libavformat/avidec.c

   1 /*
   2  * AVI demuxer
   3  * Copyright (c) 2001 Fabrice Bellard.
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21 #include "avformat.h"
  22 #include "avi.h"
  23 #include "dv.h"
  24 #include "riff.h"
  25
  26 #undef NDEBUG
  27 #include <assert.h>
  28
  29 //#define DEBUG
  30 //#define DEBUG_SEEK
  31
  32 typedef struct AVIStream {
  33     int64_t frame_offset; /* current frame (video) or byte (audio) counter
  34                          (used to compute the pts) */
  35     int remaining;
  36     int packet_size;
  37
  38     int scale;
  39     int rate;
  40     int sample_size; /* size of one sample (or packet) (in the rate/scale sense) in bytes */
  41
  42     int64_t cum_len; /* temporary storage (used during seek) */
  43
  44     int prefix;                       ///< normally 'd'<<8 + 'c' or 'w'<<8 + 'b'
  45     int prefix_count;
  46 } AVIStream;
  47
  48 typedef struct {
  49     int64_t  riff_end;
  50     int64_t  movi_end;
  51     int64_t  fsize;
  52     offset_t movi_list;
  53     int index_loaded;
  54     int is_odml;
  55     int non_interleaved;
  56     int stream_index;
  57     DVDemuxContext* dv_demux;
  58 } AVIContext;
  59
  60 static const char avi_headers[][8] = {
  61     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', ' ' },
  62     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 'X' },
  63     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 0x19},
  64     { 'O', 'N', '2', ' ',    'O', 'N', '2', 'f' },
  65     { 'R', 'I', 'F', 'F',    'A', 'M', 'V', ' ' },
  66     { 0 }
  67 };
  68
  69 static int avi_load_index(AVFormatContext *s);
  70 static int guess_ni_flag(AVFormatContext *s);
  71
  72 #ifdef DEBUG
  73 static void print_tag(const char *str, unsigned int tag, int size)
  74 {
  75     printf("%s: tag=%c%c%c%c size=0x%x\n",
  76            str, tag & 0xff,
  77            (tag >> 8) & 0xff,
  78            (tag >> 16) & 0xff,
  79            (tag >> 24) & 0xff,
  80            size);
  81 }
  82 #endif
  83
  84 static int get_riff(AVIContext *avi, ByteIOContext *pb)
  85 {
  86     char header[8];
  87     int i;
  88
  89     /* check RIFF header */
  90     get_buffer(pb, header, 4);
  91     avi->riff_end = get_le32(pb);   /* RIFF chunk size */
  92     avi->riff_end += url_ftell(pb); /* RIFF chunk end */
  93     get_buffer(pb, header+4, 4);
  94
  95     for(i=0; avi_headers[i][0]; i++)
  96         if(!memcmp(header, avi_headers[i], 8))
  97             break;
  98     if(!avi_headers[i][0])
  99         return -1;
 100
 101     if(header[7] == 0x19)
 102         av_log(NULL, AV_LOG_INFO, "file has been generated with a totally broken muxer\n");
 103
 104     return 0;
 105 }
 106
 107 static int read_braindead_odml_indx(AVFormatContext *s, int frame_num){
 108     AVIContext *avi = s->priv_data;
 109     ByteIOContext *pb = s->pb;
 110     int longs_pre_entry= get_le16(pb);
 111     int index_sub_type = get_byte(pb);
 112     int index_type     = get_byte(pb);
 113     int entries_in_use = get_le32(pb);
 114     int chunk_id       = get_le32(pb);
 115     int64_t base       = get_le64(pb);
 116     int stream_id= 10*((chunk_id&0xFF) - '0') + (((chunk_id>>8)&0xFF) - '0');
 117     AVStream *st;
 118     AVIStream *ast;
 119     int i;
 120     int64_t last_pos= -1;
 121     int64_t filesize= url_fsize(s->pb);
 122
 123 #ifdef DEBUG_SEEK
 124     av_log(s, AV_LOG_ERROR, "longs_pre_entry:%d index_type:%d entries_in_use:%d chunk_id:%X base:%16"PRIX64"\n",
 125         longs_pre_entry,index_type, entries_in_use, chunk_id, base);
 126 #endif
 127
 128     if(stream_id > s->nb_streams || stream_id < 0)
 129         return -1;
 130     st= s->streams[stream_id];
 131     ast = st->priv_data;
 132
 133     if(index_sub_type)
 134         return -1;
 135
 136     get_le32(pb);
 137
 138     if(index_type && longs_pre_entry != 2)
 139         return -1;
 140     if(index_type>1)
 141         return -1;
 142
 143     if(filesize > 0 && base >= filesize){
 144         av_log(s, AV_LOG_ERROR, "ODML index invalid\n");
 145         if(base>>32 == (base & 0xFFFFFFFF) && (base & 0xFFFFFFFF) < filesize && filesize <= 0xFFFFFFFF)
 146             base &= 0xFFFFFFFF;
 147         else
 148             return -1;
 149     }
 150
 151     for(i=0; i<entries_in_use; i++){
 152         if(index_type){
 153             int64_t pos= get_le32(pb) + base - 8;
 154             int len    = get_le32(pb);
 155             int key= len >= 0;
 156             len &= 0x7FFFFFFF;
 157
 158 #ifdef DEBUG_SEEK
 159             av_log(s, AV_LOG_ERROR, "pos:%"PRId64", len:%X\n", pos, len);
 160 #endif
 161             if(last_pos == pos || pos == base - 8)
 162                 avi->non_interleaved= 1;
 163             else
 164                 av_add_index_entry(st, pos, ast->cum_len / FFMAX(1, ast->sample_size), len, 0, key ? AVINDEX_KEYFRAME : 0);
 165
 166             if(ast->sample_size)
 167                 ast->cum_len += len;
 168             else
 169                 ast->cum_len ++;
 170             last_pos= pos;
 171         }else{
 172             int64_t offset, pos;
 173             int duration;
 174             offset = get_le64(pb);
