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ffmpeg / libavformat / nutdec.c @ 8ba3e5d8

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1
/*
2
 * "NUT" Container Format demuxer
3
 * Copyright (c) 2004-2006 Michael Niedermayer
4
 * Copyright (c) 2003 Alex Beregszaszi
5
 *
6
 * This file is part of FFmpeg.
7
 *
8
 * FFmpeg is free software; you can redistribute it and/or
9
 * modify it under the terms of the GNU Lesser General Public
10
 * License as published by the Free Software Foundation; either
11
 * version 2.1 of the License, or (at your option) any later version.
12
 *
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 * FFmpeg is distributed in the hope that it will be useful,
14
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 *
22
 */
23

    
24
#include "tree.h"
25
#include "nut.h"
26

    
27
#undef NDEBUG
28
#include <assert.h>
29

    
30
static uint64_t get_v(ByteIOContext *bc/*, maxstuffing*/){
31
    uint64_t val = 0;
32

    
33
    for(;;)
34
    {
35
        int tmp = get_byte(bc);
36

    
37
//         if(tmp=0x80){
38
//             if(!maxstuffing-- || val)
39
//                 return -1;
40
//         }
41

    
42
        if (tmp&0x80)
43
            val= (val<<7) + tmp - 0x80;
44
        else{
45
            return (val<<7) + tmp;
46
        }
47
    }
48
    return -1;
49
}
50

    
51
static int get_str(ByteIOContext *bc, char *string, unsigned int maxlen){
52
    unsigned int len= get_v(bc);
53

    
54
    if(len && maxlen)
55
        get_buffer(bc, string, FFMIN(len, maxlen));
56
    while(len > maxlen){
57
        get_byte(bc);
58
        len--;
59
    }
60

    
61
    if(maxlen)
62
        string[FFMIN(len, maxlen-1)]= 0;
63

    
64
    if(maxlen == len)
65
        return -1;
66
    else
67
        return 0;
68
}
69

    
70
static int64_t get_s(ByteIOContext *bc){
71
    int64_t v = get_v(bc) + 1;
72

    
73
    if (v&1) return -(v>>1);
74
    else     return  (v>>1);
75
}
76

    
77
static uint64_t get_fourcc(ByteIOContext *bc){
78
    unsigned int len= get_v(bc);
79

    
80
    if     (len==2) return get_le16(bc);
81
    else if(len==4) return get_le32(bc);
82
    else            return -1;
83
}
84

    
85
#ifdef TRACE
86
static inline uint64_t get_v_trace(ByteIOContext *bc, char *file, char *func, int line){
87
    uint64_t v= get_v(bc);
88

    
89
    printf("get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
90
    return v;
91
}
92

    
93
static inline int64_t get_s_trace(ByteIOContext *bc, char *file, char *func, int line){
94
    int64_t v= get_s(bc);
95

    
96
    printf("get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
97
    return v;
98
}
99

    
100
static inline uint64_t get_vb_trace(ByteIOContext *bc, char *file, char *func, int line){
101
    uint64_t v= get_vb(bc);
102

    
103
    printf("get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
104
    return v;
105
}
106
#define get_v(bc)  get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
107
#define get_s(bc)  get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
108
#define get_vb(bc)  get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
109
#endif
110

    
111
static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int calculate_checksum)
112
{
113
    int64_t start, size;
114
//    start= url_ftell(bc) - 8;
115

    
116
    size= get_v(bc);
117

    
118
    init_checksum(bc, calculate_checksum ? av_crc04C11DB7_update : NULL, 0);
119

    
120
//    nut->packet_start[2] = start;
121
//    nut->written_packet_size= size;
122

    
123
    return size;
124
}
125

    
126
static uint64_t find_any_startcode(ByteIOContext *bc, int64_t pos){
127
    uint64_t state=0;
128

    
129
    if(pos >= 0)
130
        url_fseek(bc, pos, SEEK_SET); //note, this may fail if the stream isnt seekable, but that shouldnt matter, as in this case we simply start where we are currently
131

    
132
    while(!url_feof(bc)){
133
        state= (state<<8) | get_byte(bc);
134
        if((state>>56) != 'N')
135
            continue;
136
        switch(state){
137
        case MAIN_STARTCODE:
138
        case STREAM_STARTCODE:
139
        case SYNCPOINT_STARTCODE:
140
        case INFO_STARTCODE:
141
        case INDEX_STARTCODE:
142
            return state;
143
        }
144
    }
145

