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ffmpeg / libavformat / aviobuf.c @ 8d5e638f

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1
/*
2
 * Buffered I/O for ffmpeg system
3
 * Copyright (c) 2000,2001 Fabrice Bellard
4
 *
5
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
11
 *
12
 * FFmpeg is distributed in the hope that it will be useful,
13
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
16
 *
17
 * You should have received a copy of the GNU Lesser General Public
18
 * License along with FFmpeg; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21

    
22
#include "libavutil/crc.h"
23
#include "libavutil/intreadwrite.h"
24
#include "avformat.h"
25
#include "avio.h"
26
#include <stdarg.h>
27

    
28
#define IO_BUFFER_SIZE 32768
29

    
30
static void fill_buffer(ByteIOContext *s);
31
#if LIBAVFORMAT_VERSION_MAJOR >= 53
32
static int url_resetbuf(ByteIOContext *s, int flags);
33
#endif
34

    
35
int init_put_byte(ByteIOContext *s,
36
                  unsigned char *buffer,
37
                  int buffer_size,
38
                  int write_flag,
39
                  void *opaque,
40
                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
41
                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
42
                  int64_t (*seek)(void *opaque, int64_t offset, int whence))
43
{
44
    s->buffer = buffer;
45
    s->buffer_size = buffer_size;
46
    s->buf_ptr = buffer;
47
    s->opaque = opaque;
48
    url_resetbuf(s, write_flag ? URL_WRONLY : URL_RDONLY);
49
    s->write_packet = write_packet;
50
    s->read_packet = read_packet;
51
    s->seek = seek;
52
    s->pos = 0;
53
    s->must_flush = 0;
54
    s->eof_reached = 0;
55
    s->error = 0;
56
    s->is_streamed = 0;
57
    s->max_packet_size = 0;
58
    s->update_checksum= NULL;
59
    if(!read_packet && !write_flag){
60
        s->pos = buffer_size;
61
        s->buf_end = s->buffer + buffer_size;
62
    }
63
    s->read_pause = NULL;
64
    s->read_seek  = NULL;
65
    return 0;
66
}
67

    
68
ByteIOContext *av_alloc_put_byte(
69
                  unsigned char *buffer,
70
                  int buffer_size,
71
                  int write_flag,
72
                  void *opaque,
73
                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
74
                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
75
                  int64_t (*seek)(void *opaque, int64_t offset, int whence))
76
{
77
    ByteIOContext *s = av_mallocz(sizeof(ByteIOContext));
78
    init_put_byte(s, buffer, buffer_size, write_flag, opaque,
79
                  read_packet, write_packet, seek);
80
    return s;
81
}
82

    
83
static void flush_buffer(ByteIOContext *s)
84
{
85
    if (s->buf_ptr > s->buffer) {
86
        if (s->write_packet && !s->error){
87
            int ret= s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
88
            if(ret < 0){
89
                s->error = ret;
90
            }
91
        }
92
        if(s->update_checksum){
93
            s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
94
            s->checksum_ptr= s->buffer;
95
        }
96
        s->pos += s->buf_ptr - s->buffer;
97
    }
98
    s->buf_ptr = s->buffer;
99
}
100

    
101
void put_byte(ByteIOContext *s, int b)
102
{
103
    *(s->buf_ptr)++ = b;
104
    if (s->buf_ptr >= s->buf_end)
105
        flush_buffer(s);
106
}
107

    
108
void put_buffer(ByteIOContext *s, const unsigned char *buf, int size)
109
{
110
    while (size > 0) {
111
        int len = FFMIN(s->buf_end - s->buf_ptr, size);
112
        memcpy(s->buf_ptr, buf, len);
113
        s->buf_ptr += len;
114

    
115
        if (s->buf_ptr >= s->buf_end)
116
            flush_buffer(s);
117

    
118
        buf += len;
119
        size -= len;
120
    }
121
}
122

    
123
void put_flush_packet(ByteIOContext *s)
124
{
125
    flush_buffer(s);
126
    s->must_flush = 0;
127
}
128

    
129
int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence)
130
{
131
    int64_t offset1;
132
    int64_t pos;
133

    
134
    if(!s)
135
        return AVERROR(EINVAL);
136

    
137
    pos = s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
138

    
139
    if (whence != SEEK_CUR && whence != SEEK_SET)
140
        return AVERROR(EINVAL);
141

