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ffmpeg / libavformat / nutdec.c @ 3abe5fbd

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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
 *
13
 * 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
16
 * Lesser General Public License for more details.
17
 *
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 * You should have received a copy of the GNU Lesser General Public
19
 * 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
21
 */
22

    
23
#include "tree.h"
24
#include "nut.h"
25
#include "avstring.h"
26

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

    
30
static int get_str(ByteIOContext *bc, char *string, unsigned int maxlen){
31
    unsigned int len= ff_get_v(bc);
32

    
33
    if(len && maxlen)
34
        get_buffer(bc, string, FFMIN(len, maxlen));
35
    while(len > maxlen){
36
        get_byte(bc);
37
        len--;
38
    }
39

    
40
    if(maxlen)
41
        string[FFMIN(len, maxlen-1)]= 0;
42

    
43
    if(maxlen == len)
44
        return -1;
45
    else
46
        return 0;
47
}
48

    
49
static int64_t get_s(ByteIOContext *bc){
50
    int64_t v = ff_get_v(bc) + 1;
51

    
52
    if (v&1) return -(v>>1);
53
    else     return  (v>>1);
54
}
55

    
56
static uint64_t get_fourcc(ByteIOContext *bc){
57
    unsigned int len= ff_get_v(bc);
58

    
59
    if     (len==2) return get_le16(bc);
60
    else if(len==4) return get_le32(bc);
61
    else            return -1;
62
}
63

    
64
#ifdef TRACE
65
static inline uint64_t get_v_trace(ByteIOContext *bc, char *file, char *func, int line){
66
    uint64_t v= ff_get_v(bc);
67

    
68
    av_log(NULL, AV_LOG_DEBUG, "get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
69
    return v;
70
}
71

    
72
static inline int64_t get_s_trace(ByteIOContext *bc, char *file, char *func, int line){
73
    int64_t v= get_s(bc);
74

    
75
    av_log(NULL, AV_LOG_DEBUG, "get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
76
    return v;
77
}
78

    
79
static inline uint64_t get_vb_trace(ByteIOContext *bc, char *file, char *func, int line){
80
    uint64_t v= get_vb(bc);
81

    
82
    av_log(NULL, AV_LOG_DEBUG, "get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
83
    return v;
84
}
85
#define ff_get_v(bc)  get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
86
#define get_s(bc)  get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
87
#define get_vb(bc)  get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
88
#endif
89

    
90
static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int calculate_checksum, uint64_t startcode)
91
{
92
    int64_t size;
93
//    start= url_ftell(bc) - 8;
94

    
95
    startcode= be2me_64(startcode);
96
    startcode= ff_crc04C11DB7_update(0, &startcode, 8);
97

    
98
    init_checksum(bc, ff_crc04C11DB7_update, startcode);
99
    size= ff_get_v(bc);
100
    if(size > 4096)
101
        get_be32(bc);
102
    if(get_checksum(bc) && size > 4096)
103
        return -1;
104

    
105
    init_checksum(bc, calculate_checksum ? ff_crc04C11DB7_update : NULL, 0);
106

    
107
    return size;
108
}
109

    
110
static uint64_t find_any_startcode(ByteIOContext *bc, int64_t pos){
111
    uint64_t state=0;
112

    
113
    if(pos >= 0)
114
        url_fseek(bc, pos, SEEK_SET); //note, this may fail if the stream is not seekable, but that should not matter, as in this case we simply start where we are currently
115

    
116
    while(!url_feof(bc)){
117
        state= (state<<8) | get_byte(bc);
118
        if((state>>56) != 'N')
119
            continue;
120
        switch(state){
121
        case MAIN_STARTCODE:
122
        case STREAM_STARTCODE:
123
        case SYNCPOINT_STARTCODE:
124
        case INFO_STARTCODE:
125
        case INDEX_STARTCODE:
126
            return state;
127
        }
128
    }
129

    
130
    return 0;
131
}
132

    
133
/**
134
 * Find the given startcode.
135
 * @param code the startcode
136
 * @param pos the start position of the search, or -1 if the current position
137
 * @returns the position of the startcode or -1 if not found
138
 */
139
static int64_t find_startcode(ByteIOContext *bc, uint64_t code, int64_t pos){
140
    for(;;){
141
        uint64_t startcode= find_any_startcode(bc, pos);
142
        if(startcode == code)
143
            return url_ftell(bc) - 8;
144
        else if(startcode == 0)
145
            return -1;
146
        pos=-1;
147
    }
148
}
149

