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ffmpeg / libavformat / nutdec.c @ da9e6c42

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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
21
 */
22

    
23
#include <strings.h>
24
#include "libavutil/avstring.h"
25
#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);
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    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

    
77
    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
 * @return 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 = AVMEDIA_TYPE_VIDEO;
319
            st->codec->codec_id = av_codec_get_id(
320
                (const AVCodecTag * const []) { ff_codec_bmp_tags, ff_nut_video_tags, 0 },
321
                tmp);
322
            break;
323
        case 1:
324
            st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
325
            st->codec->codec_id = ff_codec_get_id(ff_codec_wav_tags, tmp);
326
            break;
327
        case 2:
328
            st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
329
            st->codec->codec_id = ff_codec_get_id(ff_nut_subtitle_tags, tmp);
330
            break;
331
        case 3:
332
            st->codec->codec_type = AVMEDIA_TYPE_DATA;
333
            break;
334
        default:
335
            av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);
336
            return -1;
337
    }
338
    if(class<3 && st->codec->codec_id == CODEC_ID_NONE)
339
        av_log(s, AV_LOG_ERROR, "Unknown codec tag '0x%04x' for stream number %d\n",
340
               (unsigned int)tmp, stream_id);
341

    
342
    GET_V(stc->time_base_id    , tmp < nut->time_base_count);
343
    GET_V(stc->msb_pts_shift   , tmp < 16);
344
    stc->max_pts_distance= ff_get_v(bc);
345
    GET_V(stc->decode_delay    , tmp < 1000); //sanity limit, raise this if Moore's law is true
346
    st->codec->has_b_frames= stc->decode_delay;
347
    ff_get_v(bc); //stream flags
348

    
349
    GET_V(st->codec->extradata_size, tmp < (1<<30));
350
    if(st->codec->extradata_size){
351
        st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
352
        get_buffer(bc, st->codec->extradata, st->codec->extradata_size);
353
    }
354

    
355
    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO){
356
        GET_V(st->codec->width , tmp > 0)
357
        GET_V(st->codec->height, tmp > 0)
358
        st->sample_aspect_ratio.num= ff_get_v(bc);
359
        st->sample_aspect_ratio.den= ff_get_v(bc);
360
        if((!st->sample_aspect_ratio.num) != (!st->sample_aspect_ratio.den)){
361
            av_log(s, AV_LOG_ERROR, "invalid aspect ratio %d/%d\n", st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);
362
            return -1;
363
        }
364
        ff_get_v(bc); /* csp type */
365
    }else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO){
366
        GET_V(st->codec->sample_rate , tmp > 0)
367
        ff_get_v(bc); // samplerate_den
368
        GET_V(st->codec->channels, tmp > 0)
369
    }
370
    if(skip_reserved(bc, end) || get_checksum(bc)){
371
        av_log(s, AV_LOG_ERROR, "stream header %d checksum mismatch\n", stream_id);
372
        return -1;
373
    }
374
    stc->time_base= &nut->time_base[stc->time_base_id];
375
    av_set_pts_info(s->streams[stream_id], 63, stc->time_base->num, stc->time_base->den);
376
    return 0;
377
}
378

    
379
static void set_disposition_bits(AVFormatContext* avf, char* value, int stream_id){
380
    int flag = 0, i;
381
    for (i=0; ff_nut_dispositions[i].flag; ++i) {
382
        if (!strcmp(ff_nut_dispositions[i].str, value))
383
            flag = ff_nut_dispositions[i].flag;
384
    }
385
    if (!flag)
386
        av_log(avf, AV_LOG_INFO, "unknown disposition type '%s'\n", value);
387
    for (i = 0; i < avf->nb_streams; ++i)
388
        if (stream_id == i || stream_id == -1)
389
            avf->streams[i]->disposition |= flag;
390
}
391

