Maybe fix gcc 2.95
[ffmpeg.git] / 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     while (len > 1) {
126         uint8_t tmp;
127         uint32_t ch;
128
129         GET_UTF16(ch, (len -= 2) >= 0 ? get_le16(pb) : 0, break;)
130         PUT_UTF8(ch, tmp, if (q - buf < buf_size - 1) *q++ = tmp;)
131     }
132     if (len > 0)
133         url_fskip(pb, len);
134     *q = '\0';
135 }
136
137 static int asf_probe(AVProbeData *pd)
138 {
139     /* check file header */
140     if (!guidcmp(pd->buf, &ff_asf_header))
141         return AVPROBE_SCORE_MAX;
142     else
143         return 0;
144 }
145
146 static int get_value(ByteIOContext *pb, int type){
147     switch(type){
148         case 2: return get_le32(pb);
149         case 3: return get_le32(pb);
150         case 4: return get_le64(pb);
151         case 5: return get_le16(pb);
152         default:return INT_MIN;
153     }
154 }
155
156 static void get_tag(AVFormatContext *s, const char *key, int type, int len)
157 {
158     char *value;
159
160     if ((unsigned)len >= (UINT_MAX - 1)/2)
161         return;
162
163     value = av_malloc(2*len+1);
164     if (!value)
165         return;
166
167     if (type == 0) {         // UTF16-LE
168         get_str16_nolen(s->pb, len, value, 2*len + 1);
169     } else if (type > 1 && type <= 5) {  // boolean or DWORD or QWORD or WORD
170         uint64_t num = get_value(s->pb, type);
171         snprintf(value, len, "%"PRIu64, num);
172     } else {
173         url_fskip(s->pb, len);
174         av_freep(&value);
175         av_log(s, AV_LOG_DEBUG, "Unsupported value type %d in tag %s.\n", type, key);
176         return;
177     }
178     av_metadata_set2(&s->metadata, key, value, 0);
179     av_freep(&value);
180 }
181
182 static int asf_read_header(AVFormatContext *s, AVFormatParameters *ap)
183 {
184     ASFContext *asf = s->priv_data;
185     ff_asf_guid g;
186     ByteIOContext *pb = s->pb;
187     AVStream *st;
188     ASFStream *asf_st;
189     int size, i;
190     int64_t gsize;
191     AVRational dar[128];
192     uint32_t bitrate[128];
193
194     memset(dar, 0, sizeof(dar));
195     memset(bitrate, 0, sizeof(bitrate));
196
197     get_guid(pb, &g);
198     if (guidcmp(&g, &ff_asf_header))
199         return -1;
200     get_le64(pb);
201     get_le32(pb);
202     get_byte(pb);
203     get_byte(pb);
204     memset(&asf->asfid2avid, -1, sizeof(asf->asfid2avid));
205     for(;;) {
206         get_guid(pb, &g);
207         gsize = get_le64(pb);
208         dprintf(s, "%08"PRIx64": ", url_ftell(pb) - 24);
209         print_guid(&g);
210         dprintf(s, "  size=0x%"PRIx64"\n", gsize);
211         if (!guidcmp(&g, &ff_asf_data_header)) {
212             asf->data_object_offset = url_ftell(pb);
213             // if not streaming, gsize is not unlimited (how?), and there is enough space in the file..
214             if (!(asf->hdr.flags & 0x01) && gsize >= 100) {
215                 asf->data_object_size = gsize - 24;
216             } else {
217                 asf->data_object_size = (uint64_t)-1;
218             }
219             break;
220         }
221         if (gsize < 24)
222             return -1;
223         if (!guidcmp(&g, &ff_asf_file_header)) {
224             get_guid(pb, &asf->hdr.guid);
225             asf->hdr.file_size          = get_le64(pb);
226             asf->hdr.create_time        = get_le64(pb);
227             asf->nb_packets             = get_le64(pb);
228             asf->hdr.play_time          = get_le64(pb);
229             asf->hdr.send_time          = get_le64(pb);
230             asf->hdr.preroll            = get_le32(pb);
231             asf->hdr.ignore             = get_le32(pb);
232             asf->hdr.flags              = get_le32(pb);
233             asf->hdr.min_pktsize        = get_le32(pb);
234             asf->hdr.max_pktsize        = get_le32(pb);
235             asf->hdr.max_bitrate        = get_le32(pb);
236             s->packet_size = asf->hdr.max_pktsize;
237         } else if (!guidcmp(&g, &ff_asf_stream_header)) {
238             enum CodecType type;
239             int type_specific_size, sizeX;
240             uint64_t total_size;
241             unsigned int tag1;
242             int64_t pos1, pos2, start_time;
243             int test_for_ext_stream_audio, is_dvr_ms_audio=0;
244
245             pos1 = url_ftell(pb);
246
247             st = av_new_stream(s, 0);
248             if (!st)
249                 return AVERROR(ENOMEM);
250             av_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */
251             asf_st = av_mallocz(sizeof(ASFStream));
252             if (!asf_st)
253                 return AVERROR(ENOMEM);
254             st->priv_data = asf_st;
255             start_time = asf->hdr.preroll;
256
257             asf_st->stream_language_index = 128; // invalid stream index means no language info
258
259             if(!(asf->hdr.flags & 0x01)) { // if we aren't streaming...