 175             get_le32(pb);       /* size */
 176             duration = get_le32(pb);
 177             pos = url_ftell(pb);
 178
 179             url_fseek(pb, offset+8, SEEK_SET);
 180             read_braindead_odml_indx(s, frame_num);
 181             frame_num += duration;
 182
 183             url_fseek(pb, pos, SEEK_SET);
 184         }
 185     }
 186     avi->index_loaded=1;
 187     return 0;
 188 }
 189
 190 static void clean_index(AVFormatContext *s){
 191     int i;
 192     int64_t j;
 193
 194     for(i=0; i<s->nb_streams; i++){
 195         AVStream *st = s->streams[i];
 196         AVIStream *ast = st->priv_data;
 197         int n= st->nb_index_entries;
 198         int max= ast->sample_size;
 199         int64_t pos, size, ts;
 200
 201         if(n != 1 || ast->sample_size==0)
 202             continue;
 203
 204         while(max < 1024) max+=max;
 205
 206         pos= st->index_entries[0].pos;
 207         size= st->index_entries[0].size;
 208         ts= st->index_entries[0].timestamp;
 209
 210         for(j=0; j<size; j+=max){
 211             av_add_index_entry(st, pos+j, ts + j/ast->sample_size, FFMIN(max, size-j), 0, AVINDEX_KEYFRAME);
 212         }
 213     }
 214 }
 215
 216 static int avi_read_tag(ByteIOContext *pb, char *buf, int maxlen,  unsigned int size)
 217 {
 218     offset_t i = url_ftell(pb);
 219     size += (size & 1);
 220     get_strz(pb, buf, maxlen);
 221     url_fseek(pb, i+size, SEEK_SET);
 222     return 0;
 223 }
 224
 225 static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
 226 {
 227     AVIContext *avi = s->priv_data;
 228     ByteIOContext *pb = s->pb;
 229     uint32_t tag, tag1, handler;
 230     int codec_type, stream_index, frame_period, bit_rate;
 231     unsigned int size, nb_frames;
 232     int i;
 233     AVStream *st;
 234     AVIStream *ast = NULL;
 235     char str_track[4];
 236     int avih_width=0, avih_height=0;
 237     int amv_file_format=0;
 238
 239     avi->stream_index= -1;
 240
 241     if (get_riff(avi, pb) < 0)
 242         return -1;
 243
 244     avi->fsize = url_fsize(pb);
 245     if(avi->fsize<=0)
 246         avi->fsize= avi->riff_end;
 247
 248     /* first list tag */
 249     stream_index = -1;
 250     codec_type = -1;
 251     frame_period = 0;
 252     for(;;) {
 253         if (url_feof(pb))
 254             goto fail;
 255         tag = get_le32(pb);
 256         size = get_le32(pb);
 257 #ifdef DEBUG
 258         print_tag("tag", tag, size);
 259 #endif
 260
 261         switch(tag) {
 262         case MKTAG('L', 'I', 'S', 'T'):
 263             /* ignored, except when start of video packets */
 264             tag1 = get_le32(pb);
 265 #ifdef DEBUG
 266             print_tag("list", tag1, 0);
 267 #endif
 268             if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
 269                 avi->movi_list = url_ftell(pb) - 4;
 270                 if(size) avi->movi_end = avi->movi_list + size + (size & 1);
 271                 else     avi->movi_end = url_fsize(pb);
 272 #ifdef DEBUG
 273                 printf("movi end=%"PRIx64"\n", avi->movi_end);
 274 #endif
 275                 goto end_of_header;
 276             }
 277             break;
 278         case MKTAG('d', 'm', 'l', 'h'):
 279             avi->is_odml = 1;
 280             url_fskip(pb, size + (size & 1));
 281             break;
 282         case MKTAG('a', 'm', 'v', 'h'):
 283             amv_file_format=1;
 284         case MKTAG('a', 'v', 'i', 'h'):
 285             /* avi header */
 286             /* using frame_period is bad idea */
 287             frame_period = get_le32(pb);
 288             bit_rate = get_le32(pb) * 8;
 289             get_le32(pb);
 290             avi->non_interleaved |= get_le32(pb) & AVIF_MUSTUSEINDEX;
 291
 292             url_fskip(pb, 2 * 4);
 293             get_le32(pb);
 294             get_le32(pb);
 295             avih_width=get_le32(pb);
 296             avih_height=get_le32(pb);
 297
 298             url_fskip(pb, size - 10 * 4);
 299             break;
 300         case MKTAG('s', 't', 'r', 'h'):
 301             /* stream header */
 302
 303             tag1 = get_le32(pb);
 304             handler = get_le32(pb); /* codec tag */
 305
 306             if(tag1 == MKTAG('p', 'a', 'd', 's')){
 307                 url_fskip(pb, size - 8);
 308                 break;
 309             }else{
 310                 stream_index++;
 311                 st = av_new_stream(s, stream_index);
 312                 if (!st)
 313                     goto fail;
 314
 315                 ast = av_mallocz(sizeof(AVIStream));
 316                 if (!ast)
 317                     goto fail;
 318                 st->priv_data = ast;
 319             }
 320             if(amv_file_format)
 321                 tag1 = stream_index ? MKTAG('a','u','d','s') : MKTAG('v','i','d','s');
 322
 323 #ifdef DEBUG
 324             print_tag("strh", tag1, -1);
 325 #endif
 326             if(tag1 == MKTAG('i', 'a', 'v', 's') || tag1 == MKTAG('i', 'v', 'a', 's')){
 327                 int64_t dv_dur;
 328
 329                 /*
 330                  * After some consideration -- I don't think we
 331                  * have to support anything but DV in a type1 AVIs.