    
392
static int decode_info_header(NUTContext *nut){
393
    AVFormatContext *s= nut->avf;
394
    ByteIOContext *bc = s->pb;
395
    uint64_t tmp, chapter_start, chapter_len;
396
    unsigned int stream_id_plus1, count;
397
    int chapter_id, i;
398
    int64_t value, end;
399
    char name[256], str_value[1024], type_str[256];
400
    const char *type;
401
    AVChapter *chapter= NULL;
402
    AVStream *st= NULL;
403

    
404
    end= get_packetheader(nut, bc, 1, INFO_STARTCODE);
405
    end += url_ftell(bc);
406

    
407
    GET_V(stream_id_plus1, tmp <= s->nb_streams)
408
    chapter_id   = get_s(bc);
409
    chapter_start= ff_get_v(bc);
410
    chapter_len  = ff_get_v(bc);
411
    count        = ff_get_v(bc);
412

    
413
    if(chapter_id && !stream_id_plus1){
414
        int64_t start= chapter_start / nut->time_base_count;
415
        chapter= ff_new_chapter(s, chapter_id,
416
                                nut->time_base[chapter_start % nut->time_base_count],
417
                                start, start + chapter_len, NULL);
418
    } else if(stream_id_plus1)
419
        st= s->streams[stream_id_plus1 - 1];
420

    
421
    for(i=0; i<count; i++){
422
        get_str(bc, name, sizeof(name));
423
        value= get_s(bc);
424
        if(value == -1){
425
            type= "UTF-8";
426
            get_str(bc, str_value, sizeof(str_value));
427
        }else if(value == -2){
428
            get_str(bc, type_str, sizeof(type_str));
429
            type= type_str;
430
            get_str(bc, str_value, sizeof(str_value));
431
        }else if(value == -3){
432
            type= "s";
433
            value= get_s(bc);
434
        }else if(value == -4){
435
            type= "t";
436
            value= ff_get_v(bc);
437
        }else if(value < -4){
438
            type= "r";
439
            get_s(bc);
440
        }else{
441
            type= "v";
442
        }
443

    
444
        if (stream_id_plus1 > s->nb_streams) {
445
            av_log(s, AV_LOG_ERROR, "invalid stream id for info packet\n");
446
            continue;
447
        }
448

    
449
        if(!strcmp(type, "UTF-8")){
450
            AVMetadata **metadata = NULL;
451
            if(chapter_id==0 && !strcmp(name, "Disposition"))
452
                set_disposition_bits(s, str_value, stream_id_plus1 - 1);
453
            else if(chapter)          metadata= &chapter->metadata;
454
            else if(stream_id_plus1)  metadata= &st->metadata;
455
            else                      metadata= &s->metadata;
456
            if(metadata && strcasecmp(name,"Uses")
457
               && strcasecmp(name,"Depends") && strcasecmp(name,"Replaces"))
458
                av_metadata_set2(metadata, name, str_value, 0);
459
        }
460
    }
461

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

    
469
static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr){
470
    AVFormatContext *s= nut->avf;
471
    ByteIOContext *bc = s->pb;
472
    int64_t end, tmp;
473

    
474
    nut->last_syncpoint_pos= url_ftell(bc)-8;
475

    
476
    end= get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
477
    end += url_ftell(bc);
478

    
479
    tmp= ff_get_v(bc);
480
    *back_ptr= nut->last_syncpoint_pos - 16*ff_get_v(bc);
481
    if(*back_ptr < 0)
482
        return -1;
483

    
484
    ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count], tmp / nut->time_base_count);
485

    
486
    if(skip_reserved(bc, end) || get_checksum(bc)){
487
        av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
488
        return -1;
489
    }
490

    
491
    *ts= tmp / s->nb_streams * av_q2d(nut->time_base[tmp % s->nb_streams])*AV_TIME_BASE;
492
    ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
493

