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ffmpeg / libavformat / nutdec.c @ 5d97d9d5

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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 "nut.h"
25

    
26
#undef NDEBUG
27
#include <assert.h>
28

    
29
static uint64_t get_v(ByteIOContext *bc/*, maxstuffing*/){
30
    uint64_t val = 0;
31

    
32
    for(;;)
33
    {
34
        int tmp = get_byte(bc);
35

    
36
//         if(tmp=0x80){
37
//             if(!maxstuffing-- || val)
38
//                 return -1;
39
//         }
40

    
41
        if (tmp&0x80)
42
            val= (val<<7) + tmp - 0x80;
43
        else{
44
            return (val<<7) + tmp;
45
        }
46
    }
47
    return -1;
48
}
49

    
50
static int get_str(ByteIOContext *bc, char *string, unsigned int maxlen){
51
    unsigned int len= get_v(bc);
52

    
53
    if(len && maxlen)
54
        get_buffer(bc, string, FFMIN(len, maxlen));
55
    while(len > maxlen){
56
        get_byte(bc);
57
        len--;
58
    }
59

    
60
    if(maxlen)
61
        string[FFMIN(len, maxlen-1)]= 0;
62

    
63
    if(maxlen == len)
64
        return -1;
65
    else
66
        return 0;
67
}
68

    
69
static int64_t get_s(ByteIOContext *bc){
70
    int64_t v = get_v(bc) + 1;
71

    
72
    if (v&1) return -(v>>1);
73
    else     return  (v>>1);
74
}
75

    
76
static uint64_t get_fourcc(ByteIOContext *bc){
77
    unsigned int len= get_v(bc);
78

    
79
    if     (len==2) return get_le16(bc);
80
    else if(len==4) return get_le32(bc);
81
    else            return -1;
82
}
83

    
84
#ifdef TRACE
85
static inline uint64_t get_v_trace(ByteIOContext *bc, char *file, char *func, int line){
86
    uint64_t v= get_v(bc);
87

    
88
    printf("get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
89
    return v;
90
}
91

    
92
static inline int64_t get_s_trace(ByteIOContext *bc, char *file, char *func, int line){
93
    int64_t v= get_s(bc);
94

    
95
    printf("get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
96
    return v;
97
}
98

    
99
static inline uint64_t get_vb_trace(ByteIOContext *bc, char *file, char *func, int line){
100
    uint64_t v= get_vb(bc);
101

    
102
    printf("get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
103
    return v;
104
}
105
#define get_v(bc)  get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
106
#define get_s(bc)  get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
107
#define get_vb(bc)  get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
108
#endif
109

    
110
static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int calculate_checksum)
111
{
112
    int64_t start, size;
113
//    start= url_ftell(bc) - 8;
114

    
115
    size= get_v(bc);
116

    
117
    init_checksum(bc, calculate_checksum ? av_crc04C11DB7_update : NULL, 0);
118

    
119
//    nut->packet_start[2] = start;
120
//    nut->written_packet_size= size;
121

    
122
    return size;
123
}
124

    
125
static uint64_t find_any_startcode(ByteIOContext *bc, int64_t pos){
126
    uint64_t state=0;
127

    
128
    if(pos >= 0)
129
        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
130

    
131
    while(!url_feof(bc)){
132
        state= (state<<8) | get_byte(bc);
133
        if((state>>56) != 'N')
134
            continue;
135
        switch(state){
136
        case MAIN_STARTCODE:
137
        case STREAM_STARTCODE:
138
        case SYNCPOINT_STARTCODE:
139
        case INFO_STARTCODE:
140
        case INDEX_STARTCODE:
141
            return state;
142
        }
143
    }
144

    
145
    return 0;
146
}
147

    
148
/**
149
 * find the given startcode.
150
 * @param code the startcode
151
 * @param pos the start position of the search, or -1 if the current position
152
 * @returns the position of the startcode or -1 if not found
153
 */
154
static int64_t find_startcode(ByteIOContext *bc, uint64_t code, int64_t pos){
155
    for(;;){
156
        uint64_t startcode= find_any_startcode(bc, pos);
157
        if(startcode == code)
158
            return url_ftell(bc) - 8;
159
        else if(startcode == 0)
160
            return -1;
161
        pos=-1;
162
    }
163
}
164

    
165
static int64_t lsb2full(StreamContext *stream, int64_t lsb){
166
    int64_t mask = (1<<stream->msb_pts_shift)-1;
167
    int64_t delta= stream->last_pts - mask/2;
168
    return  ((lsb - delta)&mask) + delta;
169
}
170

    
171
static int nut_probe(AVProbeData *p){
172
    int i;
173
    uint64_t code= 0;
174