    
150
static int nut_probe(AVProbeData *p){
151
    int i;
152
    uint64_t code= 0;
153

    
154
    for (i = 0; i < p->buf_size; i++) {
155
        code = (code << 8) | p->buf[i];
156
        if (code == MAIN_STARTCODE)
157
            return AVPROBE_SCORE_MAX;
158
    }
159
    return 0;
160
}
161

    
162
#define GET_V(dst, check) \
163
    tmp= ff_get_v(bc);\
164
    if(!(check)){\
165
        av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp);\
166
        return -1;\
167
    }\
168
    dst= tmp;
169

    
170
static int skip_reserved(ByteIOContext *bc, int64_t pos){
171
    pos -= url_ftell(bc);
172
    if(pos<0){
173
        url_fseek(bc, pos, SEEK_CUR);
174
        return -1;
175
    }else{
176
        while(pos--)
177
            get_byte(bc);
178
        return 0;
179
    }
180
}
181

    
182
static int decode_main_header(NUTContext *nut){
183
    AVFormatContext *s= nut->avf;
184
    ByteIOContext *bc = s->pb;
185
    uint64_t tmp, end;
186
    unsigned int stream_count;
187
    int i, j, tmp_stream, tmp_mul, tmp_pts, tmp_size, count, tmp_res;
188

    
189
    end= get_packetheader(nut, bc, 1, MAIN_STARTCODE);
190
    end += url_ftell(bc);
191

    
192
    GET_V(tmp              , tmp >=2 && tmp <= 3)
193
    GET_V(stream_count     , tmp > 0 && tmp <=MAX_STREAMS)
194

    
195
    nut->max_distance = ff_get_v(bc);
196
    if(nut->max_distance > 65536){
197
        av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
198
        nut->max_distance= 65536;
199
    }
200

    
201
    GET_V(nut->time_base_count, tmp>0 && tmp<INT_MAX / sizeof(AVRational))
202
    nut->time_base= av_malloc(nut->time_base_count * sizeof(AVRational));
203

    
204
    for(i=0; i<nut->time_base_count; i++){
205
        GET_V(nut->time_base[i].num, tmp>0 && tmp<(1ULL<<31))
206
        GET_V(nut->time_base[i].den, tmp>0 && tmp<(1ULL<<31))
207
        if(ff_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1){
208
            av_log(s, AV_LOG_ERROR, "time base invalid\n");
209
            return -1;
210
        }
211
    }
212
    tmp_pts=0;
213
    tmp_mul=1;
214
    tmp_stream=0;
215
    for(i=0; i<256;){
216
        int tmp_flags = ff_get_v(bc);
217
        int tmp_fields= ff_get_v(bc);
218
        if(tmp_fields>0) tmp_pts   = get_s(bc);
219
        if(tmp_fields>1) tmp_mul   = ff_get_v(bc);
220
        if(tmp_fields>2) tmp_stream= ff_get_v(bc);
221
        if(tmp_fields>3) tmp_size  = ff_get_v(bc);
222
        else             tmp_size  = 0;
223
        if(tmp_fields>4) tmp_res   = ff_get_v(bc);
224
        else             tmp_res   = 0;
225
        if(tmp_fields>5) count     = ff_get_v(bc);
226
        else             count     = tmp_mul - tmp_size;
227

    
228
        while(tmp_fields-- > 6)
229
           ff_get_v(bc);
230

    
231
        if(count == 0 || i+count > 256){
232
            av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
233
            return -1;
234
        }
235
        if(tmp_stream >= stream_count){
236
            av_log(s, AV_LOG_ERROR, "illegal stream number\n");
237
            return -1;
238
        }
239

    
240
        for(j=0; j<count; j++,i++){
241
            if (i == 'N') {
242
                nut->frame_code[i].flags= FLAG_INVALID;
243
                j--;
244
                continue;
245
            }
246
            nut->frame_code[i].flags           = tmp_flags ;
247
            nut->frame_code[i].pts_delta       = tmp_pts   ;
248
            nut->frame_code[i].stream_id       = tmp_stream;
249
            nut->frame_code[i].size_mul        = tmp_mul   ;
250
            nut->frame_code[i].size_lsb        = tmp_size+j;
251
            nut->frame_code[i].reserved_count  = tmp_res   ;
252
        }
253
    }
254
    assert(nut->frame_code['N'].flags == FLAG_INVALID);
255

