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ffmpeg / libavformat / aviobuf.c @ 364cacc7

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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 !FF_API_URL_RESETBUF
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
        fill_buffer(s);
395
    if (s->buf_ptr < s->buf_end)
396
        return *s->buf_ptr++;
397
    return 0;
398
}
399

    
400
int url_fgetc(ByteIOContext *s)
401
{
402
    if (s->buf_ptr >= s->buf_end)
403
        fill_buffer(s);
404
    if (s->buf_ptr < s->buf_end)
405
        return *s->buf_ptr++;
406
    return URL_EOF;
407
}
408

    
409
int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
410
{
411
    int len, size1;
412

    
413
    size1 = size;
414
    while (size > 0) {
415
        len = s->buf_end - s->buf_ptr;
416
        if (len > size)
417
            len = size;
418
        if (len == 0) {
419
            if(size > s->buffer_size && !s->update_checksum){
420
                if(s->read_packet)
421
                    len = s->read_packet(s->opaque, buf, size);
422
                if (len <= 0) {
423
                    /* do not modify buffer if EOF reached so that a seek back can
424
                    be done without rereading data */
425
                    s->eof_reached = 1;
426
                    if(len<0)
427
                        s->error= len;
428
                    break;
429
                } else {
430
                    s->pos += len;
431
                    size -= len;
432
                    buf += len;
433
                    s->buf_ptr = s->buffer;
434
                    s->buf_end = s->buffer/* + len*/;
435
                }
436
            }else{
437
                fill_buffer(s);
438
                len = s->buf_end - s->buf_ptr;
439
                if (len == 0)
440
                    break;
441
            }
442
        } else {
443
            memcpy(buf, s->buf_ptr, len);
444
            buf += len;
445
            s->buf_ptr += len;
446
            size -= len;
447
        }
448
    }
449
    if (size1 == size) {
450
        if (url_ferror(s)) return url_ferror(s);
451
        if (url_feof(s))   return AVERROR_EOF;
452
    }
453
    return size1 - size;
454
}
455

    
456
int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size)
457
{
458
    int len;
459

    
460
    if(size<0)
461
        return -1;
462

    
463
    len = s->buf_end - s->buf_ptr;
464
    if (len == 0) {
465
        fill_buffer(s);
466
        len = s->buf_end - s->buf_ptr;
467
    }
468
    if (len > size)
469
        len = size;
470
    memcpy(buf, s->buf_ptr, len);
471
    s->buf_ptr += len;
472
    if (!len) {
473
        if (url_ferror(s)) return url_ferror(s);
474
        if (url_feof(s))   return AVERROR_EOF;
475
    }
476
    return len;
477
}
478

    
479
unsigned int get_le16(ByteIOContext *s)
480
{
481
    unsigned int val;
482
    val = get_byte(s);
483
    val |= get_byte(s) << 8;
484
    return val;
485
}
486

    
487
unsigned int get_le24(ByteIOContext *s)
488
{
489
    unsigned int val;
490
    val = get_le16(s);
491
    val |= get_byte(s) << 16;
492
    return val;
493
}
494

    
495
unsigned int get_le32(ByteIOContext *s)
496
{
497
    unsigned int val;
498
    val = get_le16(s);
499
    val |= get_le16(s) << 16;
500
    return val;
501
}
502

    
503
uint64_t get_le64(ByteIOContext *s)
504
{
505
    uint64_t val;
506
    val = (uint64_t)get_le32(s);
507
    val |= (uint64_t)get_le32(s) << 32;
508
    return val;
509
}
510

    
511
unsigned int get_be16(ByteIOContext *s)
512
{
513
    unsigned int val;
514
    val = get_byte(s) << 8;
515
    val |= get_byte(s);
516
    return val;
517
}
518

    
519
unsigned int get_be24(ByteIOContext *s)
520
{
521
    unsigned int val;
522
    val = get_be16(s) << 8;
523
    val |= get_byte(s);
524
    return val;
525
}
526
unsigned int get_be32(ByteIOContext *s)
527
{
528
    unsigned int val;
529
    val = get_be16(s) << 16;
530
    val |= get_be16(s);
531
    return val;
532
}
533

    
534
char *get_strz(ByteIOContext *s, char *buf, int maxlen)
535
{
536
    int i = 0;
537
    char c;
538