    
142
    if (whence == SEEK_CUR) {
143
        offset1 = pos + (s->buf_ptr - s->buffer);
144
        if (offset == 0)
145
            return offset1;
146
        offset += offset1;
147
    }
148
    offset1 = offset - pos;
149
    if (!s->must_flush &&
150
        offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
151
        /* can do the seek inside the buffer */
152
        s->buf_ptr = s->buffer + offset1;
153
    } else if(s->is_streamed && !s->write_flag && offset1 >= 0 &&
154
              (   offset1 < (s->buf_end - s->buffer) + (1<<16)
155
               || (whence & AVSEEK_FORCE))){
156
        while(s->pos < offset && !s->eof_reached)
157
            fill_buffer(s);
158
        if (s->eof_reached)
159
            return AVERROR_EOF;
160
        s->buf_ptr = s->buf_end + offset - s->pos;
161
    } else {
162
        int64_t res = AVERROR(EPIPE);
163

    
164
#if CONFIG_MUXERS || CONFIG_NETWORK
165
        if (s->write_flag) {
166
            flush_buffer(s);
167
            s->must_flush = 1;
168
        }
169
#endif /* CONFIG_MUXERS || CONFIG_NETWORK */
170
        if (!s->seek || (res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
171
            return res;
172
        if (!s->write_flag)
173
            s->buf_end = s->buffer;
174
        s->buf_ptr = s->buffer;
175
        s->pos = offset;
176
    }
177
    s->eof_reached = 0;
178
    return offset;
179
}
180

    
181
void url_fskip(ByteIOContext *s, int64_t offset)
182
{
183
    url_fseek(s, offset, SEEK_CUR);
184
}
185

    
186
int64_t url_ftell(ByteIOContext *s)
187
{
188
    return url_fseek(s, 0, SEEK_CUR);
189
}
190

    
191
int64_t url_fsize(ByteIOContext *s)
192
{
193
    int64_t size;
194

    
195
    if(!s)
196
        return AVERROR(EINVAL);
197

    
198
    if (!s->seek)
199
        return AVERROR(EPIPE);
200
    size = s->seek(s->opaque, 0, AVSEEK_SIZE);
201
    if(size<0){
202
        if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
203
            return size;
204
        size++;
205
        s->seek(s->opaque, s->pos, SEEK_SET);
206
    }
207
    return size;
208
}
209

    
210
int url_feof(ByteIOContext *s)
211
{
212
    if(!s)
213
        return 0;
214
    return s->eof_reached;
215
}
216

    
217
int url_ferror(ByteIOContext *s)
218
{
219
    if(!s)
220
        return 0;
221
    return s->error;
222
}
223

    
224
void put_le32(ByteIOContext *s, unsigned int val)
225
{
226
    put_byte(s, val);
227
    put_byte(s, val >> 8);
228
    put_byte(s, val >> 16);
229
    put_byte(s, val >> 24);
230
}
231

    
232
void put_be32(ByteIOContext *s, unsigned int val)
233
{
234
    put_byte(s, val >> 24);
235
    put_byte(s, val >> 16);
236
    put_byte(s, val >> 8);
237
    put_byte(s, val);
238
}
239

    
240
void put_strz(ByteIOContext *s, const char *str)
241
{
242
    if (str)
243
        put_buffer(s, (const unsigned char *) str, strlen(str) + 1);
244
    else
245
        put_byte(s, 0);
246
}
247

    
248
void put_le64(ByteIOContext *s, uint64_t val)
249
{
250
    put_le32(s, (uint32_t)(val & 0xffffffff));
251
    put_le32(s, (uint32_t)(val >> 32));
252
}
253

    
254
void put_be64(ByteIOContext *s, uint64_t val)
255
{
256
    put_be32(s, (uint32_t)(val >> 32));
257
    put_be32(s, (uint32_t)(val & 0xffffffff));
258
}
259

    
260
void put_le16(ByteIOContext *s, unsigned int val)
261
{
262
    put_byte(s, val);
263
    put_byte(s, val >> 8);
264
}
265

    
266
void put_be16(ByteIOContext *s, unsigned int val)
267
{
268
    put_byte(s, val >> 8);
269
    put_byte(s, val);
270
}
271

    
272
void put_le24(ByteIOContext *s, unsigned int val)
273
{
274
    put_le16(s, val & 0xffff);
275
    put_byte(s, val >> 16);
276
}
277

