libavformat/asfdec.c

   1 /*
   2  * ASF compatible demuxer
   3  * Copyright (c) 2000, 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
  22 //#define DEBUG
  23
  24 #include "libavutil/common.h"
  25 #include "libavutil/avstring.h"
  26 #include "libavcodec/mpegaudio.h"
  27 #include "avformat.h"
  28 #include "riff.h"
  29 #include "asf.h"
  30 #include "asfcrypt.h"
  31 #include "avlanguage.h"
  32
  33 void ff_mms_set_stream_selection(URLContext *h, AVFormatContext *format);
  34
  35 #undef NDEBUG
  36 #include <assert.h>
  37
  38 #define FRAME_HEADER_SIZE 17
  39 // Fix Me! FRAME_HEADER_SIZE may be different.
  40
  41 static const ff_asf_guid index_guid = {
  42     0x90, 0x08, 0x00, 0x33, 0xb1, 0xe5, 0xcf, 0x11, 0x89, 0xf4, 0x00, 0xa0, 0xc9, 0x03, 0x49, 0xcb
  43 };
  44
  45 static const ff_asf_guid stream_bitrate_guid = { /* (http://get.to/sdp) */
  46     0xce, 0x75, 0xf8, 0x7b, 0x8d, 0x46, 0xd1, 0x11, 0x8d, 0x82, 0x00, 0x60, 0x97, 0xc9, 0xa2, 0xb2
  47 };
  48 /**********************************/
  49 /* decoding */
  50
  51 static int guidcmp(const void *g1, const void *g2)
  52 {
  53     return memcmp(g1, g2, sizeof(ff_asf_guid));
  54 }
  55
  56 #ifdef DEBUG
  57 #define PRINT_IF_GUID(g,cmp) \
  58 if (!guidcmp(g, &cmp)) \
  59     dprintf(NULL, "(GUID: %s) ", #cmp)
  60
  61 static void print_guid(const ff_asf_guid *g)
  62 {
  63     int i;
  64     PRINT_IF_GUID(g, ff_asf_header);
  65     else PRINT_IF_GUID(g, ff_asf_file_header);
  66     else PRINT_IF_GUID(g, ff_asf_stream_header);
  67     else PRINT_IF_GUID(g, ff_asf_audio_stream);
  68     else PRINT_IF_GUID(g, ff_asf_audio_conceal_none);
  69     else PRINT_IF_GUID(g, ff_asf_video_stream);
  70     else PRINT_IF_GUID(g, ff_asf_video_conceal_none);
  71     else PRINT_IF_GUID(g, ff_asf_command_stream);
  72     else PRINT_IF_GUID(g, ff_asf_comment_header);
  73     else PRINT_IF_GUID(g, ff_asf_codec_comment_header);
  74     else PRINT_IF_GUID(g, ff_asf_codec_comment1_header);
  75     else PRINT_IF_GUID(g, ff_asf_data_header);
  76     else PRINT_IF_GUID(g, index_guid);
  77     else PRINT_IF_GUID(g, ff_asf_head1_guid);
  78     else PRINT_IF_GUID(g, ff_asf_head2_guid);
  79     else PRINT_IF_GUID(g, ff_asf_my_guid);
  80     else PRINT_IF_GUID(g, ff_asf_ext_stream_header);
  81     else PRINT_IF_GUID(g, ff_asf_extended_content_header);
  82     else PRINT_IF_GUID(g, ff_asf_ext_stream_embed_stream_header);
  83     else PRINT_IF_GUID(g, ff_asf_ext_stream_audio_stream);
  84     else PRINT_IF_GUID(g, ff_asf_metadata_header);
  85     else PRINT_IF_GUID(g, stream_bitrate_guid);
  86     else PRINT_IF_GUID(g, ff_asf_language_guid);
  87     else
  88         dprintf(NULL, "(GUID: unknown) ");
  89     for(i=0;i<16;i++)
  90         dprintf(NULL, " 0x%02x,", (*g)[i]);
  91     dprintf(NULL, "}\n");
  92 }
  93 #undef PRINT_IF_GUID
  94 #else
  95 #define print_guid(g)
  96 #endif
  97
  98 static void get_guid(ByteIOContext *s, ff_asf_guid *g)
  99 {
 100     assert(sizeof(*g) == 16);
 101     get_buffer(s, *g, sizeof(*g));
 102 }
 103
 104 #if 0
 105 static void get_str16(ByteIOContext *pb, char *buf, int buf_size)
 106 {
 107     int len, c;
 108     char *q;
 109
 110     len = get_le16(pb);
 111     q = buf;
 112     while (len > 0) {
 113         c = get_le16(pb);
 114         if ((q - buf) < buf_size - 1)
 115             *q++ = c;
 116         len--;
 117     }
 118     *q = '\0';
 119 }
 120 #endif
 121
 122 static void get_str16_nolen(ByteIOContext *pb, int len, char *buf, int buf_size)
 123 {
 124     char* q = buf;
 125     for (; len > 1; len -= 2) {
 126         uint8_t tmp;
 127         PUT_UTF8(get_le16(pb), tmp, if (q - buf < buf_size - 1) *q++ = tmp;)
 128     }
 129     if (len > 0)
 130         url_fskip(pb, len);
 131     *q = '\0';
 132 }
 133
 134 static int asf_probe(AVProbeData *pd)
 135 {
 136     /* check file header */
 137     if (!guidcmp(pd->buf, &ff_asf_header))
 138         return AVPROBE_SCORE_MAX;
 139     else
 140         return 0;
 141 }
 142
 143 static int get_value(ByteIOContext *pb, int type){
 144     switch(type){
 145         case 2: return get_le32(pb);
 146         case 3: return get_le32(pb);
 147         case 4: return get_le64(pb);
 148         case 5: return get_le16(pb);
 149         default:return INT_MIN;
 150     }
 151 }
 152
 153 static void get_tag(AVFormatContext *s, const char *key, int type, int len)
 154 {
 155     char value[1024];
 156     if (type <= 1) {         // unicode or byte
 157         get_str16_nolen(s->pb, len, value, sizeof(value));
 158     } else if (type <= 5) {  // boolean or DWORD or QWORD or WORD
 159         uint64_t num = get_value(s->pb, type);
 160         snprintf(value, sizeof(value), "%"PRIu64, num);
 161     } else {
 162         url_fskip(s->pb, len);
 163         return;
 164     }
 165     if (!strncmp(key, "WM/", 3))
 166         key += 3;
 167     av_metadata_set(&s->metadata, key, value);
 168 }
 169
 170 static int asf_read_header(AVFormatContext *s, AVFormatParameters *ap)
 171 {
 172     ASFContext *asf = s->priv_data;
 173     ff_asf_guid g;
 174     ByteIOContext *pb = s->pb;
 175     AVStream *st;
 176     ASFStream *asf_st;
 177     int size, i;
 178     int64_t gsize;
 179     AVRational dar[128];
 180     uint32_t bitrate[128];
 181
 182     memset(dar, 0, sizeof(dar));
 183     memset(bitrate, 0, sizeof(bitrate));
 184
 185     get_guid(pb, &g);
 186     if (guidcmp(&g, &ff_asf_header))
 187         return -1;
 188     get_le64(pb);
 189     get_le32(pb);
 190     get_byte(pb);
 191     get_byte(pb);
 192     memset(&asf->asfid2avid, -1, sizeof(asf->asfid2avid));
 193     for(;;) {
 194         get_guid(pb, &g);
 195         gsize = get_le64(pb);
 196         dprintf(s, "%08"PRIx64": ", url_ftell(pb) - 24);
 197         print_guid(&g);
 198         dprintf(s, "  size=0x%"PRIx64"\n", gsize);
 199         if (!guidcmp(&g, &ff_asf_data_header)) {
 200             asf->data_object_offset = url_ftell(pb);
 201             // if not streaming, gsize is not unlimited (how?), and there is enough space in the file..
