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ffmpeg / libavformat / nutdec.c @ 1326621c

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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
21
 */
22

    
23
#include "tree.h"
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#include "nut.h"
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#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);
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        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

    
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    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, tmp_head_idx;
188
    int64_t tmp_match;
189

    
190
    end= get_packetheader(nut, bc, 1, MAIN_STARTCODE);
191
    end += url_ftell(bc);
192

    
193
    GET_V(tmp              , tmp >=2 && tmp <= 3)
194
    GET_V(stream_count     , tmp > 0 && tmp <=MAX_STREAMS)
195

    
196
    nut->max_distance = ff_get_v(bc);
197
    if(nut->max_distance > 65536){
198
        av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
199
        nut->max_distance= 65536;
200
    }
201

    
202
    GET_V(nut->time_base_count, tmp>0 && tmp<INT_MAX / sizeof(AVRational))
203
    nut->time_base= av_malloc(nut->time_base_count * sizeof(AVRational));
204

    
205
    for(i=0; i<nut->time_base_count; i++){
206
        GET_V(nut->time_base[i].num, tmp>0 && tmp<(1ULL<<31))
207
        GET_V(nut->time_base[i].den, tmp>0 && tmp<(1ULL<<31))
208
        if(ff_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1){
209
            av_log(s, AV_LOG_ERROR, "time base invalid\n");
210
            return -1;
211
        }
212
    }
213
    tmp_pts=0;
214
    tmp_mul=1;
215
    tmp_stream=0;
216
    tmp_match= 1-(1LL<<62);
217
    tmp_head_idx= 0;
218
    for(i=0; i<256;){
219
        int tmp_flags = ff_get_v(bc);
220
        int tmp_fields= ff_get_v(bc);
221
        if(tmp_fields>0) tmp_pts   = get_s(bc);
222
        if(tmp_fields>1) tmp_mul   = ff_get_v(bc);
223
        if(tmp_fields>2) tmp_stream= ff_get_v(bc);
224
        if(tmp_fields>3) tmp_size  = ff_get_v(bc);
225
        else             tmp_size  = 0;
226
        if(tmp_fields>4) tmp_res   = ff_get_v(bc);
227
        else             tmp_res   = 0;
228
        if(tmp_fields>5) count     = ff_get_v(bc);
229
        else             count     = tmp_mul - tmp_size;
230
        if(tmp_fields>6) tmp_match = get_s(bc);
231
        if(tmp_fields>7) tmp_head_idx= ff_get_v(bc);
232

    
233
        while(tmp_fields-- > 8)
234
           ff_get_v(bc);
235

    
236
        if(count == 0 || i+count > 256){
237
            av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
238
            return -1;
239
        }
240
        if(tmp_stream >= stream_count){
241
            av_log(s, AV_LOG_ERROR, "illegal stream number\n");
242
            return -1;
243
        }
244

    
245
        for(j=0; j<count; j++,i++){
246
            if (i == 'N') {
247
                nut->frame_code[i].flags= FLAG_INVALID;
248
                j--;
249
                continue;
250
            }
251
            nut->frame_code[i].flags           = tmp_flags ;
252
            nut->frame_code[i].pts_delta       = tmp_pts   ;
253
            nut->frame_code[i].stream_id       = tmp_stream;
254
            nut->frame_code[i].size_mul        = tmp_mul   ;
255
            nut->frame_code[i].size_lsb        = tmp_size+j;
256
            nut->frame_code[i].reserved_count  = tmp_res   ;
257
            nut->frame_code[i].header_idx      = tmp_head_idx;
258
        }
259
    }
260
    assert(nut->frame_code['N'].flags == FLAG_INVALID);
261

    
262
    if(end > url_ftell(bc) + 4){
263
        int rem= 1024;
264
        GET_V(nut->header_count, tmp<128U)
265
        nut->header_count++;
266
        for(i=1; i<nut->header_count; i++){
267
            GET_V(nut->header_len[i], tmp>0 && tmp<256);
268
            rem -= nut->header_len[i];
269
            if(rem < 0){
270
                av_log(s, AV_LOG_ERROR, "invalid elision header\n");
271
                return -1;
272
            }
273
            nut->header[i]= av_malloc(nut->header_len[i]);
274
            get_buffer(bc, nut->header[i], nut->header_len[i]);
275
        }
276
        assert(nut->header_len[0]==0);
277
    }
278