    
146
    return 0;
147
}
148

    
149
/**
150
 * find the given startcode.
151
 * @param code the startcode
152
 * @param pos the start position of the search, or -1 if the current position
153
 * @returns the position of the startcode or -1 if not found
154
 */
155
static int64_t find_startcode(ByteIOContext *bc, uint64_t code, int64_t pos){
156
    for(;;){
157
        uint64_t startcode= find_any_startcode(bc, pos);
158
        if(startcode == code)
159
            return url_ftell(bc) - 8;
160
        else if(startcode == 0)
161
            return -1;
162
        pos=-1;
163
    }
164
}
165

    
166
static int64_t lsb2full(StreamContext *stream, int64_t lsb){
167
    int64_t mask = (1<<stream->msb_pts_shift)-1;
168
    int64_t delta= stream->last_pts - mask/2;
169
    return  ((lsb - delta)&mask) + delta;
170
}
171

    
172
static int nut_probe(AVProbeData *p){
173
    int i;
174
    uint64_t code= 0;
175

    
176
    for (i = 0; i < p->buf_size; i++) {
177
        code = (code << 8) | p->buf[i];
178
        if (code == MAIN_STARTCODE)
179
            return AVPROBE_SCORE_MAX;
180
    }
181
    return 0;
182
}
183

    
184
#define GET_V(dst, check) \
185
    tmp= get_v(bc);\
186
    if(!(check)){\
187
        av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp);\
188
        return -1;\
189
    }\
190
    dst= tmp;
191

    
192
static int skip_reserved(ByteIOContext *bc, int64_t pos){
193
    pos -= url_ftell(bc);
194
    if(pos<0){
195
        url_fseek(bc, pos, SEEK_CUR);
196
        return -1;
197
    }else{
198
        while(pos--)
199
            get_byte(bc);
200
        return 0;
201
    }
202
}
203

    
204
static int decode_main_header(NUTContext *nut){
205
    AVFormatContext *s= nut->avf;
206
    ByteIOContext *bc = &s->pb;
207
    uint64_t tmp, end;
208
    unsigned int stream_count;
209
    int i, j, tmp_stream, tmp_mul, tmp_pts, tmp_size, count, tmp_res;
210

    
211
    end= get_packetheader(nut, bc, 1);
212
    end += url_ftell(bc);
213

    
214
    GET_V(tmp              , tmp >=2 && tmp <= 3)
215
    GET_V(stream_count     , tmp > 0 && tmp <=MAX_STREAMS)
216

    
217
    nut->max_distance = get_v(bc);
218
    if(nut->max_distance > 65536){
219
        av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
220
        nut->max_distance= 65536;
221
    }
222

    
223
    GET_V(nut->time_base_count, tmp>0 && tmp<INT_MAX / sizeof(AVRational))
224
    nut->time_base= av_malloc(nut->time_base_count * sizeof(AVRational));
225

    
226
    for(i=0; i<nut->time_base_count; i++){
227
        GET_V(nut->time_base[i].num, tmp>0 && tmp<(1ULL<<31))
228
        GET_V(nut->time_base[i].den, tmp>0 && tmp<(1ULL<<31))
229
        if(ff_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1){
230
            av_log(s, AV_LOG_ERROR, "time base invalid\n");
231
            return -1;
232
        }
233
    }
234
    tmp_pts=0;
235
    tmp_mul=1;
236
    tmp_stream=0;
237
    for(i=0; i<256;){
238
        int tmp_flags = get_v(bc);
239
        int tmp_fields= get_v(bc);
240
        if(tmp_fields>0) tmp_pts   = get_s(bc);
241
        if(tmp_fields>1) tmp_mul   = get_v(bc);
242
        if(tmp_fields>2) tmp_stream= get_v(bc);
243
        if(tmp_fields>3) tmp_size  = get_v(bc);
244
        else             tmp_size  = 0;
245
        if(tmp_fields>4) tmp_res   = get_v(bc);
246
        else             tmp_res   = 0;
247
        if(tmp_fields>5) count     = get_v(bc);
248
        else             count     = tmp_mul - tmp_size;
249

