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 //#define DEBUG
00023 //#define DEBUG_SEEK
00024 
00025 #include <strings.h>
00026 #include "libavutil/intreadwrite.h"
00027 #include "libavutil/bswap.h"
00028 #include "libavcodec/bytestream.h"
00029 #include "avformat.h"
00030 #include "avi.h"
00031 #include "dv.h"
00032 #include "riff.h"
00033 
00034 #undef NDEBUG
00035 #include <assert.h>
00036 
00037 typedef struct AVIStream {
00038     int64_t frame_offset; /* current frame (video) or byte (audio) counter
00039                          (used to compute the pts) */
00040     int remaining;
00041     int packet_size;
00042 
00043     int scale;
00044     int rate;
00045     int sample_size; /* size of one sample (or packet) (in the rate/scale sense) in bytes */
00046 
00047     int64_t cum_len; /* temporary storage (used during seek) */
00048 
00049     int prefix;                       
00050     int prefix_count;
00051     uint32_t pal[256];
00052     int has_pal;
00053     int dshow_block_align;            
00054 
00055     AVFormatContext *sub_ctx;
00056     AVPacket sub_pkt;
00057     uint8_t *sub_buffer;
00058 } AVIStream;
00059 
00060 typedef struct {
00061     int64_t  riff_end;
00062     int64_t  movi_end;
00063     int64_t  fsize;
00064     int64_t movi_list;
00065     int64_t last_pkt_pos;
00066     int index_loaded;
00067     int is_odml;
00068     int non_interleaved;
00069     int stream_index;
00070     DVDemuxContext* dv_demux;
00071     int odml_depth;
00072 #define MAX_ODML_DEPTH 1000
00073 } AVIContext;
00074 
00075 static const char avi_headers[][8] = {
00076     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', ' ' },
00077     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 'X' },
00078     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 0x19},
00079     { 'O', 'N', '2', ' ',    'O', 'N', '2', 'f' },
00080     { 'R', 'I', 'F', 'F',    'A', 'M', 'V', ' ' },
00081     { 0 }
00082 };
00083 
00084 static int avi_load_index(AVFormatContext *s);
00085 static int guess_ni_flag(AVFormatContext *s);
00086 
00087 #ifdef DEBUG
00088 static void print_tag(const char *str, unsigned int tag, int size)
00089 {
00090     dprintf(NULL, "%s: tag=%c%c%c%c size=0x%x\n",
00091            str, tag & 0xff,
00092            (tag >> 8) & 0xff,
00093            (tag >> 16) & 0xff,
00094            (tag >> 24) & 0xff,
00095            size);
00096 }
00097 #endif
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, ByteIOContext *pb)
00109 {
00110     AVIContext *avi = s->priv_data;
00111     char header[8];
00112     int i;
00113 
00114     /* check RIFF header */
00115     get_buffer(pb, header, 4);
00116     avi->riff_end = get_le32(pb);   /* RIFF chunk size */
00117     avi->riff_end += url_ftell(pb); /* RIFF chunk end */
00118     get_buffer(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     ByteIOContext *pb = s->pb;
00135     int longs_pre_entry= get_le16(pb);
00136     int index_sub_type = get_byte(pb);
00137     int index_type     = get_byte(pb);
00138     int entries_in_use = get_le32(pb);
00139     int chunk_id       = get_le32(pb);
00140     int64_t base       = get_le64(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= url_fsize(s->pb);
00147 
00148 #ifdef DEBUG_SEEK
00149     av_log(s, AV_LOG_ERROR, "longs_pre_entry:%d index_type:%d entries_in_use:%d chunk_id:%X base:%16"PRIX64"\n",
00150         longs_pre_entry,index_type, entries_in_use, chunk_id, base);
00151 #endif
00152 
00153     if(stream_id >= s->nb_streams || stream_id < 0)
00154         return -1;
00155     st= s->streams[stream_id];
00156     ast = st->priv_data;
00157 
00158     if(index_sub_type)
00159         return -1;
00160 
00161     get_le32(pb);
00162 
00163     if(index_type && longs_pre_entry != 2)
00164         return -1;
00165     if(index_type>1)
00166         return -1;
00167 
00168     if(filesize > 0 && base >= filesize){
00169         av_log(s, AV_LOG_ERROR, "ODML index invalid\n");
00170         if(base>>32 == (base & 0xFFFFFFFF) && (base & 0xFFFFFFFF) < filesize && filesize <= 0xFFFFFFFF)
00171             base &= 0xFFFFFFFF;
00172         else
00173             return -1;
00174     }
00175 
00176     for(i=0; i<entries_in_use; i++){
00177         if(index_type){
00178             int64_t pos= get_le32(pb) + base - 8;
00179             int len    = get_le32(pb);
00180             int key= len >= 0;
00181             len &= 0x7FFFFFFF;
00182 
00183 #ifdef DEBUG_SEEK
00184             av_log(s, AV_LOG_ERROR, "pos:%"PRId64", len:%X\n", pos, len);
00185 #endif
00186             if(url_feof(pb))
00187                 return -1;
00188 
00189             if(last_pos == pos || pos == base - 8)
00190                 avi->non_interleaved= 1;
00191             if(last_pos != pos && (len || !ast->sample_size))
00192                 av_add_index_entry(st, pos, ast->cum_len, len, 0, key ? AVINDEX_KEYFRAME : 0);
00193 
00194             ast->cum_len += get_duration(ast, len);
00195             last_pos= pos;
00196         }else{
00197             int64_t offset, pos;
00198             int duration;
00199             offset = get_le64(pb);
00200             get_le32(pb);       /* size */
00201             duration = get_le32(pb);
00202 
00203             if(url_feof(pb))
00204                 return -1;
00205 
00206             pos = url_ftell(pb);
00207 
00208             if(avi->odml_depth > MAX_ODML_DEPTH){
00209                 av_log(s, AV_LOG_ERROR, "Too deeply nested ODML indexes\n");
00210                 return -1;
00211             }
00212 
00213             url_fseek(pb, offset+8, SEEK_SET);
00214             avi->odml_depth++;
00215             read_braindead_odml_indx(s, frame_num);
00216             avi->odml_depth--;
00217             frame_num += duration;
00218 
00219             url_fseek(pb, pos, SEEK_SET);
00220         }
00221     }
00222     avi->index_loaded=1;
00223     return 0;
00224 }
00225 
00226 static void clean_index(AVFormatContext *s){
00227     int i;
00228     int64_t j;
00229 
00230     for(i=0; i<s->nb_streams; i++){
00231         AVStream *st = s->streams[i];
00232         AVIStream *ast = st->priv_data;
00233         int n= st->nb_index_entries;
00234         int max= ast->sample_size;
00235         int64_t pos, size, ts;
00236 
00237         if(n != 1 || ast->sample_size==0)
00238             continue;
00239 
00240         while(max < 1024) max+=max;
00241 
00242         pos= st->index_entries[0].pos;
00243         size= st->index_entries[0].size;
00244         ts= st->index_entries[0].timestamp;
00245 
00246         for(j=0; j<size; j+=max){
00247             av_add_index_entry(st, pos+j, ts+j, FFMIN(max, size-j), 0, AVINDEX_KEYFRAME);