    
279
    if(skip_reserved(bc, end) || get_checksum(bc)){
280
        av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
281
        return -1;
282
    }
283

    
284
    nut->stream = av_mallocz(sizeof(StreamContext)*stream_count);
285
    for(i=0; i<stream_count; i++){
286
        av_new_stream(s, i);
287
    }
288

    
289
    return 0;
290
}
291

    
292
static int decode_stream_header(NUTContext *nut){
293
    AVFormatContext *s= nut->avf;
294
    ByteIOContext *bc = s->pb;
295
    StreamContext *stc;
296
    int class, stream_id;
297
    uint64_t tmp, end;
298
    AVStream *st;
299

    
300
    end= get_packetheader(nut, bc, 1, STREAM_STARTCODE);
301
    end += url_ftell(bc);
302

    
303
    GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);
304
    stc= &nut->stream[stream_id];
305

    
306
    st = s->streams[stream_id];
307
    if (!st)
308
        return AVERROR(ENOMEM);
309

    
310
    class = ff_get_v(bc);
311
    tmp = get_fourcc(bc);
312
    st->codec->codec_tag= tmp;
313
    switch(class)
314
    {
315
        case 0:
316
            st->codec->codec_type = CODEC_TYPE_VIDEO;
317
            st->codec->codec_id = codec_get_id(codec_bmp_tags, tmp);
318
            break;
319
        case 1:
320
            st->codec->codec_type = CODEC_TYPE_AUDIO;
321
            st->codec->codec_id = codec_get_id(codec_wav_tags, tmp);
322
            break;
323
        case 2:
324
            st->codec->codec_type = CODEC_TYPE_SUBTITLE;
325
            st->codec->codec_id = codec_get_id(ff_nut_subtitle_tags, tmp);
326
            break;
327
        case 3:
328
            st->codec->codec_type = CODEC_TYPE_DATA;
329
            break;
330
        default:
331
            av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);
332
            return -1;
333
    }
334
    if(class<3 && st->codec->codec_id == CODEC_ID_NONE)
335
        av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
336

    
337
    GET_V(stc->time_base_id    , tmp < nut->time_base_count);
338
    GET_V(stc->msb_pts_shift   , tmp < 16);
339
    stc->max_pts_distance= ff_get_v(bc);
340
    GET_V(stc->decode_delay    , tmp < 1000); //sanity limit, raise this if Moore's law is true
341
    st->codec->has_b_frames= stc->decode_delay;
342
    ff_get_v(bc); //stream flags
343

    
344
    GET_V(st->codec->extradata_size, tmp < (1<<30));
345
    if(st->codec->extradata_size){
346
        st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
347
        get_buffer(bc, st->codec->extradata, st->codec->extradata_size);
348
    }
349

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

    
374
static int decode_info_header(NUTContext *nut){
375
    AVFormatContext *s= nut->avf;
376
    ByteIOContext *bc = s->pb;
377
    uint64_t tmp;
378
    unsigned int stream_id_plus1, chapter_start, chapter_len, count;
379
    int chapter_id, i;
380
    int64_t value, end;
381
    char name[256], str_value[1024], type_str[256];
382
    const char *type;
383

    
384
    end= get_packetheader(nut, bc, 1, INFO_STARTCODE);
385
    end += url_ftell(bc);
386

    
387
    GET_V(stream_id_plus1, tmp <= s->nb_streams)
388
    chapter_id   = get_s(bc);
389
    chapter_start= ff_get_v(bc);
390
    chapter_len  = ff_get_v(bc);
391
    count        = ff_get_v(bc);
392
    for(i=0; i<count; i++){
393
        get_str(bc, name, sizeof(name));
394
        value= get_s(bc);
395
        if(value == -1){
396
            type= "UTF-8";
397
            get_str(bc, str_value, sizeof(str_value));
398
        }else if(value == -2){
399
            get_str(bc, type_str, sizeof(type_str));
400
            type= type_str;
401
            get_str(bc, str_value, sizeof(str_value));
402
        }else if(value == -3){
403
            type= "s";
404
            value= get_s(bc);
405
        }else if(value == -4){
406
            type= "t";
407
            value= ff_get_v(bc);
408
        }else if(value < -4){
409
            type= "r";
410
            get_s(bc);
411
        }else{
412
            type= "v";
413
        }
414