    
250
        while(tmp_fields-- > 6)
251
           get_v(bc);
252

    
253
        if(count == 0 || i+count > 256){
254
            av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
255
            return -1;
256
        }
257
        if(tmp_stream >= stream_count){
258
            av_log(s, AV_LOG_ERROR, "illegal stream number\n");
259
            return -1;
260
        }
261

    
262
        for(j=0; j<count; j++,i++){
263
            if (i == 'N') {
264
                nut->frame_code[i].flags= FLAG_INVALID;
265
                j--;
266
                continue;
267
            }
268
            nut->frame_code[i].flags           = tmp_flags ;
269
            nut->frame_code[i].pts_delta       = tmp_pts   ;
270
            nut->frame_code[i].stream_id       = tmp_stream;
271
            nut->frame_code[i].size_mul        = tmp_mul   ;
272
            nut->frame_code[i].size_lsb        = tmp_size+j;
273
            nut->frame_code[i].reserved_count  = tmp_res   ;
274
        }
275
    }
276
    assert(nut->frame_code['N'].flags == FLAG_INVALID);
277

    
278
    if(skip_reserved(bc, end) || get_checksum(bc)){
279
        av_log(s, AV_LOG_ERROR, "Main header checksum mismatch\n");
280
        return -1;
281
    }
282

    
283
    nut->stream = av_mallocz(sizeof(StreamContext)*stream_count);
284
    for(i=0; i<stream_count; i++){
285
        av_new_stream(s, i);
286
    }
287

    
288
    return 0;
289
}
290

    
291
static int decode_stream_header(NUTContext *nut){
292
    AVFormatContext *s= nut->avf;
293
    ByteIOContext *bc = &s->pb;
294
    StreamContext *stc;
295
    int class, nom, denom, stream_id;
296
    uint64_t tmp, end;
297
    AVStream *st;
298

    
299
    end= get_packetheader(nut, bc, 1);
300
    end += url_ftell(bc);
301

    
302
    GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base.num);
303
    stc= &nut->stream[stream_id];
304

    
305
    st = s->streams[stream_id];
306
    if (!st)
307
        return AVERROR_NOMEM;
308

    
309
    class = get_v(bc);
310
    tmp = get_fourcc(bc);
311
    st->codec->codec_tag= tmp;
312
    switch(class)
313
    {
314
        case 0:
315
            st->codec->codec_type = CODEC_TYPE_VIDEO;
316
            st->codec->codec_id = codec_get_bmp_id(tmp);
317
            if (st->codec->codec_id == CODEC_ID_NONE)
318
                av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
319
            break;
320
        case 1:
321
            st->codec->codec_type = CODEC_TYPE_AUDIO;
322
            st->codec->codec_id = codec_get_wav_id(tmp);
323
            if (st->codec->codec_id == CODEC_ID_NONE)
324
                av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
325
            break;
326
        case 2:
327
//            st->codec->codec_type = CODEC_TYPE_TEXT;
328
//            break;
329
        case 3:
330
            st->codec->codec_type = CODEC_TYPE_DATA;
331
            break;
332
        default:
333
            av_log(s, AV_LOG_ERROR, "Unknown stream class (%d)\n", class);
334
            return -1;
335
    }
336
    GET_V(stc->time_base_id    , tmp < nut->time_base_count);
337
    GET_V(stc->msb_pts_shift   , tmp < 16);
338
    stc->max_pts_distance= get_v(bc);
339
    GET_V(stc->decode_delay    , tmp < 1000); //sanity limit, raise this if moors law is true
340
    st->codec->has_b_frames= stc->decode_delay;
341
    get_v(bc); //stream flags
342

    
343
    GET_V(st->codec->extradata_size, tmp < (1<<30));
344
    if(st->codec->extradata_size){
345
        st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
346
        get_buffer(bc, st->codec->extradata, st->codec->extradata_size);
347
    }
348

