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ffmpeg / libavformat / aviobuf.c @ 1ae7518d

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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.
16
 *
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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;
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    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
#if defined(CONFIG_MUXERS) || defined(CONFIG_NETWORK)
140
        if (s->write_flag) {
141
            flush_buffer(s);
142
            s->must_flush = 1;
143
        } else
144
#endif /* defined(CONFIG_MUXERS) || defined(CONFIG_NETWORK) */
145
        {
146
            s->buf_end = s->buffer;
147
        }
148
        s->buf_ptr = s->buffer;
149
        if (!s->seek || s->seek(s->opaque, offset, SEEK_SET) == (offset_t)-EPIPE)
150
            return -EPIPE;
151
        s->pos = offset;
152
    }
153
    s->eof_reached = 0;
154
    return offset;
155
}
156

    
157
void url_fskip(ByteIOContext *s, offset_t offset)
158
{
159
    url_fseek(s, offset, SEEK_CUR);
160
}
161

    
162
offset_t url_ftell(ByteIOContext *s)
163
{
164
    return url_fseek(s, 0, SEEK_CUR);
165
}
166

    
167
offset_t url_fsize(ByteIOContext *s)
168
{
169
    offset_t size;
170

    
171
    if (!s->seek)
172
        return -EPIPE;
173
    size = s->seek(s->opaque, 0, AVSEEK_SIZE);
174
    if(size<0){
175
        size = s->seek(s->opaque, -1, SEEK_END) + 1;
176
        s->seek(s->opaque, s->pos, SEEK_SET);
177
    }
178
    return size;
179
}
180

    
181
int url_feof(ByteIOContext *s)
182
{
183
    return s->eof_reached;
184
}
185

    
186
int url_ferror(ByteIOContext *s)
187
{
188
    return s->error;
189
}
190

    
191
void put_le32(ByteIOContext *s, unsigned int val)
192
{
193
    put_byte(s, val);
194
    put_byte(s, val >> 8);
195
    put_byte(s, val >> 16);
196
    put_byte(s, val >> 24);
197
}
198

    
199
void put_be32(ByteIOContext *s, unsigned int val)
200
{
201
    put_byte(s, val >> 24);
202
    put_byte(s, val >> 16);
203
    put_byte(s, val >> 8);
204
    put_byte(s, val);
205
}
206

    
207
void put_strz(ByteIOContext *s, const char *str)
208
{
209
    if (str)
210
        put_buffer(s, (const unsigned char *) str, strlen(str) + 1);
211
    else
212
        put_byte(s, 0);
213
}
214

    
215
void put_le64(ByteIOContext *s, uint64_t val)
216
{
217
    put_le32(s, (uint32_t)(val & 0xffffffff));
218
    put_le32(s, (uint32_t)(val >> 32));
219
}
220

    
221
void put_be64(ByteIOContext *s, uint64_t val)
222
{
223
    put_be32(s, (uint32_t)(val >> 32));
224
    put_be32(s, (uint32_t)(val & 0xffffffff));
225
}
226

    
227
void put_le16(ByteIOContext *s, unsigned int val)
228
{
229
    put_byte(s, val);
230
    put_byte(s, val >> 8);
231
}
232

    
233
void put_be16(ByteIOContext *s, unsigned int val)
234
{
235
    put_byte(s, val >> 8);
236
    put_byte(s, val);
237
}
238

    
239
void put_le24(ByteIOContext *s, unsigned int val)
240
{
241
    put_le16(s, val & 0xffff);
242
    put_byte(s, val >> 16);
243
}
244

    
245
void put_be24(ByteIOContext *s, unsigned int val)
246
{
247
    put_be16(s, val >> 8);
248
    put_byte(s, val);
249
}
250

    
251
void put_tag(ByteIOContext *s, const char *tag)
252
{
253
    while (*tag) {
254
        put_byte(s, *tag++);
255
    }
256
}
257

    
258
/* Input stream */
259

    
260
static void fill_buffer(ByteIOContext *s)
261
{
262
    int len;
263

    
264
    /* no need to do anything if EOF already reached */
265
    if (s->eof_reached)
266
        return;
267