    
278
void put_be24(ByteIOContext *s, unsigned int val)
279
{
280
    put_be16(s, val >> 8);
281
    put_byte(s, val);
282
}
283

    
284
void put_tag(ByteIOContext *s, const char *tag)
285
{
286
    while (*tag) {
287
        put_byte(s, *tag++);
288
    }
289
}
290

    
291
/* Input stream */
292

    
293
static void fill_buffer(ByteIOContext *s)
294
{
295
    uint8_t *dst= !s->max_packet_size && s->buf_end - s->buffer < s->buffer_size ? s->buf_ptr : s->buffer;
296
    int len= s->buffer_size - (dst - s->buffer);
297

    
298
    assert(s->buf_ptr == s->buf_end);
299

    
300
    /* no need to do anything if EOF already reached */
301
    if (s->eof_reached)
302
        return;
303

    
304
    if(s->update_checksum && dst == s->buffer){
305
        if(s->buf_end > s->checksum_ptr)
306
            s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
307
        s->checksum_ptr= s->buffer;
308
    }
309

    
310
    if(s->read_packet)
311
        len = s->read_packet(s->opaque, dst, len);
312
    else
313
        len = 0;
314
    if (len <= 0) {
315
        /* do not modify buffer if EOF reached so that a seek back can
316
           be done without rereading data */
317
        s->eof_reached = 1;
318
        if(len<0)
319
            s->error= len;
320
    } else {
321
        s->pos += len;
322
        s->buf_ptr = dst;
323
        s->buf_end = dst + len;
324
    }
325
}
326

    
327
unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
328
                                    unsigned int len)
329
{
330
    return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
331
}
332

    
333
unsigned long get_checksum(ByteIOContext *s)
334
{
335
    s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
336
    s->update_checksum= NULL;
337
    return s->checksum;
338
}
339

    
340
void init_checksum(ByteIOContext *s,
341
                   unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
342
                   unsigned long checksum)
343
{
344
    s->update_checksum= update_checksum;
345
    if(s->update_checksum){
346
        s->checksum= checksum;
347
        s->checksum_ptr= s->buf_ptr;
348
    }
349
}
350

    
351
/* XXX: put an inline version */
352
int get_byte(ByteIOContext *s)
353
{
354
    if (s->buf_ptr < s->buf_end) {
355
        return *s->buf_ptr++;
356
    } else {
357
        fill_buffer(s);
358
        if (s->buf_ptr < s->buf_end)
359
            return *s->buf_ptr++;
360
        else
361
            return 0;
362
    }
363
}
364

    
365
int url_fgetc(ByteIOContext *s)
366
{
367
    if (s->buf_ptr < s->buf_end) {
368
        return *s->buf_ptr++;
369
    } else {
370
        fill_buffer(s);
371
        if (s->buf_ptr < s->buf_end)
372
            return *s->buf_ptr++;
373
        else
374
            return URL_EOF;
375
    }
376
}
377

    
378
int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
379
{
380
    int len, size1;
381

    
382
    size1 = size;
383
    while (size > 0) {
384
        len = s->buf_end - s->buf_ptr;
385
        if (len > size)
386
            len = size;
387
        if (len == 0) {
388
            if(size > s->buffer_size && !s->update_checksum){
389
                if(s->read_packet)
390
                    len = s->read_packet(s->opaque, buf, size);
391
                if (len <= 0) {
392
                    /* do not modify buffer if EOF reached so that a seek back can
393
                    be done without rereading data */
394
                    s->eof_reached = 1;
395
                    if(len<0)
396
                        s->error= len;
397
                    break;
398
                } else {
399
                    s->pos += len;
400
                    size -= len;
401
                    buf += len;
402
                    s->buf_ptr = s->buffer;
403
                    s->buf_end = s->buffer/* + len*/;
404
                }
405
            }else{
406
                fill_buffer(s);
407
                len = s->buf_end - s->buf_ptr;
408
                if (len == 0)
409
                    break;
410
            }
411
        } else {
412
            memcpy(buf, s->buf_ptr, len);
413
            buf += len;
414
            s->buf_ptr += len;
415
            size -= len;
416
        }
417
    }
418
    if (size1 == size) {
419
        if (url_ferror(s)) return url_ferror(s);
420
        if (url_feof(s))   return AVERROR_EOF;
421
    }
422
    return size1 - size;
423
}
424

