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ffmpeg / libavformat / nutdec.c @ 93951943

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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
16
 * 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
#include "tree.h"
24
#include "nut.h"
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#include "avstring.h"
26

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

    
30
static uint64_t get_v(ByteIOContext *bc){
31
    uint64_t val = 0;
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    int tmp;
33

    
34
    do{
35
        tmp = get_byte(bc);
36
        val= (val<<7) + (tmp&127);
37
    }while(tmp&128);
38
    return val;
39
}
40

    
41
static int get_str(ByteIOContext *bc, char *string, unsigned int maxlen){
42
    unsigned int len= get_v(bc);
43

    
44
    if(len && maxlen)
45
        get_buffer(bc, string, FFMIN(len, maxlen));
46
    while(len > maxlen){
47
        get_byte(bc);
48
        len--;
49
    }
50

    
51
    if(maxlen)
52
        string[FFMIN(len, maxlen-1)]= 0;
53

    
54
    if(maxlen == len)
55
        return -1;
56
    else
57
        return 0;
58
}
59

    
60
static int64_t get_s(ByteIOContext *bc){
61
    int64_t v = get_v(bc) + 1;
62

    
63
    if (v&1) return -(v>>1);
64
    else     return  (v>>1);
65
}
66

    
67
static uint64_t get_fourcc(ByteIOContext *bc){
68
    unsigned int len= get_v(bc);
69

    
70
    if     (len==2) return get_le16(bc);
71
    else if(len==4) return get_le32(bc);
72
    else            return -1;
73
}
74

    
75
#ifdef TRACE
76
static inline uint64_t get_v_trace(ByteIOContext *bc, char *file, char *func, int line){
77
    uint64_t v= get_v(bc);
78

    
79
    av_log(NULL, AV_LOG_DEBUG, "get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
80
    return v;
81
}
82

    
83
static inline int64_t get_s_trace(ByteIOContext *bc, char *file, char *func, int line){
84
    int64_t v= get_s(bc);
85

    
86
    av_log(NULL, AV_LOG_DEBUG, "get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
87
    return v;
88
}
89

    
90
static inline uint64_t get_vb_trace(ByteIOContext *bc, char *file, char *func, int line){
91
    uint64_t v= get_vb(bc);
92

    
93
    av_log(NULL, AV_LOG_DEBUG, "get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
94
    return v;
95
}
96
#define get_v(bc)  get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
97
#define get_s(bc)  get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
98
#define get_vb(bc)  get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
99
#endif
100

    
101
static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int calculate_checksum, uint64_t startcode)
102
{
103
    int64_t size;
104
//    start= url_ftell(bc) - 8;
105

    
106
    startcode= be2me_64(startcode);
107
    startcode= av_crc04C11DB7_update(0, &startcode, 8);
108

    
109
    init_checksum(bc, av_crc04C11DB7_update, startcode);
110
    size= get_v(bc);
111
    if(size > 4096)
112
        get_be32(bc);
113
    if(get_checksum(bc) && size > 4096)
114
        return -1;
115

    
116
    init_checksum(bc, calculate_checksum ? av_crc04C11DB7_update : NULL, 0);
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 is not seekable, but that should not 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 int nut_probe(AVProbeData *p){
162
    int i;
163
    uint64_t code= 0;
164

    
165
    for (i = 0; i < p->buf_size; i++) {
166
        code = (code << 8) | p->buf[i];
167
        if (code == MAIN_STARTCODE)
168
            return AVPROBE_SCORE_MAX;
169
    }
170
    return 0;
171
}
172

    
173
#define GET_V(dst, check) \
174
    tmp= get_v(bc);\
175
    if(!(check)){\
176
        av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp);\
177
        return -1;\
178
    }\
179
    dst= tmp;
180

    
181
static int skip_reserved(ByteIOContext *bc, int64_t pos){
182
    pos -= url_ftell(bc);
183
    if(pos<0){
184
        url_fseek(bc, pos, SEEK_CUR);
185
        return -1;
186
    }else{
187
        while(pos--)
188
            get_byte(bc);
189
        return 0;
190
    }
191
}
192