260                 st->duration = asf->hdr.play_time /
261                     (10000000 / 1000) - start_time;
262             }
263             get_guid(pb, &g);
264
265             test_for_ext_stream_audio = 0;
266             if (!guidcmp(&g, &ff_asf_audio_stream)) {
267                 type = CODEC_TYPE_AUDIO;
268             } else if (!guidcmp(&g, &ff_asf_video_stream)) {
269                 type = CODEC_TYPE_VIDEO;
270             } else if (!guidcmp(&g, &ff_asf_command_stream)) {
271                 type = CODEC_TYPE_DATA;
272             } else if (!guidcmp(&g, &ff_asf_ext_stream_embed_stream_header)) {
273                 test_for_ext_stream_audio = 1;
274                 type = CODEC_TYPE_UNKNOWN;
275             } else {
276                 return -1;
277             }
278             get_guid(pb, &g);
279             total_size = get_le64(pb);
280             type_specific_size = get_le32(pb);
281             get_le32(pb);
282             st->id = get_le16(pb) & 0x7f; /* stream id */
283             // mapping of asf ID to AV stream ID;
284             asf->asfid2avid[st->id] = s->nb_streams - 1;
285
286             get_le32(pb);
287
288             if (test_for_ext_stream_audio) {
289                 get_guid(pb, &g);
290                 if (!guidcmp(&g, &ff_asf_ext_stream_audio_stream)) {
291                     type = CODEC_TYPE_AUDIO;
292                     is_dvr_ms_audio=1;
293                     get_guid(pb, &g);
294                     get_le32(pb);
295                     get_le32(pb);
296                     get_le32(pb);
297                     get_guid(pb, &g);
298                     get_le32(pb);
299                 }
300             }
301
302             st->codec->codec_type = type;
303             if (type == CODEC_TYPE_AUDIO) {
304                 ff_get_wav_header(pb, st->codec, type_specific_size);
305                 if (is_dvr_ms_audio) {
306                     // codec_id and codec_tag are unreliable in dvr_ms
307                     // files. Set them later by probing stream.
308                     st->codec->codec_id = CODEC_ID_PROBE;
309                     st->codec->codec_tag = 0;
310                 }
311                 if (st->codec->codec_id == CODEC_ID_AAC) {
312                     st->need_parsing = AVSTREAM_PARSE_NONE;
313                 } else {
314                     st->need_parsing = AVSTREAM_PARSE_FULL;
315                 }
316                 /* We have to init the frame size at some point .... */
317                 pos2 = url_ftell(pb);
318                 if (gsize >= (pos2 + 8 - pos1 + 24)) {
319                     asf_st->ds_span = get_byte(pb);
320                     asf_st->ds_packet_size = get_le16(pb);
321                     asf_st->ds_chunk_size = get_le16(pb);
322                     get_le16(pb); //ds_data_size
323                     get_byte(pb); //ds_silence_data
324                 }
325                 //printf("Descrambling: ps:%d cs:%d ds:%d s:%d  sd:%d\n",
326                 //       asf_st->ds_packet_size, asf_st->ds_chunk_size,
327                 //       asf_st->ds_data_size, asf_st->ds_span, asf_st->ds_silence_data);
328                 if (asf_st->ds_span > 1) {
329                     if (!asf_st->ds_chunk_size
330                         || (asf_st->ds_packet_size/asf_st->ds_chunk_size <= 1)
331                         || asf_st->ds_packet_size % asf_st->ds_chunk_size)
332                         asf_st->ds_span = 0; // disable descrambling
333                 }
334                 switch (st->codec->codec_id) {
335                 case CODEC_ID_MP3:
336                     st->codec->frame_size = MPA_FRAME_SIZE;
337                     break;
338                 case CODEC_ID_PCM_S16LE:
339                 case CODEC_ID_PCM_S16BE:
340                 case CODEC_ID_PCM_U16LE:
341                 case CODEC_ID_PCM_U16BE:
342                 case CODEC_ID_PCM_S8:
343                 case CODEC_ID_PCM_U8:
344                 case CODEC_ID_PCM_ALAW:
345                 case CODEC_ID_PCM_MULAW:
346                     st->codec->frame_size = 1;
347                     break;
348                 default:
349                     /* This is probably wrong, but it prevents a crash later */
350                     st->codec->frame_size = 1;
351                     break;
352                 }
353             } else if (type == CODEC_TYPE_VIDEO) {
354                 get_le32(pb);
355                 get_le32(pb);
356                 get_byte(pb);
357                 size = get_le16(pb); /* size */
358                 sizeX= get_le32(pb); /* size */
359                 st->codec->width = get_le32(pb);
360                 st->codec->height = get_le32(pb);
361                 /* not available for asf */
362                 get_le16(pb); /* panes */
363                 st->codec->bits_per_coded_sample = get_le16(pb); /* depth */
364                 tag1 = get_le32(pb);
365                 url_fskip(pb, 20);
366 //                av_log(s, AV_LOG_DEBUG, "size:%d tsize:%d sizeX:%d\n", size, total_size, sizeX);
367                 size= sizeX;
368                 if (size > 40) {
369                     st->codec->extradata_size = size - 40;
370                     st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
371                     get_buffer(pb, st->codec->extradata, st->codec->extradata_size);
372                 }
373
374                 /* Extract palette from extradata if bpp <= 8 */
375                 /* This code assumes that extradata contains only palette */
376                 /* This is true for all paletted codecs implemented in ffmpeg */
377                 if (st->codec->extradata_size && (st->codec->bits_per_coded_sample <= 8)) {