    
425
int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size)
426
{
427
    int len;
428

    
429
    if(size<0)
430
        return -1;
431

    
432
    len = s->buf_end - s->buf_ptr;
433
    if (len == 0) {
434
        fill_buffer(s);
435
        len = s->buf_end - s->buf_ptr;
436
    }
437
    if (len > size)
438
        len = size;
439
    memcpy(buf, s->buf_ptr, len);
440
    s->buf_ptr += len;
441
    if (!len) {
442
        if (url_ferror(s)) return url_ferror(s);
443
        if (url_feof(s))   return AVERROR_EOF;
444
    }
445
    return len;
446
}
447

    
448
unsigned int get_le16(ByteIOContext *s)
449
{
450
    unsigned int val;
451
    val = get_byte(s);
452
    val |= get_byte(s) << 8;
453
    return val;
454
}
455

    
456
unsigned int get_le24(ByteIOContext *s)
457
{
458
    unsigned int val;
459
    val = get_le16(s);
460
    val |= get_byte(s) << 16;
461
    return val;
462
}
463

    
464
unsigned int get_le32(ByteIOContext *s)
465
{
466
    unsigned int val;
467
    val = get_le16(s);
468
    val |= get_le16(s) << 16;
469
    return val;
470
}
471

    
472
uint64_t get_le64(ByteIOContext *s)
473
{
474
    uint64_t val;
475
    val = (uint64_t)get_le32(s);
476
    val |= (uint64_t)get_le32(s) << 32;
477
    return val;
478
}
479

    
480
unsigned int get_be16(ByteIOContext *s)
481
{
482
    unsigned int val;
483
    val = get_byte(s) << 8;
484
    val |= get_byte(s);
485
    return val;
486
}
487

    
488
unsigned int get_be24(ByteIOContext *s)
489
{
490
    unsigned int val;
491
    val = get_be16(s) << 8;
492
    val |= get_byte(s);
493
    return val;
494
}
495
unsigned int get_be32(ByteIOContext *s)
496
{
497
    unsigned int val;
498
    val = get_be16(s) << 16;
499
    val |= get_be16(s);
500
    return val;
501
}
502

    
503
char *get_strz(ByteIOContext *s, char *buf, int maxlen)
504
{
505
    int i = 0;
506
    char c;
507

    
508
    while ((c = get_byte(s))) {
509
        if (i < maxlen-1)
510
            buf[i++] = c;
511
    }
512

    
513
    buf[i] = 0; /* Ensure null terminated, but may be truncated */
514

    
515
    return buf;
516
}
517

    
518
uint64_t get_be64(ByteIOContext *s)
519
{
520
    uint64_t val;
521
    val = (uint64_t)get_be32(s) << 32;
522
    val |= (uint64_t)get_be32(s);
523
    return val;
524
}
525

    
526
uint64_t ff_get_v(ByteIOContext *bc){
527
    uint64_t val = 0;
528
    int tmp;
529

    
530
    do{
531
        tmp = get_byte(bc);
532
        val= (val<<7) + (tmp&127);
533
    }while(tmp&128);
534
    return val;
535
}
536

    
537
int url_fdopen(ByteIOContext **s, URLContext *h)
538
{
539
    uint8_t *buffer;
540
    int buffer_size, max_packet_size;
541

    
542
    max_packet_size = url_get_max_packet_size(h);
543
    if (max_packet_size) {
544
        buffer_size = max_packet_size; /* no need to bufferize more than one packet */
545
    } else {
546
        buffer_size = IO_BUFFER_SIZE;
547
    }
548
    buffer = av_malloc(buffer_size);
549
    if (!buffer)
550
        return AVERROR(ENOMEM);
551

    
552
    *s = av_mallocz(sizeof(ByteIOContext));
553
    if(!*s) {
554
        av_free(buffer);
555
        return AVERROR(ENOMEM);
556
    }
557

    
558
    if (init_put_byte(*s, buffer, buffer_size,
559
                      (h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
560
                      url_read, url_write, url_seek) < 0) {
561
        av_free(buffer);
562
        av_freep(s);
563
        return AVERROR(EIO);
564
    }
565
    (*s)->is_streamed = h->is_streamed;
566
    (*s)->max_packet_size = max_packet_size;
567
    if(h->prot) {
568
        (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
569
        (*s)->read_seek  = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
570
    }
571
    return 0;
572
}
573

