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ffmpeg / libavformat / aviobuf.c @ a43416a5

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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 "internal.h"
27
#include <stdarg.h>
28

    
29
#define IO_BUFFER_SIZE 32768
30

    
31
/**
32
 * Do seeks within this distance ahead of the current buffer by skipping
33
 * data instead of calling the protocol seek function, for seekable
34
 * protocols.
35
 */
36
#define SHORT_SEEK_THRESHOLD 4096
37

    
38
static void fill_buffer(ByteIOContext *s);
39
#if LIBAVFORMAT_VERSION_MAJOR >= 53
40
static int url_resetbuf(ByteIOContext *s, int flags);
41
#endif
42

    
43
int init_put_byte(ByteIOContext *s,
44
                  unsigned char *buffer,
45
                  int buffer_size,
46
                  int write_flag,
47
                  void *opaque,
48
                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
49
                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
50
                  int64_t (*seek)(void *opaque, int64_t offset, int whence))
51
{
52
    s->buffer = buffer;
53
    s->buffer_size = buffer_size;
54
    s->buf_ptr = buffer;
55
    s->opaque = opaque;
56
    url_resetbuf(s, write_flag ? URL_WRONLY : URL_RDONLY);
57
    s->write_packet = write_packet;
58
    s->read_packet = read_packet;
59
    s->seek = seek;
60
    s->pos = 0;
61
    s->must_flush = 0;
62
    s->eof_reached = 0;
63
    s->error = 0;
64
    s->is_streamed = 0;
65
    s->max_packet_size = 0;
66
    s->update_checksum= NULL;
67
    if(!read_packet && !write_flag){
68
        s->pos = buffer_size;
69
        s->buf_end = s->buffer + buffer_size;
70
    }
71
    s->read_pause = NULL;
72
    s->read_seek  = NULL;
73
    return 0;
74
}
75

    
76
ByteIOContext *av_alloc_put_byte(
77
                  unsigned char *buffer,
78
                  int buffer_size,
79
                  int write_flag,
80
                  void *opaque,
81
                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
82
                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
83
                  int64_t (*seek)(void *opaque, int64_t offset, int whence))
84
{
85
    ByteIOContext *s = av_mallocz(sizeof(ByteIOContext));
86
    init_put_byte(s, buffer, buffer_size, write_flag, opaque,
87
                  read_packet, write_packet, seek);
88
    return s;
89
}
90

    
91
static void flush_buffer(ByteIOContext *s)
92
{
93
    if (s->buf_ptr > s->buffer) {
94
        if (s->write_packet && !s->error){
95
            int ret= s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
96
            if(ret < 0){
97
                s->error = ret;
98
            }
99
        }
100
        if(s->update_checksum){
101
            s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
102
            s->checksum_ptr= s->buffer;
103
        }
104
        s->pos += s->buf_ptr - s->buffer;
105
    }
106
    s->buf_ptr = s->buffer;
107
}
108

    
109
void put_byte(ByteIOContext *s, int b)
110
{
111
    *(s->buf_ptr)++ = b;
112
    if (s->buf_ptr >= s->buf_end)
113
        flush_buffer(s);
114
}
115

    
116
void put_buffer(ByteIOContext *s, const unsigned char *buf, int size)
117
{
118
    while (size > 0) {
119
        int len = FFMIN(s->buf_end - s->buf_ptr, size);
120
        memcpy(s->buf_ptr, buf, len);
121
        s->buf_ptr += len;
122

    
123
        if (s->buf_ptr >= s->buf_end)
124
            flush_buffer(s);
125

    
126
        buf += len;
127
        size -= len;
128
    }
129
}
130

    
131
void put_flush_packet(ByteIOContext *s)
132
{
133
    flush_buffer(s);
134
    s->must_flush = 0;
135
}
136

    
137
int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence)
138
{
139
    int64_t offset1;
140
    int64_t pos;
141
    int force = whence & AVSEEK_FORCE;
142
    whence &= ~AVSEEK_FORCE;
143

    
144
    if(!s)
145
        return AVERROR(EINVAL);
146

    
147
    pos = s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
148

    
149
    if (whence != SEEK_CUR && whence != SEEK_SET)
150
        return AVERROR(EINVAL);
151