 202             if (!(asf->hdr.flags & 0x01) && gsize >= 100) {
 203                 asf->data_object_size = gsize - 24;
 204             } else {
 205                 asf->data_object_size = (uint64_t)-1;
 206             }
 207             break;
 208         }
 209         if (gsize < 24)
 210             return -1;
 211         if (!guidcmp(&g, &ff_asf_file_header)) {
 212             get_guid(pb, &asf->hdr.guid);
 213             asf->hdr.file_size          = get_le64(pb);
 214             asf->hdr.create_time        = get_le64(pb);
 215             asf->nb_packets             = get_le64(pb);
 216             asf->hdr.play_time          = get_le64(pb);
 217             asf->hdr.send_time          = get_le64(pb);
 218             asf->hdr.preroll            = get_le32(pb);
 219             asf->hdr.ignore             = get_le32(pb);
 220             asf->hdr.flags              = get_le32(pb);
 221             asf->hdr.min_pktsize        = get_le32(pb);
 222             asf->hdr.max_pktsize        = get_le32(pb);
 223             asf->hdr.max_bitrate        = get_le32(pb);
 224             asf->packet_size = asf->hdr.max_pktsize;
 225         } else if (!guidcmp(&g, &ff_asf_stream_header)) {
 226             enum CodecType type;
 227             int type_specific_size, sizeX;
 228             uint64_t total_size;
 229             unsigned int tag1;
 230             int64_t pos1, pos2, start_time;
 231             int test_for_ext_stream_audio, is_dvr_ms_audio=0;
 232
 233             pos1 = url_ftell(pb);
 234
 235             st = av_new_stream(s, 0);
 236             if (!st)
 237                 return AVERROR(ENOMEM);
 238             av_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */
 239             asf_st = av_mallocz(sizeof(ASFStream));
 240             if (!asf_st)
 241                 return AVERROR(ENOMEM);
 242             st->priv_data = asf_st;
 243             start_time = asf->hdr.preroll;
 244
 245             asf_st->stream_language_index = 128; // invalid stream index means no language info
 246
 247             if(!(asf->hdr.flags & 0x01)) { // if we aren't streaming...
 248                 st->duration = asf->hdr.send_time /
 249                     (10000000 / 1000) - start_time;
 250             }
 251             get_guid(pb, &g);
 252
 253             test_for_ext_stream_audio = 0;
 254             if (!guidcmp(&g, &ff_asf_audio_stream)) {
 255                 type = CODEC_TYPE_AUDIO;
 256             } else if (!guidcmp(&g, &ff_asf_video_stream)) {
 257                 type = CODEC_TYPE_VIDEO;
 258             } else if (!guidcmp(&g, &ff_asf_command_stream)) {
 259                 type = CODEC_TYPE_DATA;
 260             } else if (!guidcmp(&g, &ff_asf_ext_stream_embed_stream_header)) {
 261                 test_for_ext_stream_audio = 1;
 262                 type = CODEC_TYPE_UNKNOWN;
 263             } else {
 264                 return -1;
 265             }
 266             get_guid(pb, &g);
 267             total_size = get_le64(pb);
 268             type_specific_size = get_le32(pb);
 269             get_le32(pb);
 270             st->id = get_le16(pb) & 0x7f; /* stream id */
 271             // mapping of asf ID to AV stream ID;
 272             asf->asfid2avid[st->id] = s->nb_streams - 1;
 273
 274             get_le32(pb);
 275
 276             if (test_for_ext_stream_audio) {
 277                 get_guid(pb, &g);
 278                 if (!guidcmp(&g, &ff_asf_ext_stream_audio_stream)) {
 279                     type = CODEC_TYPE_AUDIO;
 280                     is_dvr_ms_audio=1;
 281                     get_guid(pb, &g);
 282                     get_le32(pb);
 283                     get_le32(pb);
 284                     get_le32(pb);
 285                     get_guid(pb, &g);
 286                     get_le32(pb);
 287                 }
 288             }
 289
 290             st->codec->codec_type = type;
 291             if (type == CODEC_TYPE_AUDIO) {
 292                 get_wav_header(pb, st->codec, type_specific_size);
 293                 if (is_dvr_ms_audio) {
 294                     // codec_id and codec_tag are unreliable in dvr_ms
 295                     // files. Set them later by probing stream.
