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ffmpeg / libavformat / nutdec.c @ c873bc17

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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.
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 *
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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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 *
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 */
23

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

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

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

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

    
37
        if (tmp&0x80)
38
            val= (val<<7) + tmp - 0x80;
39
        else{
40
            return (val<<7) + tmp;
41
        }
42
    }
43
    return -1;
44
}
45

    
46
static int get_str(ByteIOContext *bc, char *string, unsigned int maxlen){
47
    unsigned int len= get_v(bc);
48

    
49
    if(len && maxlen)
50
        get_buffer(bc, string, FFMIN(len, maxlen));
51
    while(len > maxlen){
52
        get_byte(bc);
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        len--;
54
    }
55

    
56
    if(maxlen)
57
        string[FFMIN(len, maxlen-1)]= 0;
58

    
59
    if(maxlen == len)
60
        return -1;
61
    else
62
        return 0;
63
}
64

    
65
static int64_t get_s(ByteIOContext *bc){
66
    int64_t v = get_v(bc) + 1;
67

    
68
    if (v&1) return -(v>>1);
69
    else     return  (v>>1);
70
}
71

    
72
static uint64_t get_fourcc(ByteIOContext *bc){
73
    unsigned int len= get_v(bc);
74

    
75
    if     (len==2) return get_le16(bc);
76
    else if(len==4) return get_le32(bc);
77
    else            return -1;
78
}
79

    
80
#ifdef TRACE
81
static inline uint64_t get_v_trace(ByteIOContext *bc, char *file, char *func, int line){
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    uint64_t v= get_v(bc);
83

    
84
    printf("get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
85
    return v;
86
}
87

    
88
static inline int64_t get_s_trace(ByteIOContext *bc, char *file, char *func, int line){
89
    int64_t v= get_s(bc);
90

    
91
    printf("get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
92
    return v;
93
}
94

    
95
static inline uint64_t get_vb_trace(ByteIOContext *bc, char *file, char *func, int line){
96
    uint64_t v= get_vb(bc);
97

    
98
    printf("get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
99
    return v;
100
}
101
#define get_v(bc)  get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
102
#define get_s(bc)  get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
103
#define get_vb(bc)  get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
104
#endif
105

    
106
static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int calculate_checksum)
107
{
108
    int64_t start, size;
109
//    start= url_ftell(bc) - 8;
110

    
111
    size= get_v(bc);
112

    
113
    init_checksum(bc, calculate_checksum ? av_crc04C11DB7_update : NULL, 0);
114

    
115
//    nut->packet_start[2] = start;
116
//    nut->written_packet_size= size;
117

    
118
    return size;
119
}
120

    
121
static uint64_t find_any_startcode(ByteIOContext *bc, int64_t pos){
122
    uint64_t state=0;
123

    
124
    if(pos >= 0)
125
        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
126

    
127
    while(!url_feof(bc)){
128
        state= (state<<8) | get_byte(bc);
129
        if((state>>56) != 'N')
130
            continue;
131
        switch(state){
132
        case MAIN_STARTCODE:
133
        case STREAM_STARTCODE:
134
        case SYNCPOINT_STARTCODE:
135
        case INFO_STARTCODE:
136
        case INDEX_STARTCODE:
137
            return state;
138
        }
139
    }
140

    
141
    return 0;
142
}
143

    
144
/**
145
 * find the given startcode.
146
 * @param code the startcode
147
 * @param pos the start position of the search, or -1 if the current position
148
 * @returns the position of the startcode or -1 if not found
149
 */
150
static int64_t find_startcode(ByteIOContext *bc, uint64_t code, int64_t pos){
151
    for(;;){
152
        uint64_t startcode= find_any_startcode(bc, pos);
153
        if(startcode == code)
154
            return url_ftell(bc) - 8;
155
        else if(startcode == 0)
156
            return -1;
157
        pos=-1;
158
    }
159
}
160

