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ffmpeg / libavformat / nutdec.c @ 43382b5f

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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
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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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 */
22

    
23
#include <strings.h>
24
#include "libavutil/avstring.h"
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#include "libavutil/bswap.h"
26
#include "libavutil/tree.h"
27
#include "nut.h"
28

    
29
#undef NDEBUG
30
#include <assert.h>
31

    
32
static int get_str(ByteIOContext *bc, char *string, unsigned int maxlen){
33
    unsigned int len= ff_get_v(bc);
34

    
35
    if(len && maxlen)
36
        get_buffer(bc, string, FFMIN(len, maxlen));
37
    while(len > maxlen){
38
        get_byte(bc);
39
        len--;
40
    }
41

    
42
    if(maxlen)
43
        string[FFMIN(len, maxlen-1)]= 0;
44

    
45
    if(maxlen == len)
46
        return -1;
47
    else
48
        return 0;
49
}
50

    
51
static int64_t get_s(ByteIOContext *bc){
52
    int64_t v = ff_get_v(bc) + 1;
53

    
54
    if (v&1) return -(v>>1);
55
    else     return  (v>>1);
56
}
57

    
58
static uint64_t get_fourcc(ByteIOContext *bc){
59
    unsigned int len= ff_get_v(bc);
60

    
61
    if     (len==2) return get_le16(bc);
62
    else if(len==4) return get_le32(bc);
63
    else            return -1;
64
}
65

    
66
#ifdef TRACE
67
static inline uint64_t get_v_trace(ByteIOContext *bc, char *file, char *func, int line){
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    uint64_t v= ff_get_v(bc);
69

    
70
    av_log(NULL, AV_LOG_DEBUG, "get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
71
    return v;
72
}
73

    
74
static inline int64_t get_s_trace(ByteIOContext *bc, char *file, char *func, int line){
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    int64_t v= get_s(bc);
76

    
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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);
78
    return v;
79
}
80

    
81
static inline uint64_t get_vb_trace(ByteIOContext *bc, char *file, char *func, int line){
82
    uint64_t v= get_vb(bc);
83

    
84
    av_log(NULL, AV_LOG_DEBUG, "get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
85
    return v;
86
}
87
#define ff_get_v(bc)  get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
88
#define get_s(bc)  get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
89
#define get_vb(bc)  get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
90
#endif
91

    
92
static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int calculate_checksum, uint64_t startcode)
93
{
94
    int64_t size;
95
//    start= url_ftell(bc) - 8;
96

    
97
    startcode= be2me_64(startcode);
98
    startcode= ff_crc04C11DB7_update(0, &startcode, 8);
99

    
100
    init_checksum(bc, ff_crc04C11DB7_update, startcode);
101
    size= ff_get_v(bc);
102
    if(size > 4096)
103
        get_be32(bc);
104
    if(get_checksum(bc) && size > 4096)
105
        return -1;
106

    
107
    init_checksum(bc, calculate_checksum ? ff_crc04C11DB7_update : NULL, 0);
108

    
109
    return size;
110
}
111

    
112
static uint64_t find_any_startcode(ByteIOContext *bc, int64_t pos){
113
    uint64_t state=0;
114

    
115
    if(pos >= 0)
116
        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 currently are
117

    
118
    while(!url_feof(bc)){
119
        state= (state<<8) | get_byte(bc);
120
        if((state>>56) != 'N')
121
            continue;
122
        switch(state){
123
        case MAIN_STARTCODE:
124
        case STREAM_STARTCODE:
125
        case SYNCPOINT_STARTCODE:
126
        case INFO_STARTCODE:
127
        case INDEX_STARTCODE:
128
            return state;
129
        }
130
    }
131

    
132
    return 0;
133
}
134

    
135
/**
136
 * Find the given startcode.
137
 * @param code the startcode
138
 * @param pos the start position of the search, or -1 if the current position
139
 * @returns the position of the startcode or -1 if not found
140
 */
141
static int64_t find_startcode(ByteIOContext *bc, uint64_t code, int64_t pos){
142
    for(;;){
143
        uint64_t startcode= find_any_startcode(bc, pos);
144
        if(startcode == code)
145
            return url_ftell(bc) - 8;
146
        else if(startcode == 0)
147
            return -1;
148
        pos=-1;
149
    }
150
}
151