378                     st->codec->palctrl = av_mallocz(sizeof(AVPaletteControl));
379 #if HAVE_BIGENDIAN
380                     for (i = 0; i < FFMIN(st->codec->extradata_size, AVPALETTE_SIZE)/4; i++)
381                         st->codec->palctrl->palette[i] = bswap_32(((uint32_t*)st->codec->extradata)[i]);
382 #else
383                     memcpy(st->codec->palctrl->palette, st->codec->extradata,
384                            FFMIN(st->codec->extradata_size, AVPALETTE_SIZE));
385 #endif
386                     st->codec->palctrl->palette_changed = 1;
387                 }
388
389                 st->codec->codec_tag = tag1;
390                 st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, tag1);
391                 if(tag1 == MKTAG('D', 'V', 'R', ' '))
392                     st->need_parsing = AVSTREAM_PARSE_FULL;
393             }
394             pos2 = url_ftell(pb);
395             url_fskip(pb, gsize - (pos2 - pos1 + 24));
396         } else if (!guidcmp(&g, &ff_asf_comment_header)) {
397             int len1, len2, len3, len4, len5;
398
399             len1 = get_le16(pb);
400             len2 = get_le16(pb);
401             len3 = get_le16(pb);
402             len4 = get_le16(pb);
403             len5 = get_le16(pb);
404             get_tag(s, "title"    , 0, len1);
405             get_tag(s, "author"   , 0, len2);
406             get_tag(s, "copyright", 0, len3);
407             get_tag(s, "comment"  , 0, len4);
408             url_fskip(pb, len5);
409         } else if (!guidcmp(&g, &stream_bitrate_guid)) {
410             int stream_count = get_le16(pb);
411             int j;
412
413 //            av_log(s, AV_LOG_ERROR, "stream bitrate properties\n");
414 //            av_log(s, AV_LOG_ERROR, "streams %d\n", streams);
415             for(j = 0; j < stream_count; j++) {
416                 int flags, bitrate, stream_id;
417
418                 flags= get_le16(pb);
419                 bitrate= get_le32(pb);
420                 stream_id= (flags & 0x7f);
421 //                av_log(s, AV_LOG_ERROR, "flags: 0x%x stream id %d, bitrate %d\n", flags, stream_id, bitrate);
422                 asf->stream_bitrates[stream_id]= bitrate;
423             }
424         } else if (!guidcmp(&g, &ff_asf_language_guid)) {
425             int j;
426             int stream_count = get_le16(pb);
427             for(j = 0; j < stream_count; j++) {
428                 char lang[6];
429                 unsigned int lang_len = get_byte(pb);
430                 get_str16_nolen(pb, lang_len, lang, sizeof(lang));
431                 if (j < 128)
432                     av_strlcpy(asf->stream_languages[j], lang, sizeof(*asf->stream_languages));
433             }
434         } else if (!guidcmp(&g, &ff_asf_extended_content_header)) {
435             int desc_count, i;
436
437             desc_count = get_le16(pb);
438             for(i=0;i<desc_count;i++) {
439                     int name_len,value_type,value_len;
440                     char name[1024];
441
442                     name_len = get_le16(pb);
443                     if (name_len%2)     // must be even, broken lavf versions wrote len-1
444                         name_len += 1;
445                     get_str16_nolen(pb, name_len, name, sizeof(name));
446                     value_type = get_le16(pb);
447                     value_len  = get_le16(pb);
448                     if (!value_type && value_len%2)
449                         value_len += 1;
450                     get_tag(s, name, value_type, value_len);
451             }
452         } else if (!guidcmp(&g, &ff_asf_metadata_header)) {
453             int n, stream_num, name_len, value_len, value_type, value_num;
454             n = get_le16(pb);
455
456             for(i=0;i<n;i++) {
457                 char name[1024];
458
459                 get_le16(pb); //lang_list_index
460                 stream_num= get_le16(pb);
461                 name_len=   get_le16(pb);
462                 value_type= get_le16(pb);
463                 value_len=  get_le32(pb);
464
465                 get_str16_nolen(pb, name_len, name, sizeof(name));
466 //av_log(s, AV_LOG_ERROR, "%d %d %d %d %d <%s>\n", i, stream_num, name_len, value_type, value_len, name);
467                 value_num= get_le16(pb);//we should use get_value() here but it does not work 2 is le16 here but le32 elsewhere
468                 url_fskip(pb, value_len - 2);
469
470                 if(stream_num<128){
471                     if     (!strcmp(name, "AspectRatioX")) dar[stream_num].num= value_num;
472                     else if(!strcmp(name, "AspectRatioY")) dar[stream_num].den= value_num;
473                 }
474             }
475         } else if (!guidcmp(&g, &ff_asf_ext_stream_header)) {
476             int ext_len, payload_ext_ct, stream_ct;
477             uint32_t ext_d, leak_rate, stream_num;
478             unsigned int stream_languageid_index;
479
480             get_le64(pb); // starttime
481             get_le64(pb); // endtime
482             leak_rate = get_le32(pb); // leak-datarate
483             get_le32(pb); // bucket-datasize
484             get_le32(pb); // init-bucket-fullness
485             get_le32(pb); // alt-leak-datarate
486             get_le32(pb); // alt-bucket-datasize
487             get_le32(pb); // alt-init-bucket-fullness
488             get_le32(pb); // max-object-size
489             get_le32(pb); // flags (reliable,seekable,no_cleanpoints?,resend-live-cleanpoints, rest of bits reserved)
490             stream_num = get_le16(pb); // stream-num
491
492             stream_languageid_index = get_le16(pb); // stream-language-id-index
493             if (stream_num < 128)