    
161
static int64_t lsb2full(StreamContext *stream, int64_t lsb){
162
    int64_t mask = (1<<stream->msb_pts_shift)-1;
163
    int64_t delta= stream->last_pts - mask/2;
164
    return  ((lsb - delta)&mask) + delta;
165
}
166

    
167
static int nut_probe(AVProbeData *p){
168
    int i;
169
    uint64_t code= 0;
170

    
171
    for (i = 0; i < p->buf_size; i++) {
172
        code = (code << 8) | p->buf[i];
173
        if (code == MAIN_STARTCODE)
174
            return AVPROBE_SCORE_MAX;
175
    }
176
    return 0;
177
}
178

    
179
#define GET_V(dst, check) \
180
    tmp= get_v(bc);\
181
    if(!(check)){\
182
        av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp);\
183
        return -1;\
184
    }\
185
    dst= tmp;
186

    
187
static int skip_reserved(ByteIOContext *bc, int64_t pos){
188
    pos -= url_ftell(bc);
189
    if(pos<0){
190
        url_fseek(bc, pos, SEEK_CUR);
191
        return -1;
192
    }else{
193
        while(pos--)
194
            get_byte(bc);
195
        return 0;
196
    }
197
}
198

    
199
static int decode_main_header(NUTContext *nut){
200
    AVFormatContext *s= nut->avf;
201
    ByteIOContext *bc = &s->pb;
202
    uint64_t tmp, end;
203
    unsigned int stream_count;
204
    int i, j, tmp_stream, tmp_mul, tmp_pts, tmp_size, count, tmp_res;
205

    
206
    end= get_packetheader(nut, bc, 1);
207
    end += url_ftell(bc);
208

    
209
    GET_V(tmp              , tmp >=2 && tmp <= 3)
210
    GET_V(stream_count     , tmp > 0 && tmp <=MAX_STREAMS)
211

    
212
    nut->max_distance = get_v(bc);
213
    if(nut->max_distance > 65536){
214
        av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
215
        nut->max_distance= 65536;
216
    }
217

    
218
    GET_V(nut->time_base_count, tmp>0 && tmp<INT_MAX / sizeof(AVRational))
219
    nut->time_base= av_malloc(nut->time_base_count * sizeof(AVRational));
220

    
221
    for(i=0; i<nut->time_base_count; i++){
222
        GET_V(nut->time_base[i].num, tmp>0 && tmp<(1ULL<<31))
223
        GET_V(nut->time_base[i].den, tmp>0 && tmp<(1ULL<<31))
224
        if(ff_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1){
225
            av_log(s, AV_LOG_ERROR, "time base invalid\n");
226
            return -1;
227
        }
228
    }
229
    tmp_pts=0;
230
    tmp_mul=1;
231
    tmp_stream=0;
232
    for(i=0; i<256;){
233
        int tmp_flags = get_v(bc);
234
        int tmp_fields= get_v(bc);
235
        if(tmp_fields>0) tmp_pts   = get_s(bc);
236
        if(tmp_fields>1) tmp_mul   = get_v(bc);
237
        if(tmp_fields>2) tmp_stream= get_v(bc);
238
        if(tmp_fields>3) tmp_size  = get_v(bc);
239
        else             tmp_size  = 0;
240
        if(tmp_fields>4) tmp_res   = get_v(bc);
241
        else             tmp_res   = 0;
242
        if(tmp_fields>5) count     = get_v(bc);
243
        else             count     = tmp_mul - tmp_size;
244

    
245
        while(tmp_fields-- > 6)
246
           get_v(bc);
247

    
248
        if(count == 0 || i+count > 256){
249
            av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
250
            return -1;
251
        }
252
        if(tmp_stream >= stream_count){
253
            av_log(s, AV_LOG_ERROR, "illegal stream number\n");
254
            return -1;
255
        }
256