    
175
    for (i = 0; i < p->buf_size; i++) {
176
        code = (code << 8) | p->buf[i];
177
        if (code == MAIN_STARTCODE)
178
            return AVPROBE_SCORE_MAX;
179
    }
180
    return 0;
181
}
182

    
183
#define GET_V(dst, check) \
184
    tmp= get_v(bc);\
185
    if(!(check)){\
186
        av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp);\
187
        return -1;\
188
    }\
189
    dst= tmp;
190

    
191
static int skip_reserved(ByteIOContext *bc, int64_t pos){
192
    pos -= url_ftell(bc);
193
av_log(NULL, AV_LOG_ERROR, "skip %d\n", (int)pos);
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
static int decode_syncpoint(NUTContext *nut){
436
    AVFormatContext *s= nut->avf;
437
    ByteIOContext *bc = &s->pb;
438
    int64_t end;
439
    uint64_t tmp;
440
    int i;
441
    AVRational time_base;
442

    
443
    nut->last_syncpoint_pos= url_ftell(bc)-8;
444

    
445
    end= get_packetheader(nut, bc, 1);
446
    end += url_ftell(bc);
447

    
448
    tmp= get_v(bc);
449
    get_v(bc); //back_ptr_div16
450

    
451
    time_base= nut->time_base[tmp % nut->time_base_count];
452
    for(i=0; i<s->nb_streams; i++){
453
        nut->stream[i].last_pts= av_rescale_rnd(
454
            tmp / nut->time_base_count,
455
            time_base.num * (int64_t)nut->stream[i].time_base.den,
456
            time_base.den * (int64_t)nut->stream[i].time_base.num,
457
            AV_ROUND_DOWN);
458
        //last_key_frame ?
459
    }
460
    //FIXME put this in a reset func maybe
461

    
462
    if(skip_reserved(bc, end) || get_checksum(bc)){
463
        av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
464
        return -1;
465
    }
466
    return 0;
467
}
468

    
469
static int find_and_decode_index(NUTContext *nut){
470
    AVFormatContext *s= nut->avf;
471
    ByteIOContext *bc = &s->pb;
472
    uint64_t tmp, end;
473
    int i, j, syncpoint_count;
474
    int64_t filesize= url_fsize(bc);
475
    int64_t *syncpoints;
476
    int8_t *has_keyframe;
477

    
478
    url_fseek(bc, filesize-12, SEEK_SET);
479
    url_fseek(bc, filesize-get_be64(bc), SEEK_SET);
480
    if(get_be64(bc) != INDEX_STARTCODE){
481
        av_log(s, AV_LOG_ERROR, "no index at the end\n");
482
        return -1;
483
    }
484

    
485
    end= get_packetheader(nut, bc, 1);
486
    end += url_ftell(bc);
487

    
488
    get_v(bc); //max_pts
489
    GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
490
    syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
491
    has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
492
    for(i=0; i<syncpoint_count; i++){
493
        GET_V(syncpoints[i], tmp>0)
494
        if(i)
495
            syncpoints[i] += syncpoints[i-1];
496
    }
497

    
498
    for(i=0; i<s->nb_streams; i++){
499
        int64_t last_pts= -1;
500
        for(j=0; j<syncpoint_count;){
501
            uint64_t x= get_v(bc);
502
            int type= x&1;
503
            int n= j;
504
            x>>=1;
505
            if(type){
506
                int flag= x&1;
507
                x>>=1;
508
                if(n+x >= syncpoint_count + 1){
509
                    av_log(s, AV_LOG_ERROR, "index overflow A\n");
510
                    return -1;
511
                }
512
                while(x--)
513
                    has_keyframe[n++]= flag;
514
                has_keyframe[n++]= !flag;
515
            }else{
516
                while(x != 1){
517
                    if(n>=syncpoint_count + 1){
518
                        av_log(s, AV_LOG_ERROR, "index overflow B\n");
519
                        return -1;
520
                    }
521
                    has_keyframe[n++]= x&1;
522
                    x>>=1;
523
                }
524
            }
525
            if(has_keyframe[0]){
526
                av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
527
                return -1;
528
            }
529
            assert(n<=syncpoint_count+1);
530
            for(; j<n; j++){
531
                if(has_keyframe[j]){
532
                    uint64_t B, A= get_v(bc);
533
                    if(!A){
534
                        A= get_v(bc);
535
                        B= get_v(bc);
536
                        //eor_pts[j][i] = last_pts + A + B
537
                    }else
538
                        B= 0;
539
                    av_add_index_entry(
540
                        s->streams[i],
541
                        16*syncpoints[j-1],
542
                        last_pts + A,
543
                        0,
544
                        0,
545
                        AVINDEX_KEYFRAME);
546
                    last_pts += A + B;
547
                }
548
            }
549
        }
550
    }
551