 332                  */
 333                 if (s->nb_streams != 1)
 334                     goto fail;
 335
 336                 if (handler != MKTAG('d', 'v', 's', 'd') &&
 337                     handler != MKTAG('d', 'v', 'h', 'd') &&
 338                     handler != MKTAG('d', 'v', 's', 'l'))
 339                    goto fail;
 340
 341                 ast = s->streams[0]->priv_data;
 342                 av_freep(&s->streams[0]->codec->extradata);
 343                 av_freep(&s->streams[0]);
 344                 s->nb_streams = 0;
 345                 if (ENABLE_DV_DEMUXER) {
 346                     avi->dv_demux = dv_init_demux(s);
 347                     if (!avi->dv_demux)
 348                         goto fail;
 349                 }
 350                 s->streams[0]->priv_data = ast;
 351                 url_fskip(pb, 3 * 4);
 352                 ast->scale = get_le32(pb);
 353                 ast->rate = get_le32(pb);
 354                 url_fskip(pb, 4);  /* start time */
 355
 356                 dv_dur = get_le32(pb);
 357                 if (ast->scale > 0 && ast->rate > 0 && dv_dur > 0) {
 358                     dv_dur *= AV_TIME_BASE;
 359                     s->duration = av_rescale(dv_dur, ast->scale, ast->rate);
 360                 }
 361                 /*
 362                  * else, leave duration alone; timing estimation in utils.c
 363                  *      will make a guess based on bit rate.
 364                  */
 365
 366                 stream_index = s->nb_streams - 1;
 367                 url_fskip(pb, size - 9*4);
 368                 break;
 369             }
 370
 371             assert(stream_index < s->nb_streams);
 372             st->codec->stream_codec_tag= handler;
 373
 374             get_le32(pb); /* flags */
 375             get_le16(pb); /* priority */
 376             get_le16(pb); /* language */
 377             get_le32(pb); /* initial frame */
 378             ast->scale = get_le32(pb);
 379             ast->rate = get_le32(pb);
 380             if(ast->scale && ast->rate){
 381             }else if(frame_period){
 382                 ast->rate = 1000000;
 383                 ast->scale = frame_period;
 384             }else{
 385                 ast->rate = 25;
 386                 ast->scale = 1;
 387             }
 388             av_set_pts_info(st, 64, ast->scale, ast->rate);
 389
 390             ast->cum_len=get_le32(pb); /* start */
 391             nb_frames = get_le32(pb);
 392
 393             st->start_time = 0;
 394             st->duration = nb_frames;
 395             get_le32(pb); /* buffer size */
 396             get_le32(pb); /* quality */
 397             ast->sample_size = get_le32(pb); /* sample ssize */
 398             ast->cum_len *= FFMAX(1, ast->sample_size);
 399 //            av_log(NULL, AV_LOG_DEBUG, "%d %d %d %d\n", ast->rate, ast->scale, ast->start, ast->sample_size);
 400
 401             switch(tag1) {
 402             case MKTAG('v', 'i', 'd', 's'):
 403                 codec_type = CODEC_TYPE_VIDEO;
 404
 405                 ast->sample_size = 0;
 406                 break;
 407             case MKTAG('a', 'u', 'd', 's'):
 408                 codec_type = CODEC_TYPE_AUDIO;
 409                 break;
 410             case MKTAG('t', 'x', 't', 's'):
 411                 //FIXME
 412                 codec_type = CODEC_TYPE_DATA; //CODEC_TYPE_SUB ?  FIXME
 413                 break;
 414             default:
 415                 av_log(s, AV_LOG_ERROR, "unknown stream type %X\n", tag1);
 416                 goto fail;
 417             }
 418             ast->frame_offset= ast->cum_len;
 419             url_fskip(pb, size - 12 * 4);
 420             break;
 421         case MKTAG('s', 't', 'r', 'f'):
 422             /* stream header */
 423             if (stream_index >= (unsigned)s->nb_streams || avi->dv_demux) {
 424                 url_fskip(pb, size);
 425             } else {
 426                 st = s->streams[stream_index];
 427                 switch(codec_type) {
 428                 case CODEC_TYPE_VIDEO:
 429                     if(amv_file_format){
 430                         st->codec->width=avih_width;
 431                         st->codec->height=avih_height;
 432                         st->codec->codec_type = CODEC_TYPE_VIDEO;
 433                         st->codec->codec_id = CODEC_ID_AMV;
 434                         url_fskip(pb, size);
 435                         break;
 436                     }
 437                     get_le32(pb); /* size */
 438                     st->codec->width = get_le32(pb);
 439                     st->codec->height = get_le32(pb);
 440                     get_le16(pb); /* panes */
 441                     st->codec->bits_per_sample= get_le16(pb); /* depth */
 442                     tag1 = get_le32(pb);
 443                     get_le32(pb); /* ImageSize */
 444                     get_le32(pb); /* XPelsPerMeter */