 296                     st->codec->codec_id = CODEC_ID_PROBE;
 297                     st->codec->codec_tag = 0;
 298                 }
 299                 if (st->codec->codec_id == CODEC_ID_AAC) {
 300                     st->need_parsing = AVSTREAM_PARSE_NONE;
 301                 } else {
 302                     st->need_parsing = AVSTREAM_PARSE_FULL;
 303                 }
 304                 /* We have to init the frame size at some point .... */
 305                 pos2 = url_ftell(pb);
 306                 if (gsize >= (pos2 + 8 - pos1 + 24)) {
 307                     asf_st->ds_span = get_byte(pb);
 308                     asf_st->ds_packet_size = get_le16(pb);
 309                     asf_st->ds_chunk_size = get_le16(pb);
 310                     get_le16(pb); //ds_data_size
 311                     get_byte(pb); //ds_silence_data
 312                 }
 313                 //printf("Descrambling: ps:%d cs:%d ds:%d s:%d  sd:%d\n",
 314                 //       asf_st->ds_packet_size, asf_st->ds_chunk_size,
 315                 //       asf_st->ds_data_size, asf_st->ds_span, asf_st->ds_silence_data);
 316                 if (asf_st->ds_span > 1) {
 317                     if (!asf_st->ds_chunk_size
 318                         || (asf_st->ds_packet_size/asf_st->ds_chunk_size <= 1)
 319                         || asf_st->ds_packet_size % asf_st->ds_chunk_size)
 320                         asf_st->ds_span = 0; // disable descrambling
 321                 }
 322                 switch (st->codec->codec_id) {
 323                 case CODEC_ID_MP3:
 324                     st->codec->frame_size = MPA_FRAME_SIZE;
 325                     break;
 326                 case CODEC_ID_PCM_S16LE:
 327                 case CODEC_ID_PCM_S16BE:
 328                 case CODEC_ID_PCM_U16LE:
 329                 case CODEC_ID_PCM_U16BE:
 330                 case CODEC_ID_PCM_S8:
 331                 case CODEC_ID_PCM_U8:
 332                 case CODEC_ID_PCM_ALAW:
 333                 case CODEC_ID_PCM_MULAW:
 334                     st->codec->frame_size = 1;
 335                     break;
 336                 default:
 337                     /* This is probably wrong, but it prevents a crash later */
 338                     st->codec->frame_size = 1;
 339                     break;
 340                 }
 341             } else if (type == CODEC_TYPE_VIDEO) {
 342                 get_le32(pb);
 343                 get_le32(pb);
 344                 get_byte(pb);
 345                 size = get_le16(pb); /* size */
 346                 sizeX= get_le32(pb); /* size */
 347                 st->codec->width = get_le32(pb);
 348                 st->codec->height = get_le32(pb);
 349                 /* not available for asf */
 350                 get_le16(pb); /* panes */
 351                 st->codec->bits_per_coded_sample = get_le16(pb); /* depth */
 352                 tag1 = get_le32(pb);
 353                 url_fskip(pb, 20);
 354 //                av_log(s, AV_LOG_DEBUG, "size:%d tsize:%d sizeX:%d\n", size, total_size, sizeX);
 355                 size= sizeX;
 356                 if (size > 40) {
 357                     st->codec->extradata_size = size - 40;
 358                     st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
 359                     get_buffer(pb, st->codec->extradata, st->codec->extradata_size);
 360                 }
 361
 362                 /* Extract palette from extradata if bpp <= 8 */
 363                 /* This code assumes that extradata contains only palette */
 364                 /* This is true for all paletted codecs implemented in ffmpeg */
 365                 if (st->codec->extradata_size && (st->codec->bits_per_coded_sample <= 8)) {
 366                     st->codec->palctrl = av_mallocz(sizeof(AVPaletteControl));
 367 #ifdef WORDS_BIGENDIAN
 368                     for (i = 0; i < FFMIN(st->codec->extradata_size, AVPALETTE_SIZE)/4; i++)
 369                         st->codec->palctrl->palette[i] = bswap_32(((uint32_t*)st->codec->extradata)[i]);
 370 #else
 371                     memcpy(st->codec->palctrl->palette, st->codec->extradata,
 372                            FFMIN(st->codec->extradata_size, AVPALETTE_SIZE));
 373 #endif
 374                     st->codec->palctrl->palette_changed = 1;
 375                 }
 376
 377                 st->codec->codec_tag = tag1;
 378                 st->codec->codec_id = codec_get_id(codec_bmp_tags, tag1);
 379                 if(tag1 == MKTAG('D', 'V', 'R', ' '))
 380                     st->need_parsing = AVSTREAM_PARSE_FULL;
 381             }
 382             pos2 = url_ftell(pb);
 383             url_fskip(pb, gsize - (pos2 - pos1 + 24));
 384         } else if (!guidcmp(&g, &ff_asf_comment_header)) {
 385             int len1, len2, len3, len4, len5;
 386
 387             len1 = get_le16(pb);
 388             len2 = get_le16(pb);
 389             len3 = get_le16(pb);
 390             len4 = get_le16(pb);
 391             len5 = get_le16(pb);
 392             get_tag(s, "title"    , 0, len1);
 393             get_tag(s, "author"   , 0, len2);
 394             get_tag(s, "copyright", 0, len3);
 395             get_tag(s, "comment"  , 0, len4);
 396             url_fskip(pb, len5);
 397         } else if (!guidcmp(&g, &stream_bitrate_guid)) {
 398             int stream_count = get_le16(pb);
 399             int j;
 400
 401 //            av_log(s, AV_LOG_ERROR, "stream bitrate properties\n");
 402 //            av_log(s, AV_LOG_ERROR, "streams %d\n", streams);
 403             for(j = 0; j < stream_count; j++) {
 404                 int flags, bitrate, stream_id;
 405
 406                 flags= get_le16(pb);
 407                 bitrate= get_le32(pb);
 408                 stream_id= (flags & 0x7f);
