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ffmpeg / libavformat / aviobuf.c @ 0d9f8633

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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
 *
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 * 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.
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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
20
 */
21
#include "avformat.h"
22
#include "avio.h"
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#include <stdarg.h>
24

    
25
#define IO_BUFFER_SIZE 32768
26

    
27
static void fill_buffer(ByteIOContext *s);
28

    
29
int init_put_byte(ByteIOContext *s,
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                  unsigned char *buffer,
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                  int buffer_size,
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                  int write_flag,
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                  void *opaque,
34
                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
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                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
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                  offset_t (*seek)(void *opaque, offset_t offset, int whence))
37
{
38
    s->buffer = buffer;
39
    s->buffer_size = buffer_size;
40
    s->buf_ptr = buffer;
41
    s->write_flag = write_flag;
42
    if (!s->write_flag)
43
        s->buf_end = buffer;
44
    else
45
        s->buf_end = buffer + buffer_size;
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    s->opaque = opaque;
47
    s->write_packet = write_packet;
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    s->read_packet = read_packet;
49
    s->seek = seek;
50
    s->pos = 0;
51
    s->must_flush = 0;
52
    s->eof_reached = 0;
53
    s->error = 0;
54
    s->is_streamed = 0;
55
    s->max_packet_size = 0;
56
    s->update_checksum= NULL;
57
    if(!read_packet && !write_flag){
58
        s->pos = buffer_size;
59
        s->buf_end = s->buffer + buffer_size;
60
    }
61
    return 0;
62
}
63

    
64
static void flush_buffer(ByteIOContext *s)
65
{
66
    if (s->buf_ptr > s->buffer) {
67
        if (s->write_packet && !s->error){
68
            int ret= s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
69
            if(ret < 0){
70
                s->error = ret;
71
            }
72
        }
73
        if(s->update_checksum){
74
            s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
75
            s->checksum_ptr= s->buffer;
76
        }
77
        s->pos += s->buf_ptr - s->buffer;
78
    }
79
    s->buf_ptr = s->buffer;
80
}
81

    
82
void put_byte(ByteIOContext *s, int b)
83
{
84
    *(s->buf_ptr)++ = b;
85
    if (s->buf_ptr >= s->buf_end)
86
        flush_buffer(s);
87
}
88

    
89
void put_buffer(ByteIOContext *s, const unsigned char *buf, int size)
90
{
91
    int len;
92

    
93
    while (size > 0) {
94
        len = (s->buf_end - s->buf_ptr);
95
        if (len > size)
96
            len = size;
97
        memcpy(s->buf_ptr, buf, len);
98
        s->buf_ptr += len;
99

    
100
        if (s->buf_ptr >= s->buf_end)
101
            flush_buffer(s);
102

    
103
        buf += len;
104
        size -= len;
105
    }
106
}
107

    
108
void put_flush_packet(ByteIOContext *s)
109
{
110
    flush_buffer(s);
111
    s->must_flush = 0;
112
}
113

    
114
offset_t url_fseek(ByteIOContext *s, offset_t offset, int whence)
115
{
116
    offset_t offset1;
117
    offset_t pos= s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
118

    
119
    if (whence != SEEK_CUR && whence != SEEK_SET)
120
        return -EINVAL;
121

    
122
    if (whence == SEEK_CUR) {
123
        offset1 = pos + (s->buf_ptr - s->buffer);
124
        if (offset == 0)
125
            return offset1;
126
        offset += offset1;
127
    }
128
    offset1 = offset - pos;
129
    if (!s->must_flush &&
130
        offset1 >= 0 && offset1 < (s->buf_end - s->buffer)) {
131
        /* can do the seek inside the buffer */
132
        s->buf_ptr = s->buffer + offset1;
133
    } else if(s->is_streamed && !s->write_flag &&
134
              offset1 >= 0 && offset1 < (s->buf_end - s->buffer) + (1<<16)){
135
        while(s->pos < offset && !s->eof_reached)
136
            fill_buffer(s);
137
        s->buf_ptr = s->buf_end + offset - s->pos;
138
    } else {
139
        offset_t res = -EPIPE;
140