494                 asf->streams[stream_num].stream_language_index = stream_languageid_index;
495
496             get_le64(pb); // avg frametime in 100ns units
497             stream_ct = get_le16(pb); //stream-name-count
498             payload_ext_ct = get_le16(pb); //payload-extension-system-count
499
500             if (stream_num < 128)
501                 bitrate[stream_num] = leak_rate;
502
503             for (i=0; i<stream_ct; i++){
504                 get_le16(pb);
505                 ext_len = get_le16(pb);
506                 url_fseek(pb, ext_len, SEEK_CUR);
507             }
508
509             for (i=0; i<payload_ext_ct; i++){
510                 get_guid(pb, &g);
511                 ext_d=get_le16(pb);
512                 ext_len=get_le32(pb);
513                 url_fseek(pb, ext_len, SEEK_CUR);
514             }
515
516             // there could be a optional stream properties object to follow
517             // if so the next iteration will pick it up
518         } else if (!guidcmp(&g, &ff_asf_head1_guid)) {
519             int v1, v2;
520             get_guid(pb, &g);
521             v1 = get_le32(pb);
522             v2 = get_le16(pb);
523 #if 0
524         } else if (!guidcmp(&g, &ff_asf_codec_comment_header)) {
525             int len, v1, n, num;
526             char str[256], *q;
527             char tag[16];
528
529             get_guid(pb, &g);
530             print_guid(&g);
531
532             n = get_le32(pb);
533             for(i=0;i<n;i++) {
534                 num = get_le16(pb); /* stream number */
535                 get_str16(pb, str, sizeof(str));
536                 get_str16(pb, str, sizeof(str));
537                 len = get_le16(pb);
538                 q = tag;
539                 while (len > 0) {
540                     v1 = get_byte(pb);
541                     if ((q - tag) < sizeof(tag) - 1)
542                         *q++ = v1;
543                     len--;
544                 }
545                 *q = '\0';
546             }
547 #endif
548         } else if (url_feof(pb)) {
549             return -1;
550         } else {
551             if (!s->keylen) {
552                 if (!guidcmp(&g, &ff_asf_content_encryption)) {
553                     av_log(s, AV_LOG_WARNING, "DRM protected stream detected, decoding will likely fail!\n");
554                 } else if (!guidcmp(&g, &ff_asf_ext_content_encryption)) {
555                     av_log(s, AV_LOG_WARNING, "Ext DRM protected stream detected, decoding will likely fail!\n");
556                 } else if (!guidcmp(&g, &ff_asf_digital_signature)) {
557                     av_log(s, AV_LOG_WARNING, "Digital signature detected, decoding will likely fail!\n");
558                 }
559             }
560             url_fseek(pb, gsize - 24, SEEK_CUR);
561         }
562     }
563     get_guid(pb, &g);
564     get_le64(pb);
565     get_byte(pb);
566     get_byte(pb);
567     if (url_feof(pb))
568         return -1;
569     asf->data_offset = url_ftell(pb);
570     asf->packet_size_left = 0;
571
572
573     for(i=0; i<128; i++){
574         int stream_num= asf->asfid2avid[i];
575         if(stream_num>=0){
576             AVStream *st = s->streams[stream_num];
577             if (!st->codec->bit_rate)
578                 st->codec->bit_rate = bitrate[i];
579             if (dar[i].num > 0 && dar[i].den > 0)
580                 av_reduce(&st->sample_aspect_ratio.num,
581                           &st->sample_aspect_ratio.den,
582                           dar[i].num, dar[i].den, INT_MAX);
583 //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);
584
585             // copy and convert language codes to the frontend
586             if (asf->streams[i].stream_language_index < 128) {
587                 const char *rfc1766 = asf->stream_languages[asf->streams[i].stream_language_index];
588                 if (rfc1766 && strlen(rfc1766) > 1) {
589                     const char primary_tag[3] = { rfc1766[0], rfc1766[1], '\0' }; // ignore country code if any
590                     const char *iso6392 = av_convert_lang_to(primary_tag, AV_LANG_ISO639_2_BIBL);
591                     if (iso6392)
592                         av_metadata_set(&st->metadata, "language", iso6392);
593                 }
594             }
595         }
596     }
597
598     return 0;
599 }
600
601 #define DO_2BITS(bits, var, defval) \
602     switch (bits & 3) \
603     { \
604     case 3: var = get_le32(pb); rsize += 4; break; \
605     case 2: var = get_le16(pb); rsize += 2; break; \
606     case 1: var = get_byte(pb); rsize++; break; \
607     default: var = defval; break; \
608     }
609
610 /**
611  * Load a single ASF packet into the demuxer.
612  * @param s demux context
613  * @param pb context to read data from
614  * @returns 0 on success, <0 on error
615  */
616 static int ff_asf_get_packet(AVFormatContext *s, ByteIOContext *pb)
617 {
618     ASFContext *asf = s->priv_data;
619     uint32_t packet_length, padsize;
620     int rsize = 8;
621     int c, d, e, off;
622
623     // if we do not know packet size, allow skipping up to 32 kB
624     off= 32768;
625     if (s->packet_size > 0)
626         off= (url_ftell(pb) - s->data_offset) % s->packet_size + 3;
627
628     c=d=e=-1;
629     while(off-- > 0){
630         c=d; d=e;
631         e= get_byte(pb);
632         if(c == 0x82 && !d && !e)
633             break;
634     }
635
636     if (c != 0x82) {
637         /**
638          * This code allows handling of -EAGAIN at packet boundaries (i.e.
639          * if the packet sync code above triggers -EAGAIN). This does not
640          * imply complete -EAGAIN handling support at random positions in
641          * the stream.