 409 //                av_log(s, AV_LOG_ERROR, "flags: 0x%x stream id %d, bitrate %d\n", flags, stream_id, bitrate);
 410                 asf->stream_bitrates[stream_id]= bitrate;
 411             }
 412         } else if (!guidcmp(&g, &ff_asf_language_guid)) {
 413             int j;
 414             int stream_count = get_le16(pb);
 415             for(j = 0; j < stream_count; j++) {
 416                 char lang[6];
 417                 unsigned int lang_len = get_byte(pb);
 418                 get_str16_nolen(pb, lang_len, lang, sizeof(lang));
 419                 if (j < 128)
 420                     av_strlcpy(asf->stream_languages[j], lang, sizeof(*asf->stream_languages));
 421             }
 422         } else if (!guidcmp(&g, &ff_asf_extended_content_header)) {
 423             int desc_count, i;
 424
 425             desc_count = get_le16(pb);
 426             for(i=0;i<desc_count;i++) {
 427                     int name_len,value_type,value_len;
 428                     char name[1024];
 429
 430                     name_len = get_le16(pb);
 431                     get_str16_nolen(pb, name_len, name, sizeof(name));
 432                     value_type = get_le16(pb);
 433                     value_len  = get_le16(pb);
 434                     get_tag(s, name, value_type, value_len);
 435             }
 436         } else if (!guidcmp(&g, &ff_asf_metadata_header)) {
 437             int n, stream_num, name_len, value_len, value_type, value_num;
 438             n = get_le16(pb);
 439
 440             for(i=0;i<n;i++) {
 441                 char name[1024];
 442
 443                 get_le16(pb); //lang_list_index
 444                 stream_num= get_le16(pb);
 445                 name_len=   get_le16(pb);
 446                 value_type= get_le16(pb);
 447                 value_len=  get_le32(pb);
 448
 449                 get_str16_nolen(pb, name_len, name, sizeof(name));
 450 //av_log(s, AV_LOG_ERROR, "%d %d %d %d %d <%s>\n", i, stream_num, name_len, value_type, value_len, name);
 451                 value_num= get_le16(pb);//we should use get_value() here but it does not work 2 is le16 here but le32 elsewhere
 452                 url_fskip(pb, value_len - 2);
 453
 454                 if(stream_num<128){
 455                     if     (!strcmp(name, "AspectRatioX")) dar[stream_num].num= value_num;
 456                     else if(!strcmp(name, "AspectRatioY")) dar[stream_num].den= value_num;
 457                 }
 458             }
 459         } else if (!guidcmp(&g, &ff_asf_ext_stream_header)) {
 460             int ext_len, payload_ext_ct, stream_ct;
 461             uint32_t ext_d, leak_rate, stream_num;
 462             unsigned int stream_languageid_index;
 463
 464             get_le64(pb); // starttime
 465             get_le64(pb); // endtime
 466             leak_rate = get_le32(pb); // leak-datarate
 467             get_le32(pb); // bucket-datasize
 468             get_le32(pb); // init-bucket-fullness
 469             get_le32(pb); // alt-leak-datarate
 470             get_le32(pb); // alt-bucket-datasize
 471             get_le32(pb); // alt-init-bucket-fullness
 472             get_le32(pb); // max-object-size
 473             get_le32(pb); // flags (reliable,seekable,no_cleanpoints?,resend-live-cleanpoints, rest of bits reserved)
 474             stream_num = get_le16(pb); // stream-num
 475
 476             stream_languageid_index = get_le16(pb); // stream-language-id-index
 477             if (stream_num < 128)
 478                 asf->streams[stream_num].stream_language_index = stream_languageid_index;
 479
 480             get_le64(pb); // avg frametime in 100ns units
 481             stream_ct = get_le16(pb); //stream-name-count
 482             payload_ext_ct = get_le16(pb); //payload-extension-system-count
 483
 484             if (stream_num < 128)
 485                 bitrate[stream_num] = leak_rate;
 486
 487             for (i=0; i<stream_ct; i++){
 488                 get_le16(pb);
 489                 ext_len = get_le16(pb);
 490                 url_fseek(pb, ext_len, SEEK_CUR);
 491             }
 492
 493             for (i=0; i<payload_ext_ct; i++){
 494                 get_guid(pb, &g);
 495                 ext_d=get_le16(pb);
 496                 ext_len=get_le32(pb);
 497                 url_fseek(pb, ext_len, SEEK_CUR);
 498             }
 499
 500             // there could be a optional stream properties object to follow
 501             // if so the next iteration will pick it up
 502         } else if (!guidcmp(&g, &ff_asf_head1_guid)) {
 503             int v1, v2;
 504             get_guid(pb, &g);
 505             v1 = get_le32(pb);
 506             v2 = get_le16(pb);
 507 #if 0
 508         } else if (!guidcmp(&g, &ff_asf_codec_comment_header)) {
 509             int len, v1, n, num;
 510             char str[256], *q;
 511             char tag[16];
 512
 513             get_guid(pb, &g);
 514             print_guid(&g);
 515
 516             n = get_le32(pb);
 517             for(i=0;i<n;i++) {
 518                 num = get_le16(pb); /* stream number */
 519                 get_str16(pb, str, sizeof(str));
 520                 get_str16(pb, str, sizeof(str));
 521                 len = get_le16(pb);
 522                 q = tag;
 523                 while (len > 0) {
 524                     v1 = get_byte(pb);
 525                     if ((q - tag) < sizeof(tag) - 1)
 526                         *q++ = v1;
 527                     len--;
 528                 }
 529                 *q = '\0';
 530             }
 531 #endif
 532         } else if (url_feof(pb)) {
 533             return -1;
 534         } else {
 535             url_fseek(pb, gsize - 24, SEEK_CUR);
 536         }
 537     }
 538     get_guid(pb, &g);
 539     get_le64(pb);
 540     get_byte(pb);
 541     get_byte(pb);
 542     if (url_feof(pb))