    
141
#if defined(CONFIG_MUXERS) || defined(CONFIG_NETWORK)
142
        if (s->write_flag) {
143
            flush_buffer(s);
144
            s->must_flush = 1;
145
        } else
146
#endif /* defined(CONFIG_MUXERS) || defined(CONFIG_NETWORK) */
147
        {
148
            s->buf_end = s->buffer;
149
        }
150
        s->buf_ptr = s->buffer;
151
        if (!s->seek || (res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
152
            return res;
153
        s->pos = offset;
154
    }
155
    s->eof_reached = 0;
156
    return offset;
157
}
158

    
159
void url_fskip(ByteIOContext *s, offset_t offset)
160
{
161
    url_fseek(s, offset, SEEK_CUR);
162
}
163

    
164
offset_t url_ftell(ByteIOContext *s)
165
{
166
    return url_fseek(s, 0, SEEK_CUR);
167
}
168

    
169
offset_t url_fsize(ByteIOContext *s)
170
{
171
    offset_t size;
172

    
173
    if (!s->seek)
174
        return -EPIPE;
175
    size = s->seek(s->opaque, 0, AVSEEK_SIZE);
176
    if(size<0){
177
        if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
178
            return size;
179
        size++;
180
        s->seek(s->opaque, s->pos, SEEK_SET);
181
    }
182
    return size;
183
}
184

    
185
int url_feof(ByteIOContext *s)
186
{
187
    return s->eof_reached;
188
}
189

    
190
int url_ferror(ByteIOContext *s)
191
{
192
    return s->error;
193
}
194

    
195
void put_le32(ByteIOContext *s, unsigned int val)
196
{
197
    put_byte(s, val);
198
    put_byte(s, val >> 8);
199
    put_byte(s, val >> 16);
200
    put_byte(s, val >> 24);
201
}
202

    
203
void put_be32(ByteIOContext *s, unsigned int val)
204
{
205
    put_byte(s, val >> 24);
206
    put_byte(s, val >> 16);
207
    put_byte(s, val >> 8);
208
    put_byte(s, val);
209
}
210

    
211
void put_strz(ByteIOContext *s, const char *str)
212
{
213
    if (str)
214
        put_buffer(s, (const unsigned char *) str, strlen(str) + 1);
215
    else
216
        put_byte(s, 0);
217
}
218

    
219
void put_le64(ByteIOContext *s, uint64_t val)
220
{
221
    put_le32(s, (uint32_t)(val & 0xffffffff));
222
    put_le32(s, (uint32_t)(val >> 32));
223
}
224

    
225
void put_be64(ByteIOContext *s, uint64_t val)
226
{
227
    put_be32(s, (uint32_t)(val >> 32));
228
    put_be32(s, (uint32_t)(val & 0xffffffff));
229
}
230

    
231
void put_le16(ByteIOContext *s, unsigned int val)
232
{
233
    put_byte(s, val);
234
    put_byte(s, val >> 8);
235
}
236

    
237
void put_be16(ByteIOContext *s, unsigned int val)
238
{
239
    put_byte(s, val >> 8);
240
    put_byte(s, val);
241
}
242

    
243
void put_le24(ByteIOContext *s, unsigned int val)
244
{
245
    put_le16(s, val & 0xffff);
246
    put_byte(s, val >> 16);
247
}
248

    
249
void put_be24(ByteIOContext *s, unsigned int val)
250
{
251
    put_be16(s, val >> 8);
252
    put_byte(s, val);
253
}
254

    
255
void put_tag(ByteIOContext *s, const char *tag)
256
{
257
    while (*tag) {
258
        put_byte(s, *tag++);
259
    }
260
}
261

    
262
/* Input stream */
263

    
264
static void fill_buffer(ByteIOContext *s)
265
{
266
    int len;
267

    
268
    /* no need to do anything if EOF already reached */
269
    if (s->eof_reached)
270
        return;
271