642          */
643         if (url_ferror(pb) == AVERROR(EAGAIN))
644             return AVERROR(EAGAIN);
645         if (!url_feof(pb))
646             av_log(s, AV_LOG_ERROR, "ff asf bad header %x  at:%"PRId64"\n", c, url_ftell(pb));
647     }
648     if ((c & 0x8f) == 0x82) {
649         if (d || e) {
650             if (!url_feof(pb))
651                 av_log(s, AV_LOG_ERROR, "ff asf bad non zero\n");
652             return -1;
653         }
654         c= get_byte(pb);
655         d= get_byte(pb);
656         rsize+=3;
657     }else{
658         url_fseek(pb, -1, SEEK_CUR); //FIXME
659     }
660
661     asf->packet_flags    = c;
662     asf->packet_property = d;
663
664     DO_2BITS(asf->packet_flags >> 5, packet_length, s->packet_size);
665     DO_2BITS(asf->packet_flags >> 1, padsize, 0); // sequence ignored
666     DO_2BITS(asf->packet_flags >> 3, padsize, 0); // padding length
667
668     //the following checks prevent overflows and infinite loops
669     if(!packet_length || packet_length >= (1U<<29)){
670         av_log(s, AV_LOG_ERROR, "invalid packet_length %d at:%"PRId64"\n", packet_length, url_ftell(pb));
671         return -1;
672     }
673     if(padsize >= packet_length){
674         av_log(s, AV_LOG_ERROR, "invalid padsize %d at:%"PRId64"\n", padsize, url_ftell(pb));
675         return -1;
676     }
677
678     asf->packet_timestamp = get_le32(pb);
679     get_le16(pb); /* duration */
680     // rsize has at least 11 bytes which have to be present
681
682     if (asf->packet_flags & 0x01) {
683         asf->packet_segsizetype = get_byte(pb); rsize++;
684         asf->packet_segments = asf->packet_segsizetype & 0x3f;
685     } else {
686         asf->packet_segments = 1;
687         asf->packet_segsizetype = 0x80;
688     }
689     asf->packet_size_left = packet_length - padsize - rsize;
690     if (packet_length < asf->hdr.min_pktsize)
691         padsize += asf->hdr.min_pktsize - packet_length;
692     asf->packet_padsize = padsize;
693     dprintf(s, "packet: size=%d padsize=%d  left=%d\n", s->packet_size, asf->packet_padsize, asf->packet_size_left);
694     return 0;
695 }
696
697 /**
698  *
699  * @return <0 if error
700  */
701 static int asf_read_frame_header(AVFormatContext *s, ByteIOContext *pb){
702     ASFContext *asf = s->priv_data;
703     int rsize = 1;
704     int num = get_byte(pb);
705     int64_t ts0, ts1;
706
707     asf->packet_segments--;
708     asf->packet_key_frame = num >> 7;
709     asf->stream_index = asf->asfid2avid[num & 0x7f];
710     // sequence should be ignored!
711     DO_2BITS(asf->packet_property >> 4, asf->packet_seq, 0);
712     DO_2BITS(asf->packet_property >> 2, asf->packet_frag_offset, 0);
713     DO_2BITS(asf->packet_property, asf->packet_replic_size, 0);
714 //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);
715     if (asf->packet_replic_size >= 8) {
716         asf->packet_obj_size = get_le32(pb);
717         if(asf->packet_obj_size >= (1<<24) || asf->packet_obj_size <= 0){
718             av_log(s, AV_LOG_ERROR, "packet_obj_size invalid\n");
719             return -1;
720         }
721         asf->packet_frag_timestamp = get_le32(pb); // timestamp
722         if(asf->packet_replic_size >= 8+38+4){
723 //            for(i=0; i<asf->packet_replic_size-8; i++)
724 //                av_log(s, AV_LOG_DEBUG, "%02X ",get_byte(pb));
725 //            av_log(s, AV_LOG_DEBUG, "\n");
726             url_fskip(pb, 10);
727             ts0= get_le64(pb);
728             ts1= get_le64(pb);
729             url_fskip(pb, 12);
730             get_le32(pb);
731             url_fskip(pb, asf->packet_replic_size - 8 - 38 - 4);
732             if(ts0!= -1) asf->packet_frag_timestamp= ts0/10000;
733             else         asf->packet_frag_timestamp= AV_NOPTS_VALUE;
734         }else
735             url_fskip(pb, asf->packet_replic_size - 8);
736         rsize += asf->packet_replic_size; // FIXME - check validity
737     } else if (asf->packet_replic_size==1){
738         // multipacket - frag_offset is beginning timestamp
739         asf->packet_time_start = asf->packet_frag_offset;
740         asf->packet_frag_offset = 0;
741         asf->packet_frag_timestamp = asf->packet_timestamp;
742
743         asf->packet_time_delta = get_byte(pb);
744         rsize++;
745     }else if(asf->packet_replic_size!=0){
746         av_log(s, AV_LOG_ERROR, "unexpected packet_replic_size of %d\n", asf->packet_replic_size);
747         return -1;
748     }
749     if (asf->packet_flags & 0x01) {
750         DO_2BITS(asf->packet_segsizetype >> 6, asf->packet_frag_size, 0); // 0 is illegal
751         if(asf->packet_frag_size > asf->packet_size_left - rsize){
752             av_log(s, AV_LOG_ERROR, "packet_frag_size is invalid\n");
753             return -1;
754         }
755         //printf("Fragsize %d\n", asf->packet_frag_size);
756     } else {
757         asf->packet_frag_size = asf->packet_size_left - rsize;
758         //printf("Using rest  %d %d %d\n", asf->packet_frag_size, asf->packet_size_left, rsize);
759     }
760     if (asf->packet_replic_size == 1) {
761         asf->packet_multi_size = asf->packet_frag_size;
762         if (asf->packet_multi_size > asf->packet_size_left)
763             return -1;
764     }
765     asf->packet_size_left -= rsize;
766     //printf("___objsize____  %d   %d    rs:%d\n", asf->packet_obj_size, asf->packet_frag_offset, rsize);
767
768     return 0;
769 }
770
771 /**
772  * Parse data from individual ASF packets (which were previously loaded
773  * with asf_get_packet()).