    
152
static int nut_probe(AVProbeData *p){
153
    int i;
154
    uint64_t code= 0;
155

    
156
    for (i = 0; i < p->buf_size; i++) {
157
        code = (code << 8) | p->buf[i];
158
        if (code == MAIN_STARTCODE)
159
            return AVPROBE_SCORE_MAX;
160
    }
161
    return 0;
162
}
163

    
164
#define GET_V(dst, check) \
165
    tmp= ff_get_v(bc);\
166
    if(!(check)){\
167
        av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp);\
168
        return -1;\
169
    }\
170
    dst= tmp;
171

    
172
static int skip_reserved(ByteIOContext *bc, int64_t pos){
173
    pos -= url_ftell(bc);
174
    if(pos<0){
175
        url_fseek(bc, pos, SEEK_CUR);
176
        return -1;
177
    }else{
178
        while(pos--)
179
            get_byte(bc);
180
        return 0;
181
    }
182
}
183

    
184
static int decode_main_header(NUTContext *nut){
185
    AVFormatContext *s= nut->avf;
186
    ByteIOContext *bc = s->pb;
187
    uint64_t tmp, end;
188
    unsigned int stream_count;
189
    int i, j, tmp_stream, tmp_mul, tmp_pts, tmp_size, count, tmp_res, tmp_head_idx;
190
    int64_t tmp_match;
191

    
192
    end= get_packetheader(nut, bc, 1, MAIN_STARTCODE);
193
    end += url_ftell(bc);
194

    
195
    GET_V(tmp              , tmp >=2 && tmp <= 3)
196
    GET_V(stream_count     , tmp > 0 && tmp <=MAX_STREAMS)
197

    
198
    nut->max_distance = ff_get_v(bc);
199
    if(nut->max_distance > 65536){
200
        av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
201
        nut->max_distance= 65536;
202
    }
203

    
204
    GET_V(nut->time_base_count, tmp>0 && tmp<INT_MAX / sizeof(AVRational))
205
    nut->time_base= av_malloc(nut->time_base_count * sizeof(AVRational));
206

    
207
    for(i=0; i<nut->time_base_count; i++){
208
        GET_V(nut->time_base[i].num, tmp>0 && tmp<(1ULL<<31))
209
        GET_V(nut->time_base[i].den, tmp>0 && tmp<(1ULL<<31))
210
        if(av_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1){
211
            av_log(s, AV_LOG_ERROR, "time base invalid\n");
212
            return -1;
213
        }
214
    }
215
    tmp_pts=0;
216
    tmp_mul=1;
217
    tmp_stream=0;
218
    tmp_match= 1-(1LL<<62);
219
    tmp_head_idx= 0;
220
    for(i=0; i<256;){
221
        int tmp_flags = ff_get_v(bc);
222
        int tmp_fields= ff_get_v(bc);
223
        if(tmp_fields>0) tmp_pts   = get_s(bc);
224
        if(tmp_fields>1) tmp_mul   = ff_get_v(bc);
225
        if(tmp_fields>2) tmp_stream= ff_get_v(bc);
226
        if(tmp_fields>3) tmp_size  = ff_get_v(bc);
227
        else             tmp_size  = 0;
228
        if(tmp_fields>4) tmp_res   = ff_get_v(bc);
229
        else             tmp_res   = 0;
230
        if(tmp_fields>5) count     = ff_get_v(bc);
231
        else             count     = tmp_mul - tmp_size;
232
        if(tmp_fields>6) tmp_match = get_s(bc);
233
        if(tmp_fields>7) tmp_head_idx= ff_get_v(bc);
234

    
235
        while(tmp_fields-- > 8)
236
           ff_get_v(bc);
237

    
238
        if(count == 0 || i+count > 256){
239
            av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
240
            return -1;
241
        }
242
        if(tmp_stream >= stream_count){
243
            av_log(s, AV_LOG_ERROR, "illegal stream number\n");
244
            return -1;
245
        }
246