    
349
    if (st->codec->codec_type == CODEC_TYPE_VIDEO){
350
        GET_V(st->codec->width , tmp > 0)
351
        GET_V(st->codec->height, tmp > 0)
352
        st->codec->sample_aspect_ratio.num= get_v(bc);
353
        st->codec->sample_aspect_ratio.den= get_v(bc);
354
        if((!st->codec->sample_aspect_ratio.num) != (!st->codec->sample_aspect_ratio.den)){
355
            av_log(s, AV_LOG_ERROR, "invalid aspect ratio\n");
356
            return -1;
357
        }
358
        get_v(bc); /* csp type */
359
    }else if (st->codec->codec_type == CODEC_TYPE_AUDIO){
360
        GET_V(st->codec->sample_rate , tmp > 0)
361
        tmp= get_v(bc); // samplerate_den
362
        if(tmp > st->codec->sample_rate){
363
            av_log(s, AV_LOG_ERROR, "bleh, libnut muxed this ;)\n");
364
            st->codec->sample_rate= tmp;
365
        }
366
        GET_V(st->codec->channels, tmp > 0)
367
    }
368
    if(skip_reserved(bc, end) || get_checksum(bc)){
369
        av_log(s, AV_LOG_ERROR, "Stream header %d checksum mismatch\n", stream_id);
370
        return -1;
371
    }
372
    stc->time_base= nut->time_base[stc->time_base_id];
373
    av_set_pts_info(s->streams[stream_id], 63, stc->time_base.num, stc->time_base.den);
374
    return 0;
375
}
376

    
377
static int decode_info_header(NUTContext *nut){
378
    AVFormatContext *s= nut->avf;
379
    ByteIOContext *bc = &s->pb;
380
    uint64_t tmp;
381
    unsigned int stream_id_plus1, chapter_start, chapter_len, count;
382
    int chapter_id, i;
383
    int64_t value, end;
384
    char name[256], str_value[1024], type_str[256], *type= type_str;
385

    
386
    end= get_packetheader(nut, bc, 1);
387
    end += url_ftell(bc);
388

    
389
    GET_V(stream_id_plus1, tmp <= s->nb_streams)
390
    chapter_id   = get_s(bc);
391
    chapter_start= get_v(bc);
392
    chapter_len  = get_v(bc);
393
    count        = get_v(bc);
394
    for(i=0; i<count; i++){
395
        get_str(bc, name, sizeof(name));
396
        value= get_s(bc);
397
        if(value == -1){
398
            type= "UTF-8";
399
            get_str(bc, str_value, sizeof(str_value));
400
        }else if(value == -2){
401
            get_str(bc, type, sizeof(type));
402
            get_str(bc, str_value, sizeof(str_value));
403
        }else if(value == -3){
404
            type= "s";
405
            value= get_s(bc);
406
        }else if(value == -4){
407
            type= "t";
408
            value= get_v(bc);
409
        }else if(value < -4){
410
            type= "r";
411
            get_s(bc);
412
        }else{
413
            type= "v";
414
        }
415

    
416
        if(chapter_id==0 && !strcmp(type, "UTF-8")){
417
            if     (!strcmp(name, "Author"))
418
                pstrcpy(s->author   , sizeof(s->author)   , str_value);
419
            else if(!strcmp(name, "Title"))
420
                pstrcpy(s->title    , sizeof(s->title)    , str_value);
421
            else if(!strcmp(name, "Copyright"))
422
                pstrcpy(s->copyright, sizeof(s->copyright), str_value);
423
            else if(!strcmp(name, "Description"))
424
                pstrcpy(s->comment  , sizeof(s->comment)  , str_value);
425
        }
426
    }
427

    
428
    if(skip_reserved(bc, end) || get_checksum(bc)){
429
        av_log(s, AV_LOG_ERROR, "Info header checksum mismatch\n");
430
        return -1;
431
    }
432
    return 0;
433
}
434

    
435
int sp_pos_cmp(syncpoint_t *a, syncpoint_t *b){
436
    return (a->pos - b->pos>>32) - (b->pos - a->pos>>32);
437
}
438

    
439
int sp_pts_cmp(syncpoint_t *a, syncpoint_t *b){
440
    return (a->ts - b->ts>>32) - (b->ts - a->ts>>32);
441
}
442

    
443
static void add_sp(NUTContext *nut, int64_t pos, int64_t back_ptr, int64_t ts){
444
    syncpoint_t *sp2, *sp= av_mallocz(sizeof(syncpoint_t));
445