00248         }
00249     }
00250 }
00251 
00252 static int avi_read_tag(AVFormatContext *s, AVStream *st, uint32_t tag, uint32_t size)
00253 {
00254     ByteIOContext *pb = s->pb;
00255     char key[5] = {0}, *value;
00256 
00257     size += (size & 1);
00258 
00259     if (size == UINT_MAX)
00260         return -1;
00261     value = av_malloc(size+1);
00262     if (!value)
00263         return -1;
00264     get_buffer(pb, value, size);
00265     value[size]=0;
00266 
00267     AV_WL32(key, tag);
00268 
00269     return av_metadata_set2(st ? &st->metadata : &s->metadata, key, value,
00270                             AV_METADATA_DONT_STRDUP_VAL);
00271 }
00272 
00273 static void avi_read_info(AVFormatContext *s, uint64_t end)
00274 {
00275     while (url_ftell(s->pb) < end) {
00276         uint32_t tag  = get_le32(s->pb);
00277         uint32_t size = get_le32(s->pb);
00278         avi_read_tag(s, NULL, tag, size);
00279     }
00280 }
00281 
00282 static const char months[12][4] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
00283                                     "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
00284 
00285 static void avi_metadata_creation_time(AVMetadata **metadata, char *date)
00286 {
00287     char month[4], time[9], buffer[64];
00288     int i, day, year;
00289     /* parse standard AVI date format (ie. "Mon Mar 10 15:04:43 2003") */
00290     if (sscanf(date, "%*3s%*[ ]%3s%*[ ]%2d%*[ ]%8s%*[ ]%4d",
00291                month, &day, time, &year) == 4) {
00292         for (i=0; i<12; i++)
00293             if (!strcasecmp(month, months[i])) {
00294                 snprintf(buffer, sizeof(buffer), "%.4d-%.2d-%.2d %s",
00295                          year, i+1, day, time);
00296                 av_metadata_set2(metadata, "creation_time", buffer, 0);
00297             }
00298     } else if (date[4] == '/' && date[7] == '/') {
00299         date[4] = date[7] = '-';
00300         av_metadata_set2(metadata, "creation_time", date, 0);
00301     }
00302 }
00303 
00304 static void avi_read_nikon(AVFormatContext *s, uint64_t end)
00305 {
00306     while (url_ftell(s->pb) < end) {
00307         uint32_t tag  = get_le32(s->pb);
00308         uint32_t size = get_le32(s->pb);
00309         switch (tag) {
00310         case MKTAG('n', 'c', 't', 'g'): {  /* Nikon Tags */
00311             uint64_t tag_end = url_ftell(s->pb) + size;
00312             while (url_ftell(s->pb) < tag_end) {
00313                 uint16_t tag  = get_le16(s->pb);
00314                 uint16_t size = get_le16(s->pb);
00315                 const char *name = NULL;
00316                 char buffer[64] = {0};
00317                 size -= get_buffer(s->pb, buffer,
00318                                    FFMIN(size, sizeof(buffer)-1));
00319                 switch (tag) {
00320                 case 0x03:  name = "maker";  break;
00321                 case 0x04:  name = "model";  break;
00322                 case 0x13:  name = "creation_time";
00323                     if (buffer[4] == ':' && buffer[7] == ':')
00324                         buffer[4] = buffer[7] = '-';
00325                     break;
00326                 }
00327                 if (name)
00328                     av_metadata_set2(&s->metadata, name, buffer, 0);
00329                 url_fskip(s->pb, size);
00330             }
00331             break;
00332         }
00333         default:
00334             url_fskip(s->pb, size);
00335             break;
00336         }
00337     }
00338 }
00339 
00340 static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
00341 {
00342     AVIContext *avi = s->priv_data;
00343     ByteIOContext *pb = s->pb;
00344     unsigned int tag, tag1, handler;
00345     int codec_type, stream_index, frame_period, bit_rate;
00346     unsigned int size;
00347     int i;
00348     AVStream *st;
00349     AVIStream *ast = NULL;
00350     int avih_width=0, avih_height=0;
00351     int amv_file_format=0;
00352     uint64_t list_end = 0;
00353 
00354     avi->stream_index= -1;
00355 
00356     if (get_riff(s, pb) < 0)
00357         return -1;
00358 
00359     avi->fsize = url_fsize(pb);
00360     if(avi->fsize<=0)
00361         avi->fsize= avi->riff_end == 8 ? INT64_MAX : avi->riff_end;
00362 
00363     /* first list tag */
00364     stream_index = -1;
00365     codec_type = -1;
00366     frame_period = 0;
00367     for(;;) {
00368         if (url_feof(pb))
00369             goto fail;
00370         tag = get_le32(pb);
00371         size = get_le32(pb);
00372 #ifdef DEBUG
00373         print_tag("tag", tag, size);
00374 #endif
00375 
00376         switch(tag) {
00377         case MKTAG('L', 'I', 'S', 'T'):
00378             list_end = url_ftell(pb) + size;
00379             /* Ignored, except at start of video packets. */
00380             tag1 = get_le32(pb);
00381 #ifdef DEBUG
00382             print_tag("list", tag1, 0);
00383 #endif
00384             if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
00385                 avi->movi_list = url_ftell(pb) - 4;
00386                 if(size) avi->movi_end = avi->movi_list + size + (size & 1);
00387                 else     avi->movi_end = url_fsize(pb);
00388                 dprintf(NULL, "movi end=%"PRIx64"\n", avi->movi_end);
00389                 goto end_of_header;
00390             }
00391             else if (tag1 == MKTAG('I', 'N', 'F', 'O'))
00392                 avi_read_info(s, list_end);
00393             else if (tag1 == MKTAG('n', 'c', 'd', 't'))
00394                 avi_read_nikon(s, list_end);
00395 
00396             break;
00397         case MKTAG('I', 'D', 'I', 'T'): {
00398             unsigned char date[64] = {0};
00399             size += (size & 1);
00400             size -= get_buffer(pb, date, FFMIN(size, sizeof(date)-1));
00401             url_fskip(pb, size);
00402             avi_metadata_creation_time(&s->metadata, date);
00403             break;
00404         }
00405         case MKTAG('d', 'm', 'l', 'h'):
00406             avi->is_odml = 1;
00407             url_fskip(pb, size + (size & 1));
00408             break;
00409         case MKTAG('a', 'm', 'v', 'h'):
00410             amv_file_format=1;
00411         case MKTAG('a', 'v', 'i', 'h'):
00412             /* AVI header */
00413             /* using frame_period is bad idea */
00414             frame_period = get_le32(pb);
00415             bit_rate = get_le32(pb) * 8;
00416             get_le32(pb);
00417             avi->non_interleaved |= get_le32(pb) & AVIF_MUSTUSEINDEX;
00418 
00419             url_fskip(pb, 2 * 4);
00420             get_le32(pb);
00421             get_le32(pb);