    
193
static int decode_main_header(NUTContext *nut){
194
    AVFormatContext *s= nut->avf;
195
    ByteIOContext *bc = &s->pb;
196
    uint64_t tmp, end;
197
    unsigned int stream_count;
198
    int i, j, tmp_stream, tmp_mul, tmp_pts, tmp_size, count, tmp_res;
199

    
200
    end= get_packetheader(nut, bc, 1, MAIN_STARTCODE);
201
    end += url_ftell(bc);
202

    
203
    GET_V(tmp              , tmp >=2 && tmp <= 3)
204
    GET_V(stream_count     , tmp > 0 && tmp <=MAX_STREAMS)
205

    
206
    nut->max_distance = get_v(bc);
207
    if(nut->max_distance > 65536){
208
        av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
209
        nut->max_distance= 65536;
210
    }
211

    
212
    GET_V(nut->time_base_count, tmp>0 && tmp<INT_MAX / sizeof(AVRational))
213
    nut->time_base= av_malloc(nut->time_base_count * sizeof(AVRational));
214

    
215
    for(i=0; i<nut->time_base_count; i++){
216
        GET_V(nut->time_base[i].num, tmp>0 && tmp<(1ULL<<31))
217
        GET_V(nut->time_base[i].den, tmp>0 && tmp<(1ULL<<31))
218
        if(ff_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1){
219
            av_log(s, AV_LOG_ERROR, "time base invalid\n");
220
            return -1;
221
        }
222
    }
223
    tmp_pts=0;
224
    tmp_mul=1;
225
    tmp_stream=0;
226
    for(i=0; i<256;){
227
        int tmp_flags = get_v(bc);
228
        int tmp_fields= get_v(bc);
229
        if(tmp_fields>0) tmp_pts   = get_s(bc);
230
        if(tmp_fields>1) tmp_mul   = get_v(bc);
231
        if(tmp_fields>2) tmp_stream= get_v(bc);
232
        if(tmp_fields>3) tmp_size  = get_v(bc);
233
        else             tmp_size  = 0;
234
        if(tmp_fields>4) tmp_res   = get_v(bc);
235
        else             tmp_res   = 0;
236
        if(tmp_fields>5) count     = get_v(bc);
237
        else             count     = tmp_mul - tmp_size;
238

    
239
        while(tmp_fields-- > 6)
240
           get_v(bc);
241

    
242
        if(count == 0 || i+count > 256){
243
            av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
244
            return -1;
245
        }
246
        if(tmp_stream >= stream_count){
247
            av_log(s, AV_LOG_ERROR, "illegal stream number\n");
248
            return -1;
249
        }
250

    
251
        for(j=0; j<count; j++,i++){
252
            if (i == 'N') {
253
                nut->frame_code[i].flags= FLAG_INVALID;
254
                j--;
255
                continue;
256
            }
257
            nut->frame_code[i].flags           = tmp_flags ;
258
            nut->frame_code[i].pts_delta       = tmp_pts   ;
259
            nut->frame_code[i].stream_id       = tmp_stream;
260
            nut->frame_code[i].size_mul        = tmp_mul   ;
261
            nut->frame_code[i].size_lsb        = tmp_size+j;
262
            nut->frame_code[i].reserved_count  = tmp_res   ;
263
        }
264
    }
265
    assert(nut->frame_code['N'].flags == FLAG_INVALID);
266

    
267
    if(skip_reserved(bc, end) || get_checksum(bc)){
268
        av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
269
        return -1;
270
    }
271

    
272
    nut->stream = av_mallocz(sizeof(StreamContext)*stream_count);
273
    for(i=0; i<stream_count; i++){
274
        av_new_stream(s, i);
275
    }
276

    
277
    return 0;
278
}
279

    
280
static int decode_stream_header(NUTContext *nut){
281
    AVFormatContext *s= nut->avf;
282
    ByteIOContext *bc = &s->pb;
283
    StreamContext *stc;
284
    int class, stream_id;
285
    uint64_t tmp, end;
286
    AVStream *st;
287

    
288
    end= get_packetheader(nut, bc, 1, STREAM_STARTCODE);
289
    end += url_ftell(bc);
290