 543         return -1;
 544     asf->data_offset = url_ftell(pb);
 545     asf->packet_size_left = 0;
 546
 547
 548     for(i=0; i<128; i++){
 549         int stream_num= asf->asfid2avid[i];
 550         if(stream_num>=0){
 551             AVStream *st = s->streams[stream_num];
 552             if (!st->codec->bit_rate)
 553                 st->codec->bit_rate = bitrate[i];
 554             if (dar[i].num > 0 && dar[i].den > 0)
 555                 av_reduce(&st->sample_aspect_ratio.num,
 556                           &st->sample_aspect_ratio.den,
 557                           dar[i].num, dar[i].den, INT_MAX);
 558 //av_log(s, AV_LOG_ERROR, "dar %d:%d sar=%d:%d\n", dar[i].num, dar[i].den, st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);
 559
 560             // copy and convert language codes to the frontend
 561             if (asf->streams[i].stream_language_index < 128) {
 562                 const char *rfc1766 = asf->stream_languages[asf->streams[i].stream_language_index];
 563                 if (rfc1766 && strlen(rfc1766) > 1) {
 564                     const char primary_tag[3] = { rfc1766[0], rfc1766[1], '\0' }; // ignore country code if any
 565                     const char *iso6392 = av_convert_lang_to(primary_tag, AV_LANG_ISO639_2_BIBL);
 566                     if (iso6392)
 567                         av_metadata_set(&st->metadata, "language", iso6392);
 568                 }
 569             }
 570         }
 571     }
 572
 573     return 0;
 574 }
 575
 576 #define DO_2BITS(bits, var, defval) \
 577     switch (bits & 3) \
 578     { \
 579     case 3: var = get_le32(pb); rsize += 4; break; \
 580     case 2: var = get_le16(pb); rsize += 2; break; \
 581     case 1: var = get_byte(pb); rsize++; break; \
 582     default: var = defval; break; \
 583     }
 584
 585 int ff_asf_get_packet(AVFormatContext *s, ByteIOContext *pb)
 586 {
 587     ASFContext *asf = s->priv_data;
 588     uint32_t packet_length, padsize;
 589     int rsize = 8;
 590     int c, d, e, off;
 591
 592     off= (url_ftell(pb) - s->data_offset) % asf->packet_size + 3;
 593
 594     c=d=e=-1;
 595     while(off-- > 0){
 596         c=d; d=e;
 597         e= get_byte(pb);
 598         if(c == 0x82 && !d && !e)
 599             break;
 600     }
 601
 602     if (c != 0x82) {
 603         if (!url_feof(pb))
 604             av_log(s, AV_LOG_ERROR, "ff asf bad header %x  at:%"PRId64"\n", c, url_ftell(pb));
 605     }
 606     if ((c & 0x8f) == 0x82) {
 607         if (d || e) {
 608             if (!url_feof(pb))
 609                 av_log(s, AV_LOG_ERROR, "ff asf bad non zero\n");
 610             return -1;
 611         }
 612         c= get_byte(pb);
 613         d= get_byte(pb);
 614         rsize+=3;
 615     }else{
 616         url_fseek(pb, -1, SEEK_CUR); //FIXME
 617     }
 618
 619     asf->packet_flags    = c;
 620     asf->packet_property = d;
 621
 622     DO_2BITS(asf->packet_flags >> 5, packet_length, asf->packet_size);
 623     DO_2BITS(asf->packet_flags >> 1, padsize, 0); // sequence ignored
 624     DO_2BITS(asf->packet_flags >> 3, padsize, 0); // padding length
 625
 626     //the following checks prevent overflows and infinite loops
 627     if(packet_length >= (1U<<29)){
 628         av_log(s, AV_LOG_ERROR, "invalid packet_length %d at:%"PRId64"\n", packet_length, url_ftell(pb));
 629         return -1;
 630     }
 631     if(padsize >= packet_length){
 632         av_log(s, AV_LOG_ERROR, "invalid padsize %d at:%"PRId64"\n", padsize, url_ftell(pb));
 633         return -1;
 634     }
 635
 636     asf->packet_timestamp = get_le32(pb);
 637     get_le16(pb); /* duration */
 638     // rsize has at least 11 bytes which have to be present
 639
 640     if (asf->packet_flags & 0x01) {
 641         asf->packet_segsizetype = get_byte(pb); rsize++;
 642         asf->packet_segments = asf->packet_segsizetype & 0x3f;
 643     } else {
 644         asf->packet_segments = 1;
 645         asf->packet_segsizetype = 0x80;
 646     }
 647     asf->packet_size_left = packet_length - padsize - rsize;
 648     if (packet_length < asf->hdr.min_pktsize)
 649         padsize += asf->hdr.min_pktsize - packet_length;
 650     asf->packet_padsize = padsize;
 651     dprintf(s, "packet: size=%d padsize=%d  left=%d\n", asf->packet_size, asf->packet_padsize, asf->packet_size_left);
 652     return 0;
 653 }
 654
 655 /**
 656  *
 657  * @return <0 if error
 658  */
 659 static int asf_read_frame_header(AVFormatContext *s, ByteIOContext *pb){
 660     ASFContext *asf = s->priv_data;
 661     int rsize = 1;
 662     int num = get_byte(pb);
 663     int64_t ts0, ts1;
 664
 665     asf->packet_segments--;
 666     asf->packet_key_frame = num >> 7;
 667     asf->stream_index = asf->asfid2avid[num & 0x7f];
 668     // sequence should be ignored!
 669     DO_2BITS(asf->packet_property >> 4, asf->packet_seq, 0);
 670     DO_2BITS(asf->packet_property >> 2, asf->packet_frag_offset, 0);
 671     DO_2BITS(asf->packet_property, asf->packet_replic_size, 0);
 672 //printf("key:%d stream:%d seq:%d offset:%d replic_size:%d\n", asf->packet_key_frame, asf->stream_index, asf->packet_seq, //asf->packet_frag_offset, asf->packet_replic_size);
 673     if (asf->packet_replic_size >= 8) {
 674         asf->packet_obj_size = get_le32(pb);
 675         if(asf->packet_obj_size >= (1<<24) || asf->packet_obj_size <= 0){
 676             av_log(s, AV_LOG_ERROR, "packet_obj_size invalid\n");
 677             return -1;
 678         }
 679         asf->packet_frag_timestamp = get_le32(pb); // timestamp
 680         if(asf->packet_replic_size >= 8+38+4){
 681 //            for(i=0; i<asf->packet_replic_size-8; i++)
 682 //                av_log(s, AV_LOG_DEBUG, "%02X ",get_byte(pb));
 683 //            av_log(s, AV_LOG_DEBUG, "\n");
 684             url_fskip(pb, 10);