    
446
    sp->pos= pos;
447
    sp->back_ptr= back_ptr;
448
    sp->ts= ts;
449
    sp2= av_tree_insert(&nut->syncpoints, sp, sp_pos_cmp);
450
    if(sp2 && sp2 != sp)
451
        av_free(sp);
452
}
453

    
454
static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr){
455
    AVFormatContext *s= nut->avf;
456
    ByteIOContext *bc = &s->pb;
457
    int64_t end, tmp;
458
    int i;
459
    AVRational time_base;
460

    
461
    nut->last_syncpoint_pos= url_ftell(bc)-8;
462

    
463
    end= get_packetheader(nut, bc, 1);
464
    end += url_ftell(bc);
465

    
466
    tmp= get_v(bc);
467
    *back_ptr= nut->last_syncpoint_pos - 16*get_v(bc);
468
    if(*back_ptr < 0)
469
        return -1;
470

    
471
    time_base= nut->time_base[tmp % nut->time_base_count];
472
    for(i=0; i<s->nb_streams; i++){
473
        nut->stream[i].last_pts= av_rescale_rnd(
474
            tmp / nut->time_base_count,
475
            time_base.num * (int64_t)nut->stream[i].time_base.den,
476
            time_base.den * (int64_t)nut->stream[i].time_base.num,
477
            AV_ROUND_DOWN);
478
        //last_key_frame ?
479
    }
480
    //FIXME put this in a reset func maybe
481

    
482
    if(skip_reserved(bc, end) || get_checksum(bc)){
483
        av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
484
        return -1;
485
    }
486

    
487
    *ts= tmp / s->nb_streams * av_q2d(nut->time_base[tmp % s->nb_streams])*AV_TIME_BASE;
488
    add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
489

    
490
    return 0;
491
}
492

    
493
static int find_and_decode_index(NUTContext *nut){
494
    AVFormatContext *s= nut->avf;
495
    ByteIOContext *bc = &s->pb;
496
    uint64_t tmp, end;
497
    int i, j, syncpoint_count;
498
    int64_t filesize= url_fsize(bc);
499
    int64_t *syncpoints;
500
    int8_t *has_keyframe;
501

    
502
    url_fseek(bc, filesize-12, SEEK_SET);
503
    url_fseek(bc, filesize-get_be64(bc), SEEK_SET);
504
    if(get_be64(bc) != INDEX_STARTCODE){
505
        av_log(s, AV_LOG_ERROR, "no index at the end\n");
506
        return -1;
507
    }
508

    
509
    end= get_packetheader(nut, bc, 1);
510
    end += url_ftell(bc);
511

    
512
    get_v(bc); //max_pts
513
    GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
514
    syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
515
    has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
516
    for(i=0; i<syncpoint_count; i++){
517
        GET_V(syncpoints[i], tmp>0)
518
        if(i)
519
            syncpoints[i] += syncpoints[i-1];
520
    }
521

    
522
    for(i=0; i<s->nb_streams; i++){
523
        int64_t last_pts= -1;
524
        for(j=0; j<syncpoint_count;){
525
            uint64_t x= get_v(bc);
526
            int type= x&1;
527
            int n= j;
528
            x>>=1;
529
            if(type){
530
                int flag= x&1;
531
                x>>=1;
532
                if(n+x >= syncpoint_count + 1){
533
                    av_log(s, AV_LOG_ERROR, "index overflow A\n");
534
                    return -1;
535
                }
536
                while(x--)
537
                    has_keyframe[n++]= flag;
538
                has_keyframe[n++]= !flag;
539
            }else{
540
                while(x != 1){
541
                    if(n>=syncpoint_count + 1){
542
                        av_log(s, AV_LOG_ERROR, "index overflow B\n");
543
                        return -1;
544
                    }
545
                    has_keyframe[n++]= x&1;
546
                    x>>=1;
547
                }
548
            }
549
            if(has_keyframe[0]){
550
                av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
551
                return -1;
552
            }
553
            assert(n<=syncpoint_count+1);
554
            for(; j<n; j++){
555
                if(has_keyframe[j]){
556
                    uint64_t B, A= get_v(bc);
557
                    if(!A){
558
                        A= get_v(bc);
559
                        B= get_v(bc);
560
                        //eor_pts[j][i] = last_pts + A + B
561
                    }else
562
                        B= 0;
563
                    av_add_index_entry(
564
                        s->streams[i],
565
                        16*syncpoints[j-1],
566
                        last_pts + A,
567
                        0,
568
                        0,
569
                        AVINDEX_KEYFRAME);
570
                    last_pts += A + B;
571
                }
572
            }
573
        }
574
    }
575