    
291
    GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);
292
    stc= &nut->stream[stream_id];
293

    
294
    st = s->streams[stream_id];
295
    if (!st)
296
        return AVERROR(ENOMEM);
297

    
298
    class = get_v(bc);
299
    tmp = get_fourcc(bc);
300
    st->codec->codec_tag= tmp;
301
    switch(class)
302
    {
303
        case 0:
304
            st->codec->codec_type = CODEC_TYPE_VIDEO;
305
            st->codec->codec_id = codec_get_id(codec_bmp_tags, tmp);
306
            if (st->codec->codec_id == CODEC_ID_NONE)
307
                av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
308
            break;
309
        case 1:
310
            st->codec->codec_type = CODEC_TYPE_AUDIO;
311
            st->codec->codec_id = codec_get_id(codec_wav_tags, tmp);
312
            if (st->codec->codec_id == CODEC_ID_NONE)
313
                av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
314
            break;
315
        case 2:
316
//            st->codec->codec_type = CODEC_TYPE_TEXT;
317
//            break;
318
        case 3:
319
            st->codec->codec_type = CODEC_TYPE_DATA;
320
            break;
321
        default:
322
            av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);
323
            return -1;
324
    }
325
    GET_V(stc->time_base_id    , tmp < nut->time_base_count);
326
    GET_V(stc->msb_pts_shift   , tmp < 16);
327
    stc->max_pts_distance= get_v(bc);
328
    GET_V(stc->decode_delay    , tmp < 1000); //sanity limit, raise this if Moore's law is true
329
    st->codec->has_b_frames= stc->decode_delay;
330
    get_v(bc); //stream flags
331

    
332
    GET_V(st->codec->extradata_size, tmp < (1<<30));
333
    if(st->codec->extradata_size){
334
        st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
335
        get_buffer(bc, st->codec->extradata, st->codec->extradata_size);
336
    }
337

    
338
    if (st->codec->codec_type == CODEC_TYPE_VIDEO){
339
        GET_V(st->codec->width , tmp > 0)
340
        GET_V(st->codec->height, tmp > 0)
341
        st->codec->sample_aspect_ratio.num= get_v(bc);
342
        st->codec->sample_aspect_ratio.den= get_v(bc);
343
        if((!st->codec->sample_aspect_ratio.num) != (!st->codec->sample_aspect_ratio.den)){
344
            av_log(s, AV_LOG_ERROR, "invalid aspect ratio\n");
345
            return -1;
346
        }
347
        get_v(bc); /* csp type */
348
    }else if (st->codec->codec_type == CODEC_TYPE_AUDIO){
349
        GET_V(st->codec->sample_rate , tmp > 0)
350
        tmp= get_v(bc); // samplerate_den
351
        if(tmp > st->codec->sample_rate){
352
            av_log(s, AV_LOG_ERROR, "Bleh, libnut muxed this ;)\n");
353
            st->codec->sample_rate= tmp;
354
        }
355
        GET_V(st->codec->channels, tmp > 0)
356
    }
357
    if(skip_reserved(bc, end) || get_checksum(bc)){
358
        av_log(s, AV_LOG_ERROR, "stream header %d checksum mismatch\n", stream_id);
359
        return -1;
360
    }
361
    stc->time_base= &nut->time_base[stc->time_base_id];
362
    av_set_pts_info(s->streams[stream_id], 63, stc->time_base->num, stc->time_base->den);
363
    return 0;
364
}
365

    
366
static int decode_info_header(NUTContext *nut){
367
    AVFormatContext *s= nut->avf;
368
    ByteIOContext *bc = &s->pb;
369
    uint64_t tmp;
370
    unsigned int stream_id_plus1, chapter_start, chapter_len, count;
371
    int chapter_id, i;
372
    int64_t value, end;
373
    char name[256], str_value[1024], type_str[256], *type= type_str;
374

    
375
    end= get_packetheader(nut, bc, 1, INFO_STARTCODE);
376
    end += url_ftell(bc);
377