00422             avih_width=get_le32(pb);
00423             avih_height=get_le32(pb);
00424 
00425             url_fskip(pb, size - 10 * 4);
00426             break;
00427         case MKTAG('s', 't', 'r', 'h'):
00428             /* stream header */
00429 
00430             tag1 = get_le32(pb);
00431             handler = get_le32(pb); /* codec tag */
00432 
00433             if(tag1 == MKTAG('p', 'a', 'd', 's')){
00434                 url_fskip(pb, size - 8);
00435                 break;
00436             }else{
00437                 stream_index++;
00438                 st = av_new_stream(s, stream_index);
00439                 if (!st)
00440                     goto fail;
00441 
00442                 ast = av_mallocz(sizeof(AVIStream));
00443                 if (!ast)
00444                     goto fail;
00445                 st->priv_data = ast;
00446             }
00447             if(amv_file_format)
00448                 tag1 = stream_index ? MKTAG('a','u','d','s') : MKTAG('v','i','d','s');
00449 
00450 #ifdef DEBUG
00451             print_tag("strh", tag1, -1);
00452 #endif
00453             if(tag1 == MKTAG('i', 'a', 'v', 's') || tag1 == MKTAG('i', 'v', 'a', 's')){
00454                 int64_t dv_dur;
00455 
00456                 /*
00457                  * After some consideration -- I don't think we
00458                  * have to support anything but DV in type1 AVIs.
00459                  */
00460                 if (s->nb_streams != 1)
00461                     goto fail;
00462 
00463                 if (handler != MKTAG('d', 'v', 's', 'd') &&
00464                     handler != MKTAG('d', 'v', 'h', 'd') &&
00465                     handler != MKTAG('d', 'v', 's', 'l'))
00466                    goto fail;
00467 
00468                 ast = s->streams[0]->priv_data;
00469                 av_freep(&s->streams[0]->codec->extradata);
00470                 av_freep(&s->streams[0]->codec);
00471                 av_freep(&s->streams[0]);
00472                 s->nb_streams = 0;
00473                 if (CONFIG_DV_DEMUXER) {
00474                     avi->dv_demux = dv_init_demux(s);
00475                     if (!avi->dv_demux)
00476                         goto fail;
00477                 }
00478                 s->streams[0]->priv_data = ast;
00479                 url_fskip(pb, 3 * 4);
00480                 ast->scale = get_le32(pb);
00481                 ast->rate = get_le32(pb);
00482                 url_fskip(pb, 4);  /* start time */
00483 
00484                 dv_dur = get_le32(pb);
00485                 if (ast->scale > 0 && ast->rate > 0 && dv_dur > 0) {
00486                     dv_dur *= AV_TIME_BASE;
00487                     s->duration = av_rescale(dv_dur, ast->scale, ast->rate);
00488                 }
00489                 /*
00490                  * else, leave duration alone; timing estimation in utils.c
00491                  *      will make a guess based on bitrate.
00492                  */
00493 
00494                 stream_index = s->nb_streams - 1;
00495                 url_fskip(pb, size - 9*4);
00496                 break;
00497             }
00498 
00499             assert(stream_index < s->nb_streams);
00500             st->codec->stream_codec_tag= handler;
00501 
00502             get_le32(pb); /* flags */
00503             get_le16(pb); /* priority */
00504             get_le16(pb); /* language */
00505             get_le32(pb); /* initial frame */
00506             ast->scale = get_le32(pb);
00507             ast->rate = get_le32(pb);
00508             if(!(ast->scale && ast->rate)){
00509                 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);
00510                 if(frame_period){
00511                     ast->rate = 1000000;
00512                     ast->scale = frame_period;
00513                 }else{
00514                     ast->rate = 25;
00515                     ast->scale = 1;
00516                 }
00517             }
00518             av_set_pts_info(st, 64, ast->scale, ast->rate);
00519 
00520             ast->cum_len=get_le32(pb); /* start */
00521             st->nb_frames = get_le32(pb);
00522 
00523             st->start_time = 0;
00524             get_le32(pb); /* buffer size */
00525             get_le32(pb); /* quality */
00526             ast->sample_size = get_le32(pb); /* sample ssize */
00527             ast->cum_len *= FFMAX(1, ast->sample_size);
00528 //            av_log(s, AV_LOG_DEBUG, "%d %d %d %d\n", ast->rate, ast->scale, ast->start, ast->sample_size);
00529 
00530             switch(tag1) {
00531             case MKTAG('v', 'i', 'd', 's'):
00532                 codec_type = AVMEDIA_TYPE_VIDEO;
00533 
00534                 ast->sample_size = 0;
00535                 break;
00536             case MKTAG('a', 'u', 'd', 's'):
00537                 codec_type = AVMEDIA_TYPE_AUDIO;
00538                 break;
00539             case MKTAG('t', 'x', 't', 's'):
00540                 codec_type = AVMEDIA_TYPE_SUBTITLE;
00541                 break;
00542             case MKTAG('d', 'a', 't', 's'):
00543                 codec_type = AVMEDIA_TYPE_DATA;
00544                 break;
00545             default:
00546                 av_log(s, AV_LOG_ERROR, "unknown stream type %X\n", tag1);
00547                 goto fail;
00548             }
00549             if(ast->sample_size == 0)
00550                 st->duration = st->nb_frames;
00551             ast->frame_offset= ast->cum_len;
00552             url_fskip(pb, size - 12 * 4);
00553             break;
00554         case MKTAG('s', 't', 'r', 'f'):
00555             /* stream header */
00556             if (stream_index >= (unsigned)s->nb_streams || avi->dv_demux) {
00557                 url_fskip(pb, size);
00558             } else {
00559                 uint64_t cur_pos = url_ftell(pb);
00560                 if (cur_pos < list_end)
00561                     size = FFMIN(size, list_end - cur_pos);
00562                 st = s->streams[stream_index];
00563                 switch(codec_type) {
00564                 case AVMEDIA_TYPE_VIDEO:
00565                     if(amv_file_format){
00566                         st->codec->width=avih_width;
00567                         st->codec->height=avih_height;
00568                         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00569                         st->codec->codec_id = CODEC_ID_AMV;
00570                         url_fskip(pb, size);
00571                         break;
00572                     }
00573                     tag1 = ff_get_bmp_header(pb, st);
00574 
00575                     if (tag1 == MKTAG('D', 'X', 'S', 'B') || tag1 == MKTAG('D','X','S','A')) {
