_t pos= avio_rl32(pb) + base - 8;
00189             int len    = avio_rl32(pb);
00190             int key= len >= 0;
00191             len &= 0x7FFFFFFF;
00192 
00193 #ifdef DEBUG_SEEK
00194             av_log(s, AV_LOG_ERROR, "pos:%"PRId64", len:%X\n", pos, len);
00195 #endif
00196             if(url_feof(pb))
00197                 return -1;
00198 
00199             if(last_pos == pos || pos == base - 8)
00200                 avi->non_interleaved= 1;
00201             if(last_pos != pos && (len || !ast->sample_size))
00202                 av_add_index_entry(st, pos, ast->cum_len, len, 0, key ? AVINDEX_KEYFRAME : 0);
00203 
00204             ast->cum_len += get_duration(ast, len);
00205             last_pos= pos;
00206         }else{
00207             int64_t offset, pos;
00208             int duration;
00209             offset = avio_rl64(pb);
00210             avio_rl32(pb);       /* size */
00211             duration = avio_rl32(pb);
00212 
00213             if(url_feof(pb))
00214                 return -1;
00215 
00216             pos = avio_tell(pb);
00217 
00218             if(avi->odml_depth > MAX_ODML_DEPTH){
00219                 av_log(s, AV_LOG_ERROR, "Too deeply nested ODML indexes\n");
00220                 return -1;
00221             }
00222 
00223             if(avio_seek(pb, offset+8, SEEK_SET) < 0)
00224                 return -1;
00225             avi->odml_depth++;
00226             read_braindead_odml_indx(s, frame_num);
00227             avi->odml_depth--;
00228             frame_num += duration;
00229 
00230             if(avio_seek(pb, pos, SEEK_SET) < 0) {
00231                 av_log(s, AV_LOG_ERROR, "Failed to restore position after reading index");
00232                 return -1;
00233             }
00234 
00235         }
00236     }
00237     avi->index_loaded=1;
00238     return 0;
00239 }
00240 
00241 static void clean_index(AVFormatContext *s){
00242     int i;
00243     int64_t j;
00244 
00245     for(i=0; i<s->nb_streams; i++){
00246         AVStream *st = s->streams[i];
00247         AVIStream *ast = st->priv_data;
00248         int n= st->nb_index_entries;
00249         int max= ast->sample_size;
00250         int64_t pos, size, ts;
00251 
00252         if(n != 1 || ast->sample_size==0)
00253             continue;
00254 
00255         while(max < 1024) max+=max;
00256 
00257         pos= st->index_entries[0].pos;
00258         size= st->index_entries[0].size;
00259         ts= st->index_entries[0].timestamp;
00260 
00261         for(j=0; j<size; j+=max){
00262             av_add_index_entry(st, pos+j, ts+j, FFMIN(max, size-j), 0, AVINDEX_KEYFRAME);
00263         }
00264     }
00265 }
00266 
00267 static int avi_read_tag(AVFormatContext *s, AVStream *st, uint32_t tag, uint32_t size)
00268 {
00269     AVIOContext *pb = s->pb;
00270     char key[5] = {0}, *value;
00271 
00272     size += (size & 1);
00273 
00274     if (size == UINT_MAX)
00275         return -1;
00276     value = av_malloc(size+1);
00277     if (!value)
00278         return -1;
00279     avio_read(pb, value, size);
00280     value[size]=0;
00281 
00282     AV_WL32(key, tag);
00283 
00284     return av_dict_set(st ? &st->metadata : &s->metadata, key, value,
00285                             AV_DICT_DONT_STRDUP_VAL);
00286 }
00287 
00288 static void avi_read_info(AVFormatContext *s, uint64_t end)
00289 {
00290     while (avio_tell(s->pb) < end) {
00291         uint32_t tag  = avio_rl32(s->pb);
00292         uint32_t size = avio_rl32(s->pb);
00293         avi_read_tag(s, NULL, tag, size);
00294     }
00295 }
00296 
00297 static const char months[12][4] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
00298                                     "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
00299 
00300 static void avi_metadata_creation_time(AVDictionary **metadata, char *date)
00301 {
00302     char month[4], time[9], buffer[64];
00303     int i, day, year;
00304     /* parse standard AVI date format (ie. "Mon Mar 10 15:04:43 2003") */
00305     if (sscanf(date, "%*3s%*[ ]%3s%*[ ]%2d%*[ ]%8s%*[ ]%4d",
00306                month, &day, time, &year) == 4) {
00307         for (i=0; i<12; i++)
00308             if (!strcasecmp(month, months[i])) {
00309                 snprintf(buffer, sizeof(buffer), "%.4d-%.2d-%.2d %s",
00310                          year, i+1, day, time);
00311                 av_dict_set(metadata, "creation_time", buffer, 0);
00312             }
00313     } else if (date[4] == '/' && date[7] == '/') {
00314         date[4] = date[7] = '-';
00315         av_dict_set(metadata, "creation_time", date, 0);
00316     }
00317 }
00318 
00319 static void avi_read_nikon(AVFormatContext *s, uint64_t end)
00320 {
00321     while (avio_tell(s->pb) < end) {
00322         uint32_t tag  = avio_rl32(s->pb);
00323         uint32_t size = avio_rl32(s->pb);
00324         switch (tag) {
00325         case MKTAG('n', 'c', 't', 'g'): {  /* Nikon Tags */
00326             uint64_t tag_end = avio_tell(s->pb) + size;
00327             while (avio_tell(s->pb) < tag_end) {
00328                 uint16_t tag  = avio_rl16(s->pb);
00329                 uint16_t size = avio_rl16(s->pb);
00330                 const char *name = NULL;
00331                 char buffer[64] = {0};
00332                 size -= avio_read(s->pb, buffer,
00333                                    FFMIN(size, sizeof(buffer)-1));
00334                 switch (tag) {
00335                 case 0x03:  name = "maker";  break;
00336                 case 0x04:  name = "model";  break;
00337                 case 0x13:  name = "creation_time";
00338                     if (buffer[4] == ':' && buffer[7] == ':')
00339                         buffer[4] = buffer[7] = '-';
00340                     break;
00341                 }
00342                 if (name)
00343                     av_dict_set(&s->metadata, name, buffer, 0);
00344                 avio_skip(s->pb, size);
00345             }
00346             break;
00347         }
00348         default:
00349             avio_skip(s->pb, size);
00350             break;
00351         }
00352     }