 445                     get_le32(pb); /* YPelsPerMeter */
 446                     get_le32(pb); /* ClrUsed */
 447                     get_le32(pb); /* ClrImportant */
 448
 449                     if (tag1 == MKTAG('D', 'X', 'S', 'B')) {
 450                         st->codec->codec_type = CODEC_TYPE_SUBTITLE;
 451                         st->codec->codec_tag = tag1;
 452                         st->codec->codec_id = CODEC_ID_XSUB;
 453                         break;
 454                     }
 455
 456                     if(size > 10*4 && size<(1<<30)){
 457                         st->codec->extradata_size= size - 10*4;
 458                         st->codec->extradata= av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
 459                         get_buffer(pb, st->codec->extradata, st->codec->extradata_size);
 460                     }
 461
 462                     if(st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly
 463                         get_byte(pb);
 464
 465                     /* Extract palette from extradata if bpp <= 8 */
 466                     /* This code assumes that extradata contains only palette */
 467                     /* This is true for all paletted codecs implemented in ffmpeg */
 468                     if (st->codec->extradata_size && (st->codec->bits_per_sample <= 8)) {
 469                         st->codec->palctrl = av_mallocz(sizeof(AVPaletteControl));
 470 #ifdef WORDS_BIGENDIAN
 471                         for (i = 0; i < FFMIN(st->codec->extradata_size, AVPALETTE_SIZE)/4; i++)
 472                             st->codec->palctrl->palette[i] = bswap_32(((uint32_t*)st->codec->extradata)[i]);
 473 #else
 474                         memcpy(st->codec->palctrl->palette, st->codec->extradata,
 475                                FFMIN(st->codec->extradata_size, AVPALETTE_SIZE));
 476 #endif
 477                         st->codec->palctrl->palette_changed = 1;
 478                     }
 479
 480 #ifdef DEBUG
 481                     print_tag("video", tag1, 0);
 482 #endif
 483                     st->codec->codec_type = CODEC_TYPE_VIDEO;
 484                     st->codec->codec_tag = tag1;
 485                     st->codec->codec_id = codec_get_id(codec_bmp_tags, tag1);
 486                     st->need_parsing = AVSTREAM_PARSE_HEADERS; // this is needed to get the pict type which is needed for generating correct pts
 487 //                    url_fskip(pb, size - 5 * 4);
 488                     break;
 489                 case CODEC_TYPE_AUDIO:
 490                     get_wav_header(pb, st->codec, size);
 491                     if(ast->sample_size && st->codec->block_align && ast->sample_size % st->codec->block_align)
 492                         av_log(s, AV_LOG_DEBUG, "invalid sample size or block align detected\n");
 493                     if (size%2) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
 494                         url_fskip(pb, 1);
 495                     /* Force parsing as several audio frames can be in
 496                      * one packet and timestamps refer to packet start*/
 497                     st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;
 498                     /* ADTS header is in extradata, AAC without header must be stored as exact frames, parser not needed and it will fail */
 499                     if (st->codec->codec_id == CODEC_ID_AAC && st->codec->extradata_size)
 500                         st->need_parsing = AVSTREAM_PARSE_NONE;
 501                     /* AVI files with Xan DPCM audio (wrongly) declare PCM
 502                      * audio in the header but have Axan as stream_code_tag. */
 503                     if (st->codec->stream_codec_tag == ff_get_fourcc("Axan")){
 504                         st->codec->codec_id  = CODEC_ID_XAN_DPCM;
 505                         st->codec->codec_tag = 0;
 506                     }
 507                     if (amv_file_format)
 508                         st->codec->codec_id  = CODEC_ID_ADPCM_IMA_AMV;
 509                     break;
 510                 default:
 511                     st->codec->codec_type = CODEC_TYPE_DATA;
 512                     st->codec->codec_id= CODEC_ID_NONE;
 513                     st->codec->codec_tag= 0;
 514                     url_fskip(pb, size);
 515                     break;
 516                 }
 517             }
 518             break;
 519         case MKTAG('i', 'n', 'd', 'x'):
 520             i= url_ftell(pb);
 521             if(!url_is_streamed(pb) && !(s->flags & AVFMT_FLAG_IGNIDX)){
 522                 read_braindead_odml_indx(s, 0);
 523             }
 524             url_fseek(pb, i+size, SEEK_SET);
 525             break;
 526         case MKTAG('v', 'p', 'r', 'p'):
 527             if(stream_index < (unsigned)s->nb_streams && size > 9*4){
 528                 AVRational active, active_aspect;
 529