    
494
    return 0;
495
}
496

    
497
static int find_and_decode_index(NUTContext *nut){
498
    AVFormatContext *s= nut->avf;
499
    ByteIOContext *bc = s->pb;
500
    uint64_t tmp, end;
501
    int i, j, syncpoint_count;
502
    int64_t filesize= url_fsize(bc);
503
    int64_t *syncpoints;
504
    int8_t *has_keyframe;
505
    int ret= -1;
506

    
507
    url_fseek(bc, filesize-12, SEEK_SET);
508
    url_fseek(bc, filesize-get_be64(bc), SEEK_SET);
509
    if(get_be64(bc) != INDEX_STARTCODE){
510
        av_log(s, AV_LOG_ERROR, "no index at the end\n");
511
        return -1;
512
    }
513

    
514
    end= get_packetheader(nut, bc, 1, INDEX_STARTCODE);
515
    end += url_ftell(bc);
516

    
517
    ff_get_v(bc); //max_pts
518
    GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
519
    syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
520
    has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
521
    for(i=0; i<syncpoint_count; i++){
522
        syncpoints[i] = ff_get_v(bc);
523
        if(syncpoints[i] <= 0)
524
            goto fail;
525
        if(i)
526
            syncpoints[i] += syncpoints[i-1];
527
    }
528

    
529
    for(i=0; i<s->nb_streams; i++){
530
        int64_t last_pts= -1;
531
        for(j=0; j<syncpoint_count;){
532
            uint64_t x= ff_get_v(bc);
533
            int type= x&1;
534
            int n= j;
535
            x>>=1;
536
            if(type){
537
                int flag= x&1;
538
                x>>=1;
539
                if(n+x >= syncpoint_count + 1){
540
                    av_log(s, AV_LOG_ERROR, "index overflow A\n");
541
                    goto fail;
542
                }
543
                while(x--)
544
                    has_keyframe[n++]= flag;
545
                has_keyframe[n++]= !flag;
546
            }else{
547
                while(x != 1){
548
                    if(n>=syncpoint_count + 1){
549
                        av_log(s, AV_LOG_ERROR, "index overflow B\n");
550
                        goto fail;
551
                    }
552
                    has_keyframe[n++]= x&1;
553
                    x>>=1;
554
                }
555
            }
556
            if(has_keyframe[0]){
557
                av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
558
                goto fail;
559
            }
560
            assert(n<=syncpoint_count+1);
561
            for(; j<n && j<syncpoint_count; j++){
562
                if(has_keyframe[j]){
563
                    uint64_t B, A= ff_get_v(bc);
564
                    if(!A){
565
                        A= ff_get_v(bc);
566
                        B= ff_get_v(bc);
567
                        //eor_pts[j][i] = last_pts + A + B
568
                    }else
569
                        B= 0;
570
                    av_add_index_entry(
571
                        s->streams[i],
572
                        16*syncpoints[j-1],
573
                        last_pts + A,
574
                        0,
575
                        0,
576
                        AVINDEX_KEYFRAME);
577
                    last_pts += A + B;
578
                }
579
            }
580
        }
581
    }
582

    
583
    if(skip_reserved(bc, end) || get_checksum(bc)){
584
        av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
585
        goto fail;
586
    }
587
    ret= 0;
588
fail:
589
    av_free(syncpoints);
590
    av_free(has_keyframe);
591
    return ret;
592
}
593

    
594
static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
595
{
596
    NUTContext *nut = s->priv_data;
597
    ByteIOContext *bc = s->pb;
598
    int64_t pos;
599
    int initialized_stream_count;
600

    
601
    nut->avf= s;
602

    
603
    /* main header */
604
    pos=0;
605
    do{
606
        pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
607
        if (pos<0+1){
608
            av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
609
            return -1;
610
        }
611
    }while(decode_main_header(nut) < 0);
612

    
613
    /* stream headers */
614
    pos=0;
615
    for(initialized_stream_count=0; initialized_stream_count < s->nb_streams;){
616
        pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
617
        if (pos<0+1){
618
            av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
619
            return -1;
620
        }
621
        if(decode_stream_header(nut) >= 0)
622
            initialized_stream_count++;
623
    }
624