00353 }
00354 
00355 static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
00356 {
00357     AVIContext *avi = s->priv_data;
00358     AVIOContext *pb = s->pb;
00359     unsigned int tag, tag1, handler;
00360     int codec_type, stream_index, frame_period;
00361     unsigned int size;
00362     int i;
00363     AVStream *st;
00364     AVIStream *ast = NULL;
00365     int avih_width=0, avih_height=0;
00366     int amv_file_format=0;
00367     uint64_t list_end = 0;
00368     int ret;
00369 
00370     avi->stream_index= -1;
00371 
00372     if (get_riff(s, pb) < 0)
00373         return -1;
00374 
00375     av_log(avi, AV_LOG_DEBUG, "use odml:%d\n", avi->use_odml);
00376 
00377     avi->fsize = avio_size(pb);
00378     if(avi->fsize<=0)
00379         avi->fsize= avi->riff_end == 8 ? INT64_MAX : avi->riff_end;
00380 
00381     /* first list tag */
00382     stream_index = -1;
00383     codec_type = -1;
00384     frame_period = 0;
00385     for(;;) {
00386         if (url_feof(pb))
00387             goto fail;
00388         tag = avio_rl32(pb);
00389         size = avio_rl32(pb);
00390 
00391         print_tag("tag", tag, size);
00392 
00393         switch(tag) {
00394         case MKTAG('L', 'I', 'S', 'T'):
00395             list_end = avio_tell(pb) + size;
00396             /* Ignored, except at start of video packets. */
00397             tag1 = avio_rl32(pb);
00398 
00399             print_tag("list", tag1, 0);
00400 
00401             if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
00402                 avi->movi_list = avio_tell(pb) - 4;
00403                 if(size) avi->movi_end = avi->movi_list + size + (size & 1);
00404                 else     avi->movi_end = avio_size(pb);
00405                 av_dlog(NULL, "movi end=%"PRIx64"\n", avi->movi_end);
00406                 goto end_of_header;
00407             }
00408             else if (tag1 == MKTAG('I', 'N', 'F', 'O'))
00409                 avi_read_info(s, list_end);
00410             else if (tag1 == MKTAG('n', 'c', 'd', 't'))
00411                 avi_read_nikon(s, list_end);
00412 
00413             break;
00414         case MKTAG('I', 'D', 'I', 'T'): {
00415             unsigned char date[64] = {0};
00416             size += (size & 1);
00417             size -= avio_read(pb, date, FFMIN(size, sizeof(date)-1));
00418             avio_skip(pb, size);
00419             avi_metadata_creation_time(&s->metadata, date);
00420             break;
00421         }
00422         case MKTAG('d', 'm', 'l', 'h'):
00423             avi->is_odml = 1;
00424             avio_skip(pb, size + (size & 1));
00425             break;
00426         case MKTAG('a', 'm', 'v', 'h'):
00427             amv_file_format=1;
00428         case MKTAG('a', 'v', 'i', 'h'):
00429             /* AVI header */
00430             /* using frame_period is bad idea */
00431             frame_period = avio_rl32(pb);
00432             avio_rl32(pb); /* max. bytes per second */
00433             avio_rl32(pb);
00434             avi->non_interleaved |= avio_rl32(pb) & AVIF_MUSTUSEINDEX;
00435 
00436             avio_skip(pb, 2 * 4);
00437             avio_rl32(pb);
00438             avio_rl32(pb);
00439             avih_width=avio_rl32(pb);
00440             avih_height=avio_rl32(pb);
00441 
00442             avio_skip(pb, size - 10 * 4);
00443             break;
00444         case MKTAG('s', 't', 'r', 'h'):
00445             /* stream header */
00446 
00447             tag1 = avio_rl32(pb);
00448             handler = avio_rl32(pb); /* codec tag */
00449 
00450             if(tag1 == MKTAG('p', 'a', 'd', 's')){
00451                 avio_skip(pb, size - 8);
00452                 break;
00453             }else{
00454                 stream_index++;
00455                 st = av_new_stream(s, stream_index);
00456                 if (!st)
00457                     goto fail;
00458 
00459                 ast = av_mallocz(sizeof(AVIStream));
00460                 if (!ast)
00461                     goto fail;
00462                 st->priv_data = ast;
00463             }
00464             if(amv_file_format)
00465                 tag1 = stream_index ? MKTAG('a','u','d','s') : MKTAG('v','i','d','s');
00466 
00467             print_tag("strh", tag1, -1);
00468 
00469             if(tag1 == MKTAG('i', 'a', 'v', 's') || tag1 == MKTAG('i', 'v', 'a', 's')){
00470                 int64_t dv_dur;
00471 
00472                 /*
00473                  * After some consideration -- I don't think we
00474                  * have to support anything but DV in type1 AVIs.
00475                  */
00476                 if (s->nb_streams != 1)
00477                     goto fail;
00478 
00479                 if (handler != MKTAG('d', 'v', 's', 'd') &&
00480                     handler != MKTAG('d', 'v', 'h', 'd') &&
00481                     handler != MKTAG('d', 'v', 's', 'l'))
00482                    goto fail;
00483 
00484                 ast = s->streams[0]->priv_data;
00485                 av_freep(&s->streams[0]->codec->extradata);
00486                 av_freep(&s->streams[0]->codec);
00487                 av_freep(&s->streams[0]);
00488                 s->nb_streams = 0;
00489                 if (CONFIG_DV_DEMUXER) {
00490                     avi->dv_demux = dv_init_demux(s);
00491                     if (!avi->dv_demux)
00492                         goto fail;
00493                 }
00494                 s->streams[0]->priv_data = ast;
00495                 avio_skip(pb, 3 * 4);
00496                 ast->scale = avio_rl32(pb);
00497                 ast->rate = avio_rl32(pb);
00498                 avio_skip(pb, 4);  /* start time */
00499 
00500                 dv_dur = avio_rl32(pb);
00501                 if (ast->scale > 0 && ast->rate > 0 && dv_dur > 0) {
00502                     dv_dur *= AV_TIME_BASE;
00503                     s->duration = av_rescale(dv_dur, ast->scale, ast->rate);
00504                 }
00505                 /*
00506                  * else, leave duration alone; timing estimation in utils.c
00507                  *      will make a guess based on bitrate.