    
152
    if (whence == SEEK_CUR) {
153
        offset1 = pos + (s->buf_ptr - s->buffer);
154
        if (offset == 0)
155
            return offset1;
156
        offset += offset1;
157
    }
158
    offset1 = offset - pos;
159
    if (!s->must_flush &&
160
        offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
161
        /* can do the seek inside the buffer */
162
        s->buf_ptr = s->buffer + offset1;
163
    } else if ((s->is_streamed ||
164
               offset1 <= s->buf_end + SHORT_SEEK_THRESHOLD - s->buffer) &&
165
               !s->write_flag && offset1 >= 0 &&
166
              (whence != SEEK_END || force)) {
167
        while(s->pos < offset && !s->eof_reached)
168
            fill_buffer(s);
169
        if (s->eof_reached)
170
            return AVERROR_EOF;
171
        s->buf_ptr = s->buf_end + offset - s->pos;
172
    } else {
173
        int64_t res;
174

    
175
#if CONFIG_MUXERS || CONFIG_NETWORK
176
        if (s->write_flag) {
177
            flush_buffer(s);
178
            s->must_flush = 1;
179
        }
180
#endif /* CONFIG_MUXERS || CONFIG_NETWORK */
181
        if (!s->seek)
182
            return AVERROR(EPIPE);
183
        if ((res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
184
            return res;
185
        if (!s->write_flag)
186
            s->buf_end = s->buffer;
187
        s->buf_ptr = s->buffer;
188
        s->pos = offset;
189
    }
190
    s->eof_reached = 0;
191
    return offset;
192
}
193

    
194
int url_fskip(ByteIOContext *s, int64_t offset)
195
{
196
    int64_t ret = url_fseek(s, offset, SEEK_CUR);
197
    return ret < 0 ? ret : 0;
198
}
199

    
200
int64_t url_ftell(ByteIOContext *s)
201
{
202
    return url_fseek(s, 0, SEEK_CUR);
203
}
204

    
205
int64_t url_fsize(ByteIOContext *s)
206
{
207
    int64_t size;
208

    
209
    if(!s)
210
        return AVERROR(EINVAL);
211

    
212
    if (!s->seek)
213
        return AVERROR(ENOSYS);
214
    size = s->seek(s->opaque, 0, AVSEEK_SIZE);
215
    if(size<0){
216
        if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
217
            return size;
218
        size++;
219
        s->seek(s->opaque, s->pos, SEEK_SET);
220
    }
221
    return size;
222
}
223

    
224
int url_feof(ByteIOContext *s)
225
{
226
    if(!s)
227
        return 0;
228
    return s->eof_reached;
229
}
230

    
231
int url_ferror(ByteIOContext *s)
232
{
233
    if(!s)
234
        return 0;
235
    return s->error;
236
}
237

    
238
void put_le32(ByteIOContext *s, unsigned int val)
239
{
240
    put_byte(s, val);
241
    put_byte(s, val >> 8);
242
    put_byte(s, val >> 16);
243
    put_byte(s, val >> 24);
244
}
245

    
246
void put_be32(ByteIOContext *s, unsigned int val)
247
{
248
    put_byte(s, val >> 24);
249
    put_byte(s, val >> 16);
250
    put_byte(s, val >> 8);
251
    put_byte(s, val);
252
}
253

    
254
void put_strz(ByteIOContext *s, const char *str)
255
{
256
    if (str)
257
        put_buffer(s, (const unsigned char *) str, strlen(str) + 1);
258
    else
259
        put_byte(s, 0);
260
}
261

    
262
int ff_get_v_length(uint64_t val){
263
    int i=1;
264

    
265
    while(val>>=7)
266
        i++;
267

    
268
    return i;
269
}
270

    
271
void ff_put_v(ByteIOContext *bc, uint64_t val){
272
    int i= ff_get_v_length(val);
273

    
274
    while(--i>0)
275
        put_byte(bc, 128 | (val>>(7*i)));
276

    
277
    put_byte(bc, val&127);
278
}
279

    
280
void put_le64(ByteIOContext *s, uint64_t val)
281
{
282
    put_le32(s, (uint32_t)(val & 0xffffffff));
283
    put_le32(s, (uint32_t)(val >> 32));
284
}
285