    
257
        for(j=0; j<count; j++,i++){
258
            if (i == 'N') {
259
                nut->frame_code[i].flags= FLAG_INVALID;
260
                j--;
261
                continue;
262
            }
263
            nut->frame_code[i].flags           = tmp_flags ;
264
            nut->frame_code[i].pts_delta       = tmp_pts   ;
265
            nut->frame_code[i].stream_id       = tmp_stream;
266
            nut->frame_code[i].size_mul        = tmp_mul   ;
267
            nut->frame_code[i].size_lsb        = tmp_size+j;
268
            nut->frame_code[i].reserved_count  = tmp_res   ;
269
        }
270
    }
271
    assert(nut->frame_code['N'].flags == FLAG_INVALID);
272

    
273
    if(skip_reserved(bc, end) || get_checksum(bc)){
274
        av_log(s, AV_LOG_ERROR, "Main header checksum mismatch\n");
275
        return -1;
276
    }
277

    
278
    nut->stream = av_mallocz(sizeof(StreamContext)*stream_count);
279
    for(i=0; i<stream_count; i++){
280
        av_new_stream(s, i);
281
    }
282

    
283
    return 0;
284
}
285

    
286
static int decode_stream_header(NUTContext *nut){
287
    AVFormatContext *s= nut->avf;
288
    ByteIOContext *bc = &s->pb;
289
    StreamContext *stc;
290
    int class, stream_id;
291
    uint64_t tmp, end;
292
    AVStream *st;
293

    
294
    end= get_packetheader(nut, bc, 1);
295
    end += url_ftell(bc);
296

    
297
    GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base.num);
298
    stc= &nut->stream[stream_id];
299

    
300
    st = s->streams[stream_id];
301
    if (!st)
302
        return AVERROR_NOMEM;
303

    
304
    class = get_v(bc);
305
    tmp = get_fourcc(bc);
306
    st->codec->codec_tag= tmp;
307
    switch(class)
308
    {
309
        case 0:
310
            st->codec->codec_type = CODEC_TYPE_VIDEO;
311
            st->codec->codec_id = codec_get_bmp_id(tmp);
312
            if (st->codec->codec_id == CODEC_ID_NONE)
313
                av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
314
            break;
315
        case 1:
316
            st->codec->codec_type = CODEC_TYPE_AUDIO;
317
            st->codec->codec_id = codec_get_wav_id(tmp);
318
            if (st->codec->codec_id == CODEC_ID_NONE)
319
                av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
320
            break;
321
        case 2:
322
//            st->codec->codec_type = CODEC_TYPE_TEXT;
323
//            break;
324
        case 3:
325
            st->codec->codec_type = CODEC_TYPE_DATA;
326
            break;
327
        default:
328
            av_log(s, AV_LOG_ERROR, "Unknown stream class (%d)\n", class);
329
            return -1;
330
    }
331
    GET_V(stc->time_base_id    , tmp < nut->time_base_count);
332
    GET_V(stc->msb_pts_shift   , tmp < 16);
333
    stc->max_pts_distance= get_v(bc);
334
    GET_V(stc->decode_delay    , tmp < 1000); //sanity limit, raise this if moors law is true
335
    st->codec->has_b_frames= stc->decode_delay;
336
    get_v(bc); //stream flags
337

    
338
    GET_V(st->codec->extradata_size, tmp < (1<<30));
339
    if(st->codec->extradata_size){
340
        st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
341
        get_buffer(bc, st->codec->extradata, st->codec->extradata_size);
342
    }
343

    
344
    if (st->codec->codec_type == CODEC_TYPE_VIDEO){
345
        GET_V(st->codec->width , tmp > 0)
346
        GET_V(st->codec->height, tmp > 0)
347
        st->codec->sample_aspect_ratio.num= get_v(bc);
348
        st->codec->sample_aspect_ratio.den= get_v(bc);
349
        if((!st->codec->sample_aspect_ratio.num) != (!st->codec->sample_aspect_ratio.den)){
350
            av_log(s, AV_LOG_ERROR, "invalid aspect ratio\n");
351
            return -1;
352
        }
353
        get_v(bc); /* csp type */
354
    }else if (st->codec->codec_type == CODEC_TYPE_AUDIO){
355
        GET_V(st->codec->sample_rate , tmp > 0)
356
        tmp= get_v(bc); // samplerate_den
357
        if(tmp > st->codec->sample_rate){
358
            av_log(s, AV_LOG_ERROR, "bleh, libnut muxed this ;)\n");
359
            st->codec->sample_rate= tmp;
360
        }
361
        GET_V(st->codec->channels, tmp > 0)
362
    }
363
    if(skip_reserved(bc, end) || get_checksum(bc)){
364
        av_log(s, AV_LOG_ERROR, "Stream header %d checksum mismatch\n", stream_id);
365
        return -1;
366
    }
367
    stc->time_base= nut->time_base[stc->time_base_id];
368
    av_set_pts_info(s->streams[stream_id], 63, stc->time_base.num, stc->time_base.den);
369
    return 0;
370
}
371