    
256
    if(skip_reserved(bc, end) || get_checksum(bc)){
257
        av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
258
        return -1;
259
    }
260

    
261
    nut->stream = av_mallocz(sizeof(StreamContext)*stream_count);
262
    for(i=0; i<stream_count; i++){
263
        av_new_stream(s, i);
264
    }
265

    
266
    return 0;
267
}
268

    
269
static int decode_stream_header(NUTContext *nut){
270
    AVFormatContext *s= nut->avf;
271
    ByteIOContext *bc = s->pb;
272
    StreamContext *stc;
273
    int class, stream_id;
274
    uint64_t tmp, end;
275
    AVStream *st;
276

    
277
    end= get_packetheader(nut, bc, 1, STREAM_STARTCODE);
278
    end += url_ftell(bc);
279

    
280
    GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);
281
    stc= &nut->stream[stream_id];
282

    
283
    st = s->streams[stream_id];
284
    if (!st)
285
        return AVERROR(ENOMEM);
286

    
287
    class = ff_get_v(bc);
288
    tmp = get_fourcc(bc);
289
    st->codec->codec_tag= tmp;
290
    switch(class)
291
    {
292
        case 0:
293
            st->codec->codec_type = CODEC_TYPE_VIDEO;
294
            st->codec->codec_id = codec_get_id(codec_bmp_tags, tmp);
295
            if (st->codec->codec_id == CODEC_ID_NONE)
296
                av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
297
            break;
298
        case 1:
299
            st->codec->codec_type = CODEC_TYPE_AUDIO;
300
            st->codec->codec_id = codec_get_id(codec_wav_tags, tmp);
301
            if (st->codec->codec_id == CODEC_ID_NONE)
302
                av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
303
            break;
304
        case 2:
305
//            st->codec->codec_type = CODEC_TYPE_TEXT;
306
//            break;
307
        case 3:
308
            st->codec->codec_type = CODEC_TYPE_DATA;
309
            break;
310
        default:
311
            av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);
312
            return -1;
313
    }
314
    GET_V(stc->time_base_id    , tmp < nut->time_base_count);
315
    GET_V(stc->msb_pts_shift   , tmp < 16);
316
    stc->max_pts_distance= ff_get_v(bc);
317
    GET_V(stc->decode_delay    , tmp < 1000); //sanity limit, raise this if Moore's law is true
318
    st->codec->has_b_frames= stc->decode_delay;
319
    ff_get_v(bc); //stream flags
320

    
321
    GET_V(st->codec->extradata_size, tmp < (1<<30));
322
    if(st->codec->extradata_size){
323
        st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
324
        get_buffer(bc, st->codec->extradata, st->codec->extradata_size);
325
    }
326

    
327
    if (st->codec->codec_type == CODEC_TYPE_VIDEO){
328
        GET_V(st->codec->width , tmp > 0)
329
        GET_V(st->codec->height, tmp > 0)
330
        st->codec->sample_aspect_ratio.num= ff_get_v(bc);
331
        st->codec->sample_aspect_ratio.den= ff_get_v(bc);
332
        if((!st->codec->sample_aspect_ratio.num) != (!st->codec->sample_aspect_ratio.den)){
333
            av_log(s, AV_LOG_ERROR, "invalid aspect ratio %d/%d\n", st->codec->sample_aspect_ratio.num, st->codec->sample_aspect_ratio.den);
334
            return -1;
335
        }
336
        ff_get_v(bc); /* csp type */
337
    }else if (st->codec->codec_type == CODEC_TYPE_AUDIO){
338
        GET_V(st->codec->sample_rate , tmp > 0)
339
        tmp= ff_get_v(bc); // samplerate_den
340
        if(tmp > st->codec->sample_rate){
341
            av_log(s, AV_LOG_ERROR, "Bleh, libnut muxed this ;)\n");
342
            st->codec->sample_rate= tmp;
343
        }
344
        GET_V(st->codec->channels, tmp > 0)
345
    }
346
    if(skip_reserved(bc, end) || get_checksum(bc)){
347
        av_log(s, AV_LOG_ERROR, "stream header %d checksum mismatch\n", stream_id);
348
        return -1;
349
    }
350
    stc->time_base= &nut->time_base[stc->time_base_id];
351
    av_set_pts_info(s->streams[stream_id], 63, stc->time_base->num, stc->time_base->den);
352
    return 0;
353
}
354