    
574
int url_setbufsize(ByteIOContext *s, int buf_size)
575
{
576
    uint8_t *buffer;
577
    buffer = av_malloc(buf_size);
578
    if (!buffer)
579
        return AVERROR(ENOMEM);
580

    
581
    av_free(s->buffer);
582
    s->buffer = buffer;
583
    s->buffer_size = buf_size;
584
    s->buf_ptr = buffer;
585
    url_resetbuf(s, s->write_flag ? URL_WRONLY : URL_RDONLY);
586
    return 0;
587
}
588

    
589
#if LIBAVFORMAT_VERSION_MAJOR < 53
590
int url_resetbuf(ByteIOContext *s, int flags)
591
#else
592
static int url_resetbuf(ByteIOContext *s, int flags)
593
#endif
594
{
595
#if LIBAVFORMAT_VERSION_MAJOR < 53
596
    URLContext *h = s->opaque;
597
    if ((flags & URL_RDWR) || (h && h->flags != flags && !h->flags & URL_RDWR))
598
        return AVERROR(EINVAL);
599
#else
600
    assert(flags == URL_WRONLY || flags == URL_RDONLY);
601
#endif
602

    
603
    if (flags & URL_WRONLY) {
604
        s->buf_end = s->buffer + s->buffer_size;
605
        s->write_flag = 1;
606
    } else {
607
        s->buf_end = s->buffer;
608
        s->write_flag = 0;
609
    }
610
    return 0;
611
}
612

    
613
int url_fopen(ByteIOContext **s, const char *filename, int flags)
614
{
615
    URLContext *h;
616
    int err;
617

    
618
    err = url_open(&h, filename, flags);
619
    if (err < 0)
620
        return err;
621
    err = url_fdopen(s, h);
622
    if (err < 0) {
623
        url_close(h);
624
        return err;
625
    }
626
    return 0;
627
}
628

    
629
int url_fclose(ByteIOContext *s)
630
{
631
    URLContext *h = s->opaque;
632

    
633
    av_free(s->buffer);
634
    av_free(s);
635
    return url_close(h);
636
}
637

    
638
URLContext *url_fileno(ByteIOContext *s)
639
{
640
    return s->opaque;
641
}
642

    
643
#if CONFIG_MUXERS
644
int url_fprintf(ByteIOContext *s, const char *fmt, ...)
645
{
646
    va_list ap;
647
    char buf[4096];
648
    int ret;
649

    
650
    va_start(ap, fmt);
651
    ret = vsnprintf(buf, sizeof(buf), fmt, ap);
652
    va_end(ap);
653
    put_buffer(s, buf, strlen(buf));
654
    return ret;
655
}
656
#endif //CONFIG_MUXERS
657

    
658
char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
659
{
660
    int c;
661
    char *q;
662

    
663
    c = url_fgetc(s);
664
    if (c == EOF)
665
        return NULL;
666
    q = buf;
667
    for(;;) {
668
        if (c == EOF || c == '\n')
669
            break;
670
        if ((q - buf) < buf_size - 1)
671
            *q++ = c;
672
        c = url_fgetc(s);
673
    }
674
    if (buf_size > 0)
675
        *q = '\0';
676
    return buf;
677
}
678

    
679
int url_fget_max_packet_size(ByteIOContext *s)
680
{
681
    return s->max_packet_size;
682
}
683

    
684
int av_url_read_fpause(ByteIOContext *s, int pause)
685
{
686
    if (!s->read_pause)
687
        return AVERROR(ENOSYS);
688
    return s->read_pause(s->opaque, pause);
689
}
690

    
691
int64_t av_url_read_fseek(ByteIOContext *s, int stream_index,
692
                          int64_t timestamp, int flags)
693
{
694
    URLContext *h = s->opaque;
695
    int64_t ret;
696
    if (!s->read_seek)
697
        return AVERROR(ENOSYS);
698
    ret = s->read_seek(h, stream_index, timestamp, flags);
699
    if(ret >= 0) {
700
        s->buf_ptr = s->buf_end; // Flush buffer
701
        s->pos = s->seek(h, 0, SEEK_CUR);
702
    }
703
    return ret;
704
}
705