    
372
static int decode_info_header(NUTContext *nut){
373
    AVFormatContext *s= nut->avf;
374
    ByteIOContext *bc = &s->pb;
375
    uint64_t tmp;
376
    unsigned int stream_id_plus1, chapter_start, chapter_len, count;
377
    int chapter_id, i;
378
    int64_t value, end;
379
    char name[256], str_value[1024], type_str[256], *type= type_str;
380

    
381
    end= get_packetheader(nut, bc, 1);
382
    end += url_ftell(bc);
383

    
384
    GET_V(stream_id_plus1, tmp <= s->nb_streams)
385
    chapter_id   = get_s(bc);
386
    chapter_start= get_v(bc);
387
    chapter_len  = get_v(bc);
388
    count        = get_v(bc);
389
    for(i=0; i<count; i++){
390
        get_str(bc, name, sizeof(name));
391
        value= get_s(bc);
392
        if(value == -1){
393
            type= "UTF-8";
394
            get_str(bc, str_value, sizeof(str_value));
395
        }else if(value == -2){
396
            get_str(bc, type, sizeof(type));
397
            get_str(bc, str_value, sizeof(str_value));
398
        }else if(value == -3){
399
            type= "s";
400
            value= get_s(bc);
401
        }else if(value == -4){
402
            type= "t";
403
            value= get_v(bc);
404
        }else if(value < -4){
405
            type= "r";
406
            get_s(bc);
407
        }else{
408
            type= "v";
409
        }
410

    
411
        if(chapter_id==0 && !strcmp(type, "UTF-8")){
412
            if     (!strcmp(name, "Author"))
413
                pstrcpy(s->author   , sizeof(s->author)   , str_value);
414
            else if(!strcmp(name, "Title"))
415
                pstrcpy(s->title    , sizeof(s->title)    , str_value);
416
            else if(!strcmp(name, "Copyright"))
417
                pstrcpy(s->copyright, sizeof(s->copyright), str_value);
418
            else if(!strcmp(name, "Description"))
419
                pstrcpy(s->comment  , sizeof(s->comment)  , str_value);
420
        }
421
    }
422

    
423
    if(skip_reserved(bc, end) || get_checksum(bc)){
424
        av_log(s, AV_LOG_ERROR, "Info header checksum mismatch\n");
425
        return -1;
426
    }
427
    return 0;
428
}
429

    
430
int sp_pos_cmp(syncpoint_t *a, syncpoint_t *b){
431
    return (a->pos - b->pos>>32) - (b->pos - a->pos>>32);
432
}
433

    
434
int sp_pts_cmp(syncpoint_t *a, syncpoint_t *b){
435
    return (a->ts - b->ts>>32) - (b->ts - a->ts>>32);
436
}
437

    
438
static void add_sp(NUTContext *nut, int64_t pos, int64_t back_ptr, int64_t ts){
439
    syncpoint_t *sp2, *sp= av_mallocz(sizeof(syncpoint_t));
440

    
441
    sp->pos= pos;
442
    sp->back_ptr= back_ptr;
443
    sp->ts= ts;
444
    sp2= av_tree_insert(&nut->syncpoints, sp, sp_pos_cmp);
445
    if(sp2 && sp2 != sp)
446
        av_free(sp);
447
}
448