    
247
        for(j=0; j<count; j++,i++){
248
            if (i == 'N') {
249
                nut->frame_code[i].flags= FLAG_INVALID;
250
                j--;
251
                continue;
252
            }
253
            nut->frame_code[i].flags           = tmp_flags ;
254
            nut->frame_code[i].pts_delta       = tmp_pts   ;
255
            nut->frame_code[i].stream_id       = tmp_stream;
256
            nut->frame_code[i].size_mul        = tmp_mul   ;
257
            nut->frame_code[i].size_lsb        = tmp_size+j;
258
            nut->frame_code[i].reserved_count  = tmp_res   ;
259
            nut->frame_code[i].header_idx      = tmp_head_idx;
260
        }
261
    }
262
    assert(nut->frame_code['N'].flags == FLAG_INVALID);
263

    
264
    if(end > url_ftell(bc) + 4){
265
        int rem= 1024;
266
        GET_V(nut->header_count, tmp<128U)
267
        nut->header_count++;
268
        for(i=1; i<nut->header_count; i++){
269
            GET_V(nut->header_len[i], tmp>0 && tmp<256);
270
            rem -= nut->header_len[i];
271
            if(rem < 0){
272
                av_log(s, AV_LOG_ERROR, "invalid elision header\n");
273
                return -1;
274
            }
275
            nut->header[i]= av_malloc(nut->header_len[i]);
276
            get_buffer(bc, nut->header[i], nut->header_len[i]);
277
        }
278
        assert(nut->header_len[0]==0);
279
    }
280

    
281
    if(skip_reserved(bc, end) || get_checksum(bc)){
282
        av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
283
        return -1;
284
    }
285

    
286
    nut->stream = av_mallocz(sizeof(StreamContext)*stream_count);
287
    for(i=0; i<stream_count; i++){
288
        av_new_stream(s, i);
289
    }
290

    
291
    return 0;
292
}
293

    
294
static int decode_stream_header(NUTContext *nut){
295
    AVFormatContext *s= nut->avf;
296
    ByteIOContext *bc = s->pb;
297
    StreamContext *stc;
298
    int class, stream_id;
299
    uint64_t tmp, end;
300
    AVStream *st;
301

    
302
    end= get_packetheader(nut, bc, 1, STREAM_STARTCODE);
303
    end += url_ftell(bc);
304

    
305
    GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);
306
    stc= &nut->stream[stream_id];
307

    
308
    st = s->streams[stream_id];
309
    if (!st)
310
        return AVERROR(ENOMEM);
311

    
312
    class = ff_get_v(bc);
313
    tmp = get_fourcc(bc);
314
    st->codec->codec_tag= tmp;
315
    switch(class)
316
    {
317
        case 0:
318
            st->codec->codec_type = CODEC_TYPE_VIDEO;
319
            st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, tmp);
320
            break;
321
        case 1:
322
            st->codec->codec_type = CODEC_TYPE_AUDIO;
323
            st->codec->codec_id = ff_codec_get_id(ff_codec_wav_tags, tmp);
324
            break;
325
        case 2:
326
            st->codec->codec_type = CODEC_TYPE_SUBTITLE;
327
            st->codec->codec_id = ff_codec_get_id(ff_nut_subtitle_tags, tmp);
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
    if(class<3 && st->codec->codec_id == CODEC_ID_NONE)
337
        av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
338

    
339
    GET_V(stc->time_base_id    , tmp < nut->time_base_count);
340
    GET_V(stc->msb_pts_shift   , tmp < 16);
341
    stc->max_pts_distance= ff_get_v(bc);
342
    GET_V(stc->decode_delay    , tmp < 1000); //sanity limit, raise this if Moore's law is true
343
    st->codec->has_b_frames= stc->decode_delay;
344
    ff_get_v(bc); //stream flags
345

    
346
    GET_V(st->codec->extradata_size, tmp < (1<<30));
347
    if(st->codec->extradata_size){
348
        st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
349
        get_buffer(bc, st->codec->extradata, st->codec->extradata_size);
350
    }
351