 530                 st = s->streams[stream_index];
 531                 get_le32(pb);
 532                 get_le32(pb);
 533                 get_le32(pb);
 534                 get_le32(pb);
 535                 get_le32(pb);
 536
 537                 active_aspect.num= get_le16(pb);
 538                 active_aspect.den= get_le16(pb);
 539                 active.num       = get_le32(pb);
 540                 active.den       = get_le32(pb);
 541                 get_le32(pb); //nbFieldsPerFrame
 542
 543                 if(active_aspect.num && active_aspect.den && active.num && active.den){
 544                     st->codec->sample_aspect_ratio= av_div_q(active_aspect, active);
 545 //av_log(s, AV_LOG_ERROR, "vprp %d/%d %d/%d\n", active_aspect.num, active_aspect.den, active.num, active.den);
 546                 }
 547                 size -= 9*4;
 548             }
 549             url_fseek(pb, size, SEEK_CUR);
 550             break;
 551         case MKTAG('I', 'N', 'A', 'M'):
 552             avi_read_tag(pb, s->title, sizeof(s->title), size);
 553             break;
 554         case MKTAG('I', 'A', 'R', 'T'):
 555             avi_read_tag(pb, s->author, sizeof(s->author), size);
 556             break;
 557         case MKTAG('I', 'C', 'O', 'P'):
 558             avi_read_tag(pb, s->copyright, sizeof(s->copyright), size);
 559             break;
 560         case MKTAG('I', 'C', 'M', 'T'):
 561             avi_read_tag(pb, s->comment, sizeof(s->comment), size);
 562             break;
 563         case MKTAG('I', 'G', 'N', 'R'):
 564             avi_read_tag(pb, s->genre, sizeof(s->genre), size);
 565             break;
 566         case MKTAG('I', 'P', 'R', 'D'):
 567             avi_read_tag(pb, s->album, sizeof(s->album), size);
 568             break;
 569         case MKTAG('I', 'P', 'R', 'T'):
 570             avi_read_tag(pb, str_track, sizeof(str_track), size);
 571             sscanf(str_track, "%d", &s->track);
 572             break;
 573         default:
 574             if(size > 1000000){
 575                 av_log(s, AV_LOG_ERROR, "well something went wrong during header parsing, "
 576                                         "ill ignore it and try to continue anyway\n");
 577                 avi->movi_list = url_ftell(pb) - 4;
 578                 avi->movi_end  = url_fsize(pb);
 579                 goto end_of_header;
 580             }
 581             /* skip tag */
 582             size += (size & 1);
 583             url_fskip(pb, size);
 584             break;
 585         }
 586     }
 587  end_of_header:
 588     /* check stream number */
 589     if (stream_index != s->nb_streams - 1) {
 590     fail:
 591         for(i=0;i<s->nb_streams;i++) {
 592             av_freep(&s->streams[i]->codec->extradata);
 593             av_freep(&s->streams[i]);
 594         }
 595         return -1;
 596     }
 597
 598     if(!avi->index_loaded && !url_is_streamed(pb))
 599         avi_load_index(s);
 600     avi->index_loaded = 1;
 601     avi->non_interleaved |= guess_ni_flag(s);
 602     if(avi->non_interleaved)
 603         clean_index(s);
 604
 605     return 0;
 606 }
 607
 608 static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
 609 {
 610     AVIContext *avi = s->priv_data;
 611     ByteIOContext *pb = s->pb;
 612     int n, d[8], size;
 613     offset_t i, sync;
 614     void* dstr;
 615
 616     if (ENABLE_DV_DEMUXER && avi->dv_demux) {
 617         size = dv_get_packet(avi->dv_demux, pkt);
 618         if (size >= 0)
 619             return size;
 620     }
 621
 622     if(avi->non_interleaved){
 623         int best_stream_index = 0;
 624         AVStream *best_st= NULL;
 625         AVIStream *best_ast;
 626         int64_t best_ts= INT64_MAX;
 627         int i;
 628
 629         for(i=0; i<s->nb_streams; i++){
 630             AVStream *st = s->streams[i];
 631             AVIStream *ast = st->priv_data;
 632             int64_t ts= ast->frame_offset;
 633
 634             if(ast->sample_size)
 635                 ts /= ast->sample_size;
 636             ts= av_rescale(ts, AV_TIME_BASE * (int64_t)st->time_base.num, st->time_base.den);
 637
 638 //            av_log(NULL, AV_LOG_DEBUG, "%"PRId64" %d/%d %"PRId64"\n", ts, st->time_base.num, st->time_base.den, ast->frame_offset);
 639             if(ts < best_ts){
 640                 best_ts= ts;
 641                 best_st= st;
 642                 best_stream_index= i;
 643             }
 644         }
 645         best_ast = best_st->priv_data;
 646         best_ts= av_rescale(best_ts, best_st->time_base.den, AV_TIME_BASE * (int64_t)best_st->time_base.num); //FIXME a little ugly
 647         if(best_ast->remaining)
 648             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
 649         else
 650             i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
 651
 652 //        av_log(NULL, AV_LOG_DEBUG, "%d\n", i);
 653         if(i>=0){