00508                  */
00509 
00510                 stream_index = s->nb_streams - 1;
00511                 avio_skip(pb, size - 9*4);
00512                 break;
00513             }
00514 
00515             assert(stream_index < s->nb_streams);
00516             st->codec->stream_codec_tag= handler;
00517 
00518             avio_rl32(pb); /* flags */
00519             avio_rl16(pb); /* priority */
00520             avio_rl16(pb); /* language */
00521             avio_rl32(pb); /* initial frame */
00522             ast->scale = avio_rl32(pb);
00523             ast->rate = avio_rl32(pb);
00524             if(!(ast->scale && ast->rate)){
00525                 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);
00526                 if(frame_period){
00527                     ast->rate = 1000000;
00528                     ast->scale = frame_period;
00529                 }else{
00530                     ast->rate = 25;
00531                     ast->scale = 1;
00532                 }
00533             }
00534             av_set_pts_info(st, 64, ast->scale, ast->rate);
00535 
00536             ast->cum_len=avio_rl32(pb); /* start */
00537             st->nb_frames = avio_rl32(pb);
00538 
00539             st->start_time = 0;
00540             avio_rl32(pb); /* buffer size */
00541             avio_rl32(pb); /* quality */
00542             ast->sample_size = avio_rl32(pb); /* sample ssize */
00543             ast->cum_len *= FFMAX(1, ast->sample_size);
00544 //            av_log(s, AV_LOG_DEBUG, "%d %d %d %d\n", ast->rate, ast->scale, ast->start, ast->sample_size);
00545 
00546             switch(tag1) {
00547             case MKTAG('v', 'i', 'd', 's'):
00548                 codec_type = AVMEDIA_TYPE_VIDEO;
00549 
00550                 ast->sample_size = 0;
00551                 break;
00552             case MKTAG('a', 'u', 'd', 's'):
00553                 codec_type = AVMEDIA_TYPE_AUDIO;
00554                 break;
00555             case MKTAG('t', 'x', 't', 's'):
00556                 codec_type = AVMEDIA_TYPE_SUBTITLE;
00557                 break;
00558             case MKTAG('d', 'a', 't', 's'):
00559                 codec_type = AVMEDIA_TYPE_DATA;
00560                 break;
00561             default:
00562                 av_log(s, AV_LOG_INFO, "unknown stream type %X\n", tag1);
00563             }
00564             if(ast->sample_size == 0)
00565                 st->duration = st->nb_frames;
00566             ast->frame_offset= ast->cum_len;
00567             avio_skip(pb, size - 12 * 4);
00568             break;
00569         case MKTAG('s', 't', 'r', 'f'):
00570             /* stream header */
00571             if (stream_index >= (unsigned)s->nb_streams || avi->dv_demux) {
00572                 avio_skip(pb, size);
00573             } else {
00574                 uint64_t cur_pos = avio_tell(pb);
00575                 if (cur_pos < list_end)
00576                     size = FFMIN(size, list_end - cur_pos);
00577                 st = s->streams[stream_index];
00578                 switch(codec_type) {
00579                 case AVMEDIA_TYPE_VIDEO:
00580                     if(amv_file_format){
00581                         st->codec->width=avih_width;
00582                         st->codec->height=avih_height;
00583                         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00584                         st->codec->codec_id = CODEC_ID_AMV;
00585                         avio_skip(pb, size);
00586                         break;
00587                     }
00588                     tag1 = ff_get_bmp_header(pb, st);
00589 
00590                     if (tag1 == MKTAG('D', 'X', 'S', 'B') || tag1 == MKTAG('D','X','S','A')) {
00591                         st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
00592                         st->codec->codec_tag = tag1;
00593                         st->codec->codec_id = CODEC_ID_XSUB;
00594                         break;
00595                     }
00596 
00597                     if(size > 10*4 && size<(1<<30)){
00598                         st->codec->extradata_size= size - 10*4;
00599                         st->codec->extradata= av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00600                         if (!st->codec->extradata) {
00601                             st->codec->extradata_size= 0;
00602                             return AVERROR(ENOMEM);
00603                         }
00604                         avio_read(pb, st->codec->extradata, st->codec->extradata_size);
00605                     }
00606 
00607                     if(st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly
00608                         avio_r8(pb);
00609 
00610                     /* Extract palette from extradata if bpp <= 8. */
00611                     /* This code assumes that extradata contains only palette. */
00612                     /* This is true for all paletted codecs implemented in FFmpeg. */
00613                     if (st->codec->extradata_size && (st->codec->bits_per_coded_sample <= 8)) {
00614                         st->codec->palctrl = av_mallocz(sizeof(AVPaletteControl));
00615 #if HAVE_BIGENDIAN
00616                         for (i = 0; i < FFMIN(st->codec->extradata_size, AVPALETTE_SIZE)/4; i++)
00617                             st->codec->palctrl->palette[i] = av_bswap32(((uint32_t*)st->codec->extradata)[i]);
00618 #else
00619                         memcpy(st->codec->palctrl->palette, st->codec->extradata,
00620                                FFMIN(st->codec->extradata_size, AVPALETTE_SIZE));
00621 #endif
00622                         st->codec->palctrl->palette_changed = 1;
00623                     }
00624 
00625                     print_tag("video", tag1, 0);
00626 
00627                     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00628                     st->codec->codec_tag = tag1;
00629                     st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, tag1);
00630                     st->need_parsing = AVSTREAM_PARSE_HEADERS; // This is needed to get the pict type which is necessary for generating correct pts.