    
286
void put_be64(ByteIOContext *s, uint64_t val)
287
{
288
    put_be32(s, (uint32_t)(val >> 32));
289
    put_be32(s, (uint32_t)(val & 0xffffffff));
290
}
291

    
292
void put_le16(ByteIOContext *s, unsigned int val)
293
{
294
    put_byte(s, val);
295
    put_byte(s, val >> 8);
296
}
297

    
298
void put_be16(ByteIOContext *s, unsigned int val)
299
{
300
    put_byte(s, val >> 8);
301
    put_byte(s, val);
302
}
303

    
304
void put_le24(ByteIOContext *s, unsigned int val)
305
{
306
    put_le16(s, val & 0xffff);
307
    put_byte(s, val >> 16);
308
}
309

    
310
void put_be24(ByteIOContext *s, unsigned int val)
311
{
312
    put_be16(s, val >> 8);
313
    put_byte(s, val);
314
}
315

    
316
void put_tag(ByteIOContext *s, const char *tag)
317
{
318
    while (*tag) {
319
        put_byte(s, *tag++);
320
    }
321
}
322

    
323
/* Input stream */
324

    
325
static void fill_buffer(ByteIOContext *s)
326
{
327
    uint8_t *dst= !s->max_packet_size && s->buf_end - s->buffer < s->buffer_size ? s->buf_ptr : s->buffer;
328
    int len= s->buffer_size - (dst - s->buffer);
329
    int max_buffer_size = s->max_packet_size ? s->max_packet_size : IO_BUFFER_SIZE;
330

    
331
    /* no need to do anything if EOF already reached */
332
    if (s->eof_reached)
333
        return;
334

    
335
    if(s->update_checksum && dst == s->buffer){
336
        if(s->buf_end > s->checksum_ptr)
337
            s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
338
        s->checksum_ptr= s->buffer;
339
    }
340

    
341
    /* make buffer smaller in case it ended up large after probing */
342
    if (s->buffer_size > max_buffer_size) {
343
        url_setbufsize(s, max_buffer_size);
344

    
345
        s->checksum_ptr = dst = s->buffer;
346
        len = s->buffer_size;
347
    }
348

    
349
    if(s->read_packet)
350
        len = s->read_packet(s->opaque, dst, len);
351
    else
352
        len = 0;
353
    if (len <= 0) {
354
        /* do not modify buffer if EOF reached so that a seek back can
355
           be done without rereading data */
356
        s->eof_reached = 1;
357
        if(len<0)
358
            s->error= len;
359
    } else {
360
        s->pos += len;
361
        s->buf_ptr = dst;
362
        s->buf_end = dst + len;
363
    }
364
}
365

    
366
unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
367
                                    unsigned int len)
368
{
369
    return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
370
}
371

    
372
unsigned long get_checksum(ByteIOContext *s)
373
{
374
    s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
375
    s->update_checksum= NULL;
376
    return s->checksum;
377
}
378

    
379
void init_checksum(ByteIOContext *s,
380
                   unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
381
                   unsigned long checksum)
382
{
383
    s->update_checksum= update_checksum;
384
    if(s->update_checksum){
385
        s->checksum= checksum;
386
        s->checksum_ptr= s->buf_ptr;
387
    }
388
}
389

    
390
/* XXX: put an inline version */
391
int get_byte(ByteIOContext *s)
392
{
393
    if (s->buf_ptr < s->buf_end) {
394
        return *s->buf_ptr++;
395
    } else {
396
        fill_buffer(s);
397
        if (s->buf_ptr < s->buf_end)
398
            return *s->buf_ptr++;
399
        else
400
            return 0;
401
    }
402
}
403

    
404
int url_fgetc(ByteIOContext *s)
405
{
406
    if (s->buf_ptr < s->buf_end) {
407
        return *s->buf_ptr++;
408
    } else {
409
        fill_buffer(s);
410
        if (s->buf_ptr < s->buf_end)
411
            return *s->buf_ptr++;
412
        else
413
            return URL_EOF;
414
    }
415
}
416