    
552
    if(skip_reserved(bc, end) || get_checksum(bc)){
553
        av_log(s, AV_LOG_ERROR, "Index checksum mismatch\n");
554
        return -1;
555
    }
556
    return 0;
557
}
558

    
559
static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
560
{
561
    NUTContext *nut = s->priv_data;
562
    ByteIOContext *bc = &s->pb;
563
    int64_t pos;
564
    int inited_stream_count;
565

    
566
    nut->avf= s;
567

    
568
    /* main header */
569
    pos=0;
570
    do{
571
        pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
572
        if (pos<0+1){
573
            av_log(s, AV_LOG_ERROR, "no main startcode found\n");
574
            return -1;
575
        }
576
    }while(decode_main_header(nut) < 0);
577

    
578
    /* stream headers */
579
    pos=0;
580
    for(inited_stream_count=0; inited_stream_count < s->nb_streams;){
581
        pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
582
        if (pos<0+1){
583
            av_log(s, AV_LOG_ERROR, "not all stream headers found\n");
584
            return -1;
585
        }
586
        if(decode_stream_header(nut) >= 0)
587
            inited_stream_count++;
588
    }
589

    
590
    /* info headers */
591
    pos=0;
592
    for(;;){
593
        uint64_t startcode= find_any_startcode(bc, pos);
594
        pos= url_ftell(bc);
595

    
596
        if(startcode==0){
597
            av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
598
            return -1;
599
        }else if(startcode == SYNCPOINT_STARTCODE){
600
            nut->next_startcode= startcode;
601
            break;
602
        }else if(startcode != INFO_STARTCODE){
603
            continue;
604
        }
605

    
606
        decode_info_header(nut);
607
    }
608

    
609
    s->data_offset= pos-8;
610

    
611
    if(0 &&!url_is_streamed(bc)){
612
        int64_t orig_pos= url_ftell(bc);
613
        find_and_decode_index(nut);
614
        url_fseek(bc, orig_pos, SEEK_SET);
615
    }
616
    assert(nut->next_startcode == SYNCPOINT_STARTCODE);
617

    
618
    return 0;
619
}
620

    
621
static int decode_frame_header(NUTContext *nut, int *flags_ret, int64_t *pts, int *stream_id, int frame_code){
622
    AVFormatContext *s= nut->avf;
623
    ByteIOContext *bc = &s->pb;
624
    StreamContext *stc;
625
    int size, flags, size_mul, pts_delta, i, reserved_count;
626
    uint64_t tmp;
627

    
628
    if(url_ftell(bc) > nut->last_syncpoint_pos + nut->max_distance){
629
        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);
630
        return -1;
631
    }
632

    
633
    flags          = nut->frame_code[frame_code].flags;
634
    size_mul       = nut->frame_code[frame_code].size_mul;
635
    size           = nut->frame_code[frame_code].size_lsb;
636
    *stream_id     = nut->frame_code[frame_code].stream_id;
637
    pts_delta      = nut->frame_code[frame_code].pts_delta;
638
    reserved_count = nut->frame_code[frame_code].reserved_count;
639

    
640
    if(flags & FLAG_INVALID)
641
        return -1;
642
    if(flags & FLAG_CODED)
643
        flags ^= get_v(bc);
644
    if(flags & FLAG_STREAM_ID){
645
        GET_V(*stream_id, tmp < s->nb_streams)
646
    }
647
    stc= &nut->stream[*stream_id];
648
    if(flags&FLAG_CODED_PTS){
649
        int coded_pts= get_v(bc);
650
//FIXME check last_pts validity?
651
        if(coded_pts < (1<<stc->msb_pts_shift)){
652
            *pts=lsb2full(stc, coded_pts);
653
        }else
654
            *pts=coded_pts - (1<<stc->msb_pts_shift);
655
    }else
656
        *pts= stc->last_pts + pts_delta;
657
    if(flags&FLAG_SIZE_MSB){
658
        size += size_mul*get_v(bc);
659
    }
660
    if(flags&FLAG_RESERVED)
661
        reserved_count= get_v(bc);
662
    for(i=0; i<reserved_count; i++)
663
        get_v(bc);
664
    if(flags&FLAG_CHECKSUM){
665
        get_be32(bc); //FIXME check this
666
    }
667
    *flags_ret= flags;
668

    
669
    stc->last_pts= *pts;
670
    stc->last_key_frame= flags&FLAG_KEY; //FIXME change to last flags
671

    
672
    if(flags&FLAG_KEY){
673
        av_add_index_entry(
674
            s->streams[*stream_id],
675
            nut->last_syncpoint_pos,
676
            *pts,
677
            0,
678
            0,
679
            AVINDEX_KEYFRAME);
680
    }
681

    
682
    return size;
683
}
684

    
685
static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
686
    AVFormatContext *s= nut->avf;
687
    ByteIOContext *bc = &s->pb;
688
    int size, stream_id, flags, discard;
689
    int64_t pts, last_IP_pts;
690