    
355
static int decode_info_header(NUTContext *nut){
356
    AVFormatContext *s= nut->avf;
357
    ByteIOContext *bc = s->pb;
358
    uint64_t tmp;
359
    unsigned int stream_id_plus1, chapter_start, chapter_len, count;
360
    int chapter_id, i;
361
    int64_t value, end;
362
    char name[256], str_value[1024], type_str[256], *type= type_str;
363

    
364
    end= get_packetheader(nut, bc, 1, INFO_STARTCODE);
365
    end += url_ftell(bc);
366

    
367
    GET_V(stream_id_plus1, tmp <= s->nb_streams)
368
    chapter_id   = get_s(bc);
369
    chapter_start= ff_get_v(bc);
370
    chapter_len  = ff_get_v(bc);
371
    count        = ff_get_v(bc);
372
    for(i=0; i<count; i++){
373
        get_str(bc, name, sizeof(name));
374
        value= get_s(bc);
375
        if(value == -1){
376
            type= "UTF-8";
377
            get_str(bc, str_value, sizeof(str_value));
378
        }else if(value == -2){
379
            get_str(bc, type, sizeof(type));
380
            get_str(bc, str_value, sizeof(str_value));
381
        }else if(value == -3){
382
            type= "s";
383
            value= get_s(bc);
384
        }else if(value == -4){
385
            type= "t";
386
            value= ff_get_v(bc);
387
        }else if(value < -4){
388
            type= "r";
389
            get_s(bc);
390
        }else{
391
            type= "v";
392
        }
393

    
394
        if(chapter_id==0 && !strcmp(type, "UTF-8")){
395
            if     (!strcmp(name, "Author"))
396
                av_strlcpy(s->author   , str_value, sizeof(s->author));
397
            else if(!strcmp(name, "Title"))
398
                av_strlcpy(s->title    , str_value, sizeof(s->title));
399
            else if(!strcmp(name, "Copyright"))
400
                av_strlcpy(s->copyright, str_value, sizeof(s->copyright));
401
            else if(!strcmp(name, "Description"))
402
                av_strlcpy(s->comment  , str_value, sizeof(s->comment));
403
        }
404
    }
405

    
406
    if(skip_reserved(bc, end) || get_checksum(bc)){
407
        av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");
408
        return -1;
409
    }
410
    return 0;
411
}
412

    
413
static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr){
414
    AVFormatContext *s= nut->avf;
415
    ByteIOContext *bc = s->pb;
416
    int64_t end, tmp;
417

    
418
    nut->last_syncpoint_pos= url_ftell(bc)-8;
419

    
420
    end= get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
421
    end += url_ftell(bc);
422

    
423
    tmp= ff_get_v(bc);
424
    *back_ptr= nut->last_syncpoint_pos - 16*ff_get_v(bc);
425
    if(*back_ptr < 0)
426
        return -1;
427

    
428
    ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count], tmp);
429

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

    
435
    *ts= tmp / s->nb_streams * av_q2d(nut->time_base[tmp % s->nb_streams])*AV_TIME_BASE;
436
    ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
437

    
438
    return 0;
439
}
440

    
441
static int find_and_decode_index(NUTContext *nut){
442
    AVFormatContext *s= nut->avf;
443
    ByteIOContext *bc = s->pb;
444
    uint64_t tmp, end;
445
    int i, j, syncpoint_count;
446
    int64_t filesize= url_fsize(bc);
447
    int64_t *syncpoints;
448
    int8_t *has_keyframe;
449

    
450
    url_fseek(bc, filesize-12, SEEK_SET);
451
    url_fseek(bc, filesize-get_be64(bc), SEEK_SET);
452
    if(get_be64(bc) != INDEX_STARTCODE){
453
        av_log(s, AV_LOG_ERROR, "no index at the end\n");
454
        return -1;
455
    }
456

    
457
    end= get_packetheader(nut, bc, 1, INDEX_STARTCODE);
458
    end += url_ftell(bc);
459

    
460
    ff_get_v(bc); //max_pts
461
    GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
462
    syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
463
    has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
464
    for(i=0; i<syncpoint_count; i++){
465
        GET_V(syncpoints[i], tmp>0)
466
        if(i)
467
            syncpoints[i] += syncpoints[i-1];
468
    }
469