    
352
    if (st->codec->codec_type == CODEC_TYPE_VIDEO){
353
        GET_V(st->codec->width , tmp > 0)
354
        GET_V(st->codec->height, tmp > 0)
355
        st->sample_aspect_ratio.num= ff_get_v(bc);
356
        st->sample_aspect_ratio.den= ff_get_v(bc);
357
        if((!st->sample_aspect_ratio.num) != (!st->sample_aspect_ratio.den)){
358
            av_log(s, AV_LOG_ERROR, "invalid aspect ratio %d/%d\n", st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);
359
            return -1;
360
        }
361
        ff_get_v(bc); /* csp type */
362
    }else if (st->codec->codec_type == CODEC_TYPE_AUDIO){
363
        GET_V(st->codec->sample_rate , tmp > 0)
364
        ff_get_v(bc); // samplerate_den
365
        GET_V(st->codec->channels, tmp > 0)
366
    }
367
    if(skip_reserved(bc, end) || get_checksum(bc)){
368
        av_log(s, AV_LOG_ERROR, "stream header %d checksum mismatch\n", stream_id);
369
        return -1;
370
    }
371
    stc->time_base= &nut->time_base[stc->time_base_id];
372
    av_set_pts_info(s->streams[stream_id], 63, stc->time_base->num, stc->time_base->den);
373
    return 0;
374
}
375

    
376
static void set_disposition_bits(AVFormatContext* avf, char* value, int stream_id){
377
    int flag = 0, i;
378
    for (i=0; ff_nut_dispositions[i].flag; ++i) {
379
        if (!strcmp(ff_nut_dispositions[i].str, value))
380
            flag = ff_nut_dispositions[i].flag;
381
    }
382
    if (!flag)
383
        av_log(avf, AV_LOG_INFO, "unknown disposition type '%s'\n", value);
384
    for (i = 0; i < avf->nb_streams; ++i)
385
        if (stream_id == i || stream_id == -1)
386
            avf->streams[i]->disposition |= flag;
387
}
388

    
389
static int decode_info_header(NUTContext *nut){
390
    AVFormatContext *s= nut->avf;
391
    ByteIOContext *bc = s->pb;
392
    uint64_t tmp;
393
    unsigned int stream_id_plus1, chapter_start, chapter_len, count;
394
    int chapter_id, i;
395
    int64_t value, end;
396
    char name[256], str_value[1024], type_str[256];
397
    const char *type;
398
    AVChapter *chapter= NULL;
399
    AVStream *st= NULL;
400

    
401
    end= get_packetheader(nut, bc, 1, INFO_STARTCODE);
402
    end += url_ftell(bc);
403

    
404
    GET_V(stream_id_plus1, tmp <= s->nb_streams)
405
    chapter_id   = get_s(bc);
406
    chapter_start= ff_get_v(bc);
407
    chapter_len  = ff_get_v(bc);
408
    count        = ff_get_v(bc);
409

    
410
    if(chapter_id && !stream_id_plus1){
411
        int64_t start= chapter_start / nut->time_base_count;
412
        chapter= ff_new_chapter(s, chapter_id,
413
                                nut->time_base[chapter_start % nut->time_base_count],
414
                                start, start + chapter_len, NULL);
415
    } else if(stream_id_plus1)
416
        st= s->streams[stream_id_plus1 - 1];
417

    
418
    for(i=0; i<count; i++){
419
        get_str(bc, name, sizeof(name));
420
        value= get_s(bc);
421
        if(value == -1){
422
            type= "UTF-8";
423
            get_str(bc, str_value, sizeof(str_value));
424
        }else if(value == -2){
425
            get_str(bc, type_str, sizeof(type_str));
426
            type= type_str;
427
            get_str(bc, str_value, sizeof(str_value));
428
        }else if(value == -3){
429
            type= "s";
430
            value= get_s(bc);
431
        }else if(value == -4){
432
            type= "t";
433
            value= ff_get_v(bc);
434
        }else if(value < -4){
435
            type= "r";
436
            get_s(bc);
437
        }else{
438
            type= "v";
439
        }
440

    
441
        if (stream_id_plus1 > s->nb_streams) {
442
            av_log(s, AV_LOG_ERROR, "invalid stream id for info packet\n");
443
            continue;
444
        }
445