00631                     // Support "Resolution 1:1" for Avid AVI Codec
00632                     if(tag1 == MKTAG('A', 'V', 'R', 'n') &&
00633                        st->codec->extradata_size >= 31 &&
00634                        !memcmp(&st->codec->extradata[28], "1:1", 3))
00635                         st->codec->codec_id = CODEC_ID_RAWVIDEO;
00636 
00637                     if(st->codec->codec_tag==0 && st->codec->height > 0 && st->codec->extradata_size < 1U<<30){
00638                         st->codec->extradata_size+= 9;
00639                         st->codec->extradata= av_realloc_f(st->codec->extradata, 1, st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00640                         if(st->codec->extradata)
00641                             memcpy(st->codec->extradata + st->codec->extradata_size - 9, "BottomUp", 9);
00642                     }
00643                     st->codec->height= FFABS(st->codec->height);
00644 
00645 //                    avio_skip(pb, size - 5 * 4);
00646                     break;
00647                 case AVMEDIA_TYPE_AUDIO:
00648                     ret = ff_get_wav_header(pb, st->codec, size);
00649                     if (ret < 0)
00650                         return ret;
00651                     ast->dshow_block_align= st->codec->block_align;
00652                     if(ast->sample_size && st->codec->block_align && ast->sample_size != st->codec->block_align){
00653                         av_log(s, AV_LOG_WARNING, "sample size (%d) != block align (%d)\n", ast->sample_size, st->codec->block_align);
00654                         ast->sample_size= st->codec->block_align;
00655                     }
00656                     if (size&1) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
00657                         avio_skip(pb, 1);
00658                     /* Force parsing as several audio frames can be in
00659                      * one packet and timestamps refer to packet start. */
00660                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;
00661                     /* ADTS header is in extradata, AAC without header must be
00662                      * stored as exact frames. Parser not needed and it will
00663                      * fail. */
00664                     if (st->codec->codec_id == CODEC_ID_AAC && st->codec->extradata_size)
00665                         st->need_parsing = AVSTREAM_PARSE_NONE;
00666                     /* AVI files with Xan DPCM audio (wrongly) declare PCM
00667                      * audio in the header but have Axan as stream_code_tag. */
00668                     if (st->codec->stream_codec_tag == AV_RL32("Axan")){
00669                         st->codec->codec_id  = CODEC_ID_XAN_DPCM;
00670                         st->codec->codec_tag = 0;
00671                     }
00672                     if (amv_file_format){
00673                         st->codec->codec_id  = CODEC_ID_ADPCM_IMA_AMV;
00674                         ast->dshow_block_align = 0;
00675                     }
00676                     break;
00677                 case AVMEDIA_TYPE_SUBTITLE:
00678                     st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
00679                     st->request_probe= 1;
00680                     break;
00681                 default:
00682                     st->codec->codec_type = AVMEDIA_TYPE_DATA;
00683                     st->codec->codec_id= CODEC_ID_NONE;
00684                     st->codec->codec_tag= 0;
00685                     avio_skip(pb, size);
00686                     break;
00687                 }
00688             }
00689             break;
00690         case MKTAG('i', 'n', 'd', 'x'):
00691             i= avio_tell(pb);
00692             if(pb->seekable && !(s->flags & AVFMT_FLAG_IGNIDX) && avi->use_odml){
00693                 read_braindead_odml_indx(s, 0);
00694             }
00695             avio_seek(pb, i+size, SEEK_SET);
00696             break;
00697         case MKTAG('v', 'p', 'r', 'p'):
00698             if(stream_index < (unsigned)s->nb_streams && size > 9*4){
00699                 AVRational active, active_aspect;
00700 
00701                 st = s->streams[stream_index];
00702                 avio_rl32(pb);
00703                 avio_rl32(pb);
00704                 avio_rl32(pb);
00705                 avio_rl32(pb);
00706                 avio_rl32(pb);
00707 
00708                 active_aspect.den= avio_rl16(pb);
00709                 active_aspect.num= avio_rl16(pb);
00710                 active.num       = avio_rl32(pb);
00711                 active.den       = avio_rl32(pb);
00712                 avio_rl32(pb); //nbFieldsPerFrame
00713 
00714                 if(active_aspect.num && active_aspect.den && active.num && active.den){
00715                     st->sample_aspect_ratio= av_div_q(active_aspect, active);
00716 //av_log(s, AV_LOG_ERROR, "vprp %d/%d %d/%d\n", active_aspect.num, active_aspect.den, active.num, active.den);
00717                 }
00718                 size -= 9*4;
00719             }
00720             avio_skip(pb, size);
00721             break;
00722         case MKTAG('s', 't', 'r', 'n'):
00723             if(s->nb_streams){
00724                 avi_read_tag(s, s->streams[s->nb_streams-1], tag, size);
00725                 break;
00726             }
00727         default:
00728             if(size > 1000000){
00729                 av_log(s, AV_LOG_ERROR, "Something went wrong during header parsing, "
00730                                         "I will ignore it and try to continue anyway.\n");
00731                 avi->movi_list = avio_tell(pb) - 4;
00732                 avi->movi_end  = avio_size(pb);
00733                 goto end_of_header;
00734             }
00735             /* skip tag */
00736             size += (size & 1);
00737             avio_skip(pb, size);
00738             break;
00739         }
00740     }
00741  end_of_header:
00742     /* check stream number */
00743     if (stream_index != s->nb_streams - 1) {
00744     fail:
00745         return -1;
00746     }
00747 
00748     if(!avi->index_loaded && pb->seekable)
00749         avi_load_index(s);
00750     avi->index_loaded = 1;
00751     avi->non_interleaved |= guess_ni_flag(s) | (s->flags & AVFMT_FLAG_SORT_DTS);
00752     for(i=0; i<s->nb_streams; i++){
00753         AVStream *st = s->streams[i];
00754         if(st->nb_index_entries)
00755             break;
00756     }
00757     // DV-in-AVI cannot be non-interleaved, if set this must be
00758     // a mis-detection.