    
268
    if(s->update_checksum){
269
        if(s->buf_end > s->checksum_ptr)
270
            s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
271
        s->checksum_ptr= s->buffer;
272
    }
273

    
274
    len = s->read_packet(s->opaque, s->buffer, s->buffer_size);
275
    if (len <= 0) {
276
        /* do not modify buffer if EOF reached so that a seek back can
277
           be done without rereading data */
278
        s->eof_reached = 1;
279
    if(len<0)
280
        s->error= len;
281
    } else {
282
        s->pos += len;
283
        s->buf_ptr = s->buffer;
284
        s->buf_end = s->buffer + len;
285
    }
286
}
287

    
288
unsigned long get_checksum(ByteIOContext *s){
289
    s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
290
    s->update_checksum= NULL;
291
    return s->checksum;
292
}
293

    
294
void init_checksum(ByteIOContext *s, unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), unsigned long checksum){
295
    s->update_checksum= update_checksum;
296
    if(s->update_checksum){
297
        s->checksum= checksum;
298
        s->checksum_ptr= s->buf_ptr;
299
    }
300
}
301

    
302
/* NOTE: return 0 if EOF, so you cannot use it if EOF handling is
303
   necessary */
304
/* XXX: put an inline version */
305
int get_byte(ByteIOContext *s)
306
{
307
    if (s->buf_ptr < s->buf_end) {
308
        return *s->buf_ptr++;
309
    } else {
310
        fill_buffer(s);
311
        if (s->buf_ptr < s->buf_end)
312
            return *s->buf_ptr++;
313
        else
314
            return 0;
315
    }
316
}
317

    
318
/* NOTE: return URL_EOF (-1) if EOF */
319
int url_fgetc(ByteIOContext *s)
320
{
321
    if (s->buf_ptr < s->buf_end) {
322
        return *s->buf_ptr++;
323
    } else {
324
        fill_buffer(s);
325
        if (s->buf_ptr < s->buf_end)
326
            return *s->buf_ptr++;
327
        else
328
            return URL_EOF;
329
    }
330
}
331

    
332
int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
333
{
334
    int len, size1;
335

    
336
    size1 = size;
337
    while (size > 0) {
338
        len = s->buf_end - s->buf_ptr;
339
        if (len > size)
340
            len = size;
341
        if (len == 0) {
342
            if(size > s->buffer_size && !s->update_checksum){
343
                len = s->read_packet(s->opaque, buf, size);
344
                if (len <= 0) {
345
                    /* do not modify buffer if EOF reached so that a seek back can
346
                    be done without rereading data */
347
                    s->eof_reached = 1;
348
                    if(len<0)
349
                        s->error= len;
350
                    break;
351
                } else {
352
                    s->pos += len;
353
                    size -= len;
354
                    buf += len;
355
                    s->buf_ptr = s->buffer;
356
                    s->buf_end = s->buffer/* + len*/;
357
                }
358
            }else{
359
                fill_buffer(s);
360
                len = s->buf_end - s->buf_ptr;
361
                if (len == 0)
362
                    break;
363
            }
364
        } else {
365
            memcpy(buf, s->buf_ptr, len);
366
            buf += len;
367
            s->buf_ptr += len;
368
            size -= len;
369
        }
370
    }
371
    return size1 - size;
372
}
373

    
374
int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size)
375
{
376
    int len;
377

    
378
    if(size<0)
379
        return -1;
380

    
381
    len = s->buf_end - s->buf_ptr;
382
    if (len == 0) {
383
        fill_buffer(s);
384
        len = s->buf_end - s->buf_ptr;
385
    }
386
    if (len > size)
387
        len = size;
388
    memcpy(buf, s->buf_ptr, len);
389
    s->buf_ptr += len;
390
    return len;
391
}
392

    
393
unsigned int get_le16(ByteIOContext *s)
394
{
395
    unsigned int val;
396
    val = get_byte(s);
397
    val |= get_byte(s) << 8;
398
    return val;
399
}
400