    
417
int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
418
{
419
    int len, size1;
420

    
421
    size1 = size;
422
    while (size > 0) {
423
        len = s->buf_end - s->buf_ptr;
424
        if (len > size)
425
            len = size;
426
        if (len == 0) {
427
            if(size > s->buffer_size && !s->update_checksum){
428
                if(s->read_packet)
429
                    len = s->read_packet(s->opaque, buf, size);
430
                if (len <= 0) {
431
                    /* do not modify buffer if EOF reached so that a seek back can
432
                    be done without rereading data */
433
                    s->eof_reached = 1;
434
                    if(len<0)
435
                        s->error= len;
436
                    break;
437
                } else {
438
                    s->pos += len;
439
                    size -= len;
440
                    buf += len;
441
                    s->buf_ptr = s->buffer;
442
                    s->buf_end = s->buffer/* + len*/;
443
                }
444
            }else{
445
                fill_buffer(s);
446
                len = s->buf_end - s->buf_ptr;
447
                if (len == 0)
448
                    break;
449
            }
450
        } else {
451
            memcpy(buf, s->buf_ptr, len);
452
            buf += len;
453
            s->buf_ptr += len;
454
            size -= len;
455
        }
456
    }
457
    if (size1 == size) {
458
        if (url_ferror(s)) return url_ferror(s);
459
        if (url_feof(s))   return AVERROR_EOF;
460
    }
461
    return size1 - size;
462
}
463

    
464
int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size)
465
{
466
    int len;
467

    
468
    if(size<0)
469
        return -1;
470

    
471
    len = s->buf_end - s->buf_ptr;
472
    if (len == 0) {
473
        fill_buffer(s);
474
        len = s->buf_end - s->buf_ptr;
475
    }
476
    if (len > size)
477
        len = size;
478
    memcpy(buf, s->buf_ptr, len);
479
    s->buf_ptr += len;
480
    if (!len) {
481
        if (url_ferror(s)) return url_ferror(s);
482
        if (url_feof(s))   return AVERROR_EOF;
483
    }
484
    return len;
485
}
486

    
487
unsigned int get_le16(ByteIOContext *s)
488
{
489
    unsigned int val;
490
    val = get_byte(s);
491
    val |= get_byte(s) << 8;
492
    return val;
493
}
494

    
495
unsigned int get_le24(ByteIOContext *s)
496
{
497
    unsigned int val;
498
    val = get_le16(s);
499
    val |= get_byte(s) << 16;
500
    return val;
501
}
502

    
503
unsigned int get_le32(ByteIOContext *s)
504
{
505
    unsigned int val;
506
    val = get_le16(s);
507
    val |= get_le16(s) << 16;
508
    return val;
509
}
510

    
511
uint64_t get_le64(ByteIOContext *s)
512
{
513
    uint64_t val;
514
    val = (uint64_t)get_le32(s);
515
    val |= (uint64_t)get_le32(s) << 32;
516
    return val;
517
}
518

    
519
unsigned int get_be16(ByteIOContext *s)
520
{
521
    unsigned int val;
522
    val = get_byte(s) << 8;
523
    val |= get_byte(s);
524
    return val;
525
}
526

    
527
unsigned int get_be24(ByteIOContext *s)
528
{
529
    unsigned int val;
530
    val = get_be16(s) << 8;
531
    val |= get_byte(s);
532
    return val;
533
}
534
unsigned int get_be32(ByteIOContext *s)
535
{
536
    unsigned int val;
537
    val = get_be16(s) << 16;
538
    val |= get_be16(s);
539
    return val;
540
}
541

    
542
char *get_strz(ByteIOContext *s, char *buf, int maxlen)
543
{
544
    int i = 0;
545
    char c;
546

    
547
    while ((c = get_byte(s))) {
548
        if (i < maxlen-1)
549
            buf[i++] = c;
550
    }
551

    
552
    buf[i] = 0; /* Ensure null terminated, but may be truncated */
553

    
554
    return buf;
555
}
556

    
557
int ff_get_line(ByteIOContext *s, char *buf, int maxlen)
558
{
559
    int i = 0;
560
    char c;
561