 685             ts0= get_le64(pb);
 686             ts1= get_le64(pb);
 687             url_fskip(pb, 12);
 688             get_le32(pb);
 689             url_fskip(pb, asf->packet_replic_size - 8 - 38 - 4);
 690             if(ts0!= -1) asf->packet_frag_timestamp= ts0/10000;
 691             else         asf->packet_frag_timestamp= AV_NOPTS_VALUE;
 692         }else
 693             url_fskip(pb, asf->packet_replic_size - 8);
 694         rsize += asf->packet_replic_size; // FIXME - check validity
 695     } else if (asf->packet_replic_size==1){
 696         // multipacket - frag_offset is beginning timestamp
 697         asf->packet_time_start = asf->packet_frag_offset;
 698         asf->packet_frag_offset = 0;
 699         asf->packet_frag_timestamp = asf->packet_timestamp;
 700
 701         asf->packet_time_delta = get_byte(pb);
 702         rsize++;
 703     }else if(asf->packet_replic_size!=0){
 704         av_log(s, AV_LOG_ERROR, "unexpected packet_replic_size of %d\n", asf->packet_replic_size);
 705         return -1;
 706     }
 707     if (asf->packet_flags & 0x01) {
 708         DO_2BITS(asf->packet_segsizetype >> 6, asf->packet_frag_size, 0); // 0 is illegal
 709         if(asf->packet_frag_size > asf->packet_size_left - rsize){
 710             av_log(s, AV_LOG_ERROR, "packet_frag_size is invalid\n");
 711             return -1;
 712         }
 713         //printf("Fragsize %d\n", asf->packet_frag_size);
 714     } else {
 715         asf->packet_frag_size = asf->packet_size_left - rsize;
 716         //printf("Using rest  %d %d %d\n", asf->packet_frag_size, asf->packet_size_left, rsize);
 717     }
 718     if (asf->packet_replic_size == 1) {
 719         asf->packet_multi_size = asf->packet_frag_size;
 720         if (asf->packet_multi_size > asf->packet_size_left)
 721             return -1;
 722     }
 723     asf->packet_size_left -= rsize;
 724     //printf("___objsize____  %d   %d    rs:%d\n", asf->packet_obj_size, asf->packet_frag_offset, rsize);
 725
 726     return 0;
 727 }
 728
 729 int ff_asf_parse_packet(AVFormatContext *s, ByteIOContext *pb, AVPacket *pkt)
 730 {
 731     ASFContext *asf = s->priv_data;
 732     ASFStream *asf_st = 0;
 733     for (;;) {
 734         if(url_feof(pb))
 735             return AVERROR_EOF;
 736         if (asf->packet_size_left < FRAME_HEADER_SIZE
 737             || asf->packet_segments < 1) {
 738             //asf->packet_size_left <= asf->packet_padsize) {
 739             int ret = asf->packet_size_left + asf->packet_padsize;
 740             //printf("PacketLeftSize:%d  Pad:%d Pos:%"PRId64"\n", asf->packet_size_left, asf->packet_padsize, url_ftell(pb));
 741             assert(ret>=0);
 742             /* fail safe */
 743             url_fskip(pb, ret);
 744
 745             asf->packet_pos= url_ftell(pb);
 746             if (asf->data_object_size != (uint64_t)-1 &&
 747                 (asf->packet_pos - asf->data_object_offset >= asf->data_object_size))
 748                 return AVERROR_EOF; /* Do not exceed the size of the data object */
 749             return 1;
 750         }
 751         if (asf->packet_time_start == 0) {
 752             if(asf_read_frame_header(s, pb) < 0){
 753                 asf->packet_segments= 0;
 754                 continue;
 755             }
 756             if (asf->stream_index < 0
 757                 || s->streams[asf->stream_index]->discard >= AVDISCARD_ALL
 758                 || (!asf->packet_key_frame && s->streams[asf->stream_index]->discard >= AVDISCARD_NONKEY)
 759                 ) {
 760                 asf->packet_time_start = 0;
 761                 /* unhandled packet (should not happen) */
 762                 url_fskip(pb, asf->packet_frag_size);
 763                 asf->packet_size_left -= asf->packet_frag_size;
 764                 if(asf->stream_index < 0)
 765                     av_log(s, AV_LOG_ERROR, "ff asf skip %d (unknown stream)\n", asf->packet_frag_size);
 766                 continue;
 767             }
 768             asf->asf_st = s->streams[asf->stream_index]->priv_data;
 769         }
 770         asf_st = asf->asf_st;
 771
 772         if (asf->packet_replic_size == 1) {
 773             // frag_offset is here used as the beginning timestamp
 774             asf->packet_frag_timestamp = asf->packet_time_start;
 775             asf->packet_time_start += asf->packet_time_delta;
 776             asf->packet_obj_size = asf->packet_frag_size = get_byte(pb);
 777             asf->packet_size_left--;
 778             asf->packet_multi_size--;
 779             if (asf->packet_multi_size < asf->packet_obj_size)
 780             {
 781                 asf->packet_time_start = 0;
 782                 url_fskip(pb, asf->packet_multi_size);
 783                 asf->packet_size_left -= asf->packet_multi_size;
 784                 continue;
 785             }
 786             asf->packet_multi_size -= asf->packet_obj_size;
 787             //printf("COMPRESS size  %d  %d  %d   ms:%d\n", asf->packet_obj_size, asf->packet_frag_timestamp, asf->packet_size_left, asf->packet_multi_size);
 788         }
 789         if(   /*asf->packet_frag_size == asf->packet_obj_size*/
 790               asf_st->frag_offset + asf->packet_frag_size <= asf_st->pkt.size
 791            && asf_st->frag_offset + asf->packet_frag_size > asf->packet_obj_size){
 792             av_log(s, AV_LOG_INFO, "ignoring invalid packet_obj_size (%d %d %d %d)\n",
 793                 asf_st->frag_offset, asf->packet_frag_size,
 794                 asf->packet_obj_size, asf_st->pkt.size);
 795             asf->packet_obj_size= asf_st->pkt.size;
 796         }
 797
 798         if (   asf_st->pkt.size != asf->packet_obj_size
 799             || asf_st->frag_offset + asf->packet_frag_size > asf_st->pkt.size) { //FIXME is this condition sufficient?