    
446
        if(!strcmp(type, "UTF-8")){
447
            AVMetadata **metadata = NULL;
448
            if(chapter_id==0 && !strcmp(name, "Disposition"))
449
                set_disposition_bits(s, str_value, stream_id_plus1 - 1);
450
            else if(chapter)          metadata= &chapter->metadata;
451
            else if(stream_id_plus1)  metadata= &st->metadata;
452
            else                      metadata= &s->metadata;
453
            if(metadata && strcasecmp(name,"Uses")
454
               && strcasecmp(name,"Depends") && strcasecmp(name,"Replaces"))
455
                av_metadata_set(metadata, name, str_value);
456
        }
457
    }
458

    
459
    if(skip_reserved(bc, end) || get_checksum(bc)){
460
        av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");
461
        return -1;
462
    }
463
    return 0;
464
}
465

    
466
static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr){
467
    AVFormatContext *s= nut->avf;
468
    ByteIOContext *bc = s->pb;
469
    int64_t end, tmp;
470

    
471
    nut->last_syncpoint_pos= url_ftell(bc)-8;
472

    
473
    end= get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
474
    end += url_ftell(bc);
475

    
476
    tmp= ff_get_v(bc);
477
    *back_ptr= nut->last_syncpoint_pos - 16*ff_get_v(bc);
478
    if(*back_ptr < 0)
479
        return -1;
480

    
481
    ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count], tmp / nut->time_base_count);
482

    
483
    if(skip_reserved(bc, end) || get_checksum(bc)){
484
        av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
485
        return -1;
486
    }
487

    
488
    *ts= tmp / s->nb_streams * av_q2d(nut->time_base[tmp % s->nb_streams])*AV_TIME_BASE;
489
    ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
490

    
491
    return 0;
492
}
493

    
494
static int find_and_decode_index(NUTContext *nut){
495
    AVFormatContext *s= nut->avf;
496
    ByteIOContext *bc = s->pb;
497
    uint64_t tmp, end;
498
    int i, j, syncpoint_count;
499
    int64_t filesize= url_fsize(bc);
500
    int64_t *syncpoints;
501
    int8_t *has_keyframe;
502
    int ret= -1;
503

    
504
    url_fseek(bc, filesize-12, SEEK_SET);
505
    url_fseek(bc, filesize-get_be64(bc), SEEK_SET);
506
    if(get_be64(bc) != INDEX_STARTCODE){
507
        av_log(s, AV_LOG_ERROR, "no index at the end\n");
508
        return -1;
509
    }
510

    
511
    end= get_packetheader(nut, bc, 1, INDEX_STARTCODE);
512
    end += url_ftell(bc);
513

    
514
    ff_get_v(bc); //max_pts
515
    GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
516
    syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
517
    has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
518
    for(i=0; i<syncpoint_count; i++){
519
        syncpoints[i] = ff_get_v(bc);
520
        if(syncpoints[i] <= 0)
521
            goto fail;
522
        if(i)
523
            syncpoints[i] += syncpoints[i-1];
524
    }
525

    
526
    for(i=0; i<s->nb_streams; i++){
527
        int64_t last_pts= -1;
528
        for(j=0; j<syncpoint_count;){
529
            uint64_t x= ff_get_v(bc);
530
            int type= x&1;
531
            int n= j;
532
            x>>=1;
533
            if(type){
534
                int flag= x&1;
535
                x>>=1;
536
                if(n+x >= syncpoint_count + 1){
537
                    av_log(s, AV_LOG_ERROR, "index overflow A\n");
538
                    goto fail;
539
                }
540
                while(x--)
541
                    has_keyframe[n++]= flag;
542
                has_keyframe[n++]= !flag;
543
            }else{
544
                while(x != 1){
545
                    if(n>=syncpoint_count + 1){
546
                        av_log(s, AV_LOG_ERROR, "index overflow B\n");
547
                        goto fail;
548
                    }
549
                    has_keyframe[n++]= x&1;
550
                    x>>=1;
551
                }
552
            }
553
            if(has_keyframe[0]){
554
                av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
555
                goto fail;
556
            }
557
            assert(n<=syncpoint_count+1);
558
            for(; j<n && j<syncpoint_count; j++){
559
                if(has_keyframe[j]){
560
                    uint64_t B, A= ff_get_v(bc);
561
                    if(!A){
562
                        A= ff_get_v(bc);
563
                        B= ff_get_v(bc);
564
                        //eor_pts[j][i] = last_pts + A + B
565
                    }else
566
                        B= 0;
567
                    av_add_index_entry(
568
                        s->streams[i],
569
                        16*syncpoints[j-1],
570
                        last_pts + A,
571
                        0,
572
                        0,
573
                        AVINDEX_KEYFRAME);
574
                    last_pts += A + B;
575
                }
576
            }
577
        }
578
    }
579