    
449
static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr){
450
    AVFormatContext *s= nut->avf;
451
    ByteIOContext *bc = &s->pb;
452
    int64_t end, tmp;
453
    int i;
454
    AVRational time_base;
455

    
456
    nut->last_syncpoint_pos= url_ftell(bc)-8;
457

    
458
    end= get_packetheader(nut, bc, 1);
459
    end += url_ftell(bc);
460

    
461
    tmp= get_v(bc);
462
    *back_ptr= nut->last_syncpoint_pos - 16*get_v(bc);
463
    if(*back_ptr < 0)
464
        return -1;
465

    
466
    time_base= nut->time_base[tmp % nut->time_base_count];
467
    for(i=0; i<s->nb_streams; i++){
468
        nut->stream[i].last_pts= av_rescale_rnd(
469
            tmp / nut->time_base_count,
470
            time_base.num * (int64_t)nut->stream[i].time_base.den,
471
            time_base.den * (int64_t)nut->stream[i].time_base.num,
472
            AV_ROUND_DOWN);
473
        //last_key_frame ?
474
    }
475
    //FIXME put this in a reset func maybe
476

    
477
    if(skip_reserved(bc, end) || get_checksum(bc)){
478
        av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
479
        return -1;
480
    }
481

    
482
    *ts= tmp / s->nb_streams * av_q2d(nut->time_base[tmp % s->nb_streams])*AV_TIME_BASE;
483
    add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
484

    
485
    return 0;
486
}
487

    
488
static int find_and_decode_index(NUTContext *nut){
489
    AVFormatContext *s= nut->avf;
490
    ByteIOContext *bc = &s->pb;
491
    uint64_t tmp, end;
492
    int i, j, syncpoint_count;
493
    int64_t filesize= url_fsize(bc);
494
    int64_t *syncpoints;
495
    int8_t *has_keyframe;
496

    
497
    url_fseek(bc, filesize-12, SEEK_SET);
498
    url_fseek(bc, filesize-get_be64(bc), SEEK_SET);
499
    if(get_be64(bc) != INDEX_STARTCODE){
500
        av_log(s, AV_LOG_ERROR, "no index at the end\n");
501
        return -1;
502
    }
503

    
504
    end= get_packetheader(nut, bc, 1);
505
    end += url_ftell(bc);
506

    
507
    get_v(bc); //max_pts
508
    GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
509
    syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
510
    has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
511
    for(i=0; i<syncpoint_count; i++){
512
        GET_V(syncpoints[i], tmp>0)
513
        if(i)
514
            syncpoints[i] += syncpoints[i-1];
515
    }
516

    
517
    for(i=0; i<s->nb_streams; i++){
518
        int64_t last_pts= -1;
519
        for(j=0; j<syncpoint_count;){
520
            uint64_t x= get_v(bc);
521
            int type= x&1;
522
            int n= j;
523
            x>>=1;
524
            if(type){
525
                int flag= x&1;
526
                x>>=1;
527
                if(n+x >= syncpoint_count + 1){
528
                    av_log(s, AV_LOG_ERROR, "index overflow A\n");
529
                    return -1;
530
                }
531
                while(x--)
532
                    has_keyframe[n++]= flag;
533
                has_keyframe[n++]= !flag;
534
            }else{
535
                while(x != 1){
536
                    if(n>=syncpoint_count + 1){
537
                        av_log(s, AV_LOG_ERROR, "index overflow B\n");
538
                        return -1;
539
                    }
540
                    has_keyframe[n++]= x&1;
541
                    x>>=1;
542
                }
543
            }
544
            if(has_keyframe[0]){
545
                av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
546
                return -1;
547
            }
548
            assert(n<=syncpoint_count+1);
549
            for(; j<n; j++){
550
                if(has_keyframe[j]){
551
                    uint64_t B, A= get_v(bc);
552
                    if(!A){
553
                        A= get_v(bc);
554
                        B= get_v(bc);
555
                        //eor_pts[j][i] = last_pts + A + B
556
                    }else
557
                        B= 0;
558
                    av_add_index_entry(
559
                        s->streams[i],
560
                        16*syncpoints[j-1],
561
                        last_pts + A,
562
                        0,
563
                        0,
564
                        AVINDEX_KEYFRAME);
565
                    last_pts += A + B;
566
                }
567
            }
568
        }
569
    }
570