    
415
        if(chapter_id==0 && !strcmp(type, "UTF-8")){
416
            if     (!strcmp(name, "Author"))
417
                av_strlcpy(s->author   , str_value, sizeof(s->author));
418
            else if(!strcmp(name, "Title"))
419
                av_strlcpy(s->title    , str_value, sizeof(s->title));
420
            else if(!strcmp(name, "Copyright"))
421
                av_strlcpy(s->copyright, str_value, sizeof(s->copyright));
422
            else if(!strcmp(name, "Description"))
423
                av_strlcpy(s->comment  , str_value, sizeof(s->comment));
424
        }
425
    }
426

    
427
    if(skip_reserved(bc, end) || get_checksum(bc)){
428
        av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");
429
        return -1;
430
    }
431
    return 0;
432
}
433

    
434
static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr){
435
    AVFormatContext *s= nut->avf;
436
    ByteIOContext *bc = s->pb;
437
    int64_t end, tmp;
438

    
439
    nut->last_syncpoint_pos= url_ftell(bc)-8;
440

    
441
    end= get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
442
    end += url_ftell(bc);
443

    
444
    tmp= ff_get_v(bc);
445
    *back_ptr= nut->last_syncpoint_pos - 16*ff_get_v(bc);
446
    if(*back_ptr < 0)
447
        return -1;
448

    
449
    ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count], tmp / nut->time_base_count);
450

    
451
    if(skip_reserved(bc, end) || get_checksum(bc)){
452
        av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
453
        return -1;
454
    }
455

    
456
    *ts= tmp / s->nb_streams * av_q2d(nut->time_base[tmp % s->nb_streams])*AV_TIME_BASE;
457
    ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
458

    
459
    return 0;
460
}
461

    
462
static int find_and_decode_index(NUTContext *nut){
463
    AVFormatContext *s= nut->avf;
464
    ByteIOContext *bc = s->pb;
465
    uint64_t tmp, end;
466
    int i, j, syncpoint_count;
467
    int64_t filesize= url_fsize(bc);
468
    int64_t *syncpoints;
469
    int8_t *has_keyframe;
470

    
471
    url_fseek(bc, filesize-12, SEEK_SET);
472
    url_fseek(bc, filesize-get_be64(bc), SEEK_SET);
473
    if(get_be64(bc) != INDEX_STARTCODE){
474
        av_log(s, AV_LOG_ERROR, "no index at the end\n");
475
        return -1;
476
    }
477

    
478
    end= get_packetheader(nut, bc, 1, INDEX_STARTCODE);
479
    end += url_ftell(bc);
480

    
481
    ff_get_v(bc); //max_pts
482
    GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
483
    syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
484
    has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
485
    for(i=0; i<syncpoint_count; i++){
486
        GET_V(syncpoints[i], tmp>0)
487
        if(i)
488
            syncpoints[i] += syncpoints[i-1];
489
    }
490

    
491
    for(i=0; i<s->nb_streams; i++){
492
        int64_t last_pts= -1;
493
        for(j=0; j<syncpoint_count;){
494
            uint64_t x= ff_get_v(bc);
495
            int type= x&1;
496
            int n= j;
497
            x>>=1;
498
            if(type){
499
                int flag= x&1;
500
                x>>=1;
501
                if(n+x >= syncpoint_count + 1){
502
                    av_log(s, AV_LOG_ERROR, "index overflow A\n");
503
                    return -1;
504
                }
505
                while(x--)
506
                    has_keyframe[n++]= flag;
507
                has_keyframe[n++]= !flag;
508
            }else{
509
                while(x != 1){
510
                    if(n>=syncpoint_count + 1){
511
                        av_log(s, AV_LOG_ERROR, "index overflow B\n");
512
                        return -1;
513
                    }
514
                    has_keyframe[n++]= x&1;
515
                    x>>=1;
516
                }
517
            }
518
            if(has_keyframe[0]){
519
                av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
520
                return -1;
521
            }
522
            assert(n<=syncpoint_count+1);
523
            for(; j<n && j<syncpoint_count; j++){
524
                if(has_keyframe[j]){
525
                    uint64_t B, A= ff_get_v(bc);
526
                    if(!A){
527
                        A= ff_get_v(bc);
528
                        B= ff_get_v(bc);
529
                        //eor_pts[j][i] = last_pts + A + B
530
                    }else
531
                        B= 0;
532
                    av_add_index_entry(
533
                        s->streams[i],
534
                        16*syncpoints[j-1],
535
                        last_pts + A,
536
                        0,
537
                        0,
538
                        AVINDEX_KEYFRAME);
539
                    last_pts += A + B;
540
                }
541
            }
542
        }
543
    }
544