    
576
    if(skip_reserved(bc, end) || get_checksum(bc)){
577
        av_log(s, AV_LOG_ERROR, "Index checksum mismatch\n");
578
        return -1;
579
    }
580
    return 0;
581
}
582

    
583
static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
584
{
585
    NUTContext *nut = s->priv_data;
586
    ByteIOContext *bc = &s->pb;
587
    int64_t pos;
588
    int inited_stream_count;
589

    
590
    nut->avf= s;
591

    
592
    /* main header */
593
    pos=0;
594
    do{
595
        pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
596
        if (pos<0+1){
597
            av_log(s, AV_LOG_ERROR, "no main startcode found\n");
598
            return -1;
599
        }
600
    }while(decode_main_header(nut) < 0);
601

    
602
    /* stream headers */
603
    pos=0;
604
    for(inited_stream_count=0; inited_stream_count < s->nb_streams;){
605
        pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
606
        if (pos<0+1){
607
            av_log(s, AV_LOG_ERROR, "not all stream headers found\n");
608
            return -1;
609
        }
610
        if(decode_stream_header(nut) >= 0)
611
            inited_stream_count++;
612
    }
613

    
614
    /* info headers */
615
    pos=0;
616
    for(;;){
617
        uint64_t startcode= find_any_startcode(bc, pos);
618
        pos= url_ftell(bc);
619

    
620
        if(startcode==0){
621
            av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
622
            return -1;
623
        }else if(startcode == SYNCPOINT_STARTCODE){
624
            nut->next_startcode= startcode;
625
            break;
626
        }else if(startcode != INFO_STARTCODE){
627
            continue;
628
        }
629

    
630
        decode_info_header(nut);
631
    }
632

    
633
    s->data_offset= pos-8;
634

    
635
    if(!url_is_streamed(bc)){
636
        int64_t orig_pos= url_ftell(bc);
637
        find_and_decode_index(nut);
638
        url_fseek(bc, orig_pos, SEEK_SET);
639
    }
640
    assert(nut->next_startcode == SYNCPOINT_STARTCODE);
641

    
642
    return 0;
643
}
644

    
645
static int decode_frame_header(NUTContext *nut, int *flags_ret, int64_t *pts, int *stream_id, int frame_code){
646
    AVFormatContext *s= nut->avf;
647
    ByteIOContext *bc = &s->pb;
648
    StreamContext *stc;
649
    int size, flags, size_mul, pts_delta, i, reserved_count;
650
    uint64_t tmp;
651

    
652
    if(url_ftell(bc) > nut->last_syncpoint_pos + nut->max_distance){
653
        av_log(s, AV_LOG_ERROR, "last frame must have been damaged %Ld > %Ld + %d\n", url_ftell(bc), nut->last_syncpoint_pos, nut->max_distance);
654
        return -1;
655
    }
656

    
657
    flags          = nut->frame_code[frame_code].flags;
658
    size_mul       = nut->frame_code[frame_code].size_mul;
659
    size           = nut->frame_code[frame_code].size_lsb;
660
    *stream_id     = nut->frame_code[frame_code].stream_id;
661
    pts_delta      = nut->frame_code[frame_code].pts_delta;
662
    reserved_count = nut->frame_code[frame_code].reserved_count;
663

    
664
    if(flags & FLAG_INVALID)
665
        return -1;
666
    if(flags & FLAG_CODED)
667
        flags ^= get_v(bc);
668
    if(flags & FLAG_STREAM_ID){
669
        GET_V(*stream_id, tmp < s->nb_streams)
670
    }
671
    stc= &nut->stream[*stream_id];
672
    if(flags&FLAG_CODED_PTS){
673
        int coded_pts= get_v(bc);
674
//FIXME check last_pts validity?
675
        if(coded_pts < (1<<stc->msb_pts_shift)){
676
            *pts=lsb2full(stc, coded_pts);
677
        }else
678
            *pts=coded_pts - (1<<stc->msb_pts_shift);
679
    }else
680
        *pts= stc->last_pts + pts_delta;
681
    if(flags&FLAG_SIZE_MSB){
682
        size += size_mul*get_v(bc);
683
    }
684
    if(flags&FLAG_RESERVED)
685
        reserved_count= get_v(bc);
686
    for(i=0; i<reserved_count; i++)
687
        get_v(bc);
688
    if(flags&FLAG_CHECKSUM){
689
        get_be32(bc); //FIXME check this
690
    }
691
    *flags_ret= flags;
692