    
625
    /* info headers */
626
    pos=0;
627
    for(;;){
628
        uint64_t startcode= find_any_startcode(bc, pos);
629
        pos= url_ftell(bc);
630

    
631
        if(startcode==0){
632
            av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
633
            return -1;
634
        }else if(startcode == SYNCPOINT_STARTCODE){
635
            nut->next_startcode= startcode;
636
            break;
637
        }else if(startcode != INFO_STARTCODE){
638
            continue;
639
        }
640

    
641
        decode_info_header(nut);
642
    }
643

    
644
    s->data_offset= pos-8;
645

    
646
    if(!url_is_streamed(bc)){
647
        int64_t orig_pos= url_ftell(bc);
648
        find_and_decode_index(nut);
649
        url_fseek(bc, orig_pos, SEEK_SET);
650
    }
651
    assert(nut->next_startcode == SYNCPOINT_STARTCODE);
652

    
653
    return 0;
654
}
655

    
656
static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, uint8_t *header_idx, int frame_code){
657
    AVFormatContext *s= nut->avf;
658
    ByteIOContext *bc = s->pb;
659
    StreamContext *stc;
660
    int size, flags, size_mul, pts_delta, i, reserved_count;
661
    uint64_t tmp;
662

    
663
    if(url_ftell(bc) > nut->last_syncpoint_pos + nut->max_distance){
664
        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);
665
        return -1;
666
    }
667

    
668
    flags          = nut->frame_code[frame_code].flags;
669
    size_mul       = nut->frame_code[frame_code].size_mul;
670
    size           = nut->frame_code[frame_code].size_lsb;
671
    *stream_id     = nut->frame_code[frame_code].stream_id;
672
    pts_delta      = nut->frame_code[frame_code].pts_delta;
673
    reserved_count = nut->frame_code[frame_code].reserved_count;
674
    *header_idx    = nut->frame_code[frame_code].header_idx;
675

    
676
    if(flags & FLAG_INVALID)
677
        return -1;
678
    if(flags & FLAG_CODED)
679
        flags ^= ff_get_v(bc);
680
    if(flags & FLAG_STREAM_ID){
681
        GET_V(*stream_id, tmp < s->nb_streams)
682
    }
683
    stc= &nut->stream[*stream_id];
684
    if(flags&FLAG_CODED_PTS){
685
        int coded_pts= ff_get_v(bc);
686
//FIXME check last_pts validity?
687
        if(coded_pts < (1<<stc->msb_pts_shift)){
688
            *pts=ff_lsb2full(stc, coded_pts);
689
        }else
690
            *pts=coded_pts - (1<<stc->msb_pts_shift);
691
    }else
692
        *pts= stc->last_pts + pts_delta;
693
    if(flags&FLAG_SIZE_MSB){
694
        size += size_mul*ff_get_v(bc);
695
    }
696
    if(flags&FLAG_MATCH_TIME)
697
        get_s(bc);
698
    if(flags&FLAG_HEADER_IDX)
699
        *header_idx= ff_get_v(bc);
700
    if(flags&FLAG_RESERVED)
701
        reserved_count= ff_get_v(bc);
702
    for(i=0; i<reserved_count; i++)
703
        ff_get_v(bc);
704

    
705
    if(*header_idx >= (unsigned)nut->header_count){
706
        av_log(s, AV_LOG_ERROR, "header_idx invalid\n");
707
        return -1;
708
    }
709
    if(size > 4096)
710
        *header_idx=0;
711
    size -= nut->header_len[*header_idx];
712

    
713
    if(flags&FLAG_CHECKSUM){
714
        get_be32(bc); //FIXME check this
715
    }else if(size > 2*nut->max_distance || FFABS(stc->last_pts - *pts) > stc->max_pts_distance){
716
        av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
717
        return -1;
718
    }
719