 654             int64_t pos= best_st->index_entries[i].pos;
 655             pos += best_ast->packet_size - best_ast->remaining;
 656             url_fseek(s->pb, pos + 8, SEEK_SET);
 657 //        av_log(NULL, AV_LOG_DEBUG, "pos=%"PRId64"\n", pos);
 658
 659             assert(best_ast->remaining <= best_ast->packet_size);
 660
 661             avi->stream_index= best_stream_index;
 662             if(!best_ast->remaining)
 663                 best_ast->packet_size=
 664                 best_ast->remaining= best_st->index_entries[i].size;
 665         }
 666     }
 667
 668 resync:
 669     if(avi->stream_index >= 0){
 670         AVStream *st= s->streams[ avi->stream_index ];
 671         AVIStream *ast= st->priv_data;
 672         int size;
 673
 674         if(ast->sample_size <= 1) // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM
 675             size= INT_MAX;
 676         else if(ast->sample_size < 32)
 677             size= 64*ast->sample_size;
 678         else
 679             size= ast->sample_size;
 680
 681         if(size > ast->remaining)
 682             size= ast->remaining;
 683         av_get_packet(pb, pkt, size);
 684
 685         if (ENABLE_DV_DEMUXER && avi->dv_demux) {
 686             dstr = pkt->destruct;
 687             size = dv_produce_packet(avi->dv_demux, pkt,
 688                                     pkt->data, pkt->size);
 689             pkt->destruct = dstr;
 690             pkt->flags |= PKT_FLAG_KEY;
 691         } else {
 692             /* XXX: how to handle B frames in avi ? */
 693             pkt->dts = ast->frame_offset;
 694 //                pkt->dts += ast->start;
 695             if(ast->sample_size)
 696                 pkt->dts /= ast->sample_size;
 697 //av_log(NULL, 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);
 698             pkt->stream_index = avi->stream_index;
 699
 700             if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
 701                 AVIndexEntry *e;
 702                 int index;
 703                 assert(st->index_entries);
 704
 705                 index= av_index_search_timestamp(st, pkt->dts, 0);
 706                 e= &st->index_entries[index];
 707
 708                 if(index >= 0 && e->timestamp == ast->frame_offset){
 709                     if (e->flags & AVINDEX_KEYFRAME)
 710                         pkt->flags |= PKT_FLAG_KEY;
 711                 }
 712             } else {
 713                 pkt->flags |= PKT_FLAG_KEY;
 714             }
 715             if(ast->sample_size)
 716                 ast->frame_offset += pkt->size;
 717             else
 718                 ast->frame_offset++;
 719         }
 720         ast->remaining -= size;
 721         if(!ast->remaining){
 722             avi->stream_index= -1;
 723             ast->packet_size= 0;
 724         }
 725
 726         return size;
 727     }
 728
 729     memset(d, -1, sizeof(int)*8);
 730     for(i=sync=url_ftell(pb); !url_feof(pb); i++) {
 731         int j;
 732
 733         for(j=0; j<7; j++)
 734             d[j]= d[j+1];
 735         d[7]= get_byte(pb);
 736
 737         size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
 738
 739         if(    d[2] >= '0' && d[2] <= '9'
 740             && d[3] >= '0' && d[3] <= '9'){
 741             n= (d[2] - '0') * 10 + (d[3] - '0');
 742         }else{
 743             n= 100; //invalid stream id
 744         }
 745 //av_log(NULL, 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);
 746         if(i + size > avi->fsize || d[0]<0)
 747             continue;
 748
 749         //parse ix##
 750         if(  (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
 751         //parse JUNK
 752            ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')
 753            ||(d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')){
 754             url_fskip(pb, size);
 755 //av_log(NULL, AV_LOG_DEBUG, "SKIP\n");
 756             goto resync;
 757         }
 758
 759         if(    d[0] >= '0' && d[0] <= '9'
 760             && d[1] >= '0' && d[1] <= '9'){
 761             n= (d[0] - '0') * 10 + (d[1] - '0');
 762         }else{
 763             n= 100; //invalid stream id
 764         }
 765
 766         //parse ##dc/##wb
 767         if(n < s->nb_streams){
 768           AVStream *st;
 769           AVIStream *ast;
 770           st = s->streams[n];
 771           ast = st->priv_data;
 772
 773           if(   (st->discard >= AVDISCARD_DEFAULT && size==0)
 774              /*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & PKT_FLAG_KEY))*/ //FIXME needs a little reordering
 775              || st->discard >= AVDISCARD_ALL){
 776                 if(ast->sample_size) ast->frame_offset += pkt->size;
 777                 else                 ast->frame_offset++;
 778                 url_fskip(pb, size);
 779                 goto resync;
 780           }
 781
 782           if(   ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||