    
545
    if(skip_reserved(bc, end) || get_checksum(bc)){
546
        av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
547
        return -1;
548
    }
549
    return 0;
550
}
551

    
552
static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
553
{
554
    NUTContext *nut = s->priv_data;
555
    ByteIOContext *bc = s->pb;
556
    int64_t pos;
557
    int initialized_stream_count;
558

    
559
    nut->avf= s;
560

    
561
    /* main header */
562
    pos=0;
563
    do{
564
        pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
565
        if (pos<0+1){
566
            av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
567
            return -1;
568
        }
569
    }while(decode_main_header(nut) < 0);
570

    
571
    /* stream headers */
572
    pos=0;
573
    for(initialized_stream_count=0; initialized_stream_count < s->nb_streams;){
574
        pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
575
        if (pos<0+1){
576
            av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
577
            return -1;
578
        }
579
        if(decode_stream_header(nut) >= 0)
580
            initialized_stream_count++;
581
    }
582

    
583
    /* info headers */
584
    pos=0;
585
    for(;;){
586
        uint64_t startcode= find_any_startcode(bc, pos);
587
        pos= url_ftell(bc);
588

    
589
        if(startcode==0){
590
            av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
591
            return -1;
592
        }else if(startcode == SYNCPOINT_STARTCODE){
593
            nut->next_startcode= startcode;
594
            break;
595
        }else if(startcode != INFO_STARTCODE){
596
            continue;
597
        }
598

    
599
        decode_info_header(nut);
600
    }
601

    
602
    s->data_offset= pos-8;
603

    
604
    if(!url_is_streamed(bc)){
605
        int64_t orig_pos= url_ftell(bc);
606
        find_and_decode_index(nut);
607
        url_fseek(bc, orig_pos, SEEK_SET);
608
    }
609
    assert(nut->next_startcode == SYNCPOINT_STARTCODE);
610

    
611
    return 0;
612
}
613

    
614
static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, uint8_t *header_idx, int frame_code){
615
    AVFormatContext *s= nut->avf;
616
    ByteIOContext *bc = s->pb;
617
    StreamContext *stc;
618
    int size, flags, size_mul, pts_delta, i, reserved_count;
619
    uint64_t tmp;
620

    
621
    if(url_ftell(bc) > nut->last_syncpoint_pos + nut->max_distance){
622
        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);
623
        return -1;
624
    }
625

    
626
    flags          = nut->frame_code[frame_code].flags;
627
    size_mul       = nut->frame_code[frame_code].size_mul;
628
    size           = nut->frame_code[frame_code].size_lsb;
629
    *stream_id     = nut->frame_code[frame_code].stream_id;
630
    pts_delta      = nut->frame_code[frame_code].pts_delta;
631
    reserved_count = nut->frame_code[frame_code].reserved_count;
632
    *header_idx    = nut->frame_code[frame_code].header_idx;
633

    
634
    if(flags & FLAG_INVALID)
635
        return -1;
636
    if(flags & FLAG_CODED)
637
        flags ^= ff_get_v(bc);
638
    if(flags & FLAG_STREAM_ID){
639
        GET_V(*stream_id, tmp < s->nb_streams)
640
    }
641
    stc= &nut->stream[*stream_id];
642
    if(flags&FLAG_CODED_PTS){
643
        int coded_pts= ff_get_v(bc);
644
//FIXME check last_pts validity?
645
        if(coded_pts < (1<<stc->msb_pts_shift)){
646
            *pts=ff_lsb2full(stc, coded_pts);
647
        }else
648
            *pts=coded_pts - (1<<stc->msb_pts_shift);
649
    }else
650
        *pts= stc->last_pts + pts_delta;
651
    if(flags&FLAG_SIZE_MSB){
652
        size += size_mul*ff_get_v(bc);
653
    }
654
    if(flags&FLAG_MATCH_TIME)
655
        get_s(bc);
656
    if(flags&FLAG_HEADER_IDX)
657
        *header_idx= ff_get_v(bc);
658
    if(flags&FLAG_RESERVED)
659
        reserved_count= ff_get_v(bc);
660
    for(i=0; i<reserved_count; i++)
661
        ff_get_v(bc);
662