    
401
unsigned int get_le24(ByteIOContext *s)
402
{
403
    unsigned int val;
404
    val = get_le16(s);
405
    val |= get_byte(s) << 16;
406
    return val;
407
}
408

    
409
unsigned int get_le32(ByteIOContext *s)
410
{
411
    unsigned int val;
412
    val = get_le16(s);
413
    val |= get_le16(s) << 16;
414
    return val;
415
}
416

    
417
uint64_t get_le64(ByteIOContext *s)
418
{
419
    uint64_t val;
420
    val = (uint64_t)get_le32(s);
421
    val |= (uint64_t)get_le32(s) << 32;
422
    return val;
423
}
424

    
425
unsigned int get_be16(ByteIOContext *s)
426
{
427
    unsigned int val;
428
    val = get_byte(s) << 8;
429
    val |= get_byte(s);
430
    return val;
431
}
432

    
433
unsigned int get_be24(ByteIOContext *s)
434
{
435
    unsigned int val;
436
    val = get_be16(s) << 8;
437
    val |= get_byte(s);
438
    return val;
439
}
440
unsigned int get_be32(ByteIOContext *s)
441
{
442
    unsigned int val;
443
    val = get_be16(s) << 16;
444
    val |= get_be16(s);
445
    return val;
446
}
447

    
448
char *get_strz(ByteIOContext *s, char *buf, int maxlen)
449
{
450
    int i = 0;
451
    char c;
452

    
453
    while ((c = get_byte(s))) {
454
        if (i < maxlen-1)
455
            buf[i++] = c;
456
    }
457

    
458
    buf[i] = 0; /* Ensure null terminated, but may be truncated */
459

    
460
    return buf;
461
}
462

    
463
uint64_t get_be64(ByteIOContext *s)
464
{
465
    uint64_t val;
466
    val = (uint64_t)get_be32(s) << 32;
467
    val |= (uint64_t)get_be32(s);
468
    return val;
469
}
470

    
471
/* link with avio functions */
472

    
473
#ifdef CONFIG_MUXERS
474
static int url_write_packet(void *opaque, uint8_t *buf, int buf_size)
475
{
476
    URLContext *h = opaque;
477
    return url_write(h, buf, buf_size);
478
}
479
#else
480
#define         url_write_packet NULL
481
#endif //CONFIG_MUXERS
482

    
483
static int url_read_packet(void *opaque, uint8_t *buf, int buf_size)
484
{
485
    URLContext *h = opaque;
486
    return url_read(h, buf, buf_size);
487
}
488

    
489
static offset_t url_seek_packet(void *opaque, offset_t offset, int whence)
490
{
491
    URLContext *h = opaque;
492
    return url_seek(h, offset, whence);
493
    //return 0;
494
}
495

    
496
int url_fdopen(ByteIOContext *s, URLContext *h)
497
{
498
    uint8_t *buffer;
499
    int buffer_size, max_packet_size;
500

    
501

    
502
    max_packet_size = url_get_max_packet_size(h);
503
    if (max_packet_size) {
504
        buffer_size = max_packet_size; /* no need to bufferize more than one packet */
505
    } else {
506
        buffer_size = IO_BUFFER_SIZE;
507
    }
508
    buffer = av_malloc(buffer_size);
509
    if (!buffer)
510
        return -ENOMEM;
511

    
512
    if (init_put_byte(s, buffer, buffer_size,
513
                      (h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
514
                      url_read_packet, url_write_packet, url_seek_packet) < 0) {
515
        av_free(buffer);
516
        return AVERROR_IO;
517
    }
518
    s->is_streamed = h->is_streamed;
519
    s->max_packet_size = max_packet_size;
520
    return 0;
521
}
522

    
523
/* XXX: must be called before any I/O */
524
int url_setbufsize(ByteIOContext *s, int buf_size)
525
{
526
    uint8_t *buffer;
527
    buffer = av_malloc(buf_size);
528
    if (!buffer)
529
        return -ENOMEM;
530

    
531
    av_free(s->buffer);
532
    s->buffer = buffer;
533
    s->buffer_size = buf_size;
534
    s->buf_ptr = buffer;
535
    if (!s->write_flag)
536
        s->buf_end = buffer;
537
    else
538
        s->buf_end = buffer + buf_size;
539
    return 0;
540
}
541