    
378
    GET_V(stream_id_plus1, tmp <= s->nb_streams)
379
    chapter_id   = get_s(bc);
380
    chapter_start= get_v(bc);
381
    chapter_len  = get_v(bc);
382
    count        = get_v(bc);
383
    for(i=0; i<count; i++){
384
        get_str(bc, name, sizeof(name));
385
        value= get_s(bc);
386
        if(value == -1){
387
            type= "UTF-8";
388
            get_str(bc, str_value, sizeof(str_value));
389
        }else if(value == -2){
390
            get_str(bc, type, sizeof(type));
391
            get_str(bc, str_value, sizeof(str_value));
392
        }else if(value == -3){
393
            type= "s";
394
            value= get_s(bc);
395
        }else if(value == -4){
396
            type= "t";
397
            value= get_v(bc);
398
        }else if(value < -4){
399
            type= "r";
400
            get_s(bc);
401
        }else{
402
            type= "v";
403
        }
404

    
405
        if(chapter_id==0 && !strcmp(type, "UTF-8")){
406
            if     (!strcmp(name, "Author"))
407
                av_strlcpy(s->author   , str_value, sizeof(s->author));
408
            else if(!strcmp(name, "Title"))
409
                av_strlcpy(s->title    , str_value, sizeof(s->title));
410
            else if(!strcmp(name, "Copyright"))
411
                av_strlcpy(s->copyright, str_value, sizeof(s->copyright));
412
            else if(!strcmp(name, "Description"))
413
                av_strlcpy(s->comment  , str_value, sizeof(s->comment));
414
        }
415
    }
416

    
417
    if(skip_reserved(bc, end) || get_checksum(bc)){
418
        av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");
419
        return -1;
420
    }
421
    return 0;
422
}
423

    
424
static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr){
425
    AVFormatContext *s= nut->avf;
426
    ByteIOContext *bc = &s->pb;
427
    int64_t end, tmp;
428
    AVRational time_base;
429

    
430
    nut->last_syncpoint_pos= url_ftell(bc)-8;
431

    
432
    end= get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
433
    end += url_ftell(bc);
434

    
435
    tmp= get_v(bc);
436
    *back_ptr= nut->last_syncpoint_pos - 16*get_v(bc);
437
    if(*back_ptr < 0)
438
        return -1;
439

    
440
    ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count], tmp);
441

    
442
    if(skip_reserved(bc, end) || get_checksum(bc)){
443
        av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
444
        return -1;
445
    }
446

    
447
    *ts= tmp / s->nb_streams * av_q2d(nut->time_base[tmp % s->nb_streams])*AV_TIME_BASE;
448
    ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
449

    
450
    return 0;
451
}
452

    
453
static int find_and_decode_index(NUTContext *nut){
454
    AVFormatContext *s= nut->avf;
455
    ByteIOContext *bc = &s->pb;
456
    uint64_t tmp, end;
457
    int i, j, syncpoint_count;
458
    int64_t filesize= url_fsize(bc);
459
    int64_t *syncpoints;
460
    int8_t *has_keyframe;
461

    
462
    url_fseek(bc, filesize-12, SEEK_SET);
463
    url_fseek(bc, filesize-get_be64(bc), SEEK_SET);
464
    if(get_be64(bc) != INDEX_STARTCODE){
465
        av_log(s, AV_LOG_ERROR, "no index at the end\n");
466
        return -1;
467
    }
468

    
469
    end= get_packetheader(nut, bc, 1, INDEX_STARTCODE);
470
    end += url_ftell(bc);
471

    
472
    get_v(bc); //max_pts
473
    GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
474
    syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
475
    has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
476
    for(i=0; i<syncpoint_count; i++){
477
        GET_V(syncpoints[i], tmp>0)
478
        if(i)
479
            syncpoints[i] += syncpoints[i-1];
480
    }
481