    
580
    if(skip_reserved(bc, end) || get_checksum(bc)){
581
        av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
582
        goto fail;
583
    }
584
    ret= 0;
585
fail:
586
    av_free(syncpoints);
587
    av_free(has_keyframe);
588
    return ret;
589
}
590

    
591
static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
592
{
593
    NUTContext *nut = s->priv_data;
594
    ByteIOContext *bc = s->pb;
595
    int64_t pos;
596
    int initialized_stream_count;
597

    
598
    nut->avf= s;
599

    
600
    /* main header */
601
    pos=0;
602
    do{
603
        pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
604
        if (pos<0+1){
605
            av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
606
            return -1;
607
        }
608
    }while(decode_main_header(nut) < 0);
609

    
610
    /* stream headers */
611
    pos=0;
612
    for(initialized_stream_count=0; initialized_stream_count < s->nb_streams;){
613
        pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
614
        if (pos<0+1){
615
            av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
616
            return -1;
617
        }
618
        if(decode_stream_header(nut) >= 0)
619
            initialized_stream_count++;
620
    }
621

    
622
    /* info headers */
623
    pos=0;
624
    for(;;){
625
        uint64_t startcode= find_any_startcode(bc, pos);
626
        pos= url_ftell(bc);
627

    
628
        if(startcode==0){
629
            av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
630
            return -1;
631
        }else if(startcode == SYNCPOINT_STARTCODE){
632
            nut->next_startcode= startcode;
633
            break;
634
        }else if(startcode != INFO_STARTCODE){
635
            continue;
636
        }
637

    
638
        decode_info_header(nut);
639
    }
640

    
641
    s->data_offset= pos-8;
642

    
643
    if(!url_is_streamed(bc)){
644
        int64_t orig_pos= url_ftell(bc);
645
        find_and_decode_index(nut);
646
        url_fseek(bc, orig_pos, SEEK_SET);
647
    }
648
    assert(nut->next_startcode == SYNCPOINT_STARTCODE);
649

    
650
    return 0;
651
}
652

    
653
static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, uint8_t *header_idx, int frame_code){
654
    AVFormatContext *s= nut->avf;
655
    ByteIOContext *bc = s->pb;
656
    StreamContext *stc;
657
    int size, flags, size_mul, pts_delta, i, reserved_count;
658
    uint64_t tmp;
659

    
660
    if(url_ftell(bc) > nut->last_syncpoint_pos + nut->max_distance){
661
        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);
662
        return -1;
663
    }
664

    
665
    flags          = nut->frame_code[frame_code].flags;
666
    size_mul       = nut->frame_code[frame_code].size_mul;
667
    size           = nut->frame_code[frame_code].size_lsb;
668
    *stream_id     = nut->frame_code[frame_code].stream_id;
669
    pts_delta      = nut->frame_code[frame_code].pts_delta;
670
    reserved_count = nut->frame_code[frame_code].reserved_count;
671
    *header_idx    = nut->frame_code[frame_code].header_idx;
672

    
673
    if(flags & FLAG_INVALID)
674
        return -1;
675
    if(flags & FLAG_CODED)
676
        flags ^= ff_get_v(bc);
677
    if(flags & FLAG_STREAM_ID){
678
        GET_V(*stream_id, tmp < s->nb_streams)
679
    }
680
    stc= &nut->stream[*stream_id];
681
    if(flags&FLAG_CODED_PTS){
682
        int coded_pts= ff_get_v(bc);
683
//FIXME check last_pts validity?
684
        if(coded_pts < (1<<stc->msb_pts_shift)){
685
            *pts=ff_lsb2full(stc, coded_pts);
686
        }else
687
            *pts=coded_pts - (1<<stc->msb_pts_shift);
688
    }else
689
        *pts= stc->last_pts + pts_delta;
690
    if(flags&FLAG_SIZE_MSB){
691
        size += size_mul*ff_get_v(bc);
692
    }
693
    if(flags&FLAG_MATCH_TIME)
694
        get_s(bc);
695
    if(flags&FLAG_HEADER_IDX)
696
        *header_idx= ff_get_v(bc);
697
    if(flags&FLAG_RESERVED)
698
        reserved_count= ff_get_v(bc);
699
    for(i=0; i<reserved_count; i++)
700
        ff_get_v(bc);
701