    
693
    stc->last_pts= *pts;
694
    stc->last_key_frame= flags&FLAG_KEY; //FIXME change to last flags
695

    
696
    return size;
697
}
698

    
699
static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
700
    AVFormatContext *s= nut->avf;
701
    ByteIOContext *bc = &s->pb;
702
    int size, stream_id, flags, discard;
703
    int64_t pts, last_IP_pts;
704

    
705
    size= decode_frame_header(nut, &flags, &pts, &stream_id, frame_code);
706
    if(size < 0)
707
        return -1;
708

    
709
    discard= s->streams[ stream_id ]->discard;
710
    last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
711
    if(  (discard >= AVDISCARD_NONKEY && !(flags & FLAG_KEY))
712
       ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
713
       || discard >= AVDISCARD_ALL){
714
        url_fskip(bc, size);
715
        return 1;
716
    }
717

    
718
    av_get_packet(bc, pkt, size);
719
    pkt->stream_index = stream_id;
720
    if (flags & FLAG_KEY)
721
        pkt->flags |= PKT_FLAG_KEY;
722
    pkt->pts = pts;
723

    
724
    return 0;
725
}
726

    
727
static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
728
{
729
    NUTContext *nut = s->priv_data;
730
    ByteIOContext *bc = &s->pb;
731
    int i, frame_code=0, ret, skip;
732
    int64_t ts, back_ptr;
733

    
734
    for(;;){
735
        int64_t pos= url_ftell(bc);
736
        uint64_t tmp= nut->next_startcode;
737
        nut->next_startcode=0;
738

    
739
        if (url_feof(bc))
740
            return -1;
741

    
742
        if(tmp){
743
            pos-=8;
744
        }else{
745
            frame_code = get_byte(bc);
746
            if(frame_code == 'N'){
747
                tmp= frame_code;
748
                for(i=1; i<8; i++)
749
                    tmp = (tmp<<8) + get_byte(bc);
750
            }
751
        }
752
        switch(tmp){
753
        case MAIN_STARTCODE:
754
        case STREAM_STARTCODE:
755
        case INDEX_STARTCODE:
756
            skip= get_packetheader(nut, bc, 0);
757
            url_fseek(bc, skip, SEEK_CUR);
758
            break;
759
        case INFO_STARTCODE:
760
            if(decode_info_header(nut)<0)
761
                goto resync;
762
            break;
763
        case SYNCPOINT_STARTCODE:
764
            if(decode_syncpoint(nut, &ts, &back_ptr)<0)
765
                goto resync;
766
            frame_code = get_byte(bc);
767
        case 0:
768
            ret= decode_frame(nut, pkt, frame_code);
769
            if(ret==0)
770
                return 0;
771
            else if(ret==1) //ok but discard packet
772
                break;
773
        default:
774
resync:
775
av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
776
            tmp= find_any_startcode(bc, nut->last_syncpoint_pos+1);
777
            if(tmp==0)
778
                return -1;
779
av_log(s, AV_LOG_DEBUG, "sync\n");
780
            nut->next_startcode= tmp;
781
        }
782
    }
783
}
784

    
785
static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
786
    NUTContext *nut = s->priv_data;
787
    ByteIOContext *bc = &s->pb;
788
    int64_t pos, pts, back_ptr;
789
    int frame_code, stream_id,size, flags;
790
av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
791

    
792
    pos= *pos_arg;
793
resync:
794
    do{
795
        pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
796
        if(pos < 1){
797
            assert(nut->next_startcode == 0);
798
            av_log(s, AV_LOG_ERROR, "read_timestamp failed\n");
799
            return AV_NOPTS_VALUE;
800
        }
801
    }while(decode_syncpoint(nut, &pts, &back_ptr) < 0);
802
    *pos_arg = pos-1;
803
    assert(nut->last_syncpoint_pos == *pos_arg);
804