    
571
    if(skip_reserved(bc, end) || get_checksum(bc)){
572
        av_log(s, AV_LOG_ERROR, "Index checksum mismatch\n");
573
        return -1;
574
    }
575
    return 0;
576
}
577

    
578
static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
579
{
580
    NUTContext *nut = s->priv_data;
581
    ByteIOContext *bc = &s->pb;
582
    int64_t pos;
583
    int inited_stream_count;
584

    
585
    nut->avf= s;
586

    
587
    /* main header */
588
    pos=0;
589
    do{
590
        pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
591
        if (pos<0+1){
592
            av_log(s, AV_LOG_ERROR, "no main startcode found\n");
593
            return -1;
594
        }
595
    }while(decode_main_header(nut) < 0);
596

    
597
    /* stream headers */
598
    pos=0;
599
    for(inited_stream_count=0; inited_stream_count < s->nb_streams;){
600
        pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
601
        if (pos<0+1){
602
            av_log(s, AV_LOG_ERROR, "not all stream headers found\n");
603
            return -1;
604
        }
605
        if(decode_stream_header(nut) >= 0)
606
            inited_stream_count++;
607
    }
608

    
609
    /* info headers */
610
    pos=0;
611
    for(;;){
612
        uint64_t startcode= find_any_startcode(bc, pos);
613
        pos= url_ftell(bc);
614

    
615
        if(startcode==0){
616
            av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
617
            return -1;
618
        }else if(startcode == SYNCPOINT_STARTCODE){
619
            nut->next_startcode= startcode;
620
            break;
621
        }else if(startcode != INFO_STARTCODE){
622
            continue;
623
        }
624

    
625
        decode_info_header(nut);
626
    }
627

    
628
    s->data_offset= pos-8;
629

    
630
    if(!url_is_streamed(bc)){
631
        int64_t orig_pos= url_ftell(bc);
632
        find_and_decode_index(nut);
633
        url_fseek(bc, orig_pos, SEEK_SET);
634
    }
635
    assert(nut->next_startcode == SYNCPOINT_STARTCODE);
636

    
637
    return 0;
638
}
639

    
640
static int decode_frame_header(NUTContext *nut, int *flags_ret, int64_t *pts, int *stream_id, int frame_code){
641
    AVFormatContext *s= nut->avf;
642
    ByteIOContext *bc = &s->pb;
643
    StreamContext *stc;
644
    int size, flags, size_mul, pts_delta, i, reserved_count;
645
    uint64_t tmp;
646

    
647
    if(url_ftell(bc) > nut->last_syncpoint_pos + nut->max_distance){
648
        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);
649
        return -1;
650
    }
651

    
652
    flags          = nut->frame_code[frame_code].flags;
653
    size_mul       = nut->frame_code[frame_code].size_mul;
654
    size           = nut->frame_code[frame_code].size_lsb;
655
    *stream_id     = nut->frame_code[frame_code].stream_id;
656
    pts_delta      = nut->frame_code[frame_code].pts_delta;
657
    reserved_count = nut->frame_code[frame_code].reserved_count;
658