 783                 d[2]*256+d[3] == ast->prefix /*||
 784                 (d[2] == 'd' && d[3] == 'c') ||
 785                 (d[2] == 'w' && d[3] == 'b')*/) {
 786
 787 //av_log(NULL, AV_LOG_DEBUG, "OK\n");
 788             if(d[2]*256+d[3] == ast->prefix)
 789                 ast->prefix_count++;
 790             else{
 791                 ast->prefix= d[2]*256+d[3];
 792                 ast->prefix_count= 0;
 793             }
 794
 795             avi->stream_index= n;
 796             ast->packet_size= size + 8;
 797             ast->remaining= size;
 798
 799             {
 800                 uint64_t pos= url_ftell(pb) - 8;
 801                 if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){
 802                     av_add_index_entry(st, pos, ast->frame_offset / FFMAX(1, ast->sample_size), size, 0, AVINDEX_KEYFRAME);
 803                 }
 804             }
 805             goto resync;
 806           }
 807         }
 808         /* palette changed chunk */
 809         if (   d[0] >= '0' && d[0] <= '9'
 810             && d[1] >= '0' && d[1] <= '9'
 811             && ((d[2] == 'p' && d[3] == 'c'))
 812             && n < s->nb_streams && i + size <= avi->fsize) {
 813
 814             AVStream *st;
 815             int first, clr, flags, k, p;
 816
 817             st = s->streams[n];
 818
 819             first = get_byte(pb);
 820             clr = get_byte(pb);
 821             if(!clr) /* all 256 colors used */
 822                 clr = 256;
 823             flags = get_le16(pb);
 824             p = 4;
 825             for (k = first; k < clr + first; k++) {
 826                 int r, g, b;
 827                 r = get_byte(pb);
 828                 g = get_byte(pb);
 829                 b = get_byte(pb);
 830                     get_byte(pb);
 831                 st->codec->palctrl->palette[k] = b + (g << 8) + (r << 16);
 832             }
 833             st->codec->palctrl->palette_changed = 1;
 834             goto resync;
 835         }
 836
 837     }
 838
 839     return -1;
 840 }
 841
 842 /* XXX: we make the implicit supposition that the position are sorted
 843    for each stream */
 844 static int avi_read_idx1(AVFormatContext *s, int size)
 845 {
 846     AVIContext *avi = s->priv_data;
 847     ByteIOContext *pb = s->pb;
 848     int nb_index_entries, i;
 849     AVStream *st;
 850     AVIStream *ast;
 851     unsigned int index, tag, flags, pos, len;
 852     unsigned last_pos= -1;
 853
 854     nb_index_entries = size / 16;
 855     if (nb_index_entries <= 0)
 856         return -1;
 857
 858     /* read the entries and sort them in each stream component */
 859     for(i = 0; i < nb_index_entries; i++) {
 860         tag = get_le32(pb);
 861         flags = get_le32(pb);
 862         pos = get_le32(pb);
 863         len = get_le32(pb);
 864 #if defined(DEBUG_SEEK)
 865         av_log(NULL, AV_LOG_DEBUG, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
 866                i, tag, flags, pos, len);
 867 #endif
 868         if(i==0 && pos > avi->movi_list)
 869             avi->movi_list= 0; //FIXME better check
 870         pos += avi->movi_list;
 871
 872         index = ((tag & 0xff) - '0') * 10;
 873         index += ((tag >> 8) & 0xff) - '0';
 874         if (index >= s->nb_streams)
 875             continue;
 876         st = s->streams[index];
 877         ast = st->priv_data;
 878
 879 #if defined(DEBUG_SEEK)
 880         av_log(NULL, AV_LOG_DEBUG, "%d cum_len=%"PRId64"\n", len, ast->cum_len);
 881 #endif
 882         if(last_pos == pos)
 883             avi->non_interleaved= 1;
 884         else
 885             av_add_index_entry(st, pos, ast->cum_len / FFMAX(1, ast->sample_size), len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
 886         if(ast->sample_size)
 887             ast->cum_len += len;
 888         else
 889             ast->cum_len ++;
 890         last_pos= pos;
 891     }
 892     return 0;
 893 }
 894
 895 static int guess_ni_flag(AVFormatContext *s){
 896     int i;
 897     int64_t last_start=0;
 898     int64_t first_end= INT64_MAX;
 899
 900     for(i=0; i<s->nb_streams; i++){
 901         AVStream *st = s->streams[i];
 902         int n= st->nb_index_entries;
 903
 904         if(n <= 0)
 905             continue;
 906
 907         if(st->index_entries[0].pos > last_start)
 908             last_start= st->index_entries[0].pos;
 909         if(st->index_entries[n-1].pos < first_end)
 910             first_end= st->index_entries[n-1].pos;
 911     }
 912     return last_start > first_end;
 913 }
 914
 915 static int avi_load_index(AVFormatContext *s)
 916 {
 917     AVIContext *avi = s->priv_data;
 918     ByteIOContext *pb = s->pb;
 919     uint32_t tag, size;
 920     offset_t pos= url_ftell(pb);
 921
 922     url_fseek(pb, avi->movi_end, SEEK_SET);
 923 #ifdef DEBUG_SEEK
 924     printf("movi_end=0x%"PRIx64"\n", avi->movi_end);