    
805
    av_log(s, AV_LOG_DEBUG, "return %Ld %Ld\n", pts,back_ptr );
806
    if     (stream_index == -1) return pts;
807
    else if(stream_index == -2) return back_ptr;
808

    
809
assert(0);
810
    do{
811
        frame_code= get_byte(bc);
812
        if(frame_code == 'N'){
813
            pos= url_ftell(bc)-1;
814
            goto resync;
815
        }
816
        //FIXME consider pos_limit and eof
817
        size= decode_frame_header(nut, &flags, &pts, &stream_id, frame_code);
818

    
819
        if(size < 0)
820
            goto resync;
821

    
822
        url_fseek(bc, size, SEEK_CUR);
823
    }while(stream_id != stream_index || !(flags & FLAG_KEY));
824
    assert(nut->next_startcode == 0);
825
    av_log(s, AV_LOG_DEBUG, "read_timestamp success\n");
826

    
827
    return pts;
828
}
829

    
830
static int read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags){
831
    NUTContext *nut = s->priv_data;
832
    AVStream *st= s->streams[stream_index];
833
    syncpoint_t dummy={.ts= pts*av_q2d(st->time_base)*AV_TIME_BASE};
834
    syncpoint_t nopts_sp= {.ts= AV_NOPTS_VALUE, .back_ptr= AV_NOPTS_VALUE};
835
    syncpoint_t *sp, *next_node[2]= {&nopts_sp, &nopts_sp};
836
    int64_t pos, pos2, ts;
837

    
838
    if(st->index_entries){
839
        int index= av_index_search_timestamp(st, pts, flags);
840
        if(index<0)
841
            return -1;
842

    
843
        pos2= st->index_entries[index].pos;
844
        ts  = st->index_entries[index].timestamp;
845
    }else{
846
        av_tree_find(nut->syncpoints, &dummy, sp_pts_cmp, next_node);
847
        av_log(s, AV_LOG_DEBUG, "%Ld-%Ld %Ld-%Ld\n", next_node[0]->pos, next_node[1]->pos,
848
                                                    next_node[0]->ts , next_node[1]->ts);
849
        pos= av_gen_search(s, -1, dummy.ts, next_node[0]->pos, next_node[1]->pos, next_node[1]->pos,
850
                                            next_node[0]->ts , next_node[1]->ts, AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
851

    
852
        if(!(flags & AVSEEK_FLAG_BACKWARD)){
853
            dummy.pos= pos+16;
854
            next_node[1]= &nopts_sp;
855
            av_tree_find(nut->syncpoints, &dummy, sp_pos_cmp, next_node);
856
            pos2= av_gen_search(s, -2, dummy.pos, next_node[0]->pos     , next_node[1]->pos, next_node[1]->pos,
857
                                                next_node[0]->back_ptr, next_node[1]->back_ptr, flags, &ts, nut_read_timestamp);
858
            if(pos2>=0)
859
                pos= pos2;
860
            //FIXME dir but i think it doesnt matter
861
        }
862
        dummy.pos= pos;
863
        sp= av_tree_find(nut->syncpoints, &dummy, sp_pos_cmp, NULL);
864

    
865
        assert(sp);
866
        pos2= sp->back_ptr  - 15;
867
    }
868
    av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
869
    pos= find_startcode(&s->pb, SYNCPOINT_STARTCODE, pos2);
870
    url_fseek(&s->pb, pos, SEEK_SET);
871
    av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
872
    if(pos2 > pos || pos2 + 15 < pos){
873
        av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
874
    }
875
    return 0;
876
}
877

    
878
static int nut_read_close(AVFormatContext *s)
879
{
880
    NUTContext *nut = s->priv_data;
881

    
882
    av_freep(&nut->time_base);
883
    av_freep(&nut->stream);
884

    
885
    return 0;
886
}
887

    
888
#ifdef CONFIG_NUT_DEMUXER
889
AVInputFormat nut_demuxer = {
890
    "nut",
891
    "nut format",
892
    sizeof(NUTContext),
893
    nut_probe,
894
    nut_read_header,
895
    nut_read_packet,
896
    nut_read_close,
897
    read_seek,
898
//    nut_read_timestamp,
899
    .extensions = "nut",
900
};
901
#endif