    
702
    if(*header_idx >= (unsigned)nut->header_count){
703
        av_log(s, AV_LOG_ERROR, "header_idx invalid\n");
704
        return -1;
705
    }
706
    if(size > 4096)
707
        *header_idx=0;
708
    size -= nut->header_len[*header_idx];
709

    
710
    if(flags&FLAG_CHECKSUM){
711
        get_be32(bc); //FIXME check this
712
    }else if(size > 2*nut->max_distance || FFABS(stc->last_pts - *pts) > stc->max_pts_distance){
713
        av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
714
        return -1;
715
    }
716

    
717
    stc->last_pts= *pts;
718
    stc->last_flags= flags;
719

    
720
    return size;
721
}
722

    
723
static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
724
    AVFormatContext *s= nut->avf;
725
    ByteIOContext *bc = s->pb;
726
    int size, stream_id, discard;
727
    int64_t pts, last_IP_pts;
728
    StreamContext *stc;
729
    uint8_t header_idx;
730

    
731
    size= decode_frame_header(nut, &pts, &stream_id, &header_idx, frame_code);
732
    if(size < 0)
733
        return -1;
734

    
735
    stc= &nut->stream[stream_id];
736

    
737
    if (stc->last_flags & FLAG_KEY)
738
        stc->skip_until_key_frame=0;
739

    
740
    discard= s->streams[ stream_id ]->discard;
741
    last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
742
    if(  (discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY))
743
       ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
744
       || discard >= AVDISCARD_ALL
745
       || stc->skip_until_key_frame){
746
        url_fskip(bc, size);
747
        return 1;
748
    }
749

    
750
    av_new_packet(pkt, size + nut->header_len[header_idx]);
751
    memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
752
    pkt->pos= url_ftell(bc); //FIXME
753
    get_buffer(bc, pkt->data + nut->header_len[header_idx], size);
754

    
755
    pkt->stream_index = stream_id;
756
    if (stc->last_flags & FLAG_KEY)
757
        pkt->flags |= PKT_FLAG_KEY;
758
    pkt->pts = pts;
759

    
760
    return 0;
761
}
762

    
763
static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
764
{
765
    NUTContext *nut = s->priv_data;
766
    ByteIOContext *bc = s->pb;
767
    int i, frame_code=0, ret, skip;
768
    int64_t ts, back_ptr;
769

    
770
    for(;;){
771
        int64_t pos= url_ftell(bc);
772
        uint64_t tmp= nut->next_startcode;
773
        nut->next_startcode=0;
774

    
775
        if(tmp){
776
            pos-=8;
777
        }else{
778
            frame_code = get_byte(bc);
779
            if(url_feof(bc))
780
                return -1;
781
            if(frame_code == 'N'){
782
                tmp= frame_code;
783
                for(i=1; i<8; i++)
784
                    tmp = (tmp<<8) + get_byte(bc);
785
            }
786
        }
787
        switch(tmp){
788
        case MAIN_STARTCODE:
789
        case STREAM_STARTCODE:
790
        case INDEX_STARTCODE:
791
            skip= get_packetheader(nut, bc, 0, tmp);
792
            url_fseek(bc, skip, SEEK_CUR);
793
            break;
794
        case INFO_STARTCODE:
795
            if(decode_info_header(nut)<0)
796
                goto resync;
797
            break;
798
        case SYNCPOINT_STARTCODE:
799
            if(decode_syncpoint(nut, &ts, &back_ptr)<0)
800
                goto resync;
801
            frame_code = get_byte(bc);
802
        case 0:
803
            ret= decode_frame(nut, pkt, frame_code);
804
            if(ret==0)
805
                return 0;
806
            else if(ret==1) //ok but discard packet
807
                break;
808
        default:
809
resync:
810
av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
811
            tmp= find_any_startcode(bc, nut->last_syncpoint_pos+1);
812
            if(tmp==0)
813
                return -1;
814
av_log(s, AV_LOG_DEBUG, "sync\n");
815
            nut->next_startcode= tmp;
816
        }
817
    }
818
}
819