    
272
    if(s->update_checksum){
273
        if(s->buf_end > s->checksum_ptr)
274
            s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
275
        s->checksum_ptr= s->buffer;
276
    }
277

    
278
    len = s->read_packet(s->opaque, s->buffer, s->buffer_size);
279
    if (len <= 0) {
280
        /* do not modify buffer if EOF reached so that a seek back can
281
           be done without rereading data */
282
        s->eof_reached = 1;
283
    if(len<0)
284
        s->error= len;
285
    } else {
286
        s->pos += len;
287
        s->buf_ptr = s->buffer;
288
        s->buf_end = s->buffer + len;
289
    }
290
}
291

    
292
unsigned long get_checksum(ByteIOContext *s){
293
    s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
294
    s->update_checksum= NULL;
295
    return s->checksum;
296
}
297

    
298
void init_checksum(ByteIOContext *s, unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), unsigned long checksum){
299
    s->update_checksum= update_checksum;
300
    if(s->update_checksum){
301
        s->checksum= checksum;
302
        s->checksum_ptr= s->buf_ptr;
303
    }
304
}
305

    
306
/* NOTE: return 0 if EOF, so you cannot use it if EOF handling is
307
   necessary */
308
/* XXX: put an inline version */
309
int get_byte(ByteIOContext *s)
310
{
311
    if (s->buf_ptr < s->buf_end) {
312
        return *s->buf_ptr++;
313
    } else {
314
        fill_buffer(s);
315
        if (s->buf_ptr < s->buf_end)
316
            return *s->buf_ptr++;
317
        else
318
            return 0;
319
    }
320
}
321

    
322
/* NOTE: return URL_EOF (-1) if EOF */
323
int url_fgetc(ByteIOContext *s)
324
{
325
    if (s->buf_ptr < s->buf_end) {
326
        return *s->buf_ptr++;
327
    } else {
328
        fill_buffer(s);
329
        if (s->buf_ptr < s->buf_end)
330
            return *s->buf_ptr++;
331
        else
332
            return URL_EOF;
333
    }
334
}
335

    
336
int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
337
{
338
    int len, size1;
339

    
340
    size1 = size;
341
    while (size > 0) {
342
        len = s->buf_end - s->buf_ptr;
343
        if (len > size)
344
            len = size;
345
        if (len == 0) {
346
            if(size > s->buffer_size && !s->update_checksum){
347
                len = s->read_packet(s->opaque, buf, size);
348
                if (len <= 0) {
349
                    /* do not modify buffer if EOF reached so that a seek back can
350
                    be done without rereading data */
351
                    s->eof_reached = 1;
352
                    if(len<0)
353
                        s->error= len;
354
                    break;
355
                } else {
356
                    s->pos += len;
357
                    size -= len;
358
                    buf += len;
359
                    s->buf_ptr = s->buffer;
360
                    s->buf_end = s->buffer/* + len*/;
361
                }
362
            }else{
363
                fill_buffer(s);
364
                len = s->buf_end - s->buf_ptr;
365
                if (len == 0)
366
                    break;
367
            }
368
        } else {
369
            memcpy(buf, s->buf_ptr, len);
370
            buf += len;
371
            s->buf_ptr += len;
372
            size -= len;
373
        }
374
    }
375
    return size1 - size;
376
}
377

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

    
382
    if(size<0)
383
        return -1;
384

    
385
    len = s->buf_end - s->buf_ptr;
386
    if (len == 0) {
387
        fill_buffer(s);
388
        len = s->buf_end - s->buf_ptr;
389
    }
390
    if (len > size)
391
        len = size;
392
    memcpy(buf, s->buf_ptr, len);
393
    s->buf_ptr += len;
394
    return len;
395
}
396

    
397
unsigned int get_le16(ByteIOContext *s)
398
{
399
    unsigned int val;
400
    val = get_byte(s);
401
    val |= get_byte(s) << 8;
402
    return val;
403
}
404

    
405
unsigned int get_le24(ByteIOContext *s)
406
{
407
    unsigned int val;
408
    val = get_le16(s);
409
    val |= get_byte(s) << 16;
410
    return val;
411
}
412