00576                         st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
00577                         st->codec->codec_tag = tag1;
00578                         st->codec->codec_id = CODEC_ID_XSUB;
00579                         break;
00580                     }
00581 
00582                     if(size > 10*4 && size<(1<<30)){
00583                         st->codec->extradata_size= size - 10*4;
00584                         st->codec->extradata= av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00585                         if (!st->codec->extradata) {
00586                             st->codec->extradata_size= 0;
00587                             return AVERROR(ENOMEM);
00588                         }
00589                         get_buffer(pb, st->codec->extradata, st->codec->extradata_size);
00590                     }
00591 
00592                     if(st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly
00593                         get_byte(pb);
00594 
00595                     /* Extract palette from extradata if bpp <= 8. */
00596                     /* This code assumes that extradata contains only palette. */
00597                     /* This is true for all paletted codecs implemented in FFmpeg. */
00598                     if (st->codec->extradata_size && (st->codec->bits_per_coded_sample <= 8)) {
00599                         st->codec->palctrl = av_mallocz(sizeof(AVPaletteControl));
00600 #if HAVE_BIGENDIAN
00601                         for (i = 0; i < FFMIN(st->codec->extradata_size, AVPALETTE_SIZE)/4; i++)
00602                             st->codec->palctrl->palette[i] = av_bswap32(((uint32_t*)st->codec->extradata)[i]);
00603 #else
00604                         memcpy(st->codec->palctrl->palette, st->codec->extradata,
00605                                FFMIN(st->codec->extradata_size, AVPALETTE_SIZE));
00606 #endif
00607                         st->codec->palctrl->palette_changed = 1;
00608                     }
00609 
00610 #ifdef DEBUG
00611                     print_tag("video", tag1, 0);
00612 #endif
00613                     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00614                     st->codec->codec_tag = tag1;
00615                     st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, tag1);
00616                     st->need_parsing = AVSTREAM_PARSE_HEADERS; // This is needed to get the pict type which is necessary for generating correct pts.
00617                     // Support "Resolution 1:1" for Avid AVI Codec
00618                     if(tag1 == MKTAG('A', 'V', 'R', 'n') &&
00619                        st->codec->extradata_size >= 31 &&
00620                        !memcmp(&st->codec->extradata[28], "1:1", 3))
00621                         st->codec->codec_id = CODEC_ID_RAWVIDEO;
00622 
00623                     if(st->codec->codec_tag==0 && st->codec->height > 0 && st->codec->extradata_size < 1U<<30){
00624                         st->codec->extradata_size+= 9;
00625                         st->codec->extradata= av_realloc(st->codec->extradata, st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00626                         if(st->codec->extradata)
00627                             memcpy(st->codec->extradata + st->codec->extradata_size - 9, "BottomUp", 9);
00628                     }
00629                     st->codec->height= FFABS(st->codec->height);
00630 
00631 //                    url_fskip(pb, size - 5 * 4);
00632                     break;
00633                 case AVMEDIA_TYPE_AUDIO:
00634                     ff_get_wav_header(pb, st->codec, size);
00635                     ast->dshow_block_align= st->codec->block_align;
00636                     if(ast->sample_size && st->codec->block_align && ast->sample_size != st->codec->block_align){
00637                         av_log(s, AV_LOG_WARNING, "sample size (%d) != block align (%d)\n", ast->sample_size, st->codec->block_align);
00638                         ast->sample_size= st->codec->block_align;
00639                     }
00640                     if (size&1) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
00641                         url_fskip(pb, 1);
00642                     /* Force parsing as several audio frames can be in
00643                      * one packet and timestamps refer to packet start. */
00644                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;
00645                     /* ADTS header is in extradata, AAC without header must be
00646                      * stored as exact frames. Parser not needed and it will
00647                      * fail. */
00648                     if (st->codec->codec_id == CODEC_ID_AAC && st->codec->extradata_size)
00649                         st->need_parsing = AVSTREAM_PARSE_NONE;
00650                     /* AVI files with Xan DPCM audio (wrongly) declare PCM
00651                      * audio in the header but have Axan as stream_code_tag. */
00652                     if (st->codec->stream_codec_tag == AV_RL32("Axan")){
00653                         st->codec->codec_id  = CODEC_ID_XAN_DPCM;
00654                         st->codec->codec_tag = 0;
00655                     }
00656                     if (amv_file_format){
00657                         st->codec->codec_id  = CODEC_ID_ADPCM_IMA_AMV;
00658                         ast->dshow_block_align = 0;
00659                     }
00660                     break;
00661                 case AVMEDIA_TYPE_SUBTITLE:
00662                     st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
00663                     st->codec->codec_id   = CODEC_ID_PROBE;
00664                     break;
00665                 default:
00666                     st->codec->codec_type = AVMEDIA_TYPE_DATA;
00667                     st->codec->codec_id= CODEC_ID_NONE;
00668                     st->codec->codec_tag= 0;
00669                     url_fskip(pb, size);
00670                     break;
00671                 }
00672             }
00673             break;
00674         case MKTAG('i', 'n', 'd', 'x'):
00675             i= url_ftell(pb);
00676             if(!url_is_streamed(pb) && !(s->flags & AVFMT_FLAG_IGNIDX)){
00677                 read_braindead_odml_indx(s, 0);
00678             }
00679             url_fseek(pb, i+size, SEEK_SET);
00680             break;
00681         case MKTAG('v', 'p', 'r', 'p'):
00682             if(stream_index < (unsigned)s->nb_streams && size > 9*4){
00683                 AVRational active, active_aspect;
00684 
00685                 st = s->streams[stream_index];
00686                 get_le32(pb);
00687                 get_le32(pb);
