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