00759     if(avi->dv_demux)
00760         avi->non_interleaved=0;
00761     if(i==s->nb_streams && avi->non_interleaved) {
00762         av_log(s, AV_LOG_WARNING, "non-interleaved AVI without index, switching to interleaved\n");
00763         avi->non_interleaved=0;
00764     }
00765 
00766     if(avi->non_interleaved) {
00767         av_log(s, AV_LOG_INFO, "non-interleaved AVI\n");
00768         clean_index(s);
00769     }
00770 
00771     ff_metadata_conv_ctx(s, NULL, ff_avi_metadata_conv);
00772 
00773     return 0;
00774 }
00775 
00776 static int read_gab2_sub(AVStream *st, AVPacket *pkt) {
00777     if (!strcmp(pkt->data, "GAB2") && AV_RL16(pkt->data+5) == 2) {
00778         uint8_t desc[256];
00779         int score = AVPROBE_SCORE_MAX / 2, ret;
00780         AVIStream *ast = st->priv_data;
00781         AVInputFormat *sub_demuxer;
00782         AVRational time_base;
00783         AVIOContext *pb = avio_alloc_context( pkt->data + 7,
00784                                               pkt->size - 7,
00785                                               0, NULL, NULL, NULL, NULL);
00786         AVProbeData pd;
00787         unsigned int desc_len = avio_rl32(pb);
00788 
00789         if (desc_len > pb->buf_end - pb->buf_ptr)
00790             goto error;
00791 
00792         ret = avio_get_str16le(pb, desc_len, desc, sizeof(desc));
00793         avio_skip(pb, desc_len - ret);
00794         if (*desc)
00795             av_dict_set(&st->metadata, "title", desc, 0);
00796 
00797         avio_rl16(pb);   /* flags? */
00798         avio_rl32(pb);   /* data size */
00799 
00800         pd = (AVProbeData) { .buf = pb->buf_ptr, .buf_size = pb->buf_end - pb->buf_ptr };
00801         if (!(sub_demuxer = av_probe_input_format2(&pd, 1, &score)))
00802             goto error;
00803 
00804         if (!(ast->sub_ctx = avformat_alloc_context()))
00805             goto error;
00806 
00807         ast->sub_ctx->pb      = pb;
00808         if (!avformat_open_input(&ast->sub_ctx, "", sub_demuxer, NULL)) {
00809             av_read_packet(ast->sub_ctx, &ast->sub_pkt);
00810             *st->codec = *ast->sub_ctx->streams[0]->codec;
00811             ast->sub_ctx->streams[0]->codec->extradata = NULL;
00812             time_base = ast->sub_ctx->streams[0]->time_base;
00813             av_set_pts_info(st, 64, time_base.num, time_base.den);
00814         }
00815         ast->sub_buffer = pkt->data;
00816         memset(pkt, 0, sizeof(*pkt));
00817         return 1;
00818 error:
00819         av_freep(&pb);
00820     }
00821     return 0;
00822 }
00823 
00824 static AVStream *get_subtitle_pkt(AVFormatContext *s, AVStream *next_st,
00825                                   AVPacket *pkt)
00826 {
00827     AVIStream *ast, *next_ast = next_st->priv_data;
00828     int64_t ts, next_ts, ts_min = INT64_MAX;
00829     AVStream *st, *sub_st = NULL;
00830     int i;
00831 
00832     next_ts = av_rescale_q(next_ast->frame_offset, next_st->time_base,
00833                            AV_TIME_BASE_Q);
00834 
00835     for (i=0; i<s->nb_streams; i++) {
00836         st  = s->streams[i];
00837         ast = st->priv_data;
00838         if (st->discard < AVDISCARD_ALL && ast && ast->sub_pkt.data) {
00839             ts = av_rescale_q(ast->sub_pkt.dts, st->time_base, AV_TIME_BASE_Q);
00840             if (ts <= next_ts && ts < ts_min) {
00841                 ts_min = ts;
00842                 sub_st = st;
00843             }
00844         }
00845     }
00846 
00847     if (sub_st) {
00848         ast = sub_st->priv_data;
00849         *pkt = ast->sub_pkt;
00850         pkt->stream_index = sub_st->index;
00851         if (av_read_packet(ast->sub_ctx, &ast->sub_pkt) < 0)
00852             ast->sub_pkt.data = NULL;
00853     }
00854     return sub_st;
00855 }
00856 
00857 static int get_stream_idx(int *d){
00858     if(    d[0] >= '0' && d[0] <= '9'
00859         && d[1] >= '0' && d[1] <= '9'){
00860         return (d[0] - '0') * 10 + (d[1] - '0');
00861     }else{
00862         return 100; //invalid stream ID
00863     }
00864 }
00865 
00866 static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
00867 {
00868     AVIContext *avi = s->priv_data;
00869     AVIOContext *pb = s->pb;
00870     int n, d[8];
00871     unsigned int size;
00872     int64_t i, sync;
00873     void* dstr;
00874 
00875     if (CONFIG_DV_DEMUXER && avi->dv_demux) {
00876         int size = dv_get_packet(avi->dv_demux, pkt);
00877         if (size >= 0)
00878             return size;
00879     }
00880 
00881     if(avi->non_interleaved){
00882         int best_stream_index = 0;
00883         AVStream *best_st= NULL;
00884         AVIStream *best_ast;
00885         int64_t best_ts= INT64_MAX;
00886         int i;
00887 
00888         for(i=0; i<s->nb_streams; i++){
00889             AVStream *st = s->streams[i];
00890             AVIStream *ast = st->priv_data;
00891             int64_t ts= ast->frame_offset;
00892             int64_t last_ts;
00893 
00894             if(!st->nb_index_entries)
00895                 continue;
00896 
00897             last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;
00898             if(!ast->remaining && ts > last_ts)
00899                 continue;
00900 
00901             ts = av_rescale_q(ts, st->time_base, (AVRational){FFMAX(1, ast->sample_size), AV_TIME_BASE});
00902 
00903 //            av_log(s, AV_LOG_DEBUG, "%"PRId64" %d/%d %"PRId64"\n", ts, st->time_base.num, st->time_base.den, ast->frame_offset);
00904             if(ts < best_ts){
00905                 best_ts= ts;
00906                 best_st= st;
00907                 best_stream_index= i;
00908             }
00909         }
00910         if(!best_st)
00911             return -1;
00912 
00913         best_ast = best_st->priv_data;
00914         best_ts = av_rescale_q(best_ts, (AVRational){FFMAX(1, best_ast->sample_size), AV_TIME_BASE}, best_st->time_base);
00915         if(best_ast->remaining)
00916             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
00917         else{
00918             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
00919             if(i>=0)
00920                 best_ast->frame_offset= best_st->index_entries[i].timestamp;
00921         }
00922 
00923 //        av_log(s, AV_LOG_DEBUG, "%d\n", i);
00924         if(i>=0){
00925             int64_t pos= best_st->index_entries[i].pos;
00926             pos += best_ast->packet_size - best_ast->remaining;
00927             avio_seek(s->pb, pos + 8, SEEK_SET);