00688                 get_le32(pb);
00689                 get_le32(pb);
00690                 get_le32(pb);
00691 
00692                 active_aspect.den= get_le16(pb);
00693                 active_aspect.num= get_le16(pb);
00694                 active.num       = get_le32(pb);
00695                 active.den       = get_le32(pb);
00696                 get_le32(pb); //nbFieldsPerFrame
00697 
00698                 if(active_aspect.num && active_aspect.den && active.num && active.den){
00699                     st->sample_aspect_ratio= av_div_q(active_aspect, active);
00700 //av_log(s, AV_LOG_ERROR, "vprp %d/%d %d/%d\n", active_aspect.num, active_aspect.den, active.num, active.den);
00701                 }
00702                 size -= 9*4;
00703             }
00704             url_fseek(pb, size, SEEK_CUR);
00705             break;
00706         case MKTAG('s', 't', 'r', 'n'):
00707             if(s->nb_streams){
00708                 avi_read_tag(s, s->streams[s->nb_streams-1], tag, size);
00709                 break;
00710             }
00711         default:
00712             if(size > 1000000){
00713                 av_log(s, AV_LOG_ERROR, "Something went wrong during header parsing, "
00714                                         "I will ignore it and try to continue anyway.\n");
00715                 avi->movi_list = url_ftell(pb) - 4;
00716                 avi->movi_end  = url_fsize(pb);
00717                 goto end_of_header;
00718             }
00719             /* skip tag */
00720             size += (size & 1);
00721             url_fskip(pb, size);
00722             break;
00723         }
00724     }
00725  end_of_header:
00726     /* check stream number */
00727     if (stream_index != s->nb_streams - 1) {
00728     fail:
00729         return -1;
00730     }
00731 
00732     if(!avi->index_loaded && !url_is_streamed(pb))
00733         avi_load_index(s);
00734     avi->index_loaded = 1;
00735     avi->non_interleaved |= guess_ni_flag(s);
00736     for(i=0; i<s->nb_streams; i++){
00737         AVStream *st = s->streams[i];
00738         if(st->nb_index_entries)
00739             break;
00740     }
00741     if(i==s->nb_streams && avi->non_interleaved) {
00742         av_log(s, AV_LOG_WARNING, "non-interleaved AVI without index, switching to interleaved\n");
00743         avi->non_interleaved=0;
00744     }
00745 
00746     if(avi->non_interleaved) {
00747         av_log(s, AV_LOG_INFO, "non-interleaved AVI\n");
00748         clean_index(s);
00749     }
00750 
00751     ff_metadata_conv_ctx(s, NULL, ff_avi_metadata_conv);
00752 
00753     return 0;
00754 }
00755 
00756 static int read_gab2_sub(AVStream *st, AVPacket *pkt) {
00757     if (!strcmp(pkt->data, "GAB2") && AV_RL16(pkt->data+5) == 2) {
00758         uint8_t desc[256], *d = desc;
00759         uint8_t *end, *ptr = pkt->data+7;
00760         unsigned int size, desc_len = bytestream_get_le32(&ptr);
00761         int score = AVPROBE_SCORE_MAX / 2;
00762         AVIStream *ast = st->priv_data;
00763         AVInputFormat *sub_demuxer;
00764         AVRational time_base;
00765         ByteIOContext *pb;
00766         AVProbeData pd;
00767 
00768         if (desc_len > FFMAX(pkt->size-17, 0))
00769             return 0;
00770 
00771         end = ptr + desc_len;
00772         while (ptr < end-1) {
00773             uint8_t tmp;
00774             uint32_t ch;
00775             GET_UTF16(ch, ptr < end-1 ? bytestream_get_le16(&ptr) : 0, break;);
00776             PUT_UTF8(ch, tmp, if(d-desc < sizeof(desc)-1)  *d++ = tmp;);
00777         }
00778         *d = 0;
00779         if (*desc)
00780             av_metadata_set2(&st->metadata, "title", desc, 0);
00781 
00782         ptr = end + 2;
00783         size = bytestream_get_le32(&ptr);
00784         size = FFMIN(size, pkt->size+pkt->data-ptr);
00785 
00786         pd = (AVProbeData) { .buf = ptr, .buf_size = size };
00787         if (!(sub_demuxer = av_probe_input_format2(&pd, 1, &score)))
00788             return 0;
00789 
00790         pb = av_alloc_put_byte(ptr, size, 0, NULL, NULL, NULL, NULL);
00791         if (!av_open_input_stream(&ast->sub_ctx, pb, "", sub_demuxer, NULL)) {
00792             av_read_packet(ast->sub_ctx, &ast->sub_pkt);
00793             *st->codec = *ast->sub_ctx->streams[0]->codec;
00794             ast->sub_ctx->streams[0]->codec->extradata = NULL;
00795             time_base = ast->sub_ctx->streams[0]->time_base;
00796             av_set_pts_info(st, 64, time_base.num, time_base.den);
00797         }
00798         ast->sub_buffer = pkt->data;
00799         memset(pkt, 0, sizeof(*pkt));
00800         return 1;
00801     }
00802     return 0;
00803 }
00804 
00805 static AVStream *get_subtitle_pkt(AVFormatContext *s, AVStream *next_st,
00806                                   AVPacket *pkt)
00807 {
00808     AVIStream *ast, *next_ast = next_st->priv_data;
00809     int64_t ts, next_ts, ts_min = INT64_MAX;
00810     AVStream *st, *sub_st = NULL;
00811     int i;
00812 
00813     next_ts = av_rescale_q(next_ast->frame_offset, next_st->time_base,
00814                            AV_TIME_BASE_Q);
00815 
00816     for (i=0; i<s->nb_streams; i++) {
00817         st  = s->streams[i];
00818         ast = st->priv_data;
00819         if (st->discard < AVDISCARD_ALL && ast && ast->sub_pkt.data) {
00820             ts = av_rescale_q(ast->sub_pkt.dts, st->time_base, AV_TIME_BASE_Q);
00821             if (ts <= next_ts && ts < ts_min) {
00822                 ts_min = ts;
00823                 sub_st = st;
00824             }
00825         }
00826     }
00827 
00828     if (sub_st) {
00829         ast = sub_st->priv_data;
00830         *pkt = ast->sub_pkt;
00831         pkt->stream_index = sub_st->index;
00832         if (av_read_packet(ast->sub_ctx, &ast->sub_pkt) < 0)
00833             ast->sub_pkt.data = NULL;
00834     }
00835     return sub_st;
00836 }
00837 
00838 static int get_stream_idx(int *d){
00839     if(    d[0] >= '0' && d[0] <= '9'
00840         && d[1] >= '0' && d[1] <= '9'){
00841         return (d[0] - '0') * 10 + (d[1] - '0');
00842     }else{
00843         return 100; //invalid stream ID
00844     }
00845 }
00846 
00847 static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
00848 {
00849     AVIContext *avi = s->priv_data;
00850     ByteIOContext *pb = s->pb;
00851     int n, d[8];
00852     unsigned int size;
00853     int64_t i, sync;
00854     void* dstr;
00855 
00856     if (CONFIG_DV_DEMUXER && avi->dv_demux) {
00857         int size = dv_get_packet(avi->dv_demux, pkt);
00858         if (size >= 0)
00859             return size;
00860     }
00861 
00862     if(avi->non_interleaved){