    
413
unsigned int get_le32(ByteIOContext *s)
414
{
415
    unsigned int val;
416
    val = get_le16(s);
417
    val |= get_le16(s) << 16;
418
    return val;
419
}
420

    
421
uint64_t get_le64(ByteIOContext *s)
422
{
423
    uint64_t val;
424
    val = (uint64_t)get_le32(s);
425
    val |= (uint64_t)get_le32(s) << 32;
426
    return val;
427
}
428

    
429
unsigned int get_be16(ByteIOContext *s)
430
{
431
    unsigned int val;
432
    val = get_byte(s) << 8;
433
    val |= get_byte(s);
434
    return val;
435
}
436

    
437
unsigned int get_be24(ByteIOContext *s)
438
{
439
    unsigned int val;
440
    val = get_be16(s) << 8;
441
    val |= get_byte(s);
442
    return val;
443
}
444
unsigned int get_be32(ByteIOContext *s)
445
{
446
    unsigned int val;
447
    val = get_be16(s) << 16;
448
    val |= get_be16(s);
449
    return val;
450
}
451

    
452
char *get_strz(ByteIOContext *s, char *buf, int maxlen)
453
{
454
    int i = 0;
455
    char c;
456

    
457
    while ((c = get_byte(s))) {
458
        if (i < maxlen-1)
459
            buf[i++] = c;
460
    }
461

    
462
    buf[i] = 0; /* Ensure null terminated, but may be truncated */
463

    
464
    return buf;
465
}
466

    
467
uint64_t get_be64(ByteIOContext *s)
468
{
469
    uint64_t val;
470
    val = (uint64_t)get_be32(s) << 32;
471
    val |= (uint64_t)get_be32(s);
472
    return val;
473
}
474

    
475
/* link with avio functions */
476

    
477
#ifdef CONFIG_MUXERS
478
static int url_write_packet(void *opaque, uint8_t *buf, int buf_size)
479
{
480
    URLContext *h = opaque;
481
    return url_write(h, buf, buf_size);
482
}
483
#else
484
#define         url_write_packet NULL
485
#endif //CONFIG_MUXERS
486

    
487
static int url_read_packet(void *opaque, uint8_t *buf, int buf_size)
488
{
489
    URLContext *h = opaque;
490
    return url_read(h, buf, buf_size);
491
}
492

    
493
static offset_t url_seek_packet(void *opaque, offset_t offset, int whence)
494
{
495
    URLContext *h = opaque;
496
    return url_seek(h, offset, whence);
497
    //return 0;
498
}
499

    
500
int url_fdopen(ByteIOContext *s, URLContext *h)
501
{
502
    uint8_t *buffer;
503
    int buffer_size, max_packet_size;
504

    
505

    
506
    max_packet_size = url_get_max_packet_size(h);
507
    if (max_packet_size) {
508
        buffer_size = max_packet_size; /* no need to bufferize more than one packet */
509
    } else {
510
        buffer_size = IO_BUFFER_SIZE;
511
    }
512
    buffer = av_malloc(buffer_size);
513
    if (!buffer)
514
        return -ENOMEM;
515

    
516
    if (init_put_byte(s, buffer, buffer_size,
517
                      (h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
518
                      url_read_packet, url_write_packet, url_seek_packet) < 0) {
519
        av_free(buffer);
520
        return AVERROR_IO;
521
    }
522
    s->is_streamed = h->is_streamed;
523
    s->max_packet_size = max_packet_size;
524
    return 0;
525
}
526

    
527
/* XXX: must be called before any I/O */
528
int url_setbufsize(ByteIOContext *s, int buf_size)
529
{
530
    uint8_t *buffer;
531
    buffer = av_malloc(buf_size);
532
    if (!buffer)
533
        return -ENOMEM;
534

    
535
    av_free(s->buffer);
536
    s->buffer = buffer;
537
    s->buffer_size = buf_size;
538
    s->buf_ptr = buffer;
539
    if (!s->write_flag)
540
        s->buf_end = buffer;
541
    else
542
        s->buf_end = buffer + buf_size;
543
    return 0;
544
}
545