 925 #endif
 926     for(;;) {
 927         if (url_feof(pb))
 928             break;
 929         tag = get_le32(pb);
 930         size = get_le32(pb);
 931 #ifdef DEBUG_SEEK
 932         printf("tag=%c%c%c%c size=0x%x\n",
 933                tag & 0xff,
 934                (tag >> 8) & 0xff,
 935                (tag >> 16) & 0xff,
 936                (tag >> 24) & 0xff,
 937                size);
 938 #endif
 939         switch(tag) {
 940         case MKTAG('i', 'd', 'x', '1'):
 941             if (avi_read_idx1(s, size) < 0)
 942                 goto skip;
 943             else
 944                 goto the_end;
 945             break;
 946         default:
 947         skip:
 948             size += (size & 1);
 949             url_fskip(pb, size);
 950             break;
 951         }
 952     }
 953  the_end:
 954     url_fseek(pb, pos, SEEK_SET);
 955     return 0;
 956 }
 957
 958 static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
 959 {
 960     AVIContext *avi = s->priv_data;
 961     AVStream *st;
 962     int i, index;
 963     int64_t pos;
 964
 965     if (!avi->index_loaded) {
 966         /* we only load the index on demand */
 967         avi_load_index(s);
 968         avi->index_loaded = 1;
 969     }
 970     assert(stream_index>= 0);
 971
 972     st = s->streams[stream_index];
 973     index= av_index_search_timestamp(st, timestamp, flags);
 974     if(index<0)
 975         return -1;
 976
 977     /* find the position */
 978     pos = st->index_entries[index].pos;
 979     timestamp = st->index_entries[index].timestamp;
 980
 981 //    av_log(NULL, AV_LOG_DEBUG, "XX %"PRId64" %d %"PRId64"\n", timestamp, index, st->index_entries[index].timestamp);
 982
 983     if (ENABLE_DV_DEMUXER && avi->dv_demux) {
 984         /* One and only one real stream for DV in AVI, and it has video  */
 985         /* offsets. Calling with other stream indices should have failed */
 986         /* the av_index_search_timestamp call above.                     */
 987         assert(stream_index == 0);
 988
 989         /* Feed the DV video stream version of the timestamp to the */
 990         /* DV demux so it can synth correct timestamps              */
 991         dv_offset_reset(avi->dv_demux, timestamp);
 992
 993         url_fseek(s->pb, pos, SEEK_SET);
 994         avi->stream_index= -1;
 995         return 0;
 996     }
 997
 998     for(i = 0; i < s->nb_streams; i++) {
 999         AVStream *st2 = s->streams[i];
1000         AVIStream *ast2 = st2->priv_data;
1001
1002         ast2->packet_size=
1003         ast2->remaining= 0;
1004
1005         if (st2->nb_index_entries <= 0)
1006             continue;
1007
1008 //        assert(st2->codec->block_align);
1009         assert(st2->time_base.den == ast2->rate);
1010         assert(st2->time_base.num == ast2->scale);
1011         index = av_index_search_timestamp(
1012                 st2,
1013                 av_rescale(timestamp, st2->time_base.den*(int64_t)st->time_base.num, st->time_base.den * (int64_t)st2->time_base.num),
1014                 flags | AVSEEK_FLAG_BACKWARD);
1015         if(index<0)
1016             index=0;
1017
1018         if(!avi->non_interleaved){
1019             while(index>0 && st2->index_entries[index].pos > pos)
1020                 index--;
1021             while(index+1 < st2->nb_index_entries && st2->index_entries[index].pos < pos)
1022                 index++;
1023         }
1024
1025 //        av_log(NULL, AV_LOG_DEBUG, "%"PRId64" %d %"PRId64"\n", timestamp, index, st2->index_entries[index].timestamp);
1026         /* extract the current frame number */
1027         ast2->frame_offset = st2->index_entries[index].timestamp;
1028         if(ast2->sample_size)
1029             ast2->frame_offset *=ast2->sample_size;
1030     }
1031
1032     /* do the seek */
1033     url_fseek(s->pb, pos, SEEK_SET);
1034     avi->stream_index= -1;
1035     return 0;
1036 }
1037
1038 static int avi_read_close(AVFormatContext *s)
1039 {
1040     int i;
1041     AVIContext *avi = s->priv_data;
1042
1043     for(i=0;i<s->nb_streams;i++) {
1044         AVStream *st = s->streams[i];
1045         AVIStream *ast = st->priv_data;
1046         av_free(ast);
1047         av_free(st->codec->palctrl);
1048     }
1049
1050     if (avi->dv_demux)
1051         av_free(avi->dv_demux);
1052
1053     return 0;
1054 }
1055
1056 static int avi_probe(AVProbeData *p)
1057 {
1058     int i;
1059
1060     /* check file header */
1061     for(i=0; avi_headers[i][0]; i++)
1062         if(!memcmp(p->buf  , avi_headers[i]  , 4) &&
1063            !memcmp(p->buf+8, avi_headers[i]+4, 4))
1064             return AVPROBE_SCORE_MAX;
1065
1066     return 0;
1067 }
1068
1069 AVInputFormat avi_demuxer = {
1070     "avi",
1071     "avi format",
1072     sizeof(AVIContext),
1073     avi_probe,
1074     avi_read_header,
1075     avi_read_packet,
1076     avi_read_close,
1077     avi_read_seek,
1078 };