774  * @param s demux context
775  * @param pb context to read data from
776  * @param pkt pointer to store packet data into
777  * @returns 0 if data was stored in pkt, <0 on error or 1 if more ASF
778  *          packets need to be loaded (through asf_get_packet())
779  */
780 static int ff_asf_parse_packet(AVFormatContext *s, ByteIOContext *pb, AVPacket *pkt)
781 {
782     ASFContext *asf = s->priv_data;
783     ASFStream *asf_st = 0;
784     for (;;) {
785         if(url_feof(pb))
786             return AVERROR_EOF;
787         if (asf->packet_size_left < FRAME_HEADER_SIZE
788             || asf->packet_segments < 1) {
789             //asf->packet_size_left <= asf->packet_padsize) {
790             int ret = asf->packet_size_left + asf->packet_padsize;
791             //printf("PacketLeftSize:%d  Pad:%d Pos:%"PRId64"\n", asf->packet_size_left, asf->packet_padsize, url_ftell(pb));
792             assert(ret>=0);
793             /* fail safe */
794             url_fskip(pb, ret);
795
796             asf->packet_pos= url_ftell(pb);
797             if (asf->data_object_size != (uint64_t)-1 &&
798                 (asf->packet_pos - asf->data_object_offset >= asf->data_object_size))
799                 return AVERROR_EOF; /* Do not exceed the size of the data object */
800             return 1;
801         }
802         if (asf->packet_time_start == 0) {
803             if(asf_read_frame_header(s, pb) < 0){
804                 asf->packet_segments= 0;
805                 continue;
806             }
807             if (asf->stream_index < 0
808                 || s->streams[asf->stream_index]->discard >= AVDISCARD_ALL
809                 || (!asf->packet_key_frame && s->streams[asf->stream_index]->discard >= AVDISCARD_NONKEY)
810                 ) {
811                 asf->packet_time_start = 0;
812                 /* unhandled packet (should not happen) */
813                 url_fskip(pb, asf->packet_frag_size);
814                 asf->packet_size_left -= asf->packet_frag_size;
815                 if(asf->stream_index < 0)
816                     av_log(s, AV_LOG_ERROR, "ff asf skip %d (unknown stream)\n", asf->packet_frag_size);
817                 continue;
818             }
819             asf->asf_st = s->streams[asf->stream_index]->priv_data;
820         }
821         asf_st = asf->asf_st;
822
823         if (asf->packet_replic_size == 1) {
824             // frag_offset is here used as the beginning timestamp
825             asf->packet_frag_timestamp = asf->packet_time_start;
826             asf->packet_time_start += asf->packet_time_delta;
827             asf->packet_obj_size = asf->packet_frag_size = get_byte(pb);
828             asf->packet_size_left--;
829             asf->packet_multi_size--;
830             if (asf->packet_multi_size < asf->packet_obj_size)
831             {
832                 asf->packet_time_start = 0;
833                 url_fskip(pb, asf->packet_multi_size);
834                 asf->packet_size_left -= asf->packet_multi_size;
835                 continue;
836             }
837             asf->packet_multi_size -= asf->packet_obj_size;
838             //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);
839         }
840         if(   /*asf->packet_frag_size == asf->packet_obj_size*/
841               asf_st->frag_offset + asf->packet_frag_size <= asf_st->pkt.size
842            && asf_st->frag_offset + asf->packet_frag_size > asf->packet_obj_size){
843             av_log(s, AV_LOG_INFO, "ignoring invalid packet_obj_size (%d %d %d %d)\n",
844                 asf_st->frag_offset, asf->packet_frag_size,
845                 asf->packet_obj_size, asf_st->pkt.size);
846             asf->packet_obj_size= asf_st->pkt.size;
847         }
848
849         if (   asf_st->pkt.size != asf->packet_obj_size
850             || asf_st->frag_offset + asf->packet_frag_size > asf_st->pkt.size) { //FIXME is this condition sufficient?
851             if(asf_st->pkt.data){
852                 av_log(s, AV_LOG_INFO, "freeing incomplete packet size %d, new %d\n", asf_st->pkt.size, asf->packet_obj_size);
853                 asf_st->frag_offset = 0;
854                 av_free_packet(&asf_st->pkt);
855             }
856             /* new packet */
857             av_new_packet(&asf_st->pkt, asf->packet_obj_size);
858             asf_st->seq = asf->packet_seq;
859             asf_st->pkt.dts = asf->packet_frag_timestamp;
860             asf_st->pkt.stream_index = asf->stream_index;
861             asf_st->pkt.pos =
862             asf_st->packet_pos= asf->packet_pos;
863 //printf("new packet: stream:%d key:%d packet_key:%d audio:%d size:%d\n",
864 //asf->stream_index, asf->packet_key_frame, asf_st->pkt.flags & PKT_FLAG_KEY,
865 //s->streams[asf->stream_index]->codec->codec_type == CODEC_TYPE_AUDIO, asf->packet_obj_size);
866             if (s->streams[asf->stream_index]->codec->codec_type == CODEC_TYPE_AUDIO)
867                 asf->packet_key_frame = 1;
868             if (asf->packet_key_frame)
869                 asf_st->pkt.flags |= PKT_FLAG_KEY;
870         }
871
872         /* read data */
873         //printf("READ PACKET s:%d  os:%d  o:%d,%d  l:%d   DATA:%p\n",
874         //       s->packet_size, asf_st->pkt.size, asf->packet_frag_offset,
875         //       asf_st->frag_offset, asf->packet_frag_size, asf_st->pkt.data);
876         asf->packet_size_left -= asf->packet_frag_size;