    
539
    while ((c = get_byte(s))) {
540
        if (i < maxlen-1)
541
            buf[i++] = c;
542
    }
543

    
544
    buf[i] = 0; /* Ensure null terminated, but may be truncated */
545

    
546
    return buf;
547
}
548

    
549
int ff_get_line(ByteIOContext *s, char *buf, int maxlen)
550
{
551
    int i = 0;
552
    char c;
553

    
554
    do {
555
        c = get_byte(s);
556
        if (c && i < maxlen-1)
557
            buf[i++] = c;
558
    } while (c != '\n' && c);
559

    
560
    buf[i] = 0;
561
    return i;
562
}
563

    
564
uint64_t get_be64(ByteIOContext *s)
565
{
566
    uint64_t val;
567
    val = (uint64_t)get_be32(s) << 32;
568
    val |= (uint64_t)get_be32(s);
569
    return val;
570
}
571

    
572
uint64_t ff_get_v(ByteIOContext *bc){
573
    uint64_t val = 0;
574
    int tmp;
575

    
576
    do{
577
        tmp = get_byte(bc);
578
        val= (val<<7) + (tmp&127);
579
    }while(tmp&128);
580
    return val;
581
}
582

    
583
int url_fdopen(ByteIOContext **s, URLContext *h)
584
{
585
    uint8_t *buffer;
586
    int buffer_size, max_packet_size;
587

    
588
    max_packet_size = url_get_max_packet_size(h);
589
    if (max_packet_size) {
590
        buffer_size = max_packet_size; /* no need to bufferize more than one packet */
591
    } else {
592
        buffer_size = IO_BUFFER_SIZE;
593
    }
594
    buffer = av_malloc(buffer_size);
595
    if (!buffer)
596
        return AVERROR(ENOMEM);
597

    
598
    *s = av_mallocz(sizeof(ByteIOContext));
599
    if(!*s) {
600
        av_free(buffer);
601
        return AVERROR(ENOMEM);
602
    }
603

    
604
    if (init_put_byte(*s, buffer, buffer_size,
605
                      (h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
606
                      url_read, url_write, url_seek) < 0) {
607
        av_free(buffer);
608
        av_freep(s);
609
        return AVERROR(EIO);
610
    }
611
    (*s)->is_streamed = h->is_streamed;
612
    (*s)->max_packet_size = max_packet_size;
613
    if(h->prot) {
614
        (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
615
        (*s)->read_seek  = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
616
    }
617
    return 0;
618
}
619

    
620
int url_setbufsize(ByteIOContext *s, int buf_size)
621
{
622
    uint8_t *buffer;
623
    buffer = av_malloc(buf_size);
624
    if (!buffer)
625
        return AVERROR(ENOMEM);
626

    
627
    av_free(s->buffer);
628
    s->buffer = buffer;
629
    s->buffer_size = buf_size;
630
    s->buf_ptr = buffer;
631
    url_resetbuf(s, s->write_flag ? URL_WRONLY : URL_RDONLY);
632
    return 0;
633
}
634

    
635
#if FF_API_URL_RESETBUF
636
int url_resetbuf(ByteIOContext *s, int flags)
637
#else
638
static int url_resetbuf(ByteIOContext *s, int flags)
639
#endif
640
{
641
#if FF_API_URL_RESETBUF
642
    if (flags & URL_RDWR)
643
        return AVERROR(EINVAL);
644
#else
645
    assert(flags == URL_WRONLY || flags == URL_RDONLY);
646
#endif
647

    
648
    if (flags & URL_WRONLY) {
649
        s->buf_end = s->buffer + s->buffer_size;
650
        s->write_flag = 1;
651
    } else {
652
        s->buf_end = s->buffer;
653
        s->write_flag = 0;
654
    }
655
    return 0;
656
}
657

    
658
int ff_rewind_with_probe_data(ByteIOContext *s, unsigned char *buf, int buf_size)
659
{
660
    int64_t buffer_start;
661
    int buffer_size;
662
    int overlap, new_size, alloc_size;
663

    
664
    if (s->write_flag)
665
        return AVERROR(EINVAL);
666

    
667
    buffer_size = s->buf_end - s->buffer;
668

    
669
    /* the buffers must touch or overlap */
670
    if ((buffer_start = s->pos - buffer_size) > buf_size)
671
        return AVERROR(EINVAL);
672