    
720
    stc->last_pts= *pts;
721
    stc->last_flags= flags;
722

    
723
    return size;
724
}
725

    
726
static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
727
    AVFormatContext *s= nut->avf;
728
    ByteIOContext *bc = s->pb;
729
    int size, stream_id, discard;
730
    int64_t pts, last_IP_pts;
731
    StreamContext *stc;
732
    uint8_t header_idx;
733

    
734
    size= decode_frame_header(nut, &pts, &stream_id, &header_idx, frame_code);
735
    if(size < 0)
736
        return -1;
737

    
738
    stc= &nut->stream[stream_id];
739

    
740
    if (stc->last_flags & FLAG_KEY)
741
        stc->skip_until_key_frame=0;
742

    
743
    discard= s->streams[ stream_id ]->discard;
744
    last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
745
    if(  (discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY))
746
       ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
747
       || discard >= AVDISCARD_ALL
748
       || stc->skip_until_key_frame){
749
        url_fskip(bc, size);
750
        return 1;
751
    }
752

    
753
    av_new_packet(pkt, size + nut->header_len[header_idx]);
754
    memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
755
    pkt->pos= url_ftell(bc); //FIXME
756
    get_buffer(bc, pkt->data + nut->header_len[header_idx], size);
757

    
758
    pkt->stream_index = stream_id;
759
    if (stc->last_flags & FLAG_KEY)
760
        pkt->flags |= AV_PKT_FLAG_KEY;
761
    pkt->pts = pts;
762

    
763
    return 0;
764
}
765

    
766
static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
767
{
768
    NUTContext *nut = s->priv_data;
769
    ByteIOContext *bc = s->pb;
770
    int i, frame_code=0, ret, skip;
771
    int64_t ts, back_ptr;
772

    
773
    for(;;){
774
        int64_t pos= url_ftell(bc);
775
        uint64_t tmp= nut->next_startcode;
776
        nut->next_startcode=0;
777

    
778
        if(tmp){
779
            pos-=8;
780
        }else{
781
            frame_code = get_byte(bc);
782
            if(url_feof(bc))
783
                return -1;
784
            if(frame_code == 'N'){
785
                tmp= frame_code;
786
                for(i=1; i<8; i++)
787
                    tmp = (tmp<<8) + get_byte(bc);
788
            }
789
        }
790
        switch(tmp){
791
        case MAIN_STARTCODE:
792
        case STREAM_STARTCODE:
793
        case INDEX_STARTCODE:
794
            skip= get_packetheader(nut, bc, 0, tmp);
795
            url_fseek(bc, skip, SEEK_CUR);
796
            break;
797
        case INFO_STARTCODE:
798
            if(decode_info_header(nut)<0)
799
                goto resync;
800
            break;
801
        case SYNCPOINT_STARTCODE:
802
            if(decode_syncpoint(nut, &ts, &back_ptr)<0)
803
                goto resync;
804
            frame_code = get_byte(bc);
805
        case 0:
806
            ret= decode_frame(nut, pkt, frame_code);
807
            if(ret==0)
808
                return 0;
809
            else if(ret==1) //ok but discard packet
810
                break;
811
        default:
812
resync:
813
av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
814
            tmp= find_any_startcode(bc, nut->last_syncpoint_pos+1);
815
            if(tmp==0)
816
                return -1;
817
av_log(s, AV_LOG_DEBUG, "sync\n");
818
            nut->next_startcode= tmp;
819
        }
820
    }
821
}
822

    
823
static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
824
    NUTContext *nut = s->priv_data;
825
    ByteIOContext *bc = s->pb;
826
    int64_t pos, pts, back_ptr;
827
av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
828

    
829
    pos= *pos_arg;
830
    do{
831
        pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
832
        if(pos < 1){
833
            assert(nut->next_startcode == 0);
834
            av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
835
            return AV_NOPTS_VALUE;
836
        }
837
    }while(decode_syncpoint(nut, &pts, &back_ptr) < 0);
838
    *pos_arg = pos-1;
839
    assert(nut->last_syncpoint_pos == *pos_arg);
840