    
663
    if(*header_idx >= (unsigned)nut->header_count){
664
        av_log(s, AV_LOG_ERROR, "header_idx invalid\n");
665
        return -1;
666
    }
667
    if(size > 4096)
668
        *header_idx=0;
669
    size -= nut->header_len[*header_idx];
670

    
671
    if(flags&FLAG_CHECKSUM){
672
        get_be32(bc); //FIXME check this
673
    }else if(size > 2*nut->max_distance || FFABS(stc->last_pts - *pts) > stc->max_pts_distance){
674
        av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
675
        return -1;
676
    }
677

    
678
    stc->last_pts= *pts;
679
    stc->last_flags= flags;
680

    
681
    return size;
682
}
683

    
684
static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
685
    AVFormatContext *s= nut->avf;
686
    ByteIOContext *bc = s->pb;
687
    int size, stream_id, discard;
688
    int64_t pts, last_IP_pts;
689
    StreamContext *stc;
690
    uint8_t header_idx;
691

    
692
    size= decode_frame_header(nut, &pts, &stream_id, &header_idx, frame_code);
693
    if(size < 0)
694
        return -1;
695

    
696
    stc= &nut->stream[stream_id];
697

    
698
    if (stc->last_flags & FLAG_KEY)
699
        stc->skip_until_key_frame=0;
700

    
701
    discard= s->streams[ stream_id ]->discard;
702
    last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
703
    if(  (discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY))
704
       ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
705
       || discard >= AVDISCARD_ALL
706
       || stc->skip_until_key_frame){
707
        url_fskip(bc, size);
708
        return 1;
709
    }
710

    
711
    av_new_packet(pkt, size + nut->header_len[header_idx]);
712
    memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
713
    pkt->pos= url_ftell(bc); //FIXME
714
    get_buffer(bc, pkt->data + nut->header_len[header_idx], size);
715

    
716
    pkt->stream_index = stream_id;
717
    if (stc->last_flags & FLAG_KEY)
718
        pkt->flags |= PKT_FLAG_KEY;
719
    pkt->pts = pts;
720

    
721
    return 0;
722
}
723

    
724
static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
725
{
726
    NUTContext *nut = s->priv_data;
727
    ByteIOContext *bc = s->pb;
728
    int i, frame_code=0, ret, skip;
729
    int64_t ts, back_ptr;
730

    
731
    for(;;){
732
        int64_t pos= url_ftell(bc);
733
        uint64_t tmp= nut->next_startcode;
734
        nut->next_startcode=0;
735

    
736
        if(tmp){
737
            pos-=8;
738
        }else{
739
            frame_code = get_byte(bc);
740
            if(url_feof(bc))
741
                return -1;
742
            if(frame_code == 'N'){
743
                tmp= frame_code;
744
                for(i=1; i<8; i++)
745
                    tmp = (tmp<<8) + get_byte(bc);
746
            }
747
        }
748
        switch(tmp){
749
        case MAIN_STARTCODE:
750
        case STREAM_STARTCODE:
751
        case INDEX_STARTCODE:
752
            skip= get_packetheader(nut, bc, 0, tmp);
753
            url_fseek(bc, skip, SEEK_CUR);
754
            break;
755
        case INFO_STARTCODE:
756
            if(decode_info_header(nut)<0)
757
                goto resync;
758
            break;
759
        case SYNCPOINT_STARTCODE:
760
            if(decode_syncpoint(nut, &ts, &back_ptr)<0)
761
                goto resync;
762
            frame_code = get_byte(bc);
763
        case 0:
764
            ret= decode_frame(nut, pkt, frame_code);
765
            if(ret==0)
766
                return 0;
767
            else if(ret==1) //ok but discard packet
768
                break;
769
        default:
770
resync:
771
av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
772
            tmp= find_any_startcode(bc, nut->last_syncpoint_pos+1);
773
            if(tmp==0)
774
                return -1;
775
av_log(s, AV_LOG_DEBUG, "sync\n");
776
            nut->next_startcode= tmp;
777
        }
778
    }
779
}
780