    
542
/* NOTE: when opened as read/write, the buffers are only used for
543
   reading */
544
int url_fopen(ByteIOContext *s, const char *filename, int flags)
545
{
546
    URLContext *h;
547
    int err;
548

    
549
    err = url_open(&h, filename, flags);
550
    if (err < 0)
551
        return err;
552
    err = url_fdopen(s, h);
553
    if (err < 0) {
554
        url_close(h);
555
        return err;
556
    }
557
    return 0;
558
}
559

    
560
int url_fclose(ByteIOContext *s)
561
{
562
    URLContext *h = s->opaque;
563

    
564
    av_free(s->buffer);
565
    memset(s, 0, sizeof(ByteIOContext));
566
    return url_close(h);
567
}
568

    
569
URLContext *url_fileno(ByteIOContext *s)
570
{
571
    return s->opaque;
572
}
573

    
574
#ifdef CONFIG_MUXERS
575
/* XXX: currently size is limited */
576
int url_fprintf(ByteIOContext *s, const char *fmt, ...)
577
{
578
    va_list ap;
579
    char buf[4096];
580
    int ret;
581

    
582
    va_start(ap, fmt);
583
    ret = vsnprintf(buf, sizeof(buf), fmt, ap);
584
    va_end(ap);
585
    put_buffer(s, buf, strlen(buf));
586
    return ret;
587
}
588
#endif //CONFIG_MUXERS
589

    
590
/* note: unlike fgets, the EOL character is not returned and a whole
591
   line is parsed. return NULL if first char read was EOF */
592
char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
593
{
594
    int c;
595
    char *q;
596

    
597
    c = url_fgetc(s);
598
    if (c == EOF)
599
        return NULL;
600
    q = buf;
601
    for(;;) {
602
        if (c == EOF || c == '\n')
603
            break;
604
        if ((q - buf) < buf_size - 1)
605
            *q++ = c;
606
        c = url_fgetc(s);
607
    }
608
    if (buf_size > 0)
609
        *q = '\0';
610
    return buf;
611
}
612

    
613
/*
614
 * Return the maximum packet size associated to packetized buffered file
615
 * handle. If the file is not packetized (stream like http or file on
616
 * disk), then 0 is returned.
617
 *
618
 * @param h buffered file handle
619
 * @return maximum packet size in bytes
620
 */
621
int url_fget_max_packet_size(ByteIOContext *s)
622
{
623
    return s->max_packet_size;
624
}
625

    
626
/* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
627
 * back to the server even if CONFIG_MUXERS is not set. */
628
#if defined(CONFIG_MUXERS) || defined(CONFIG_NETWORK)
629
/* buffer handling */
630
int url_open_buf(ByteIOContext *s, uint8_t *buf, int buf_size, int flags)
631
{
632
    return init_put_byte(s, buf, buf_size,
633
                         (flags & URL_WRONLY || flags & URL_RDWR),
634
                         NULL, NULL, NULL, NULL);
635
}
636

    
637
/* return the written or read size */
638
int url_close_buf(ByteIOContext *s)
639
{
640
    put_flush_packet(s);
641
    return s->buf_ptr - s->buffer;
642
}
643

    
644
/* output in a dynamic buffer */
645

    
646
typedef struct DynBuffer {
647
    int pos, size, allocated_size;
648
    uint8_t *buffer;
649
    int io_buffer_size;
650
    uint8_t io_buffer[1];
651
} DynBuffer;
652

    
653
static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
654
{
655
    DynBuffer *d = opaque;
656
    int new_size, new_allocated_size;
657

    
658
    /* reallocate buffer if needed */
659
    new_size = d->pos + buf_size;
660
    new_allocated_size = d->allocated_size;
661
    if(new_size < d->pos || new_size > INT_MAX/2)
662
        return -1;
663
    while (new_size > new_allocated_size) {
664
        if (!new_allocated_size)
665
            new_allocated_size = new_size;
666
        else
667
            new_allocated_size += new_allocated_size / 2 + 1;
668
    }
669