    
691
    size= decode_frame_header(nut, &flags, &pts, &stream_id, frame_code);
692
    if(size < 0)
693
        return -1;
694

    
695
    discard= s->streams[ stream_id ]->discard;
696
    last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
697
    if(  (discard >= AVDISCARD_NONKEY && !(flags & FLAG_KEY))
698
       ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
699
       || discard >= AVDISCARD_ALL){
700
        url_fskip(bc, size);
701
        return 1;
702
    }
703

    
704
    av_get_packet(bc, pkt, size);
705
    pkt->stream_index = stream_id;
706
    if (flags & FLAG_KEY)
707
        pkt->flags |= PKT_FLAG_KEY;
708
    pkt->pts = pts;
709

    
710
    return 0;
711
}
712

    
713
static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
714
{
715
    NUTContext *nut = s->priv_data;
716
    ByteIOContext *bc = &s->pb;
717
    int i, frame_code=0, ret, skip;
718

    
719
    for(;;){
720
        int64_t pos= url_ftell(bc);
721
        uint64_t tmp= nut->next_startcode;
722
        nut->next_startcode=0;
723

    
724
        if (url_feof(bc))
725
            return -1;
726

    
727
        if(tmp){
728
            pos-=8;
729
        }else{
730
            frame_code = get_byte(bc);
731
            if(frame_code == 'N'){
732
                tmp= frame_code;
733
                for(i=1; i<8; i++)
734
                    tmp = (tmp<<8) + get_byte(bc);
735
            }
736
        }
737
        switch(tmp){
738
        case MAIN_STARTCODE:
739
        case STREAM_STARTCODE:
740
        case INDEX_STARTCODE:
741
            skip= get_packetheader(nut, bc, 0);
742
            url_fseek(bc, skip, SEEK_CUR);
743
            break;
744
        case INFO_STARTCODE:
745
            if(decode_info_header(nut)<0)
746
                goto resync;
747
            break;
748
        case SYNCPOINT_STARTCODE:
749
            if(decode_syncpoint(nut)<0)
750
                goto resync;
751
            frame_code = get_byte(bc);
752
        case 0:
753
            ret= decode_frame(nut, pkt, frame_code);
754
            if(ret==0)
755
                return 0;
756
            else if(ret==1) //ok but discard packet
757
                break;
758
        default:
759
resync:
760
av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
761
            tmp= find_any_startcode(bc, pos+1);
762
            if(tmp==0)
763
                return -1;
764
av_log(s, AV_LOG_DEBUG, "sync\n");
765
            nut->next_startcode= tmp;
766
        }
767
    }
768
}
769

    
770
static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
771
    NUTContext *nut = s->priv_data;
772
    ByteIOContext *bc = &s->pb;
773
    int64_t pos, pts;
774
    int frame_code, stream_id,size, flags;
775
av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
776

    
777
    pos= *pos_arg;
778
resync:
779
    do{
780
        pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
781
        if(pos < 1){
782
            assert(nut->next_startcode == 0);
783
            av_log(s, AV_LOG_ERROR, "read_timestamp failed\n");
784
            return AV_NOPTS_VALUE;
785
        }
786
    }while(decode_syncpoint(nut) < 0);
787
    *pos_arg = pos-1;
788
    assert(nut->last_syncpoint_pos == *pos_arg);
789

    
790
    do{
791
        frame_code= get_byte(bc);
792
        if(frame_code == 'N'){
793
            pos= url_ftell(bc)-1;
794
            goto resync;
795
        }
796
        //FIXME consider pos_limit and eof
797
        size= decode_frame_header(nut, &flags, &pts, &stream_id, frame_code);
798

    
799
        if(size < 0)
800
            goto resync;
801

    
802
        url_fseek(bc, size, SEEK_CUR);
803
    }while(stream_id != stream_index || !(flags & FLAG_KEY));
804
    assert(nut->next_startcode == 0);
805
    av_log(s, AV_LOG_DEBUG, "read_timestamp success\n");
806

    
807
    return pts;
808
}
809

    
810
static int nut_read_close(AVFormatContext *s)
811
{
812
    NUTContext *nut = s->priv_data;
813

    
814
    av_freep(&nut->time_base);
815
    av_freep(&nut->stream);
816

    
817
    return 0;
818
}
819

    
820
#ifdef CONFIG_NUT_DEMUXER
821
AVInputFormat nut_demuxer = {
822
    "nut",
823
    "nut format",
824
    sizeof(NUTContext),
825
    nut_probe,
826
    nut_read_header,
827
    nut_read_packet,
828
    nut_read_close,
829
    NULL,
830
    nut_read_timestamp,
831
    .extensions = "nut",
832
};
833
#endif