    
820
static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
821
    NUTContext *nut = s->priv_data;
822
    ByteIOContext *bc = s->pb;
823
    int64_t pos, pts, back_ptr;
824
av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
825

    
826
    pos= *pos_arg;
827
    do{
828
        pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
829
        if(pos < 1){
830
            assert(nut->next_startcode == 0);
831
            av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
832
            return AV_NOPTS_VALUE;
833
        }
834
    }while(decode_syncpoint(nut, &pts, &back_ptr) < 0);
835
    *pos_arg = pos-1;
836
    assert(nut->last_syncpoint_pos == *pos_arg);
837

    
838
    av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts,back_ptr );
839
    if     (stream_index == -1) return pts;
840
    else if(stream_index == -2) return back_ptr;
841

    
842
assert(0);
843
}
844

    
845
static int read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags){
846
    NUTContext *nut = s->priv_data;
847
    AVStream *st= s->streams[stream_index];
848
    Syncpoint dummy={.ts= pts*av_q2d(st->time_base)*AV_TIME_BASE};
849
    Syncpoint nopts_sp= {.ts= AV_NOPTS_VALUE, .back_ptr= AV_NOPTS_VALUE};
850
    Syncpoint *sp, *next_node[2]= {&nopts_sp, &nopts_sp};
851
    int64_t pos, pos2, ts;
852
    int i;
853

    
854
    if(st->index_entries){
855
        int index= av_index_search_timestamp(st, pts, flags);
856
        if(index<0)
857
            return -1;
858

    
859
        pos2= st->index_entries[index].pos;
860
        ts  = st->index_entries[index].timestamp;
861
    }else{
862
        av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pts_cmp, next_node);
863
        av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n", next_node[0]->pos, next_node[1]->pos,
864
                                                    next_node[0]->ts , next_node[1]->ts);
865
        pos= av_gen_search(s, -1, dummy.ts, next_node[0]->pos, next_node[1]->pos, next_node[1]->pos,
866
                                            next_node[0]->ts , next_node[1]->ts, AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
867

    
868
        if(!(flags & AVSEEK_FLAG_BACKWARD)){
869
            dummy.pos= pos+16;
870
            next_node[1]= &nopts_sp;
871
            av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, next_node);
872
            pos2= av_gen_search(s, -2, dummy.pos, next_node[0]->pos     , next_node[1]->pos, next_node[1]->pos,
873
                                                next_node[0]->back_ptr, next_node[1]->back_ptr, flags, &ts, nut_read_timestamp);
874
            if(pos2>=0)
875
                pos= pos2;
876
            //FIXME dir but I think it does not matter
877
        }
878
        dummy.pos= pos;
879
        sp= av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, NULL);
880

    
881
        assert(sp);
882
        pos2= sp->back_ptr  - 15;
883
    }
884
    av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
885
    pos= find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);
886
    url_fseek(s->pb, pos, SEEK_SET);
887
    av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
888
    if(pos2 > pos || pos2 + 15 < pos){
889
        av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
890
    }
891
    for(i=0; i<s->nb_streams; i++)
892
        nut->stream[i].skip_until_key_frame=1;
893

    
894
    return 0;
895
}
896

    
897
static int nut_read_close(AVFormatContext *s)
898
{
899
    NUTContext *nut = s->priv_data;
900

    
901
    av_freep(&nut->time_base);
902
    av_freep(&nut->stream);
903

    
904
    return 0;
905
}
906

    
907
#if CONFIG_NUT_DEMUXER
908
AVInputFormat nut_demuxer = {
909
    "nut",
910
    NULL_IF_CONFIG_SMALL("NUT format"),
911
    sizeof(NUTContext),
912
    nut_probe,
913
    nut_read_header,
914
    nut_read_packet,
915
    nut_read_close,
916
    read_seek,
917
    .extensions = "nut",
918
    .metadata_conv = ff_nut_metadata_conv,
919
};
920
#endif