    
706
/* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
707
 * back to the server even if CONFIG_MUXERS is false. */
708
#if CONFIG_MUXERS || CONFIG_NETWORK
709
/* buffer handling */
710
int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags)
711
{
712
    int ret;
713
    *s = av_mallocz(sizeof(ByteIOContext));
714
    if(!*s)
715
        return AVERROR(ENOMEM);
716
    ret = init_put_byte(*s, buf, buf_size,
717
                        (flags & URL_WRONLY || flags & URL_RDWR),
718
                        NULL, NULL, NULL, NULL);
719
    if(ret != 0)
720
        av_freep(s);
721
    return ret;
722
}
723

    
724
int url_close_buf(ByteIOContext *s)
725
{
726
    put_flush_packet(s);
727
    return s->buf_ptr - s->buffer;
728
}
729

    
730
/* output in a dynamic buffer */
731

    
732
typedef struct DynBuffer {
733
    int pos, size, allocated_size;
734
    uint8_t *buffer;
735
    int io_buffer_size;
736
    uint8_t io_buffer[1];
737
} DynBuffer;
738

    
739
static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
740
{
741
    DynBuffer *d = opaque;
742
    unsigned new_size, new_allocated_size;
743

    
744
    /* reallocate buffer if needed */
745
    new_size = d->pos + buf_size;
746
    new_allocated_size = d->allocated_size;
747
    if(new_size < d->pos || new_size > INT_MAX/2)
748
        return -1;
749
    while (new_size > new_allocated_size) {
750
        if (!new_allocated_size)
751
            new_allocated_size = new_size;
752
        else
753
            new_allocated_size += new_allocated_size / 2 + 1;
754
    }
755

    
756
    if (new_allocated_size > d->allocated_size) {
757
        d->buffer = av_realloc(d->buffer, new_allocated_size);
758
        if(d->buffer == NULL)
759
             return AVERROR(ENOMEM);
760
        d->allocated_size = new_allocated_size;
761
    }
762
    memcpy(d->buffer + d->pos, buf, buf_size);
763
    d->pos = new_size;
764
    if (d->pos > d->size)
765
        d->size = d->pos;
766
    return buf_size;
767
}
768

    
769
static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
770
{
771
    unsigned char buf1[4];
772
    int ret;
773

    
774
    /* packetized write: output the header */
775
    AV_WB32(buf1, buf_size);
776
    ret= dyn_buf_write(opaque, buf1, 4);
777
    if(ret < 0)
778
        return ret;
779

    
780
    /* then the data */
781
    return dyn_buf_write(opaque, buf, buf_size);
782
}
783

    
784
static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
785
{
786
    DynBuffer *d = opaque;
787

    
788
    if (whence == SEEK_CUR)
789
        offset += d->pos;
790
    else if (whence == SEEK_END)
791
        offset += d->size;
792
    if (offset < 0 || offset > 0x7fffffffLL)
793
        return -1;
794
    d->pos = offset;
795
    return 0;
796
}
797

    
798
static int url_open_dyn_buf_internal(ByteIOContext **s, int max_packet_size)
799
{
800
    DynBuffer *d;
801
    int ret;
802
    unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
803

    
804
    if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
805
        return -1;
806
    d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
807
    if (!d)
808
        return AVERROR(ENOMEM);
809
    *s = av_mallocz(sizeof(ByteIOContext));
810
    if(!*s) {
811
        av_free(d);
812
        return AVERROR(ENOMEM);
813
    }
814
    d->io_buffer_size = io_buffer_size;
815
    ret = init_put_byte(*s, d->io_buffer, io_buffer_size,
816
                        1, d, NULL,
817
                        max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
818
                        max_packet_size ? NULL : dyn_buf_seek);
819
    if (ret == 0) {
820
        (*s)->max_packet_size = max_packet_size;
821
    } else {
822
        av_free(d);
823
        av_freep(s);
824
    }
825
    return ret;
826
}
827

    
828
int url_open_dyn_buf(ByteIOContext **s)
829
{
830
    return url_open_dyn_buf_internal(s, 0);
831
}
832

    
833
int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size)
834
{
835
    if (max_packet_size <= 0)
836
        return -1;
837
    return url_open_dyn_buf_internal(s, max_packet_size);
838
}
839

    
840
int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
841
{
842
    DynBuffer *d = s->opaque;
843
    int size;
844

    
845
    put_flush_packet(s);
846

    
847
    *pbuffer = d->buffer;
848
    size = d->size;
849
    av_free(d);
850
    av_free(s);
851
    return size;
852
}
853
#endif /* CONFIG_MUXERS || CONFIG_NETWORK */