00863         int best_stream_index = 0;
00864         AVStream *best_st= NULL;
00865         AVIStream *best_ast;
00866         int64_t best_ts= INT64_MAX;
00867         int i;
00868 
00869         for(i=0; i<s->nb_streams; i++){
00870             AVStream *st = s->streams[i];
00871             AVIStream *ast = st->priv_data;
00872             int64_t ts= ast->frame_offset;
00873             int64_t last_ts;
00874 
00875             if(!st->nb_index_entries)
00876                 continue;
00877 
00878             last_ts = st->index_entries[st->nb_index_entries - 1].timestamp;
00879             if(!ast->remaining && ts > last_ts)
00880                 continue;
00881 
00882             ts = av_rescale_q(ts, st->time_base, (AVRational){FFMAX(1, ast->sample_size), AV_TIME_BASE});
00883 
00884 //            av_log(s, AV_LOG_DEBUG, "%"PRId64" %d/%d %"PRId64"\n", ts, st->time_base.num, st->time_base.den, ast->frame_offset);
00885             if(ts < best_ts){
00886                 best_ts= ts;
00887                 best_st= st;
00888                 best_stream_index= i;
00889             }
00890         }
00891         if(!best_st)
00892             return -1;
00893 
00894         best_ast = best_st->priv_data;
00895         best_ts = av_rescale_q(best_ts, (AVRational){FFMAX(1, best_ast->sample_size), AV_TIME_BASE}, best_st->time_base);
00896         if(best_ast->remaining)
00897             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
00898         else{
00899             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
00900             if(i>=0)
00901                 best_ast->frame_offset= best_st->index_entries[i].timestamp;
00902         }
00903 
00904 //        av_log(s, AV_LOG_DEBUG, "%d\n", i);
00905         if(i>=0){
00906             int64_t pos= best_st->index_entries[i].pos;
00907             pos += best_ast->packet_size - best_ast->remaining;
00908             url_fseek(s->pb, pos + 8, SEEK_SET);
00909 //        av_log(s, AV_LOG_DEBUG, "pos=%"PRId64"\n", pos);
00910 
00911             assert(best_ast->remaining <= best_ast->packet_size);
00912 
00913             avi->stream_index= best_stream_index;
00914             if(!best_ast->remaining)
00915                 best_ast->packet_size=
00916                 best_ast->remaining= best_st->index_entries[i].size;
00917         }
00918     }
00919 
00920 resync:
00921     if(avi->stream_index >= 0){
00922         AVStream *st= s->streams[ avi->stream_index ];
00923         AVIStream *ast= st->priv_data;
00924         int size, err;
00925 
00926         if(get_subtitle_pkt(s, st, pkt))
00927             return 0;
00928 
00929         if(ast->sample_size <= 1) // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM
00930             size= INT_MAX;
00931         else if(ast->sample_size < 32)
00932             // arbitrary multiplier to avoid tiny packets for raw PCM data
00933             size= 1024*ast->sample_size;
00934         else
00935             size= ast->sample_size;
00936 
00937         if(size > ast->remaining)
00938             size= ast->remaining;
00939         avi->last_pkt_pos= url_ftell(pb);
00940         err= av_get_packet(pb, pkt, size);
00941         if(err<0)
00942             return err;
00943 
00944         if(ast->has_pal && pkt->data && pkt->size<(unsigned)INT_MAX/2){
00945             void *ptr= av_realloc(pkt->data, pkt->size + 4*256 + FF_INPUT_BUFFER_PADDING_SIZE);
00946             if(ptr){
00947             ast->has_pal=0;
00948             pkt->size += 4*256;
00949             pkt->data= ptr;
00950                 memcpy(pkt->data + pkt->size - 4*256, ast->pal, 4*256);
00951             }else
00952                 av_log(s, AV_LOG_ERROR, "Failed to append palette\n");
00953         }
00954 
00955         if (CONFIG_DV_DEMUXER && avi->dv_demux) {
00956             dstr = pkt->destruct;
00957             size = dv_produce_packet(avi->dv_demux, pkt,
00958                                     pkt->data, pkt->size);
00959             pkt->destruct = dstr;
00960             pkt->flags |= AV_PKT_FLAG_KEY;
00961             if (size < 0)
00962                 av_free_packet(pkt);
00963         } else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE
00964                    && !st->codec->codec_tag && read_gab2_sub(st, pkt)) {
00965             ast->frame_offset++;
00966             avi->stream_index = -1;
00967             ast->remaining = 0;
00968             goto resync;
00969         } else {
00970             /* XXX: How to handle B-frames in AVI? */
00971             pkt->dts = ast->frame_offset;
00972 //                pkt->dts += ast->start;
00973             if(ast->sample_size)
00974                 pkt->dts /= ast->sample_size;
00975 //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);
00976             pkt->stream_index = avi->stream_index;
00977 
00978             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
00979                 AVIndexEntry *e;
00980                 int index;
00981                 assert(st->index_entries);
00982 
00983                 index= av_index_search_timestamp(st, ast->frame_offset, 0);
00984                 e= &st->index_entries[index];
00985 
00986                 if(index >= 0 && e->timestamp == ast->frame_offset){
00987                     if (e->flags & AVINDEX_KEYFRAME)
00988                         pkt->flags |= AV_PKT_FLAG_KEY;
00989                 }
00990             } else {
00991                 pkt->flags |= AV_PKT_FLAG_KEY;
00992             }
00993             ast->frame_offset += get_duration(ast, pkt->size);
00994         }
00995         ast->remaining -= size;
00996         if(!ast->remaining){
00997             avi->stream_index= -1;
00998             ast->packet_size= 0;
00999         }
01000 
01001         return size;
01002     }
01003 
01004     memset(d, -1, sizeof(int)*8);
01005     for(i=sync=url_ftell(pb); !url_feof(pb); i++) {
01006         int j;
01007 
01008         for(j=0; j<7; j++)
01009             d[j]= d[j+1];
01010         d[7]= get_byte(pb);
01011 
01012         size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
01013 
01014         n= get_stream_idx(d+2);
01015 //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);
01016         if(i + (uint64_t)size > avi->fsize || d[0]<0)
01017             continue;
01018 
01019         //parse ix##
01020         if(  (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
01021         //parse JUNK
01022            ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')
01023            ||(d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')){
01024             url_fskip(pb, size);
01025 //av_log(s, AV_LOG_DEBUG, "SKIP\n");