    
670
    if (new_allocated_size > d->allocated_size) {
671
        d->buffer = av_realloc(d->buffer, new_allocated_size);
672
        if(d->buffer == NULL)
673
             return -1234;
674
        d->allocated_size = new_allocated_size;
675
    }
676
    memcpy(d->buffer + d->pos, buf, buf_size);
677
    d->pos = new_size;
678
    if (d->pos > d->size)
679
        d->size = d->pos;
680
    return buf_size;
681
}
682

    
683
static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
684
{
685
    unsigned char buf1[4];
686
    int ret;
687

    
688
    /* packetized write: output the header */
689
    buf1[0] = (buf_size >> 24);
690
    buf1[1] = (buf_size >> 16);
691
    buf1[2] = (buf_size >> 8);
692
    buf1[3] = (buf_size);
693
    ret= dyn_buf_write(opaque, buf1, 4);
694
    if(ret < 0)
695
        return ret;
696

    
697
    /* then the data */
698
    return dyn_buf_write(opaque, buf, buf_size);
699
}
700

    
701
static offset_t dyn_buf_seek(void *opaque, offset_t offset, int whence)
702
{
703
    DynBuffer *d = opaque;
704

    
705
    if (whence == SEEK_CUR)
706
        offset += d->pos;
707
    else if (whence == SEEK_END)
708
        offset += d->size;
709
    if (offset < 0 || offset > 0x7fffffffLL)
710
        return -1;
711
    d->pos = offset;
712
    return 0;
713
}
714

    
715
static int url_open_dyn_buf_internal(ByteIOContext *s, int max_packet_size)
716
{
717
    DynBuffer *d;
718
    int io_buffer_size, ret;
719

    
720
    if (max_packet_size)
721
        io_buffer_size = max_packet_size;
722
    else
723
        io_buffer_size = 1024;
724

    
725
    if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
726
        return -1;
727
    d = av_malloc(sizeof(DynBuffer) + io_buffer_size);
728
    if (!d)
729
        return -1;
730
    d->io_buffer_size = io_buffer_size;
731
    d->buffer = NULL;
732
    d->pos = 0;
733
    d->size = 0;
734
    d->allocated_size = 0;
735
    ret = init_put_byte(s, d->io_buffer, io_buffer_size,
736
                        1, d, NULL,
737
                        max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
738
                        max_packet_size ? NULL : dyn_buf_seek);
739
    if (ret == 0) {
740
        s->max_packet_size = max_packet_size;
741
    }
742
    return ret;
743
}
744

    
745
/*
746
 * Open a write only memory stream.
747
 *
748
 * @param s new IO context
749
 * @return zero if no error.
750
 */
751
int url_open_dyn_buf(ByteIOContext *s)
752
{
753
    return url_open_dyn_buf_internal(s, 0);
754
}
755

    
756
/*
757
 * Open a write only packetized memory stream with a maximum packet
758
 * size of 'max_packet_size'.  The stream is stored in a memory buffer
759
 * with a big endian 4 byte header giving the packet size in bytes.
760
 *
761
 * @param s new IO context
762
 * @param max_packet_size maximum packet size (must be > 0)
763
 * @return zero if no error.
764
 */
765
int url_open_dyn_packet_buf(ByteIOContext *s, int max_packet_size)
766
{
767
    if (max_packet_size <= 0)
768
        return -1;
769
    return url_open_dyn_buf_internal(s, max_packet_size);
770
}
771

    
772
/*
773
 * Return the written size and a pointer to the buffer. The buffer
774
 *  must be freed with av_free().
775
 * @param s IO context
776
 * @param pointer to a byte buffer
777
 * @return the length of the byte buffer
778
 */
779
int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
780
{
781
    DynBuffer *d = s->opaque;
782
    int size;
783

    
784
    put_flush_packet(s);
785

    
786
    *pbuffer = d->buffer;
787
    size = d->size;
788
    av_free(d);
789
    return size;
790
}
791
#endif /* CONFIG_MUXERS || CONFIG_NETWORK */