    
659
    if(flags & FLAG_INVALID)
660
        return -1;
661
    if(flags & FLAG_CODED)
662
        flags ^= get_v(bc);
663
    if(flags & FLAG_STREAM_ID){
664
        GET_V(*stream_id, tmp < s->nb_streams)
665
    }
666
    stc= &nut->stream[*stream_id];
667
    if(flags&FLAG_CODED_PTS){
668
        int coded_pts= get_v(bc);
669
//FIXME check last_pts validity?
670
        if(coded_pts < (1<<stc->msb_pts_shift)){
671
            *pts=lsb2full(stc, coded_pts);
672
        }else
673
            *pts=coded_pts - (1<<stc->msb_pts_shift);
674
    }else
675
        *pts= stc->last_pts + pts_delta;
676
    if(flags&FLAG_SIZE_MSB){
677
        size += size_mul*get_v(bc);
678
    }
679
    if(flags&FLAG_RESERVED)
680
        reserved_count= get_v(bc);
681
    for(i=0; i<reserved_count; i++)
682
        get_v(bc);
683
    if(flags&FLAG_CHECKSUM){
684
        get_be32(bc); //FIXME check this
685
    }else if(size > 2*nut->max_distance){
686
        av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
687
        return -1;
688
    }
689
    *flags_ret= flags;
690

    
691
    stc->last_pts= *pts;
692
    stc->last_key_frame= flags&FLAG_KEY; //FIXME change to last flags
693

    
694
    return size;
695
}
696

    
697
static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
698
    AVFormatContext *s= nut->avf;
699
    ByteIOContext *bc = &s->pb;
700
    int size, stream_id, flags, discard;
701
    int64_t pts, last_IP_pts;
702

    
703
    size= decode_frame_header(nut, &flags, &pts, &stream_id, frame_code);
704
    if(size < 0)
705
        return -1;
706

    
707
    discard= s->streams[ stream_id ]->discard;
708
    last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
709
    if(  (discard >= AVDISCARD_NONKEY && !(flags & FLAG_KEY))
710
       ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
711
       || discard >= AVDISCARD_ALL){
712
        url_fskip(bc, size);
713
        return 1;
714
    }
715

    
716
    av_get_packet(bc, pkt, size);
717
    pkt->stream_index = stream_id;
718
    if (flags & FLAG_KEY)
719
        pkt->flags |= PKT_FLAG_KEY;
720
    pkt->pts = pts;
721

    
722
    return 0;
723
}
724

    
725
static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
726
{
727
    NUTContext *nut = s->priv_data;
728
    ByteIOContext *bc = &s->pb;
729
    int i, frame_code=0, ret, skip;
730
    int64_t ts, back_ptr;
731

    
732
    for(;;){
733
        int64_t pos= url_ftell(bc);
734
        uint64_t tmp= nut->next_startcode;
735
        nut->next_startcode=0;
736

    
737
        if (url_feof(bc))
738
            return -1;
739

    
740
        if(tmp){
741
            pos-=8;
742
        }else{
743
            frame_code = get_byte(bc);
744
            if(frame_code == 'N'){
745
                tmp= frame_code;
746
                for(i=1; i<8; i++)
747
                    tmp = (tmp<<8) + get_byte(bc);
748
            }
749
        }
750
        switch(tmp){
751
        case MAIN_STARTCODE:
752
        case STREAM_STARTCODE:
753
        case INDEX_STARTCODE:
754
            skip= get_packetheader(nut, bc, 0);
755
            url_fseek(bc, skip, SEEK_CUR);
756
            break;
757
        case INFO_STARTCODE:
758
            if(decode_info_header(nut)<0)
759
                goto resync;
760
            break;
761
        case SYNCPOINT_STARTCODE:
762
            if(decode_syncpoint(nut, &ts, &back_ptr)<0)
763
                goto resync;
764
            frame_code = get_byte(bc);
765
        case 0:
766
            ret= decode_frame(nut, pkt, frame_code);
767
            if(ret==0)
768
                return 0;
769
            else if(ret==1) //ok but discard packet
770
                break;
771
        default:
772
resync:
773
av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
774
            tmp= find_any_startcode(bc, nut->last_syncpoint_pos+1);
775
            if(tmp==0)
776
                return -1;
777
av_log(s, AV_LOG_DEBUG, "sync\n");
778
            nut->next_startcode= tmp;
779
        }
780
    }
781
}
782

    
783
static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
784
    NUTContext *nut = s->priv_data;
785
    ByteIOContext *bc = &s->pb;
786
    int64_t pos, pts, back_ptr;
787
av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
788