    
841
    av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts,back_ptr );
842
    if     (stream_index == -1) return pts;
843
    else if(stream_index == -2) return back_ptr;
844

    
845
assert(0);
846
}
847

    
848
static int read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags){
849
    NUTContext *nut = s->priv_data;
850
    AVStream *st= s->streams[stream_index];
851
    Syncpoint dummy={.ts= pts*av_q2d(st->time_base)*AV_TIME_BASE};
852
    Syncpoint nopts_sp= {.ts= AV_NOPTS_VALUE, .back_ptr= AV_NOPTS_VALUE};
853
    Syncpoint *sp, *next_node[2]= {&nopts_sp, &nopts_sp};
854
    int64_t pos, pos2, ts;
855
    int i;
856

    
857
    if(st->index_entries){
858
        int index= av_index_search_timestamp(st, pts, flags);
859
        if(index<0)
860
            return -1;
861

    
862
        pos2= st->index_entries[index].pos;
863
        ts  = st->index_entries[index].timestamp;
864
    }else{
865
        av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pts_cmp,
866
                     (void **) next_node);
867
        av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n", next_node[0]->pos, next_node[1]->pos,
868
                                                    next_node[0]->ts , next_node[1]->ts);
869
        pos= av_gen_search(s, -1, dummy.ts, next_node[0]->pos, next_node[1]->pos, next_node[1]->pos,
870
                                            next_node[0]->ts , next_node[1]->ts, AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
871

    
872
        if(!(flags & AVSEEK_FLAG_BACKWARD)){
873
            dummy.pos= pos+16;
874
            next_node[1]= &nopts_sp;
875
            av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
876
                         (void **) next_node);
877
            pos2= av_gen_search(s, -2, dummy.pos, next_node[0]->pos     , next_node[1]->pos, next_node[1]->pos,
878
                                                next_node[0]->back_ptr, next_node[1]->back_ptr, flags, &ts, nut_read_timestamp);
879
            if(pos2>=0)
880
                pos= pos2;
881
            //FIXME dir but I think it does not matter
882
        }
883
        dummy.pos= pos;
884
        sp= av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
885
                         NULL);
886

    
887
        assert(sp);
888
        pos2= sp->back_ptr  - 15;
889
    }
890
    av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
891
    pos= find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);
892
    url_fseek(s->pb, pos, SEEK_SET);
893
    av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
894
    if(pos2 > pos || pos2 + 15 < pos){
895
        av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
896
    }
897
    for(i=0; i<s->nb_streams; i++)
898
        nut->stream[i].skip_until_key_frame=1;
899

    
900
    return 0;
901
}
902

    
903
static int nut_read_close(AVFormatContext *s)
904
{
905
    NUTContext *nut = s->priv_data;
906
    int i;
907

    
908
    av_freep(&nut->time_base);
909
    av_freep(&nut->stream);
910
    ff_nut_free_sp(nut);
911
    for(i = 1; i < nut->header_count; i++)
912
        av_freep(&nut->header[i]);
913

    
914
    return 0;
915
}
916

    
917
#if CONFIG_NUT_DEMUXER
918
AVInputFormat nut_demuxer = {
919
    "nut",
920
    NULL_IF_CONFIG_SMALL("NUT format"),
921
    sizeof(NUTContext),
922
    nut_probe,
923
    nut_read_header,
924
    nut_read_packet,
925
    nut_read_close,
926
    read_seek,
927
    .extensions = "nut",
928
    .metadata_conv = ff_nut_metadata_conv,
929
    .codec_tag = (const AVCodecTag * const []) { ff_codec_bmp_tags, ff_nut_video_tags, ff_codec_wav_tags, ff_nut_subtitle_tags, 0 },
930
};
931
#endif