    
482
    for(i=0; i<s->nb_streams; i++){
483
        int64_t last_pts= -1;
484
        for(j=0; j<syncpoint_count;){
485
            uint64_t x= get_v(bc);
486
            int type= x&1;
487
            int n= j;
488
            x>>=1;
489
            if(type){
490
                int flag= x&1;
491
                x>>=1;
492
                if(n+x >= syncpoint_count + 1){
493
                    av_log(s, AV_LOG_ERROR, "index overflow A\n");
494
                    return -1;
495
                }
496
                while(x--)
497
                    has_keyframe[n++]= flag;
498
                has_keyframe[n++]= !flag;
499
            }else{
500
                while(x != 1){
501
                    if(n>=syncpoint_count + 1){
502
                        av_log(s, AV_LOG_ERROR, "index overflow B\n");
503
                        return -1;
504
                    }
505
                    has_keyframe[n++]= x&1;
506
                    x>>=1;
507
                }
508
            }
509
            if(has_keyframe[0]){
510
                av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
511
                return -1;
512
            }
513
            assert(n<=syncpoint_count+1);
514
            for(; j<n; j++){
515
                if(has_keyframe[j]){
516
                    uint64_t B, A= get_v(bc);
517
                    if(!A){
518
                        A= get_v(bc);
519
                        B= get_v(bc);
520
                        //eor_pts[j][i] = last_pts + A + B
521
                    }else
522
                        B= 0;
523
                    av_add_index_entry(
524
                        s->streams[i],
525
                        16*syncpoints[j-1],
526
                        last_pts + A,
527
                        0,
528
                        0,
529
                        AVINDEX_KEYFRAME);
530
                    last_pts += A + B;
531
                }
532
            }
533
        }
534
    }
535

    
536
    if(skip_reserved(bc, end) || get_checksum(bc)){
537
        av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
538
        return -1;
539
    }
540
    return 0;
541
}
542

    
543
static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
544
{
545
    NUTContext *nut = s->priv_data;
546
    ByteIOContext *bc = &s->pb;
547
    int64_t pos;
548
    int inited_stream_count;
549

    
550
    nut->avf= s;
551

    
552
    /* main header */
553
    pos=0;
554
    do{
555
        pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
556
        if (pos<0+1){
557
            av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
558
            return -1;
559
        }
560
    }while(decode_main_header(nut) < 0);
561

    
562
    /* stream headers */
563
    pos=0;
564
    for(inited_stream_count=0; inited_stream_count < s->nb_streams;){
565
        pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
566
        if (pos<0+1){
567
            av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
568
            return -1;
569
        }
570
        if(decode_stream_header(nut) >= 0)
571
            inited_stream_count++;
572
    }
573

    
574
    /* info headers */
575
    pos=0;
576
    for(;;){
577
        uint64_t startcode= find_any_startcode(bc, pos);
578
        pos= url_ftell(bc);
579

    
580
        if(startcode==0){
581
            av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
582
            return -1;
583
        }else if(startcode == SYNCPOINT_STARTCODE){
584
            nut->next_startcode= startcode;
585
            break;
586
        }else if(startcode != INFO_STARTCODE){
587
            continue;
588
        }
589

    
590
        decode_info_header(nut);
591
    }
592

    
593
    s->data_offset= pos-8;
594

    
595
    if(!url_is_streamed(bc)){
596
        int64_t orig_pos= url_ftell(bc);
597
        find_and_decode_index(nut);
598
        url_fseek(bc, orig_pos, SEEK_SET);
599
    }
600
    assert(nut->next_startcode == SYNCPOINT_STARTCODE);
601

    
602
    return 0;
603
}
604

    
605
static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, int frame_code){
606
    AVFormatContext *s= nut->avf;
607
    ByteIOContext *bc = &s->pb;
608
    StreamContext *stc;
609
    int size, flags, size_mul, pts_delta, i, reserved_count;
610
    uint64_t tmp;
611

    
612
    if(url_ftell(bc) > nut->last_syncpoint_pos + nut->max_distance){
613
        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);
614
        return -1;
615
    }
616

    
617
    flags          = nut->frame_code[frame_code].flags;
618
    size_mul       = nut->frame_code[frame_code].size_mul;
619
    size           = nut->frame_code[frame_code].size_lsb;
620
    *stream_id     = nut->frame_code[frame_code].stream_id;
621
    pts_delta      = nut->frame_code[frame_code].pts_delta;
622
    reserved_count = nut->frame_code[frame_code].reserved_count;
623