    
789
    pos= *pos_arg;
790
resync:
791
    do{
792
        pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
793
        if(pos < 1){
794
            assert(nut->next_startcode == 0);
795
            av_log(s, AV_LOG_ERROR, "read_timestamp failed\n");
796
            return AV_NOPTS_VALUE;
797
        }
798
    }while(decode_syncpoint(nut, &pts, &back_ptr) < 0);
799
    *pos_arg = pos-1;
800
    assert(nut->last_syncpoint_pos == *pos_arg);
801

    
802
    av_log(s, AV_LOG_DEBUG, "return %Ld %Ld\n", pts,back_ptr );
803
    if     (stream_index == -1) return pts;
804
    else if(stream_index == -2) return back_ptr;
805

    
806
assert(0);
807
}
808

    
809
static int read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags){
810
    NUTContext *nut = s->priv_data;
811
    AVStream *st= s->streams[stream_index];
812
    syncpoint_t dummy={.ts= pts*av_q2d(st->time_base)*AV_TIME_BASE};
813
    syncpoint_t nopts_sp= {.ts= AV_NOPTS_VALUE, .back_ptr= AV_NOPTS_VALUE};
814
    syncpoint_t *sp, *next_node[2]= {&nopts_sp, &nopts_sp};
815
    int64_t pos, pos2, ts;
816

    
817
    if(st->index_entries){
818
        int index= av_index_search_timestamp(st, pts, flags);
819
        if(index<0)
820
            return -1;
821

    
822
        pos2= st->index_entries[index].pos;
823
        ts  = st->index_entries[index].timestamp;
824
    }else{
825
        av_tree_find(nut->syncpoints, &dummy, sp_pts_cmp, next_node);
826
        av_log(s, AV_LOG_DEBUG, "%Ld-%Ld %Ld-%Ld\n", next_node[0]->pos, next_node[1]->pos,
827
                                                    next_node[0]->ts , next_node[1]->ts);
828
        pos= av_gen_search(s, -1, dummy.ts, next_node[0]->pos, next_node[1]->pos, next_node[1]->pos,
829
                                            next_node[0]->ts , next_node[1]->ts, AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
830

    
831
        if(!(flags & AVSEEK_FLAG_BACKWARD)){
832
            dummy.pos= pos+16;
833
            next_node[1]= &nopts_sp;
834
            av_tree_find(nut->syncpoints, &dummy, sp_pos_cmp, next_node);
835
            pos2= av_gen_search(s, -2, dummy.pos, next_node[0]->pos     , next_node[1]->pos, next_node[1]->pos,
836
                                                next_node[0]->back_ptr, next_node[1]->back_ptr, flags, &ts, nut_read_timestamp);
837
            if(pos2>=0)
838
                pos= pos2;
839
            //FIXME dir but i think it doesnt matter
840
        }
841
        dummy.pos= pos;
842
        sp= av_tree_find(nut->syncpoints, &dummy, sp_pos_cmp, NULL);
843

    
844
        assert(sp);
845
        pos2= sp->back_ptr  - 15;
846
    }
847
    av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
848
    pos= find_startcode(&s->pb, SYNCPOINT_STARTCODE, pos2);
849
    url_fseek(&s->pb, pos, SEEK_SET);
850
    av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
851
    if(pos2 > pos || pos2 + 15 < pos){
852
        av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
853
    }
854
    return 0;
855
}
856

    
857
static int nut_read_close(AVFormatContext *s)
858
{
859
    NUTContext *nut = s->priv_data;
860

    
861
    av_freep(&nut->time_base);
862
    av_freep(&nut->stream);
863

    
864
    return 0;
865
}
866

    
867
#ifdef CONFIG_NUT_DEMUXER
868
AVInputFormat nut_demuxer = {
869
    "nut",
870
    "nut format",
871
    sizeof(NUTContext),
872
    nut_probe,
873
    nut_read_header,
874
    nut_read_packet,
875
    nut_read_close,
876
    read_seek,
877
    .extensions = "nut",
878
};
879
#endif