    
470
    for(i=0; i<s->nb_streams; i++){
471
        int64_t last_pts= -1;
472
        for(j=0; j<syncpoint_count;){
473
            uint64_t x= ff_get_v(bc);
474
            int type= x&1;
475
            int n= j;
476
            x>>=1;
477
            if(type){
478
                int flag= x&1;
479
                x>>=1;
480
                if(n+x >= syncpoint_count + 1){
481
                    av_log(s, AV_LOG_ERROR, "index overflow A\n");
482
                    return -1;
483
                }
484
                while(x--)
485
                    has_keyframe[n++]= flag;
486
                has_keyframe[n++]= !flag;
487
            }else{
488
                while(x != 1){
489
                    if(n>=syncpoint_count + 1){
490
                        av_log(s, AV_LOG_ERROR, "index overflow B\n");
491
                        return -1;
492
                    }
493
                    has_keyframe[n++]= x&1;
494
                    x>>=1;
495
                }
496
            }
497
            if(has_keyframe[0]){
498
                av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
499
                return -1;
500
            }
501
            assert(n<=syncpoint_count+1);
502
            for(; j<n; j++){
503
                if(has_keyframe[j]){
504
                    uint64_t B, A= ff_get_v(bc);
505
                    if(!A){
506
                        A= ff_get_v(bc);
507
                        B= ff_get_v(bc);
508
                        //eor_pts[j][i] = last_pts + A + B
509
                    }else
510
                        B= 0;
511
                    av_add_index_entry(
512
                        s->streams[i],
513
                        16*syncpoints[j-1],
514
                        last_pts + A,
515
                        0,
516
                        0,
517
                        AVINDEX_KEYFRAME);
518
                    last_pts += A + B;
519
                }
520
            }
521
        }
522
    }
523

    
524
    if(skip_reserved(bc, end) || get_checksum(bc)){
525
        av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
526
        return -1;
527
    }
528
    return 0;
529
}
530

    
531
static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
532
{
533
    NUTContext *nut = s->priv_data;
534
    ByteIOContext *bc = s->pb;
535
    int64_t pos;
536
    int inited_stream_count;
537

    
538
    nut->avf= s;
539

    
540
    /* main header */
541
    pos=0;
542
    do{
543
        pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
544
        if (pos<0+1){
545
            av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
546
            return -1;
547
        }
548
    }while(decode_main_header(nut) < 0);
549

    
550
    /* stream headers */
551
    pos=0;
552
    for(inited_stream_count=0; inited_stream_count < s->nb_streams;){
553
        pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
554
        if (pos<0+1){
555
            av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
556
            return -1;
557
        }
558
        if(decode_stream_header(nut) >= 0)
559
            inited_stream_count++;
560
    }
561

    
562
    /* info headers */
563
    pos=0;
564
    for(;;){
565
        uint64_t startcode= find_any_startcode(bc, pos);
566
        pos= url_ftell(bc);
567

    
568
        if(startcode==0){
569
            av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
570
            return -1;
571
        }else if(startcode == SYNCPOINT_STARTCODE){
572
            nut->next_startcode= startcode;
573
            break;
574
        }else if(startcode != INFO_STARTCODE){
575
            continue;
576
        }
577

    
578
        decode_info_header(nut);
579
    }
580

    
581
    s->data_offset= pos-8;
582

    
583
    if(!url_is_streamed(bc)){
584
        int64_t orig_pos= url_ftell(bc);
585
        find_and_decode_index(nut);
586
        url_fseek(bc, orig_pos, SEEK_SET);
587
    }
588
    assert(nut->next_startcode == SYNCPOINT_STARTCODE);
589

    
590
    return 0;
591
}
592

    
593
static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, int frame_code){
594
    AVFormatContext *s= nut->avf;
595
    ByteIOContext *bc = s->pb;
596
    StreamContext *stc;
597
    int size, flags, size_mul, pts_delta, i, reserved_count;
598
    uint64_t tmp;
599

    
600
    if(url_ftell(bc) > nut->last_syncpoint_pos + nut->max_distance){
601
        av_log(s, AV_LOG_ERROR, "Last frame must have been damaged %"PRId64" > %"PRId64" + %d\n", url_ftell(bc), nut->last_syncpoint_pos, nut->max_distance);
602
        return -1;
603
    }
604