 800             if(asf_st->pkt.data){
 801                 av_log(s, AV_LOG_INFO, "freeing incomplete packet size %d, new %d\n", asf_st->pkt.size, asf->packet_obj_size);
 802                 asf_st->frag_offset = 0;
 803                 av_free_packet(&asf_st->pkt);
 804             }
 805             /* new packet */
 806             av_new_packet(&asf_st->pkt, asf->packet_obj_size);
 807             asf_st->seq = asf->packet_seq;
 808             asf_st->pkt.dts = asf->packet_frag_timestamp;
 809             asf_st->pkt.stream_index = asf->stream_index;
 810             asf_st->pkt.pos =
 811             asf_st->packet_pos= asf->packet_pos;
 812 //printf("new packet: stream:%d key:%d packet_key:%d audio:%d size:%d\n",
 813 //asf->stream_index, asf->packet_key_frame, asf_st->pkt.flags & PKT_FLAG_KEY,
 814 //s->streams[asf->stream_index]->codec->codec_type == CODEC_TYPE_AUDIO, asf->packet_obj_size);
 815             if (s->streams[asf->stream_index]->codec->codec_type == CODEC_TYPE_AUDIO)
 816                 asf->packet_key_frame = 1;
 817             if (asf->packet_key_frame)
 818                 asf_st->pkt.flags |= PKT_FLAG_KEY;
 819         }
 820
 821         /* read data */
 822         //printf("READ PACKET s:%d  os:%d  o:%d,%d  l:%d   DATA:%p\n",
 823         //       asf->packet_size, asf_st->pkt.size, asf->packet_frag_offset,
 824         //       asf_st->frag_offset, asf->packet_frag_size, asf_st->pkt.data);
 825         asf->packet_size_left -= asf->packet_frag_size;
 826         if (asf->packet_size_left < 0)
 827             continue;
 828
 829         if(   asf->packet_frag_offset >= asf_st->pkt.size
 830            || asf->packet_frag_size > asf_st->pkt.size - asf->packet_frag_offset){
 831             av_log(s, AV_LOG_ERROR, "packet fragment position invalid %u,%u not in %u\n",
 832                 asf->packet_frag_offset, asf->packet_frag_size, asf_st->pkt.size);
 833             continue;
 834         }
 835
 836         get_buffer(pb, asf_st->pkt.data + asf->packet_frag_offset,
 837                    asf->packet_frag_size);
 838         if (s->key && s->keylen == 20)
 839             ff_asfcrypt_dec(s->key, asf_st->pkt.data + asf->packet_frag_offset,
 840                             asf->packet_frag_size);
 841         asf_st->frag_offset += asf->packet_frag_size;
 842         /* test if whole packet is read */
 843         if (asf_st->frag_offset == asf_st->pkt.size) {
 844             //workaround for macroshit radio DVR-MS files
 845             if(   s->streams[asf->stream_index]->codec->codec_id == CODEC_ID_MPEG2VIDEO
 846                && asf_st->pkt.size > 100){
 847                 int i;
 848                 for(i=0; i<asf_st->pkt.size && !asf_st->pkt.data[i]; i++);
 849                 if(i == asf_st->pkt.size){
 850                     av_log(s, AV_LOG_DEBUG, "discarding ms fart\n");
 851                     asf_st->frag_offset = 0;
 852                     av_free_packet(&asf_st->pkt);
 853                     continue;
 854                 }
 855             }
 856
 857             /* return packet */
 858             if (asf_st->ds_span > 1) {
 859               if(asf_st->pkt.size != asf_st->ds_packet_size * asf_st->ds_span){
 860                     av_log(s, AV_LOG_ERROR, "pkt.size != ds_packet_size * ds_span (%d %d %d)\n", asf_st->pkt.size, asf_st->ds_packet_size, asf_st->ds_span);
 861               }else{
 862                 /* packet descrambling */
 863                 uint8_t *newdata = av_malloc(asf_st->pkt.size);
 864                 if (newdata) {
 865                     int offset = 0;
 866                     while (offset < asf_st->pkt.size) {
 867                         int off = offset / asf_st->ds_chunk_size;
 868                         int row = off / asf_st->ds_span;
 869                         int col = off % asf_st->ds_span;
 870                         int idx = row + col * asf_st->ds_packet_size / asf_st->ds_chunk_size;
 871                         //printf("off:%d  row:%d  col:%d  idx:%d\n", off, row, col, idx);
 872
 873                         assert(offset + asf_st->ds_chunk_size <= asf_st->pkt.size);
 874                         assert(idx+1 <= asf_st->pkt.size / asf_st->ds_chunk_size);
 875                         memcpy(newdata + offset,
 876                                asf_st->pkt.data + idx * asf_st->ds_chunk_size,
 877                                asf_st->ds_chunk_size);
 878                         offset += asf_st->ds_chunk_size;
 879                     }
 880                     av_free(asf_st->pkt.data);
 881                     asf_st->pkt.data = newdata;
 882                 }
 883               }
 884             }
 885             asf_st->frag_offset = 0;
 886             *pkt= asf_st->pkt;
 887             //printf("packet %d %d\n", asf_st->pkt.size, asf->packet_frag_size);
 888             asf_st->pkt.size = 0;
 889             asf_st->pkt.data = 0;
 890             break; // packet completed
 891         }
 892     }
 893     return 0;
 894 }
 895
 896 static int asf_read_packet(AVFormatContext *s, AVPacket *pkt)
 897 {
 898     ASFContext *asf = s->priv_data;
 899
 900     for (;;) {
 901         int ret;
 902
 903         /* parse cached packets, if any */
 904         if ((ret = ff_asf_parse_packet(s, s->pb, pkt)) <= 0)
 905             return ret;
 906         if ((ret = ff_asf_get_packet(s, s->pb)) < 0)
 907             assert(asf->packet_size_left < FRAME_HEADER_SIZE || asf->packet_segments < 1);
 908         asf->packet_time_start = 0;
 909     }
 910
 911     return 0;
 912 }
 913
 914 // Added to support seeking after packets have been read
 915 // If information is not reset, read_packet fails due to
 916 // leftover information from previous reads
 917 static void asf_reset_header(AVFormatContext *s)
 918 {
 919     ASFContext *asf = s->priv_data;
 920     ASFStream *asf_st;
 921     int i;
 922
 923     asf->packet_nb_frames = 0;
 924     asf->packet_size_left = 0;
 925     asf->packet_segments = 0;
 926     asf->packet_flags = 0;
 927     asf->packet_property = 0;
 928     asf->packet_timestamp = 0;
 929     asf->packet_segsizetype = 0;
 930     asf->packet_segments = 0;
 931     asf->packet_seq = 0;