    
546
/* NOTE: when opened as read/write, the buffers are only used for
547
   reading */
548
int url_fopen(ByteIOContext *s, const char *filename, int flags)
549
{
550
    URLContext *h;
551
    int err;
552

    
553
    err = url_open(&h, filename, flags);
554
    if (err < 0)
555
        return err;
556
    err = url_fdopen(s, h);
557
    if (err < 0) {
558
        url_close(h);
559
        return err;
560
    }
561
    return 0;
562
}
563

    
564
int url_fclose(ByteIOContext *s)
565
{
566
    URLContext *h = s->opaque;
567

    
568
    av_free(s->buffer);
569
    memset(s, 0, sizeof(ByteIOContext));
570
    return url_close(h);
571
}
572

    
573
URLContext *url_fileno(ByteIOContext *s)
574
{
575
    return s->opaque;
576
}
577

    
578
#ifdef CONFIG_MUXERS
579
/* XXX: currently size is limited */
580
int url_fprintf(ByteIOContext *s, const char *fmt, ...)
581
{
582
    va_list ap;
583
    char buf[4096];
584
    int ret;
585

    
586
    va_start(ap, fmt);
587
    ret = vsnprintf(buf, sizeof(buf), fmt, ap);
588
    va_end(ap);
589
    put_buffer(s, buf, strlen(buf));
590
    return ret;
591
}
592
#endif //CONFIG_MUXERS
593

    
594
/* note: unlike fgets, the EOL character is not returned and a whole
595
   line is parsed. return NULL if first char read was EOF */
596
char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
597
{
598
    int c;
599
    char *q;
600

    
601
    c = url_fgetc(s);
602
    if (c == EOF)
603
        return NULL;
604
    q = buf;
605
    for(;;) {
606
        if (c == EOF || c == '\n')
607
            break;
608
        if ((q - buf) < buf_size - 1)
609
            *q++ = c;
610
        c = url_fgetc(s);
611
    }
612
    if (buf_size > 0)
613
        *q = '\0';
614
    return buf;
615
}
616

    
617
/*
618
 * Return the maximum packet size associated to packetized buffered file
619
 * handle. If the file is not packetized (stream like http or file on
620
 * disk), then 0 is returned.
621
 *
622
 * @param h buffered file handle
623
 * @return maximum packet size in bytes
624
 */
625
int url_fget_max_packet_size(ByteIOContext *s)
626
{
627
    return s->max_packet_size;
628
}
629

    
630
/* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
631
 * back to the server even if CONFIG_MUXERS is not set. */
632
#if defined(CONFIG_MUXERS) || defined(CONFIG_NETWORK)
633
/* buffer handling */
634
int url_open_buf(ByteIOContext *s, uint8_t *buf, int buf_size, int flags)
635
{
636
    return init_put_byte(s, buf, buf_size,
637
                         (flags & URL_WRONLY || flags & URL_RDWR),
638
                         NULL, NULL, NULL, NULL);
639
}
640

    
641
/* return the written or read size */
642
int url_close_buf(ByteIOContext *s)
643
{
644
    put_flush_packet(s);
645
    return s->buf_ptr - s->buffer;
646
}
647

    
648
/* output in a dynamic buffer */
649

    
650
typedef struct DynBuffer {
651
    int pos, size, allocated_size;
652
    uint8_t *buffer;
653
    int io_buffer_size;
654
    uint8_t io_buffer[1];
655
} DynBuffer;
656

    
657
static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
658
{
659
    DynBuffer *d = opaque;
660
    int new_size, new_allocated_size;
661

    
662
    /* reallocate buffer if needed */
663
    new_size = d->pos + buf_size;
664
    new_allocated_size = d->allocated_size;
665
    if(new_size < d->pos || new_size > INT_MAX/2)
666
        return -1;
667
    while (new_size > new_allocated_size) {
668
        if (!new_allocated_size)
669
            new_allocated_size = new_size;
670
        else
671
            new_allocated_size += new_allocated_size / 2 + 1;
672
    }
673