01026             goto resync;
01027         }
01028 
01029         //parse stray LIST
01030         if(d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T'){
01031             url_fskip(pb, 4);
01032             goto resync;
01033         }
01034 
01035         n= get_stream_idx(d);
01036 
01037         if(!((i-avi->last_pkt_pos)&1) && get_stream_idx(d+1) < s->nb_streams)
01038             continue;
01039 
01040         //detect ##ix chunk and skip
01041         if(d[2] == 'i' && d[3] == 'x' && n < s->nb_streams){
01042             url_fskip(pb, size);
01043             goto resync;
01044         }
01045 
01046         //parse ##dc/##wb
01047         if(n < s->nb_streams){
01048             AVStream *st;
01049             AVIStream *ast;
01050             st = s->streams[n];
01051             ast = st->priv_data;
01052 
01053             if(s->nb_streams>=2){
01054                 AVStream *st1  = s->streams[1];
01055                 AVIStream *ast1= st1->priv_data;
01056                 //workaround for broken small-file-bug402.avi
01057                 if(   d[2] == 'w' && d[3] == 'b'
01058                    && n==0
01059                    && st ->codec->codec_type == AVMEDIA_TYPE_VIDEO
01060                    && st1->codec->codec_type == AVMEDIA_TYPE_AUDIO
01061                    && ast->prefix == 'd'*256+'c'
01062                    && (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)
01063                   ){
01064                     n=1;
01065                     st = st1;
01066                     ast = ast1;
01067                     av_log(s, AV_LOG_WARNING, "Invalid stream + prefix combination, assuming audio.\n");
01068                 }
01069             }
01070 
01071 
01072             if(   (st->discard >= AVDISCARD_DEFAULT && size==0)
01073                /*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & AV_PKT_FLAG_KEY))*/ //FIXME needs a little reordering
01074                || st->discard >= AVDISCARD_ALL){
01075                 ast->frame_offset += get_duration(ast, size);
01076                 url_fskip(pb, size);
01077                 goto resync;
01078             }
01079 
01080             if (d[2] == 'p' && d[3] == 'c' && size<=4*256+4) {
01081                 int k = get_byte(pb);
01082                 int last = (k + get_byte(pb) - 1) & 0xFF;
01083 
01084                 get_le16(pb); //flags
01085 
01086                 for (; k <= last; k++)
01087                     ast->pal[k] = get_be32(pb)>>8;// b + (g << 8) + (r << 16);
01088                 ast->has_pal= 1;
01089                 goto resync;
01090             } else if(   ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||
01091                          d[2]*256+d[3] == ast->prefix /*||
01092                          (d[2] == 'd' && d[3] == 'c') ||
01093                          (d[2] == 'w' && d[3] == 'b')*/) {
01094 
01095 //av_log(s, AV_LOG_DEBUG, "OK\n");
01096                 if(d[2]*256+d[3] == ast->prefix)
01097                     ast->prefix_count++;
01098                 else{
01099                     ast->prefix= d[2]*256+d[3];
01100                     ast->prefix_count= 0;
01101                 }
01102 
01103                 avi->stream_index= n;
01104                 ast->packet_size= size + 8;
01105                 ast->remaining= size;
01106 
01107                 if(size || !ast->sample_size){
01108                     uint64_t pos= url_ftell(pb) - 8;
01109                     if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){
01110                         av_add_index_entry(st, pos, ast->frame_offset, size, 0, AVINDEX_KEYFRAME);
01111                     }
01112                 }
01113                 goto resync;
01114             }
01115         }
01116     }
01117 
01118     return AVERROR_EOF;
01119 }
01120 
01121 /* XXX: We make the implicit supposition that the positions are sorted
01122    for each stream. */
01123 static int avi_read_idx1(AVFormatContext *s, int size)
01124 {
01125     AVIContext *avi = s->priv_data;
01126     ByteIOContext *pb = s->pb;
01127     int nb_index_entries, i;
01128     AVStream *st;
01129     AVIStream *ast;
01130     unsigned int index, tag, flags, pos, len;
01131     unsigned last_pos= -1;
01132 
01133     nb_index_entries = size / 16;
01134     if (nb_index_entries <= 0)
01135         return -1;
01136 
01137     /* Read the entries and sort them in each stream component. */
01138     for(i = 0; i < nb_index_entries; i++) {
01139         tag = get_le32(pb);
01140         flags = get_le32(pb);
01141         pos = get_le32(pb);
01142         len = get_le32(pb);
01143 #if defined(DEBUG_SEEK)
01144         av_log(s, AV_LOG_DEBUG, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
01145                i, tag, flags, pos, len);
01146 #endif
01147         if(i==0 && pos > avi->movi_list)
01148             avi->movi_list= 0; //FIXME better check
01149         pos += avi->movi_list;
01150 
01151         index = ((tag & 0xff) - '0') * 10;
01152         index += ((tag >> 8) & 0xff) - '0';
01153         if (index >= s->nb_streams)
01154             continue;
01155         st = s->streams[index];
01156         ast = st->priv_data;
01157 
01158 #if defined(DEBUG_SEEK)
01159         av_log(s, AV_LOG_DEBUG, "%d cum_len=%"PRId64"\n", len, ast->cum_len);
01160 #endif
01161         if(url_feof(pb))
01162             return -1;
01163 
01164         if(last_pos == pos)
01165             avi->non_interleaved= 1;
01166         else if(len || !ast->sample_size)
01167             av_add_index_entry(st, pos, ast->cum_len, len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
01168         ast->cum_len += get_duration(ast, len);
01169         last_pos= pos;
01170     }
01171     return 0;
01172 }
01173 
01174 static int guess_ni_flag(AVFormatContext *s){
01175     int i;
01176     int64_t last_start=0;
01177     int64_t first_end= INT64_MAX;
01178     int64_t oldpos= url_ftell(s->pb);
01179 
01180     for(i=0; i<s->nb_streams; i++){
01181         AVStream *st = s->streams[i];
01182         int n= st->nb_index_entries;
01183         unsigned int size;
01184 
01185         if(n <= 0)
01186             continue;
01187 
01188         if(n >= 2){
01189             int64_t pos= st->index_entries[0].pos;
01190             url_fseek(s->pb, pos + 4, SEEK_SET);
01191             size= get_le32(s->pb);
01192             if(pos + size > st->index_entries[1].pos)
01193                 last_start= INT64_MAX;
01194         }
01195 
01196         if(st->index_entries[0].pos > last_start)
01197             last_start= st->index_entries[0].pos;
01198         if(st->index_entries[n-1].pos < first_end)