    
673
    overlap = buf_size - buffer_start;
674
    new_size = buf_size + buffer_size - overlap;
675

    
676
    alloc_size = FFMAX(s->buffer_size, new_size);
677
    if (alloc_size > buf_size)
678
        if (!(buf = av_realloc(buf, alloc_size)))
679
            return AVERROR(ENOMEM);
680

    
681
    if (new_size > buf_size) {
682
        memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
683
        buf_size = new_size;
684
    }
685

    
686
    av_free(s->buffer);
687
    s->buf_ptr = s->buffer = buf;
688
    s->buffer_size = alloc_size;
689
    s->pos = buf_size;
690
    s->buf_end = s->buf_ptr + buf_size;
691
    s->eof_reached = 0;
692
    s->must_flush = 0;
693

    
694
    return 0;
695
}
696

    
697
int url_fopen(ByteIOContext **s, const char *filename, int flags)
698
{
699
    URLContext *h;
700
    int err;
701

    
702
    err = url_open(&h, filename, flags);
703
    if (err < 0)
704
        return err;
705
    err = url_fdopen(s, h);
706
    if (err < 0) {
707
        url_close(h);
708
        return err;
709
    }
710
    return 0;
711
}
712

    
713
int url_fclose(ByteIOContext *s)
714
{
715
    URLContext *h = s->opaque;
716

    
717
    av_free(s->buffer);
718
    av_free(s);
719
    return url_close(h);
720
}
721

    
722
URLContext *url_fileno(ByteIOContext *s)
723
{
724
    return s->opaque;
725
}
726

    
727
#if CONFIG_MUXERS
728
int url_fprintf(ByteIOContext *s, const char *fmt, ...)
729
{
730
    va_list ap;
731
    char buf[4096];
732
    int ret;
733

    
734
    va_start(ap, fmt);
735
    ret = vsnprintf(buf, sizeof(buf), fmt, ap);
736
    va_end(ap);
737
    put_buffer(s, buf, strlen(buf));
738
    return ret;
739
}
740
#endif //CONFIG_MUXERS
741

    
742
char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
743
{
744
    int c;
745
    char *q;
746

    
747
    c = url_fgetc(s);
748
    if (c == EOF)
749
        return NULL;
750
    q = buf;
751
    for(;;) {
752
        if (c == EOF || c == '\n')
753
            break;
754
        if ((q - buf) < buf_size - 1)
755
            *q++ = c;
756
        c = url_fgetc(s);
757
    }
758
    if (buf_size > 0)
759
        *q = '\0';
760
    return buf;
761
}
762

    
763
int url_fget_max_packet_size(ByteIOContext *s)
764
{
765
    return s->max_packet_size;
766
}
767

    
768
int av_url_read_fpause(ByteIOContext *s, int pause)
769
{
770
    if (!s->read_pause)
771
        return AVERROR(ENOSYS);
772
    return s->read_pause(s->opaque, pause);
773
}
774

    
775
int64_t av_url_read_fseek(ByteIOContext *s, int stream_index,
776
                          int64_t timestamp, int flags)
777
{
778
    URLContext *h = s->opaque;
779
    int64_t ret;
780
    if (!s->read_seek)
781
        return AVERROR(ENOSYS);
782
    ret = s->read_seek(h, stream_index, timestamp, flags);
783
    if(ret >= 0) {
784
        int64_t pos;
785
        s->buf_ptr = s->buf_end; // Flush buffer
786
        pos = s->seek(h, 0, SEEK_CUR);
787
        if (pos >= 0)
788
            s->pos = pos;
789
        else if (pos != AVERROR(ENOSYS))
790
            ret = pos;
791
    }
792
    return ret;
793
}
794

    
795
/* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
796
 * back to the server even if CONFIG_MUXERS is false. */
797
#if CONFIG_MUXERS || CONFIG_NETWORK
798
/* buffer handling */
799
int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags)
800
{
801
    int ret;
802
    *s = av_mallocz(sizeof(ByteIOContext));
803
    if(!*s)
804
        return AVERROR(ENOMEM);
805
    ret = init_put_byte(*s, buf, buf_size,
806
                        (flags & URL_WRONLY || flags & URL_RDWR),
807
                        NULL, NULL, NULL, NULL);
808
    if(ret != 0)
809
        av_freep(s);
810
    return ret;
811
}
812