00928 //        av_log(s, AV_LOG_DEBUG, "pos=%"PRId64"\n", pos);
00929 
00930             assert(best_ast->remaining <= best_ast->packet_size);
00931 
00932             avi->stream_index= best_stream_index;
00933             if(!best_ast->remaining)
00934                 best_ast->packet_size=
00935                 best_ast->remaining= best_st->index_entries[i].size;
00936         }
00937     }
00938 
00939 resync:
00940     if(avi->stream_index >= 0){
00941         AVStream *st= s->streams[ avi->stream_index ];
00942         AVIStream *ast= st->priv_data;
00943         int size, err;
00944 
00945         if(get_subtitle_pkt(s, st, pkt))
00946             return 0;
00947 
00948         if(ast->sample_size <= 1) // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM
00949             size= INT_MAX;
00950         else if(ast->sample_size < 32)
00951             // arbitrary multiplier to avoid tiny packets for raw PCM data
00952             size= 1024*ast->sample_size;
00953         else
00954             size= ast->sample_size;
00955 
00956         if(size > ast->remaining)
00957             size= ast->remaining;
00958         avi->last_pkt_pos= avio_tell(pb);
00959         err= av_get_packet(pb, pkt, size);
00960         if(err<0)
00961             return err;
00962 
00963         if(ast->has_pal && pkt->data && pkt->size<(unsigned)INT_MAX/2){
00964             void *ptr= av_realloc(pkt->data, pkt->size + 4*256 + FF_INPUT_BUFFER_PADDING_SIZE);
00965             if(ptr){
00966             ast->has_pal=0;
00967             pkt->size += 4*256;
00968             pkt->data= ptr;
00969                 memcpy(pkt->data + pkt->size - 4*256, ast->pal, 4*256);
00970             }else
00971                 av_log(s, AV_LOG_ERROR, "Failed to append palette\n");
00972         }
00973 
00974         if (CONFIG_DV_DEMUXER && avi->dv_demux) {
00975             dstr = pkt->destruct;
00976             size = dv_produce_packet(avi->dv_demux, pkt,
00977                                     pkt->data, pkt->size, pkt->pos);
00978             pkt->destruct = dstr;
00979             pkt->flags |= AV_PKT_FLAG_KEY;
00980             if (size < 0)
00981                 av_free_packet(pkt);
00982         } else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE
00983                    && !st->codec->codec_tag && read_gab2_sub(st, pkt)) {
00984             ast->frame_offset++;
00985             avi->stream_index = -1;
00986             ast->remaining = 0;
00987             goto resync;
00988         } else {
00989             /* XXX: How to handle B-frames in AVI? */
00990             pkt->dts = ast->frame_offset;
00991 //                pkt->dts += ast->start;
00992             if(ast->sample_size)
00993                 pkt->dts /= ast->sample_size;
00994 //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);
00995             pkt->stream_index = avi->stream_index;
00996 
00997             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
00998                 AVIndexEntry *e;
00999                 int index;
01000                 assert(st->index_entries);
01001 
01002                 index= av_index_search_timestamp(st, ast->frame_offset, 0);
01003                 e= &st->index_entries[index];
01004 
01005                 if(index >= 0 && e->timestamp == ast->frame_offset){
01006                     if (index == st->nb_index_entries-1){
01007                         int key=1;
01008                         int i;
01009                         uint32_t state=-1;
01010                         for(i=0; i<FFMIN(size,256); i++){
01011                             if(st->codec->codec_id == CODEC_ID_MPEG4){
01012                                 if(state == 0x1B6){
01013                                     key= !(pkt->data[i]&0xC0);
01014                                     break;
01015                                 }
01016                             }else
01017                                 break;
01018                             state= (state<<8) + pkt->data[i];
01019                         }
01020                         if(!key)
01021                             e->flags &= ~AVINDEX_KEYFRAME;
01022                     }
01023                     if (e->flags & AVINDEX_KEYFRAME)
01024                         pkt->flags |= AV_PKT_FLAG_KEY;
01025                 }
01026             } else {
01027                 pkt->flags |= AV_PKT_FLAG_KEY;
01028             }
01029             ast->frame_offset += get_duration(ast, pkt->size);
01030         }
01031         ast->remaining -= size;
01032         if(!ast->remaining){
01033             avi->stream_index= -1;
01034             ast->packet_size= 0;
01035         }
01036 
01037         if(!avi->non_interleaved && pkt->pos >= 0 && ast->seek_pos > pkt->pos){
01038             av_free_packet(pkt);
01039             goto resync;
01040         }
01041         ast->seek_pos= 0;
01042 
01043         return size;
01044     }
01045 
01046     memset(d, -1, sizeof(int)*8);
01047     for(i=sync=avio_tell(pb); !url_feof(pb); i++) {
01048         int j;
01049 
01050         for(j=0; j<7; j++)
01051             d[j]= d[j+1];
01052         d[7]= avio_r8(pb);
01053 
01054         size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
01055 
01056         n= get_stream_idx(d+2);
01057 //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);
01058         if(i + (uint64_t)size > avi->fsize || d[0]<0)
01059             continue;
01060 
01061         //parse ix##
01062         if(  (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
01063         //parse JUNK
01064            ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')
01065            ||(d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')){
01066             avio_skip(pb, size);
01067 //av_log(s, AV_LOG_DEBUG, "SKIP\n");
01068             goto resync;
01069         }
01070 
01071         //parse stray LIST
01072         if(d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T'){
01073             avio_skip(pb, 4);
01074             goto resync;
01075         }
01076 
01077         n= get_stream_idx(d);
01078 
01079         if(!((i-avi->last_pkt_pos)&1) && get_stream_idx(d+1) < s->nb_streams)
01080             continue;
01081 
01082         //detect ##ix chunk and skip
01083         if(d[2] == 'i' && d[3] == 'x' && n < s->nb_streams){
01084             avio_skip(pb, size);
01085             goto resync;
01086         }
01087 
01088         //parse ##dc/##wb
01089         if(n < s->nb_streams){