    
562
    do {
563
        c = get_byte(s);
564
        if (c && i < maxlen-1)
565
            buf[i++] = c;
566
    } while (c != '\n' && c);
567

    
568
    buf[i] = 0;
569
    return i;
570
}
571

    
572
uint64_t get_be64(ByteIOContext *s)
573
{
574
    uint64_t val;
575
    val = (uint64_t)get_be32(s) << 32;
576
    val |= (uint64_t)get_be32(s);
577
    return val;
578
}
579

    
580
uint64_t ff_get_v(ByteIOContext *bc){
581
    uint64_t val = 0;
582
    int tmp;
583

    
584
    do{
585
        tmp = get_byte(bc);
586
        val= (val<<7) + (tmp&127);
587
    }while(tmp&128);
588
    return val;
589
}
590

    
591
int url_fdopen(ByteIOContext **s, URLContext *h)
592
{
593
    uint8_t *buffer;
594
    int buffer_size, max_packet_size;
595

    
596
    max_packet_size = url_get_max_packet_size(h);
597
    if (max_packet_size) {
598
        buffer_size = max_packet_size; /* no need to bufferize more than one packet */
599
    } else {
600
        buffer_size = IO_BUFFER_SIZE;
601
    }
602
    buffer = av_malloc(buffer_size);
603
    if (!buffer)
604
        return AVERROR(ENOMEM);
605

    
606
    *s = av_mallocz(sizeof(ByteIOContext));
607
    if(!*s) {
608
        av_free(buffer);
609
        return AVERROR(ENOMEM);
610
    }
611

    
612
    if (init_put_byte(*s, buffer, buffer_size,
613
                      (h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
614
                      url_read, url_write, url_seek) < 0) {
615
        av_free(buffer);
616
        av_freep(s);
617
        return AVERROR(EIO);
618
    }
619
    (*s)->is_streamed = h->is_streamed;
620
    (*s)->max_packet_size = max_packet_size;
621
    if(h->prot) {
622
        (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
623
        (*s)->read_seek  = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
624
    }
625
    return 0;
626
}
627

    
628
int url_setbufsize(ByteIOContext *s, int buf_size)
629
{
630
    uint8_t *buffer;
631
    buffer = av_malloc(buf_size);
632
    if (!buffer)
633
        return AVERROR(ENOMEM);
634

    
635
    av_free(s->buffer);
636
    s->buffer = buffer;
637
    s->buffer_size = buf_size;
638
    s->buf_ptr = buffer;
639
    url_resetbuf(s, s->write_flag ? URL_WRONLY : URL_RDONLY);
640
    return 0;
641
}
642

    
643
#if LIBAVFORMAT_VERSION_MAJOR < 53
644
int url_resetbuf(ByteIOContext *s, int flags)
645
#else
646
static int url_resetbuf(ByteIOContext *s, int flags)
647
#endif
648
{
649
#if LIBAVFORMAT_VERSION_MAJOR < 53
650
    if (flags & URL_RDWR)
651
        return AVERROR(EINVAL);
652
#else
653
    assert(flags == URL_WRONLY || flags == URL_RDONLY);
654
#endif
655

    
656
    if (flags & URL_WRONLY) {
657
        s->buf_end = s->buffer + s->buffer_size;
658
        s->write_flag = 1;
659
    } else {
660
        s->buf_end = s->buffer;
661
        s->write_flag = 0;
662
    }
663
    return 0;
664
}
665

    
666
int ff_rewind_with_probe_data(ByteIOContext *s, unsigned char *buf, int buf_size)
667
{
668
    int64_t buffer_start;
669
    int buffer_size;
670
    int overlap, new_size;
671

    
672
    if (s->write_flag)
673
        return AVERROR(EINVAL);
674

    
675
    buffer_size = s->buf_end - s->buffer;
676

    
677
    /* the buffers must touch or overlap */
678
    if ((buffer_start = s->pos - buffer_size) > buf_size)
679
        return AVERROR(EINVAL);
680

    
681
    overlap = buf_size - buffer_start;
682
    new_size = buf_size + buffer_size - overlap;
683