    
781
static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
782
    NUTContext *nut = s->priv_data;
783
    ByteIOContext *bc = s->pb;
784
    int64_t pos, pts, back_ptr;
785
av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
786

    
787
    pos= *pos_arg;
788
    do{
789
        pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
790
        if(pos < 1){
791
            assert(nut->next_startcode == 0);
792
            av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
793
            return AV_NOPTS_VALUE;
794
        }
795
    }while(decode_syncpoint(nut, &pts, &back_ptr) < 0);
796
    *pos_arg = pos-1;
797
    assert(nut->last_syncpoint_pos == *pos_arg);
798

    
799
    av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts,back_ptr );
800
    if     (stream_index == -1) return pts;
801
    else if(stream_index == -2) return back_ptr;
802

    
803
assert(0);
804
}
805

    
806
static int read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags){
807
    NUTContext *nut = s->priv_data;
808
    AVStream *st= s->streams[stream_index];
809
    syncpoint_t dummy={.ts= pts*av_q2d(st->time_base)*AV_TIME_BASE};
810
    syncpoint_t nopts_sp= {.ts= AV_NOPTS_VALUE, .back_ptr= AV_NOPTS_VALUE};
811
    syncpoint_t *sp, *next_node[2]= {&nopts_sp, &nopts_sp};
812
    int64_t pos, pos2, ts;
813
    int i;
814

    
815
    if(st->index_entries){
816
        int index= av_index_search_timestamp(st, pts, flags);
817
        if(index<0)
818
            return -1;
819

    
820
        pos2= st->index_entries[index].pos;
821
        ts  = st->index_entries[index].timestamp;
822
    }else{
823
        av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pts_cmp, next_node);
824
        av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n", next_node[0]->pos, next_node[1]->pos,
825
                                                    next_node[0]->ts , next_node[1]->ts);
826
        pos= av_gen_search(s, -1, dummy.ts, next_node[0]->pos, next_node[1]->pos, next_node[1]->pos,
827
                                            next_node[0]->ts , next_node[1]->ts, AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
828

    
829
        if(!(flags & AVSEEK_FLAG_BACKWARD)){
830
            dummy.pos= pos+16;
831
            next_node[1]= &nopts_sp;
832
            av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, next_node);
833
            pos2= av_gen_search(s, -2, dummy.pos, next_node[0]->pos     , next_node[1]->pos, next_node[1]->pos,
834
                                                next_node[0]->back_ptr, next_node[1]->back_ptr, flags, &ts, nut_read_timestamp);
835
            if(pos2>=0)
836
                pos= pos2;
837
            //FIXME dir but i think it does not matter
838
        }
839
        dummy.pos= pos;
840
        sp= av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, NULL);
841

    
842
        assert(sp);
843
        pos2= sp->back_ptr  - 15;
844
    }
845
    av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
846
    pos= find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);
847
    url_fseek(s->pb, pos, SEEK_SET);
848
    av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
849
    if(pos2 > pos || pos2 + 15 < pos){
850
        av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
851
    }
852
    for(i=0; i<s->nb_streams; i++)
853
        nut->stream[i].skip_until_key_frame=1;
854

    
855
    return 0;
856
}
857

    
858
static int nut_read_close(AVFormatContext *s)
859
{
860
    NUTContext *nut = s->priv_data;
861

    
862
    av_freep(&nut->time_base);
863
    av_freep(&nut->stream);
864

    
865
    return 0;
866
}
867

    
868
#ifdef CONFIG_NUT_DEMUXER
869
AVInputFormat nut_demuxer = {
870
    "nut",
871
    "nut format",
872
    sizeof(NUTContext),
873
    nut_probe,
874
    nut_read_header,
875
    nut_read_packet,
876
    nut_read_close,
877
    read_seek,
878
    .extensions = "nut",
879
};
880
#endif