    
605
    flags          = nut->frame_code[frame_code].flags;
606
    size_mul       = nut->frame_code[frame_code].size_mul;
607
    size           = nut->frame_code[frame_code].size_lsb;
608
    *stream_id     = nut->frame_code[frame_code].stream_id;
609
    pts_delta      = nut->frame_code[frame_code].pts_delta;
610
    reserved_count = nut->frame_code[frame_code].reserved_count;
611

    
612
    if(flags & FLAG_INVALID)
613
        return -1;
614
    if(flags & FLAG_CODED)
615
        flags ^= ff_get_v(bc);
616
    if(flags & FLAG_STREAM_ID){
617
        GET_V(*stream_id, tmp < s->nb_streams)
618
    }
619
    stc= &nut->stream[*stream_id];
620
    if(flags&FLAG_CODED_PTS){
621
        int coded_pts= ff_get_v(bc);
622
//FIXME check last_pts validity?
623
        if(coded_pts < (1<<stc->msb_pts_shift)){
624
            *pts=ff_lsb2full(stc, coded_pts);
625
        }else
626
            *pts=coded_pts - (1<<stc->msb_pts_shift);
627
    }else
628
        *pts= stc->last_pts + pts_delta;
629
    if(flags&FLAG_SIZE_MSB){
630
        size += size_mul*ff_get_v(bc);
631
    }
632
    if(flags&FLAG_RESERVED)
633
        reserved_count= ff_get_v(bc);
634
    for(i=0; i<reserved_count; i++)
635
        ff_get_v(bc);
636
    if(flags&FLAG_CHECKSUM){
637
        get_be32(bc); //FIXME check this
638
    }else if(size > 2*nut->max_distance || FFABS(stc->last_pts - *pts) > stc->max_pts_distance){
639
        av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
640
        return -1;
641
    }
642

    
643
    stc->last_pts= *pts;
644
    stc->last_flags= flags;
645

    
646
    return size;
647
}
648

    
649
static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
650
    AVFormatContext *s= nut->avf;
651
    ByteIOContext *bc = s->pb;
652
    int size, stream_id, discard;
653
    int64_t pts, last_IP_pts;
654
    StreamContext *stc;
655

    
656
    size= decode_frame_header(nut, &pts, &stream_id, frame_code);
657
    if(size < 0)
658
        return -1;
659

    
660
    stc= &nut->stream[stream_id];
661

    
662
    if (stc->last_flags & FLAG_KEY)
663
        stc->skip_until_key_frame=0;
664

    
665
    discard= s->streams[ stream_id ]->discard;
666
    last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
667
    if(  (discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY))
668
       ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
669
       || discard >= AVDISCARD_ALL
670
       || stc->skip_until_key_frame){
671
        url_fskip(bc, size);
672
        return 1;
673
    }
674

    
675
    av_get_packet(bc, pkt, size);
676
    pkt->stream_index = stream_id;
677
    if (stc->last_flags & FLAG_KEY)
678
        pkt->flags |= PKT_FLAG_KEY;
679
    pkt->pts = pts;
680

    
681
    return 0;
682
}
683

    
684
static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
685
{
686
    NUTContext *nut = s->priv_data;
687
    ByteIOContext *bc = s->pb;
688
    int i, frame_code=0, ret, skip;
689
    int64_t ts, back_ptr;
690

    
691
    for(;;){
692
        int64_t pos= url_ftell(bc);
693
        uint64_t tmp= nut->next_startcode;
694
        nut->next_startcode=0;
695

    
696
        if(tmp){
697
            pos-=8;
698
        }else{
699
            frame_code = get_byte(bc);
700
            if(url_feof(bc))
701
                return -1;
702
            if(frame_code == 'N'){
703
                tmp= frame_code;
704
                for(i=1; i<8; i++)
705
                    tmp = (tmp<<8) + get_byte(bc);
706
            }
707
        }
708
        switch(tmp){
709
        case MAIN_STARTCODE:
710
        case STREAM_STARTCODE:
711
        case INDEX_STARTCODE:
712
            skip= get_packetheader(nut, bc, 0, tmp);
713
            url_fseek(bc, skip, SEEK_CUR);
714
            break;
715
        case INFO_STARTCODE:
716
            if(decode_info_header(nut)<0)
717
                goto resync;
718
            break;
719
        case SYNCPOINT_STARTCODE:
720
            if(decode_syncpoint(nut, &ts, &back_ptr)<0)
721
                goto resync;
722
            frame_code = get_byte(bc);
723
        case 0:
724
            ret= decode_frame(nut, pkt, frame_code);
725
            if(ret==0)
726
                return 0;
727
            else if(ret==1) //ok but discard packet
728
                break;
729
        default:
730
resync:
731
av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
732
            tmp= find_any_startcode(bc, nut->last_syncpoint_pos+1);
733
            if(tmp==0)
734
                return -1;
735
av_log(s, AV_LOG_DEBUG, "sync\n");
736
            nut->next_startcode= tmp;
737
        }
738
    }
739
}
740