01090             AVStream *st;
01091             AVIStream *ast;
01092             st = s->streams[n];
01093             ast = st->priv_data;
01094 
01095             if(s->nb_streams>=2){
01096                 AVStream *st1  = s->streams[1];
01097                 AVIStream *ast1= st1->priv_data;
01098                 //workaround for broken small-file-bug402.avi
01099                 if(   d[2] == 'w' && d[3] == 'b'
01100                    && n==0
01101                    && st ->codec->codec_type == AVMEDIA_TYPE_VIDEO
01102                    && st1->codec->codec_type == AVMEDIA_TYPE_AUDIO
01103                    && ast->prefix == 'd'*256+'c'
01104                    && (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)
01105                   ){
01106                     n=1;
01107                     st = st1;
01108                     ast = ast1;
01109                     av_log(s, AV_LOG_WARNING, "Invalid stream + prefix combination, assuming audio.\n");
01110                 }
01111             }
01112 
01113 
01114             if(   (st->discard >= AVDISCARD_DEFAULT && size==0)
01115                /*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & AV_PKT_FLAG_KEY))*/ //FIXME needs a little reordering
01116                || st->discard >= AVDISCARD_ALL){
01117                 ast->frame_offset += get_duration(ast, size);
01118                 avio_skip(pb, size);
01119                 goto resync;
01120             }
01121 
01122             if (d[2] == 'p' && d[3] == 'c' && size<=4*256+4) {
01123                 int k = avio_r8(pb);
01124                 int last = (k + avio_r8(pb) - 1) & 0xFF;
01125 
01126                 avio_rl16(pb); //flags
01127 
01128                 for (; k <= last; k++)
01129                     ast->pal[k] = avio_rb32(pb)>>8;// b + (g << 8) + (r << 16);
01130                 ast->has_pal= 1;
01131                 goto resync;
01132             } else if(   ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||
01133                          d[2]*256+d[3] == ast->prefix /*||
01134                          (d[2] == 'd' && d[3] == 'c') ||
01135                          (d[2] == 'w' && d[3] == 'b')*/) {
01136 
01137 //av_log(s, AV_LOG_DEBUG, "OK\n");
01138                 if(d[2]*256+d[3] == ast->prefix)
01139                     ast->prefix_count++;
01140                 else{
01141                     ast->prefix= d[2]*256+d[3];
01142                     ast->prefix_count= 0;
01143                 }
01144 
01145                 avi->stream_index= n;
01146                 ast->packet_size= size + 8;
01147                 ast->remaining= size;
01148 
01149                 if(size || !ast->sample_size){
01150                     uint64_t pos= avio_tell(pb) - 8;
01151                     if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){
01152                         av_add_index_entry(st, pos, ast->frame_offset, size, 0, AVINDEX_KEYFRAME);
01153                     }
01154                 }
01155                 goto resync;
01156             }
01157         }
01158     }
01159 
01160     return AVERROR_EOF;
01161 }
01162 
01163 /* XXX: We make the implicit supposition that the positions are sorted
01164    for each stream. */
01165 static int avi_read_idx1(AVFormatContext *s, int size)
01166 {
01167     AVIContext *avi = s->priv_data;
01168     AVIOContext *pb = s->pb;
01169     int nb_index_entries, i;
01170     AVStream *st;
01171     AVIStream *ast;
01172     unsigned int index, tag, flags, pos, len;
01173     unsigned last_pos= -1;
01174 
01175     nb_index_entries = size / 16;
01176     if (nb_index_entries <= 0)
01177         return -1;
01178 
01179     /* Read the entries and sort them in each stream component. */
01180     for(i = 0; i < nb_index_entries; i++) {
01181         tag = avio_rl32(pb);
01182         flags = avio_rl32(pb);
01183         pos = avio_rl32(pb);
01184         len = avio_rl32(pb);
01185         av_dlog(s, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
01186                 i, tag, flags, pos, len);
01187         if(i==0 && pos > avi->movi_list)
01188             avi->movi_list= 0; //FIXME better check
01189         pos += avi->movi_list;
01190 
01191         index = ((tag & 0xff) - '0') * 10;
01192         index += ((tag >> 8) & 0xff) - '0';
01193         if (index >= s->nb_streams)
01194             continue;
01195         st = s->streams[index];
01196         ast = st->priv_data;
01197 
01198 #if defined(DEBUG_SEEK)
01199         av_log(s, AV_LOG_DEBUG, "%d cum_len=%"PRId64"\n", len, ast->cum_len);
01200 #endif
01201         if(url_feof(pb))
01202             return -1;
01203 
01204         if(last_pos == pos)
01205             avi->non_interleaved= 1;
01206         else if(len || !ast->sample_size)
01207             av_add_index_entry(st, pos, ast->cum_len, len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
01208         ast->cum_len += get_duration(ast, len);
01209         last_pos= pos;
01210     }
01211     return 0;
01212 }
01213 
01214 static int guess_ni_flag(AVFormatContext *s){
01215     int i;
01216     int64_t last_start=0;
01217     int64_t first_end= INT64_MAX;
01218     int64_t oldpos= avio_tell(s->pb);
01219 
01220     for(i=0; i<s->nb_streams; i++){
01221         AVStream *st = s->streams[i];
01222         int n= st->nb_index_entries;
01223         unsigned int size;
01224 
01225         if(n <= 0)
01226             continue;
01227 
01228         if(n >= 2){
01229             int64_t pos= st->index_entries[0].pos;
01230             avio_seek(s->pb, pos + 4, SEEK_SET);
01231             size= avio_rl32(s->pb);
01232             if(pos + size > st->index_entries[1].pos)
01233                 last_start= INT64_MAX;
01234         }
01235 
01236         if(st->index_entries[0].pos > last_start)
01237             last_start= st->index_entries[0].pos;
01238         if(st->index_entries[n-1].pos < first_end)
01239             first_end= st->index_entries[n-1].pos;
01240     }
01241     avio_seek(s->pb, oldpos, SEEK_SET);
01242     return last_start > first_end;
01243 }
01244 
01245 static int avi_load_index(AVFormatContext *s)
01246 {
01247     AVIContext *avi = s->priv_data;
01248     AVIOContext *pb = s->pb;
01249     uint32_t tag, size;
01250     int64_t pos= avio_tell(pb);
01251     int ret = -1;
01252 
01253     if (avio_seek(pb, avi->movi_end, SEEK_SET) < 0)
01254         goto the_end; // maybe truncated file
01255     av_dlog(s, "movi_end=0x%"PRIx64"\n", avi->movi_end);