    
624
    if(flags & FLAG_INVALID)
625
        return -1;
626
    if(flags & FLAG_CODED)
627
        flags ^= get_v(bc);
628
    if(flags & FLAG_STREAM_ID){
629
        GET_V(*stream_id, tmp < s->nb_streams)
630
    }
631
    stc= &nut->stream[*stream_id];
632
    if(flags&FLAG_CODED_PTS){
633
        int coded_pts= get_v(bc);
634
//FIXME check last_pts validity?
635
        if(coded_pts < (1<<stc->msb_pts_shift)){
636
            *pts=ff_lsb2full(stc, coded_pts);
637
        }else
638
            *pts=coded_pts - (1<<stc->msb_pts_shift);
639
    }else
640
        *pts= stc->last_pts + pts_delta;
641
    if(flags&FLAG_SIZE_MSB){
642
        size += size_mul*get_v(bc);
643
    }
644
    if(flags&FLAG_RESERVED)
645
        reserved_count= get_v(bc);
646
    for(i=0; i<reserved_count; i++)
647
        get_v(bc);
648
    if(flags&FLAG_CHECKSUM){
649
        get_be32(bc); //FIXME check this
650
    }else if(size > 2*nut->max_distance || FFABS(stc->last_pts - *pts) > stc->max_pts_distance){
651
        av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
652
        return -1;
653
    }
654

    
655
    stc->last_pts= *pts;
656
    stc->last_flags= flags;
657

    
658
    return size;
659
}
660

    
661
static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
662
    AVFormatContext *s= nut->avf;
663
    ByteIOContext *bc = &s->pb;
664
    int size, stream_id, discard;
665
    int64_t pts, last_IP_pts;
666
    StreamContext *stc;
667

    
668
    size= decode_frame_header(nut, &pts, &stream_id, frame_code);
669
    if(size < 0)
670
        return -1;
671

    
672
    stc= &nut->stream[stream_id];
673

    
674
    if (stc->last_flags & FLAG_KEY)
675
        stc->skip_until_key_frame=0;
676

    
677
    discard= s->streams[ stream_id ]->discard;
678
    last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
679
    if(  (discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY))
680
       ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
681
       || discard >= AVDISCARD_ALL
682
       || stc->skip_until_key_frame){
683
        url_fskip(bc, size);
684
        return 1;
685
    }
686

    
687
    av_get_packet(bc, pkt, size);
688
    pkt->stream_index = stream_id;
689
    if (stc->last_flags & FLAG_KEY)
690
        pkt->flags |= PKT_FLAG_KEY;
691
    pkt->pts = pts;
692

    
693
    return 0;
694
}
695

    
696
static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
697
{
698
    NUTContext *nut = s->priv_data;
699
    ByteIOContext *bc = &s->pb;
700
    int i, frame_code=0, ret, skip;
701
    int64_t ts, back_ptr;
702

    
703
    for(;;){
704
        int64_t pos= url_ftell(bc);
705
        uint64_t tmp= nut->next_startcode;
706
        nut->next_startcode=0;
707

    
708
        if(tmp){
709
            pos-=8;
710
        }else{
711
            frame_code = get_byte(bc);
712
            if(url_feof(bc))
713
                return -1;
714
            if(frame_code == 'N'){
715
                tmp= frame_code;
716
                for(i=1; i<8; i++)
717
                    tmp = (tmp<<8) + get_byte(bc);
718
            }
719
        }
720
        switch(tmp){
721
        case MAIN_STARTCODE:
722
        case STREAM_STARTCODE:
723
        case INDEX_STARTCODE:
724
            skip= get_packetheader(nut, bc, 0, tmp);
725
            url_fseek(bc, skip, SEEK_CUR);
726
            break;
727
        case INFO_STARTCODE:
728
            if(decode_info_header(nut)<0)
729
                goto resync;
730
            break;
731
        case SYNCPOINT_STARTCODE:
732
            if(decode_syncpoint(nut, &ts, &back_ptr)<0)
733
                goto resync;
734
            frame_code = get_byte(bc);
735
        case 0:
736
            ret= decode_frame(nut, pkt, frame_code);
737
            if(ret==0)
738
                return 0;
739
            else if(ret==1) //ok but discard packet
740
                break;
741
        default:
742
resync:
743
av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
744
            tmp= find_any_startcode(bc, nut->last_syncpoint_pos+1);
745
            if(tmp==0)
746
                return -1;
747
av_log(s, AV_LOG_DEBUG, "sync\n");
748
            nut->next_startcode= tmp;
749
        }
750
    }
751
}
752