877         if (asf->packet_size_left < 0)
878             continue;
879
880         if(   asf->packet_frag_offset >= asf_st->pkt.size
881            || asf->packet_frag_size > asf_st->pkt.size - asf->packet_frag_offset){
882             av_log(s, AV_LOG_ERROR, "packet fragment position invalid %u,%u not in %u\n",
883                 asf->packet_frag_offset, asf->packet_frag_size, asf_st->pkt.size);
884             continue;
885         }
886
887         get_buffer(pb, asf_st->pkt.data + asf->packet_frag_offset,
888                    asf->packet_frag_size);
889         if (s->key && s->keylen == 20)
890             ff_asfcrypt_dec(s->key, asf_st->pkt.data + asf->packet_frag_offset,
891                             asf->packet_frag_size);
892         asf_st->frag_offset += asf->packet_frag_size;
893         /* test if whole packet is read */
894         if (asf_st->frag_offset == asf_st->pkt.size) {
895             //workaround for macroshit radio DVR-MS files
896             if(   s->streams[asf->stream_index]->codec->codec_id == CODEC_ID_MPEG2VIDEO
897                && asf_st->pkt.size > 100){
898                 int i;
899                 for(i=0; i<asf_st->pkt.size && !asf_st->pkt.data[i]; i++);
900                 if(i == asf_st->pkt.size){
901                     av_log(s, AV_LOG_DEBUG, "discarding ms fart\n");
902                     asf_st->frag_offset = 0;
903                     av_free_packet(&asf_st->pkt);
904                     continue;
905                 }
906             }
907
908             /* return packet */
909             if (asf_st->ds_span > 1) {
910               if(asf_st->pkt.size != asf_st->ds_packet_size * asf_st->ds_span){
911                     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);
912               }else{
913                 /* packet descrambling */
914                 uint8_t *newdata = av_malloc(asf_st->pkt.size);
915                 if (newdata) {
916                     int offset = 0;
917                     while (offset < asf_st->pkt.size) {
918                         int off = offset / asf_st->ds_chunk_size;
919                         int row = off / asf_st->ds_span;
920                         int col = off % asf_st->ds_span;
921                         int idx = row + col * asf_st->ds_packet_size / asf_st->ds_chunk_size;
922                         //printf("off:%d  row:%d  col:%d  idx:%d\n", off, row, col, idx);
923
924                         assert(offset + asf_st->ds_chunk_size <= asf_st->pkt.size);
925                         assert(idx+1 <= asf_st->pkt.size / asf_st->ds_chunk_size);
926                         memcpy(newdata + offset,
927                                asf_st->pkt.data + idx * asf_st->ds_chunk_size,
928                                asf_st->ds_chunk_size);
929                         offset += asf_st->ds_chunk_size;
930                     }
931                     av_free(asf_st->pkt.data);
932                     asf_st->pkt.data = newdata;
933                 }
934               }
935             }
936             asf_st->frag_offset = 0;
937             *pkt= asf_st->pkt;
938             //printf("packet %d %d\n", asf_st->pkt.size, asf->packet_frag_size);
939             asf_st->pkt.size = 0;
940             asf_st->pkt.data = 0;
941             break; // packet completed
942         }
943     }
944     return 0;
945 }
946
947 static int asf_read_packet(AVFormatContext *s, AVPacket *pkt)
948 {
949     ASFContext *asf = s->priv_data;
950
951     for (;;) {
952         int ret;
953
954         /* parse cached packets, if any */
955         if ((ret = ff_asf_parse_packet(s, s->pb, pkt)) <= 0)
956             return ret;
957         if ((ret = ff_asf_get_packet(s, s->pb)) < 0)
958             assert(asf->packet_size_left < FRAME_HEADER_SIZE || asf->packet_segments < 1);
959         asf->packet_time_start = 0;
960     }
961
962     return 0;
963 }
964
965 // Added to support seeking after packets have been read
966 // If information is not reset, read_packet fails due to
967 // leftover information from previous reads
968 static void asf_reset_header(AVFormatContext *s)
969 {
970     ASFContext *asf = s->priv_data;
971     ASFStream *asf_st;
972     int i;
973
974     asf->packet_nb_frames = 0;
975     asf->packet_size_left = 0;
976     asf->packet_segments = 0;
977     asf->packet_flags = 0;
978     asf->packet_property = 0;
979     asf->packet_timestamp = 0;
980     asf->packet_segsizetype = 0;
981     asf->packet_segments = 0;
982     asf->packet_seq = 0;
983     asf->packet_replic_size = 0;
984     asf->packet_key_frame = 0;
985     asf->packet_padsize = 0;
986     asf->packet_frag_offset = 0;
987     asf->packet_frag_size = 0;
988     asf->packet_frag_timestamp = 0;
989     asf->packet_multi_size = 0;
990     asf->packet_obj_size = 0;
991     asf->packet_time_delta = 0;
992     asf->packet_time_start = 0;
993
994     for(i=0; i<s->nb_streams; i++){
995         asf_st= s->streams[i]->priv_data;
996         av_free_packet(&asf_st->pkt);
997         asf_st->frag_offset=0;
998         asf_st->seq=0;
999     }
1000     asf->asf_st= NULL;
1001 }
1002
1003 static int asf_read_close(AVFormatContext *s)
1004 {
1005     int i;
1006
1007     asf_reset_header(s);
1008     for(i=0;i<s->nb_streams;i++) {
1009         AVStream *st = s->streams[i];
1010         av_free(st->codec->palctrl);
1011     }
1012     return 0;
1013 }
1014