    
684
    if (new_size > buf_size) {
685
        if (!(buf = av_realloc(buf, new_size)))
686
            return AVERROR(ENOMEM);
687

    
688
        memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
689
        buf_size = new_size;
690
    }
691

    
692
    av_free(s->buffer);
693
    s->buf_ptr = s->buffer = buf;
694
    s->pos = s->buffer_size = buf_size;
695
    s->buf_end = s->buf_ptr + buf_size;
696
    s->eof_reached = 0;
697
    s->must_flush = 0;
698

    
699
    return 0;
700
}
701

    
702
int url_fopen(ByteIOContext **s, const char *filename, int flags)
703
{
704
    URLContext *h;
705
    int err;
706

    
707
    err = url_open(&h, filename, flags);
708
    if (err < 0)
709
        return err;
710
    err = url_fdopen(s, h);
711
    if (err < 0) {
712
        url_close(h);
713
        return err;
714
    }
715
    return 0;
716
}
717

    
718
int url_fclose(ByteIOContext *s)
719
{
720
    URLContext *h = s->opaque;
721

    
722
    av_free(s->buffer);
723
    av_free(s);
724
    return url_close(h);
725
}
726

    
727
URLContext *url_fileno(ByteIOContext *s)
728
{
729
    return s->opaque;
730
}
731

    
732
#if CONFIG_MUXERS
733
int url_fprintf(ByteIOContext *s, const char *fmt, ...)
734
{
735
    va_list ap;
736
    char buf[4096];
737
    int ret;
738

    
739
    va_start(ap, fmt);
740
    ret = vsnprintf(buf, sizeof(buf), fmt, ap);
741
    va_end(ap);
742
    put_buffer(s, buf, strlen(buf));
743
    return ret;
744
}
745
#endif //CONFIG_MUXERS
746

    
747
char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
748
{
749
    int c;
750
    char *q;
751

    
752
    c = url_fgetc(s);
753
    if (c == EOF)
754
        return NULL;
755
    q = buf;
756
    for(;;) {
757
        if (c == EOF || c == '\n')
758
            break;
759
        if ((q - buf) < buf_size - 1)
760
            *q++ = c;
761
        c = url_fgetc(s);
762
    }
763
    if (buf_size > 0)
764
        *q = '\0';
765
    return buf;
766
}
767

    
768
int url_fget_max_packet_size(ByteIOContext *s)
769
{
770
    return s->max_packet_size;
771
}
772

    
773
int av_url_read_fpause(ByteIOContext *s, int pause)
774
{
775
    if (!s->read_pause)
776
        return AVERROR(ENOSYS);
777
    return s->read_pause(s->opaque, pause);
778
}
779

    
780
int64_t av_url_read_fseek(ByteIOContext *s, int stream_index,
781
                          int64_t timestamp, int flags)
782
{
783
    URLContext *h = s->opaque;
784
    int64_t ret;
785
    if (!s->read_seek)
786
        return AVERROR(ENOSYS);
787
    ret = s->read_seek(h, stream_index, timestamp, flags);
788
    if(ret >= 0) {
789
        int64_t pos;
790
        s->buf_ptr = s->buf_end; // Flush buffer
791
        pos = s->seek(h, 0, SEEK_CUR);
792
        if (pos >= 0)
793
            s->pos = pos;
794
        else if (pos != AVERROR(ENOSYS))
795
            ret = pos;
796
    }
797
    return ret;
798
}
799

    
800
/* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
801
 * back to the server even if CONFIG_MUXERS is false. */
802
#if CONFIG_MUXERS || CONFIG_NETWORK
803
/* buffer handling */
804
int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags)
805
{
806
    int ret;
807
    *s = av_mallocz(sizeof(ByteIOContext));
808
    if(!*s)
809
        return AVERROR(ENOMEM);
810
    ret = init_put_byte(*s, buf, buf_size,
811
                        (flags & URL_WRONLY || flags & URL_RDWR),
812
                        NULL, NULL, NULL, NULL);
813
    if(ret != 0)
814
        av_freep(s);
815
    return ret;
816
}
817

    
818
int url_close_buf(ByteIOContext *s)
819
{
820
    put_flush_packet(s);
821
    return s->buf_ptr - s->buffer;
822
}
823