 932     asf->packet_replic_size = 0;
 933     asf->packet_key_frame = 0;
 934     asf->packet_padsize = 0;
 935     asf->packet_frag_offset = 0;
 936     asf->packet_frag_size = 0;
 937     asf->packet_frag_timestamp = 0;
 938     asf->packet_multi_size = 0;
 939     asf->packet_obj_size = 0;
 940     asf->packet_time_delta = 0;
 941     asf->packet_time_start = 0;
 942
 943     for(i=0; i<s->nb_streams; i++){
 944         asf_st= s->streams[i]->priv_data;
 945         av_free_packet(&asf_st->pkt);
 946         asf_st->frag_offset=0;
 947         asf_st->seq=0;
 948     }
 949     asf->asf_st= NULL;
 950 }
 951
 952 static int asf_read_close(AVFormatContext *s)
 953 {
 954     int i;
 955
 956     asf_reset_header(s);
 957     for(i=0;i<s->nb_streams;i++) {
 958         AVStream *st = s->streams[i];
 959         av_free(st->codec->palctrl);
 960     }
 961     return 0;
 962 }
 963
 964 static int64_t asf_read_pts(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit)
 965 {
 966     ASFContext *asf = s->priv_data;
 967     AVPacket pkt1, *pkt = &pkt1;
 968     ASFStream *asf_st;
 969     int64_t pts;
 970     int64_t pos= *ppos;
 971     int i;
 972     int64_t start_pos[s->nb_streams];
 973
 974     for(i=0; i<s->nb_streams; i++){
 975         start_pos[i]= pos;
 976     }
 977
 978     pos= (pos+asf->packet_size-1-s->data_offset)/asf->packet_size*asf->packet_size+ s->data_offset;
 979     *ppos= pos;
 980     url_fseek(s->pb, pos, SEEK_SET);
 981
 982 //printf("asf_read_pts\n");
 983     asf_reset_header(s);
 984     for(;;){
 985         if (av_read_frame(s, pkt) < 0){
 986             av_log(s, AV_LOG_INFO, "asf_read_pts failed\n");
 987             return AV_NOPTS_VALUE;
 988         }
 989
 990         pts= pkt->pts;
 991
 992         av_free_packet(pkt);
 993         if(pkt->flags&PKT_FLAG_KEY){
 994             i= pkt->stream_index;
 995
 996             asf_st= s->streams[i]->priv_data;
 997
 998 //            assert((asf_st->packet_pos - s->data_offset) % asf->packet_size == 0);
 999             pos= asf_st->packet_pos;
1000
1001             av_add_index_entry(s->streams[i], pos, pts, pkt->size, pos - start_pos[i] + 1, AVINDEX_KEYFRAME);
1002             start_pos[i]= asf_st->packet_pos + 1;
1003
1004             if(pkt->stream_index == stream_index)
1005                break;
1006         }
1007     }
1008
1009     *ppos= pos;
1010 //printf("found keyframe at %"PRId64" stream %d stamp:%"PRId64"\n", *ppos, stream_index, pts);
1011
1012     return pts;
1013 }
1014
1015 static void asf_build_simple_index(AVFormatContext *s, int stream_index)
1016 {
1017     ff_asf_guid g;
1018     ASFContext *asf = s->priv_data;
1019     int64_t current_pos= url_ftell(s->pb);
1020     int i;
1021
1022     url_fseek(s->pb, asf->data_object_offset + asf->data_object_size, SEEK_SET);
1023     get_guid(s->pb, &g);
1024     if (!guidcmp(&g, &index_guid)) {
1025         int64_t itime;
1026         int pct, ict;
1027         int64_t av_unused gsize= get_le64(s->pb);
1028         get_guid(s->pb, &g);
1029         itime=get_le64(s->pb);
1030         pct=get_le32(s->pb);
1031         ict=get_le32(s->pb);
1032         av_log(s, AV_LOG_DEBUG, "itime:0x%"PRIx64", pct:%d, ict:%d\n",itime,pct,ict);
1033
1034         for (i=0;i<ict;i++){
1035             int pktnum=get_le32(s->pb);
1036             int pktct =get_le16(s->pb);
1037             int64_t pos      = s->data_offset + asf->packet_size*(int64_t)pktnum;
1038             int64_t index_pts= av_rescale(itime, i, 10000);
1039
1040             av_log(s, AV_LOG_DEBUG, "pktnum:%d, pktct:%d\n", pktnum, pktct);
1041             av_add_index_entry(s->streams[stream_index], pos, index_pts, asf->packet_size, 0, AVINDEX_KEYFRAME);
1042         }
1043         asf->index_read= 1;
1044     }
1045     url_fseek(s->pb, current_pos, SEEK_SET);
1046 }
1047
1048 static int asf_read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags)
1049 {
1050     ASFContext *asf = s->priv_data;
1051     AVStream *st = s->streams[stream_index];
1052     int64_t pos;
1053     int index;
1054
1055     if (asf->packet_size <= 0)
1056         return -1;
1057
1058     /* Try using the protocol's read_seek if available */
1059     if(s->pb) {
1060         int ret = av_url_read_fseek(s->pb, stream_index, pts, flags);
1061         if(ret >= 0)
1062             asf_reset_header(s);
1063         if (ret != AVERROR(ENOSYS))
1064             return ret;
1065     }
1066
1067     if (!asf->index_read)
1068         asf_build_simple_index(s, stream_index);
1069
1070     if(!(asf->index_read && st->index_entries)){
1071         if(av_seek_frame_binary(s, stream_index, pts, flags)<0)
1072             return -1;
1073     }else{
1074         index= av_index_search_timestamp(st, pts, flags);
1075         if(index<0)
1076             return -1;
1077
1078         /* find the position */
1079         pos = st->index_entries[index].pos;
1080
1081     // various attempts to find key frame have failed so far
1082     //    asf_reset_header(s);
1083     //    url_fseek(s->pb, pos, SEEK_SET);
1084     //    key_pos = pos;
1085     //     for(i=0;i<16;i++){
1086     //         pos = url_ftell(s->pb);
1087     //         if (av_read_frame(s, &pkt) < 0){
1088     //             av_log(s, AV_LOG_INFO, "seek failed\n");
1089     //             return -1;
1090     //         }
1091     //         asf_st = s->streams[stream_index]->priv_data;
1092     //         pos += st->parser->frame_offset;
1093     //
1094     //         if (pkt.size > b) {
1095     //             b = pkt.size;
1096     //             key_pos = pos;
1097     //         }
1098     //
1099     //         av_free_packet(&pkt);
1100     //     }
1101
1102         /* do the seek */
1103         av_log(s, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos);
1104         url_fseek(s->pb, pos, SEEK_SET);
1105     }
1106     asf_reset_header(s);
1107     return 0;
1108 }
1109
1110 AVInputFormat asf_demuxer = {
1111     "asf",
1112     NULL_IF_CONFIG_SMALL("ASF format"),
1113     sizeof(ASFContext),
1114     asf_probe,
1115     asf_read_header,
1116     asf_read_packet,
1117     asf_read_close,
1118     asf_read_seek,
1119     asf_read_pts,
1120     .metadata_conv = ff_asf_metadata_conv,
1121 };