01199             first_end= st->index_entries[n-1].pos;
01200     }
01201     url_fseek(s->pb, oldpos, SEEK_SET);
01202     return last_start > first_end;
01203 }
01204 
01205 static int avi_load_index(AVFormatContext *s)
01206 {
01207     AVIContext *avi = s->priv_data;
01208     ByteIOContext *pb = s->pb;
01209     uint32_t tag, size;
01210     int64_t pos= url_ftell(pb);
01211     int ret = -1;
01212 
01213     if (url_fseek(pb, avi->movi_end, SEEK_SET) < 0)
01214         goto the_end; // maybe truncated file
01215 #ifdef DEBUG_SEEK
01216     printf("movi_end=0x%"PRIx64"\n", avi->movi_end);
01217 #endif
01218     for(;;) {
01219         if (url_feof(pb))
01220             break;
01221         tag = get_le32(pb);
01222         size = get_le32(pb);
01223 #ifdef DEBUG_SEEK
01224         printf("tag=%c%c%c%c size=0x%x\n",
01225                tag & 0xff,
01226                (tag >> 8) & 0xff,
01227                (tag >> 16) & 0xff,
01228                (tag >> 24) & 0xff,
01229                size);
01230 #endif
01231         switch(tag) {
01232         case MKTAG('i', 'd', 'x', '1'):
01233             if (avi_read_idx1(s, size) < 0)
01234                 goto skip;
01235             ret = 0;
01236                 goto the_end;
01237             break;
01238         default:
01239         skip:
01240             size += (size & 1);
01241             if (url_fseek(pb, size, SEEK_CUR) < 0)
01242                 goto the_end; // something is wrong here
01243             break;
01244         }
01245     }
01246  the_end:
01247     url_fseek(pb, pos, SEEK_SET);
01248     return ret;
01249 }
01250 
01251 static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)
01252 {
01253     AVIStream *ast2 = st2->priv_data;
01254     int64_t ts2 = av_rescale_q(timestamp, st->time_base, st2->time_base);
01255     av_free_packet(&ast2->sub_pkt);
01256     if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||
01257         avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)
01258         av_read_packet(ast2->sub_ctx, &ast2->sub_pkt);
01259 }
01260 
01261 static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
01262 {
01263     AVIContext *avi = s->priv_data;
01264     AVStream *st;
01265     int i, index;
01266     int64_t pos;
01267     AVIStream *ast;
01268 
01269     if (!avi->index_loaded) {
01270         /* we only load the index on demand */
01271         avi_load_index(s);
01272         avi->index_loaded = 1;
01273     }
01274     assert(stream_index>= 0);
01275 
01276     st = s->streams[stream_index];
01277     ast= st->priv_data;
01278     index= av_index_search_timestamp(st, timestamp * FFMAX(ast->sample_size, 1), flags);
01279     if(index<0)
01280         return -1;
01281 
01282     /* find the position */
01283     pos = st->index_entries[index].pos;
01284     timestamp = st->index_entries[index].timestamp / FFMAX(ast->sample_size, 1);
01285 
01286 //    av_log(s, AV_LOG_DEBUG, "XX %"PRId64" %d %"PRId64"\n", timestamp, index, st->index_entries[index].timestamp);
01287 
01288     if (CONFIG_DV_DEMUXER && avi->dv_demux) {
01289         /* One and only one real stream for DV in AVI, and it has video  */
01290         /* offsets. Calling with other stream indexes should have failed */
01291         /* the av_index_search_timestamp call above.                     */
01292         assert(stream_index == 0);
01293 
01294         /* Feed the DV video stream version of the timestamp to the */
01295         /* DV demux so it can synthesize correct timestamps.        */
01296         dv_offset_reset(avi->dv_demux, timestamp);
01297 
01298         url_fseek(s->pb, pos, SEEK_SET);
01299         avi->stream_index= -1;
01300         return 0;
01301     }
01302 
01303     for(i = 0; i < s->nb_streams; i++) {
01304         AVStream *st2 = s->streams[i];
01305         AVIStream *ast2 = st2->priv_data;
01306 
01307         ast2->packet_size=
01308         ast2->remaining= 0;
01309 
01310         if (ast2->sub_ctx) {
01311             seek_subtitle(st, st2, timestamp);
01312             continue;
01313         }
01314 
01315         if (st2->nb_index_entries <= 0)
01316             continue;
01317 
01318 //        assert(st2->codec->block_align);
01319         assert((int64_t)st2->time_base.num*ast2->rate == (int64_t)st2->time_base.den*ast2->scale);
01320         index = av_index_search_timestamp(
01321                 st2,
01322                 av_rescale_q(timestamp, st->time_base, st2->time_base) * FFMAX(ast2->sample_size, 1),
01323                 flags | AVSEEK_FLAG_BACKWARD);
01324         if(index<0)
01325             index=0;
01326 
01327         if(!avi->non_interleaved){
01328             while(index>0 && st2->index_entries[index].pos > pos)
01329                 index--;
01330             while(index+1 < st2->nb_index_entries && st2->index_entries[index].pos < pos)
01331                 index++;
01332         }
01333 
01334 //        av_log(s, AV_LOG_DEBUG, "%"PRId64" %d %"PRId64"\n", timestamp, index, st2->index_entries[index].timestamp);
01335         /* extract the current frame number */
01336         ast2->frame_offset = st2->index_entries[index].timestamp;
01337     }
01338 
01339     /* do the seek */
01340     url_fseek(s->pb, pos, SEEK_SET);
01341     avi->stream_index= -1;
01342     return 0;
01343 }
01344 
01345 static int avi_read_close(AVFormatContext *s)
01346 {
01347     int i;
01348     AVIContext *avi = s->priv_data;
01349 
01350     for(i=0;i<s->nb_streams;i++) {
01351         AVStream *st = s->streams[i];
01352         AVIStream *ast = st->priv_data;
01353         av_free(st->codec->palctrl);
01354         if (ast) {
01355             if (ast->sub_ctx) {
01356                 av_freep(&ast->sub_ctx->pb);
01357                 av_close_input_stream(ast->sub_ctx);
01358             }
01359             av_free(ast->sub_buffer);
01360             av_free_packet(&ast->sub_pkt);
01361         }
01362     }
01363 
01364     if (avi->dv_demux)
01365         av_free(avi->dv_demux);
01366 
01367     return 0;
01368 }
01369 
01370 static int avi_probe(AVProbeData *p)
01371 {
01372     int i;
01373 
01374     /* check file header */
01375     for(i=0; avi_headers[i][0]; i++)
01376         if(!memcmp(p->buf  , avi_headers[i]  , 4) &&
01377            !memcmp(p->buf+8, avi_headers[i]+4, 4))
01378             return AVPROBE_SCORE_MAX;
01379 
01380     return 0;
01381 }
01382 
01383 AVInputFormat avi_demuxer = {
01384     "avi",
01385     NULL_IF_CONFIG_SMALL("AVI format"),
01386     sizeof(AVIContext),
01387     avi_probe,
01388     avi_read_header,
01389     avi_read_packet,
01390     avi_read_close,
01391     avi_read_seek,
01392 };