    
824
/* output in a dynamic buffer */
825

    
826
typedef struct DynBuffer {
827
    int pos, size, allocated_size;
828
    uint8_t *buffer;
829
    int io_buffer_size;
830
    uint8_t io_buffer[1];
831
} DynBuffer;
832

    
833
static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
834
{
835
    DynBuffer *d = opaque;
836
    unsigned new_size, new_allocated_size;
837

    
838
    /* reallocate buffer if needed */
839
    new_size = d->pos + buf_size;
840
    new_allocated_size = d->allocated_size;
841
    if(new_size < d->pos || new_size > INT_MAX/2)
842
        return -1;
843
    while (new_size > new_allocated_size) {
844
        if (!new_allocated_size)
845
            new_allocated_size = new_size;
846
        else
847
            new_allocated_size += new_allocated_size / 2 + 1;
848
    }
849

    
850
    if (new_allocated_size > d->allocated_size) {
851
        d->buffer = av_realloc(d->buffer, new_allocated_size);
852
        if(d->buffer == NULL)
853
             return AVERROR(ENOMEM);
854
        d->allocated_size = new_allocated_size;
855
    }
856
    memcpy(d->buffer + d->pos, buf, buf_size);
857
    d->pos = new_size;
858
    if (d->pos > d->size)
859
        d->size = d->pos;
860
    return buf_size;
861
}
862

    
863
static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
864
{
865
    unsigned char buf1[4];
866
    int ret;
867

    
868
    /* packetized write: output the header */
869
    AV_WB32(buf1, buf_size);
870
    ret= dyn_buf_write(opaque, buf1, 4);
871
    if(ret < 0)
872
        return ret;
873

    
874
    /* then the data */
875
    return dyn_buf_write(opaque, buf, buf_size);
876
}
877

    
878
static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
879
{
880
    DynBuffer *d = opaque;
881

    
882
    if (whence == SEEK_CUR)
883
        offset += d->pos;
884
    else if (whence == SEEK_END)
885
        offset += d->size;
886
    if (offset < 0 || offset > 0x7fffffffLL)
887
        return -1;
888
    d->pos = offset;
889
    return 0;
890
}
891

    
892
static int url_open_dyn_buf_internal(ByteIOContext **s, int max_packet_size)
893
{
894
    DynBuffer *d;
895
    int ret;
896
    unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
897

    
898
    if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
899
        return -1;
900
    d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
901
    if (!d)
902
        return AVERROR(ENOMEM);
903
    *s = av_mallocz(sizeof(ByteIOContext));
904
    if(!*s) {
905
        av_free(d);
906
        return AVERROR(ENOMEM);
907
    }
908
    d->io_buffer_size = io_buffer_size;
909
    ret = init_put_byte(*s, d->io_buffer, io_buffer_size,
910
                        1, d, NULL,
911
                        max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
912
                        max_packet_size ? NULL : dyn_buf_seek);
913
    if (ret == 0) {
914
        (*s)->max_packet_size = max_packet_size;
915
    } else {
916
        av_free(d);
917
        av_freep(s);
918
    }
919
    return ret;
920
}
921

    
922
int url_open_dyn_buf(ByteIOContext **s)
923
{
924
    return url_open_dyn_buf_internal(s, 0);
925
}
926

    
927
int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size)
928
{
929
    if (max_packet_size <= 0)
930
        return -1;
931
    return url_open_dyn_buf_internal(s, max_packet_size);
932
}
933

    
934
int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
935
{
936
    DynBuffer *d = s->opaque;
937
    int size;
938
    static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
939
    int padding = 0;
940

    
941
    /* don't attempt to pad fixed-size packet buffers */
942
    if (!s->max_packet_size) {
943
        put_buffer(s, padbuf, sizeof(padbuf));
944
        padding = FF_INPUT_BUFFER_PADDING_SIZE;
945
    }
946

    
947
    put_flush_packet(s);
948

    
949
    *pbuffer = d->buffer;
950
    size = d->size;
951
    av_free(d);
952
    av_free(s);
953
    return size - padding;
954
}
955
#endif /* CONFIG_MUXERS || CONFIG_NETWORK */