    
753
static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
754
    NUTContext *nut = s->priv_data;
755
    ByteIOContext *bc = &s->pb;
756
    int64_t pos, pts, back_ptr;
757
av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
758

    
759
    pos= *pos_arg;
760
resync:
761
    do{
762
        pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
763
        if(pos < 1){
764
            assert(nut->next_startcode == 0);
765
            av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
766
            return AV_NOPTS_VALUE;
767
        }
768
    }while(decode_syncpoint(nut, &pts, &back_ptr) < 0);
769
    *pos_arg = pos-1;
770
    assert(nut->last_syncpoint_pos == *pos_arg);
771

    
772
    av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts,back_ptr );
773
    if     (stream_index == -1) return pts;
774
    else if(stream_index == -2) return back_ptr;
775

    
776
assert(0);
777
}
778

    
779
static int read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags){
780
    NUTContext *nut = s->priv_data;
781
    AVStream *st= s->streams[stream_index];
782
    syncpoint_t dummy={.ts= pts*av_q2d(st->time_base)*AV_TIME_BASE};
783
    syncpoint_t nopts_sp= {.ts= AV_NOPTS_VALUE, .back_ptr= AV_NOPTS_VALUE};
784
    syncpoint_t *sp, *next_node[2]= {&nopts_sp, &nopts_sp};
785
    int64_t pos, pos2, ts;
786
    int i;
787

    
788
    if(st->index_entries){
789
        int index= av_index_search_timestamp(st, pts, flags);
790
        if(index<0)
791
            return -1;
792

    
793
        pos2= st->index_entries[index].pos;
794
        ts  = st->index_entries[index].timestamp;
795
    }else{
796
        av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pts_cmp, next_node);
797
        av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n", next_node[0]->pos, next_node[1]->pos,
798
                                                    next_node[0]->ts , next_node[1]->ts);
799
        pos= av_gen_search(s, -1, dummy.ts, next_node[0]->pos, next_node[1]->pos, next_node[1]->pos,
800
                                            next_node[0]->ts , next_node[1]->ts, AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
801

    
802
        if(!(flags & AVSEEK_FLAG_BACKWARD)){
803
            dummy.pos= pos+16;
804
            next_node[1]= &nopts_sp;
805
            av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, next_node);
806
            pos2= av_gen_search(s, -2, dummy.pos, next_node[0]->pos     , next_node[1]->pos, next_node[1]->pos,
807
                                                next_node[0]->back_ptr, next_node[1]->back_ptr, flags, &ts, nut_read_timestamp);
808
            if(pos2>=0)
809
                pos= pos2;
810
            //FIXME dir but i think it does not matter
811
        }
812
        dummy.pos= pos;
813
        sp= av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, NULL);
814

    
815
        assert(sp);
816
        pos2= sp->back_ptr  - 15;
817
    }
818
    av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
819
    pos= find_startcode(&s->pb, SYNCPOINT_STARTCODE, pos2);
820
    url_fseek(&s->pb, pos, SEEK_SET);
821
    av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
822
    if(pos2 > pos || pos2 + 15 < pos){
823
        av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
824
    }
825
    for(i=0; i<s->nb_streams; i++)
826
        nut->stream[i].skip_until_key_frame=1;
827

    
828
    return 0;
829
}
830

    
831
static int nut_read_close(AVFormatContext *s)
832
{
833
    NUTContext *nut = s->priv_data;
834

    
835
    av_freep(&nut->time_base);
836
    av_freep(&nut->stream);
837

    
838
    return 0;
839
}
840

    
841
#ifdef CONFIG_NUT_DEMUXER
842
AVInputFormat nut_demuxer = {
843
    "nut",
844
    "nut format",
845
    sizeof(NUTContext),
846
    nut_probe,
847
    nut_read_header,
848
    nut_read_packet,
849
    nut_read_close,
850
    read_seek,
851
    .extensions = "nut",
852
};
853
#endif