    
813
int url_close_buf(ByteIOContext *s)
814
{
815
    put_flush_packet(s);
816
    return s->buf_ptr - s->buffer;
817
}
818

    
819
/* output in a dynamic buffer */
820

    
821
typedef struct DynBuffer {
822
    int pos, size, allocated_size;
823
    uint8_t *buffer;
824
    int io_buffer_size;
825
    uint8_t io_buffer[1];
826
} DynBuffer;
827

    
828
static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
829
{
830
    DynBuffer *d = opaque;
831
    unsigned new_size, new_allocated_size;
832

    
833
    /* reallocate buffer if needed */
834
    new_size = d->pos + buf_size;
835
    new_allocated_size = d->allocated_size;
836
    if(new_size < d->pos || new_size > INT_MAX/2)
837
        return -1;
838
    while (new_size > new_allocated_size) {
839
        if (!new_allocated_size)
840
            new_allocated_size = new_size;
841
        else
842
            new_allocated_size += new_allocated_size / 2 + 1;
843
    }
844

    
845
    if (new_allocated_size > d->allocated_size) {
846
        d->buffer = av_realloc(d->buffer, new_allocated_size);
847
        if(d->buffer == NULL)
848
             return AVERROR(ENOMEM);
849
        d->allocated_size = new_allocated_size;
850
    }
851
    memcpy(d->buffer + d->pos, buf, buf_size);
852
    d->pos = new_size;
853
    if (d->pos > d->size)
854
        d->size = d->pos;
855
    return buf_size;
856
}
857

    
858
static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
859
{
860
    unsigned char buf1[4];
861
    int ret;
862

    
863
    /* packetized write: output the header */
864
    AV_WB32(buf1, buf_size);
865
    ret= dyn_buf_write(opaque, buf1, 4);
866
    if(ret < 0)
867
        return ret;
868

    
869
    /* then the data */
870
    return dyn_buf_write(opaque, buf, buf_size);
871
}
872

    
873
static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
874
{
875
    DynBuffer *d = opaque;
876

    
877
    if (whence == SEEK_CUR)
878
        offset += d->pos;
879
    else if (whence == SEEK_END)
880
        offset += d->size;
881
    if (offset < 0 || offset > 0x7fffffffLL)
882
        return -1;
883
    d->pos = offset;
884
    return 0;
885
}
886

    
887
static int url_open_dyn_buf_internal(ByteIOContext **s, int max_packet_size)
888
{
889
    DynBuffer *d;
890
    int ret;
891
    unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
892

    
893
    if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
894
        return -1;
895
    d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
896
    if (!d)
897
        return AVERROR(ENOMEM);
898
    *s = av_mallocz(sizeof(ByteIOContext));
899
    if(!*s) {
900
        av_free(d);
901
        return AVERROR(ENOMEM);
902
    }
903
    d->io_buffer_size = io_buffer_size;
904
    ret = init_put_byte(*s, d->io_buffer, io_buffer_size,
905
                        1, d, NULL,
906
                        max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
907
                        max_packet_size ? NULL : dyn_buf_seek);
908
    if (ret == 0) {
909
        (*s)->max_packet_size = max_packet_size;
910
    } else {
911
        av_free(d);
912
        av_freep(s);
913
    }
914
    return ret;
915
}
916

    
917
int url_open_dyn_buf(ByteIOContext **s)
918
{
919
    return url_open_dyn_buf_internal(s, 0);
920
}
921

    
922
int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size)
923
{
924
    if (max_packet_size <= 0)
925
        return -1;
926
    return url_open_dyn_buf_internal(s, max_packet_size);
927
}
928

    
929
int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
930
{
931
    DynBuffer *d = s->opaque;
932
    int size;
933
    static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
934
    int padding = 0;
935

    
936
    /* don't attempt to pad fixed-size packet buffers */
937
    if (!s->max_packet_size) {
938
        put_buffer(s, padbuf, sizeof(padbuf));
939
        padding = FF_INPUT_BUFFER_PADDING_SIZE;
940
    }
941

    
942
    put_flush_packet(s);
943

    
944
    *pbuffer = d->buffer;
945
    size = d->size;
946
    av_free(d);
947
    av_free(s);
948
    return size - padding;
949
}
950
#endif /* CONFIG_MUXERS || CONFIG_NETWORK */