    
741
static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
742
    NUTContext *nut = s->priv_data;
743
    ByteIOContext *bc = s->pb;
744
    int64_t pos, pts, back_ptr;
745
av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
746

    
747
    pos= *pos_arg;
748
    do{
749
        pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
750
        if(pos < 1){
751
            assert(nut->next_startcode == 0);
752
            av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
753
            return AV_NOPTS_VALUE;
754
        }
755
    }while(decode_syncpoint(nut, &pts, &back_ptr) < 0);
756
    *pos_arg = pos-1;
757
    assert(nut->last_syncpoint_pos == *pos_arg);
758

    
759
    av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts,back_ptr );
760
    if     (stream_index == -1) return pts;
761
    else if(stream_index == -2) return back_ptr;
762

    
763
assert(0);
764
}
765

    
766
static int read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags){
767
    NUTContext *nut = s->priv_data;
768
    AVStream *st= s->streams[stream_index];
769
    syncpoint_t dummy={.ts= pts*av_q2d(st->time_base)*AV_TIME_BASE};
770
    syncpoint_t nopts_sp= {.ts= AV_NOPTS_VALUE, .back_ptr= AV_NOPTS_VALUE};
771
    syncpoint_t *sp, *next_node[2]= {&nopts_sp, &nopts_sp};
772
    int64_t pos, pos2, ts;
773
    int i;
774

    
775
    if(st->index_entries){
776
        int index= av_index_search_timestamp(st, pts, flags);
777
        if(index<0)
778
            return -1;
779

    
780
        pos2= st->index_entries[index].pos;
781
        ts  = st->index_entries[index].timestamp;
782
    }else{
783
        av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pts_cmp, next_node);
784
        av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n", next_node[0]->pos, next_node[1]->pos,
785
                                                    next_node[0]->ts , next_node[1]->ts);
786
        pos= av_gen_search(s, -1, dummy.ts, next_node[0]->pos, next_node[1]->pos, next_node[1]->pos,
787
                                            next_node[0]->ts , next_node[1]->ts, AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
788

    
789
        if(!(flags & AVSEEK_FLAG_BACKWARD)){
790
            dummy.pos= pos+16;
791
            next_node[1]= &nopts_sp;
792
            av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, next_node);
793
            pos2= av_gen_search(s, -2, dummy.pos, next_node[0]->pos     , next_node[1]->pos, next_node[1]->pos,
794
                                                next_node[0]->back_ptr, next_node[1]->back_ptr, flags, &ts, nut_read_timestamp);
795
            if(pos2>=0)
796
                pos= pos2;
797
            //FIXME dir but i think it does not matter
798
        }
799
        dummy.pos= pos;
800
        sp= av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, NULL);
801

    
802
        assert(sp);
803
        pos2= sp->back_ptr  - 15;
804
    }
805
    av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
806
    pos= find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);
807
    url_fseek(s->pb, pos, SEEK_SET);
808
    av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
809
    if(pos2 > pos || pos2 + 15 < pos){
810
        av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
811
    }
812
    for(i=0; i<s->nb_streams; i++)
813
        nut->stream[i].skip_until_key_frame=1;
814

    
815
    return 0;
816
}
817

    
818
static int nut_read_close(AVFormatContext *s)
819
{
820
    NUTContext *nut = s->priv_data;
821

    
822
    av_freep(&nut->time_base);
823
    av_freep(&nut->stream);
824

    
825
    return 0;
826
}
827

    
828
#ifdef CONFIG_NUT_DEMUXER
829
AVInputFormat nut_demuxer = {
830
    "nut",
831
    "nut format",
832
    sizeof(NUTContext),
833
    nut_probe,
834
    nut_read_header,
835
    nut_read_packet,
836
    nut_read_close,
837
    read_seek,
838
    .extensions = "nut",
839
};
840
#endif