1015 static int64_t asf_read_pts(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit)
1016 {
1017     AVPacket pkt1, *pkt = &pkt1;
1018     ASFStream *asf_st;
1019     int64_t pts;
1020     int64_t pos= *ppos;
1021     int i;
1022     int64_t start_pos[s->nb_streams];
1023
1024     for(i=0; i<s->nb_streams; i++){
1025         start_pos[i]= pos;
1026     }
1027
1028     if (s->packet_size > 0)
1029         pos= (pos+s->packet_size-1-s->data_offset)/s->packet_size*s->packet_size+ s->data_offset;
1030     *ppos= pos;
1031     url_fseek(s->pb, pos, SEEK_SET);
1032
1033 //printf("asf_read_pts\n");
1034     asf_reset_header(s);
1035     for(;;){
1036         if (av_read_frame(s, pkt) < 0){
1037             av_log(s, AV_LOG_INFO, "asf_read_pts failed\n");
1038             return AV_NOPTS_VALUE;
1039         }
1040
1041         pts= pkt->pts;
1042
1043         av_free_packet(pkt);
1044         if(pkt->flags&PKT_FLAG_KEY){
1045             i= pkt->stream_index;
1046
1047             asf_st= s->streams[i]->priv_data;
1048
1049 //            assert((asf_st->packet_pos - s->data_offset) % s->packet_size == 0);
1050             pos= asf_st->packet_pos;
1051
1052             av_add_index_entry(s->streams[i], pos, pts, pkt->size, pos - start_pos[i] + 1, AVINDEX_KEYFRAME);
1053             start_pos[i]= asf_st->packet_pos + 1;
1054
1055             if(pkt->stream_index == stream_index)
1056                break;
1057         }
1058     }
1059
1060     *ppos= pos;
1061 //printf("found keyframe at %"PRId64" stream %d stamp:%"PRId64"\n", *ppos, stream_index, pts);
1062
1063     return pts;
1064 }
1065
1066 static void asf_build_simple_index(AVFormatContext *s, int stream_index)
1067 {
1068     ff_asf_guid g;
1069     ASFContext *asf = s->priv_data;
1070     int64_t current_pos= url_ftell(s->pb);
1071     int i;
1072
1073     url_fseek(s->pb, asf->data_object_offset + asf->data_object_size, SEEK_SET);
1074     get_guid(s->pb, &g);
1075     if (!guidcmp(&g, &index_guid)) {
1076         int64_t itime, last_pos=-1;
1077         int pct, ict;
1078         int64_t av_unused gsize= get_le64(s->pb);
1079         get_guid(s->pb, &g);
1080         itime=get_le64(s->pb);
1081         pct=get_le32(s->pb);
1082         ict=get_le32(s->pb);
1083         av_log(s, AV_LOG_DEBUG, "itime:0x%"PRIx64", pct:%d, ict:%d\n",itime,pct,ict);
1084
1085         for (i=0;i<ict;i++){
1086             int pktnum=get_le32(s->pb);
1087             int pktct =get_le16(s->pb);
1088             int64_t pos      = s->data_offset + s->packet_size*(int64_t)pktnum;
1089             int64_t index_pts= av_rescale(itime, i, 10000);
1090
1091             if(pos != last_pos){
1092             av_log(s, AV_LOG_DEBUG, "pktnum:%d, pktct:%d\n", pktnum, pktct);
1093             av_add_index_entry(s->streams[stream_index], pos, index_pts, s->packet_size, 0, AVINDEX_KEYFRAME);
1094             last_pos=pos;
1095             }
1096         }
1097         asf->index_read= 1;
1098     }
1099     url_fseek(s->pb, current_pos, SEEK_SET);
1100 }
1101
1102 static int asf_read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags)
1103 {
1104     ASFContext *asf = s->priv_data;
1105     AVStream *st = s->streams[stream_index];
1106     int64_t pos;
1107     int index;
1108
1109     if (s->packet_size <= 0)
1110         return -1;
1111
1112     /* Try using the protocol's read_seek if available */
1113     if(s->pb) {
1114         int ret = av_url_read_fseek(s->pb, stream_index, pts, flags);
1115         if(ret >= 0)
1116             asf_reset_header(s);
1117         if (ret != AVERROR(ENOSYS))
1118             return ret;
1119     }
1120
1121     if (!asf->index_read)
1122         asf_build_simple_index(s, stream_index);
1123
1124     if(!(asf->index_read && st->index_entries)){
1125         if(av_seek_frame_binary(s, stream_index, pts, flags)<0)
1126             return -1;
1127     }else{
1128         index= av_index_search_timestamp(st, pts, flags);
1129         if(index<0)
1130             return -1;
1131
1132         /* find the position */
1133         pos = st->index_entries[index].pos;
1134
1135     // various attempts to find key frame have failed so far
1136     //    asf_reset_header(s);
1137     //    url_fseek(s->pb, pos, SEEK_SET);
1138     //    key_pos = pos;
1139     //     for(i=0;i<16;i++){
1140     //         pos = url_ftell(s->pb);
1141     //         if (av_read_frame(s, &pkt) < 0){
1142     //             av_log(s, AV_LOG_INFO, "seek failed\n");
1143     //             return -1;
1144     //         }
1145     //         asf_st = s->streams[stream_index]->priv_data;
1146     //         pos += st->parser->frame_offset;
1147     //
1148     //         if (pkt.size > b) {
1149     //             b = pkt.size;
1150     //             key_pos = pos;
1151     //         }
1152     //
1153     //         av_free_packet(&pkt);
1154     //     }
1155
1156         /* do the seek */
1157         av_log(s, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos);
1158         url_fseek(s->pb, pos, SEEK_SET);
1159     }
1160     asf_reset_header(s);
1161     return 0;
1162 }
1163
1164 AVInputFormat asf_demuxer = {
1165     "asf",
1166     NULL_IF_CONFIG_SMALL("ASF format"),
1167     sizeof(ASFContext),
1168     asf_probe,
1169     asf_read_header,
1170     asf_read_packet,
1171     asf_read_close,
1172     asf_read_seek,
1173     asf_read_pts,
1174     .metadata_conv = ff_asf_metadata_conv,
1175 };