01256     for(;;) {
01257         if (url_feof(pb))
01258             break;
01259         tag = avio_rl32(pb);
01260         size = avio_rl32(pb);
01261         av_dlog(s, "tag=%c%c%c%c size=0x%x\n",
01262                  tag        & 0xff,
01263                 (tag >>  8) & 0xff,
01264                 (tag >> 16) & 0xff,
01265                 (tag >> 24) & 0xff,
01266                 size);
01267         switch(tag) {
01268         case MKTAG('i', 'd', 'x', '1'):
01269             if (avi_read_idx1(s, size) < 0)
01270                 goto skip;
01271             ret = 0;
01272                 goto the_end;
01273             break;
01274         default:
01275         skip:
01276             size += (size & 1);
01277             if (avio_skip(pb, size) < 0)
01278                 goto the_end; // something is wrong here
01279             break;
01280         }
01281     }
01282  the_end:
01283     avio_seek(pb, pos, SEEK_SET);
01284     return ret;
01285 }
01286 
01287 static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)
01288 {
01289     AVIStream *ast2 = st2->priv_data;
01290     int64_t ts2 = av_rescale_q(timestamp, st->time_base, st2->time_base);
01291     av_free_packet(&ast2->sub_pkt);
01292     if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||
01293         avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)
01294         av_read_packet(ast2->sub_ctx, &ast2->sub_pkt);
01295 }
01296 
01297 static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
01298 {
01299     AVIContext *avi = s->priv_data;
01300     AVStream *st;
01301     int i, index;
01302     int64_t pos, pos_min;
01303     AVIStream *ast;
01304 
01305     if (!avi->index_loaded) {
01306         /* we only load the index on demand */
01307         avi_load_index(s);
01308         avi->index_loaded = 1;
01309     }
01310     assert(stream_index>= 0);
01311 
01312     st = s->streams[stream_index];
01313     ast= st->priv_data;
01314     index= av_index_search_timestamp(st, timestamp * FFMAX(ast->sample_size, 1), flags);
01315     if(index<0)
01316         return -1;
01317 
01318     /* find the position */
01319     pos = st->index_entries[index].pos;
01320     timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);
01321 
01322 //    av_log(s, AV_LOG_DEBUG, "XX %"PRId64" %d %"PRId64"\n", timestamp, index, st->index_entries[index].timestamp);
01323 
01324     if (CONFIG_DV_DEMUXER && avi->dv_demux) {
01325         /* One and only one real stream for DV in AVI, and it has video  */
01326         /* offsets. Calling with other stream indexes should have failed */
01327         /* the av_index_search_timestamp call above.                     */
01328         assert(stream_index == 0);
01329 
01330         if(avio_seek(s->pb, pos, SEEK_SET) < 0)
01331             return -1;
01332 
01333         /* Feed the DV video stream version of the timestamp to the */
01334         /* DV demux so it can synthesize correct timestamps.        */
01335         dv_offset_reset(avi->dv_demux, timestamp);
01336 
01337         avi->stream_index= -1;
01338         return 0;
01339     }
01340 
01341     pos_min= pos;
01342     for(i = 0; i < s->nb_streams; i++) {
01343         AVStream *st2 = s->streams[i];
01344         AVIStream *ast2 = st2->priv_data;
01345 
01346         ast2->packet_size=
01347         ast2->remaining= 0;
01348 
01349         if (ast2->sub_ctx) {
01350             seek_subtitle(st, st2, timestamp);
01351             continue;
01352         }
01353 
01354         if (st2->nb_index_entries <= 0)
01355             continue;
01356 
01357 //        assert(st2->codec->block_align);
01358         assert((int64_t)st2->time_base.num*ast2->rate == (int64_t)st2->time_base.den*ast2->scale);
01359         index = av_index_search_timestamp(
01360                 st2,
01361                 av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),
01362                 flags | AVSEEK_FLAG_BACKWARD | (st2->codec->codec_type != AVMEDIA_TYPE_VIDEO ? AVSEEK_FLAG_ANY : 0));
01363         if(index<0)
01364             index=0;
01365         ast2->seek_pos= st2->index_entries[index].pos;
01366         pos_min= FFMIN(pos_min,ast2->seek_pos);
01367     }
01368     for(i = 0; i < s->nb_streams; i++) {
01369         AVStream *st2 = s->streams[i];
01370         AVIStream *ast2 = st2->priv_data;
01371 
01372         if (ast2->sub_ctx || st2->nb_index_entries <= 0)
01373             continue;
01374 
01375         index = av_index_search_timestamp(
01376                 st2,
01377                 av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),
01378                 flags | AVSEEK_FLAG_BACKWARD | (st2->codec->codec_type != AVMEDIA_TYPE_VIDEO ? AVSEEK_FLAG_ANY : 0));
01379         if(index<0)
01380             index=0;
01381         while(index>0 && st2->index_entries[index-1].pos >= pos_min)
01382             index--;
01383         ast2->frame_offset = st2->index_entries[index].timestamp;
01384     }
01385 
01386     /* do the seek */
01387     if (avio_seek(s->pb, pos_min, SEEK_SET) < 0)
01388         return -1;
01389     avi->stream_index= -1;
01390     return 0;
01391 }
01392 
01393 static int avi_read_close(AVFormatContext *s)
01394 {
01395     int i;
01396     AVIContext *avi = s->priv_data;
01397 
01398     for(i=0;i<s->nb_streams;i++) {
01399         AVStream *st = s->streams[i];
01400         AVIStream *ast = st->priv_data;
01401         av_free(st->codec->palctrl);
01402         if (ast) {
01403             if (ast->sub_ctx) {
01404                 av_freep(&ast->sub_ctx->pb);
01405                 av_close_input_file(ast->sub_ctx);
01406             }
01407             av_free(ast->sub_buffer);
01408             av_free_packet(&ast->sub_pkt);
01409         }
01410     }
01411 
01412     av_free(avi->dv_demux);
01413 
01414     return 0;
01415 }
01416 
01417 static int avi_probe(AVProbeData *p)
01418 {
01419     int i;
01420 
01421     /* check file header */
01422     for(i=0; avi_headers[i][0]; i++)
01423         if(!memcmp(p->buf  , avi_headers[i]  , 4) &&
01424            !memcmp(p->buf+8, avi_headers[i]+4, 4))
01425             return AVPROBE_SCORE_MAX;
01426 
01427     return 0;
01428 }
01429 
01430 AVInputFormat ff_avi_demuxer = {
01431     "avi",
01432     NULL_IF_CONFIG_SMALL("AVI format"),
01433     sizeof(AVIContext),
01434     avi_probe,
01435     avi_read_header,
01436     avi_read_packet,
01437     avi_read_close,
01438     avi_read_seek,
01439     .priv_class = &demuxer_class,
01440 };