    
674
    if (new_allocated_size > d->allocated_size) {
675
        d->buffer = av_realloc(d->buffer, new_allocated_size);
676
        if(d->buffer == NULL)
677
             return -1234;
678
        d->allocated_size = new_allocated_size;
679
    }
680
    memcpy(d->buffer + d->pos, buf, buf_size);
681
    d->pos = new_size;
682
    if (d->pos > d->size)
683
        d->size = d->pos;
684
    return buf_size;
685
}
686

    
687
static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
688
{
689
    unsigned char buf1[4];
690
    int ret;
691

    
692
    /* packetized write: output the header */
693
    buf1[0] = (buf_size >> 24);
694
    buf1[1] = (buf_size >> 16);
695
    buf1[2] = (buf_size >> 8);
696
    buf1[3] = (buf_size);
697
    ret= dyn_buf_write(opaque, buf1, 4);
698
    if(ret < 0)
699
        return ret;
700

    
701
    /* then the data */
702
    return dyn_buf_write(opaque, buf, buf_size);
703
}
704

    
705
static offset_t dyn_buf_seek(void *opaque, offset_t offset, int whence)
706
{
707
    DynBuffer *d = opaque;
708

    
709
    if (whence == SEEK_CUR)
710
        offset += d->pos;
711
    else if (whence == SEEK_END)
712
        offset += d->size;
713
    if (offset < 0 || offset > 0x7fffffffLL)
714
        return -1;
715
    d->pos = offset;
716
    return 0;
717
}
718

    
719
static int url_open_dyn_buf_internal(ByteIOContext *s, int max_packet_size)
720
{
721
    DynBuffer *d;
722
    int io_buffer_size, ret;
723

    
724
    if (max_packet_size)
725
        io_buffer_size = max_packet_size;
726
    else
727
        io_buffer_size = 1024;
728

    
729
    if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
730
        return -1;
731
    d = av_malloc(sizeof(DynBuffer) + io_buffer_size);
732
    if (!d)
733
        return -1;
734
    d->io_buffer_size = io_buffer_size;
735
    d->buffer = NULL;
736
    d->pos = 0;
737
    d->size = 0;
738
    d->allocated_size = 0;
739
    ret = init_put_byte(s, d->io_buffer, io_buffer_size,
740
                        1, d, NULL,
741
                        max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
742
                        max_packet_size ? NULL : dyn_buf_seek);
743
    if (ret == 0) {
744
        s->max_packet_size = max_packet_size;
745
    }
746
    return ret;
747
}
748

    
749
/*
750
 * Open a write only memory stream.
751
 *
752
 * @param s new IO context
753
 * @return zero if no error.
754
 */
755
int url_open_dyn_buf(ByteIOContext *s)
756
{
757
    return url_open_dyn_buf_internal(s, 0);
758
}
759

    
760
/*
761
 * Open a write only packetized memory stream with a maximum packet
762
 * size of 'max_packet_size'.  The stream is stored in a memory buffer
763
 * with a big endian 4 byte header giving the packet size in bytes.
764
 *
765
 * @param s new IO context
766
 * @param max_packet_size maximum packet size (must be > 0)
767
 * @return zero if no error.
768
 */
769
int url_open_dyn_packet_buf(ByteIOContext *s, int max_packet_size)
770
{
771
    if (max_packet_size <= 0)
772
        return -1;
773
    return url_open_dyn_buf_internal(s, max_packet_size);
774
}
775

    
776
/*
777
 * Return the written size and a pointer to the buffer. The buffer
778
 *  must be freed with av_free().
779
 * @param s IO context
780
 * @param pointer to a byte buffer
781
 * @return the length of the byte buffer
782
 */
783
int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
784
{
785
    DynBuffer *d = s->opaque;
786
    int size;
787

    
788
    put_flush_packet(s);
789

    
790
    *pbuffer = d->buffer;
791
    size = d->size;
792
    av_free(d);
793
    return size;
794
}
795
#endif /* CONFIG_MUXERS || CONFIG_NETWORK */