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