Statistics
| Branch: | Revision:

ffmpeg / libavformat / aviobuf.c @ 7c892951

History | View | Annotate | Download (22.8 KB)

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
void 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 (i < maxlen-1)
565
            buf[i++] = c;
566
    } while (c != '\n' && c);
567

    
568
    buf[i] = 0;
569
}
570

    
571
uint64_t get_be64(ByteIOContext *s)
572
{
573
    uint64_t val;
574
    val = (uint64_t)get_be32(s) << 32;
575
    val |= (uint64_t)get_be32(s);
576
    return val;
577
}
578

    
579
uint64_t ff_get_v(ByteIOContext *bc){
580
    uint64_t val = 0;
581
    int tmp;
582

    
583
    do{
584
        tmp = get_byte(bc);
585
        val= (val<<7) + (tmp&127);
586
    }while(tmp&128);
587
    return val;
588
}
589

    
590
int url_fdopen(ByteIOContext **s, URLContext *h)
591
{
592
    uint8_t *buffer;
593
    int buffer_size, max_packet_size;
594

    
595
    max_packet_size = url_get_max_packet_size(h);
596
    if (max_packet_size) {
597
        buffer_size = max_packet_size; /* no need to bufferize more than one packet */
598
    } else {
599
        buffer_size = IO_BUFFER_SIZE;
600
    }
601
    buffer = av_malloc(buffer_size);
602
    if (!buffer)
603
        return AVERROR(ENOMEM);
604

    
605
    *s = av_mallocz(sizeof(ByteIOContext));
606
    if(!*s) {
607
        av_free(buffer);
608
        return AVERROR(ENOMEM);
609
    }
610

    
611
    if (init_put_byte(*s, buffer, buffer_size,
612
                      (h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
613
                      url_read, url_write, url_seek) < 0) {
614
        av_free(buffer);
615
        av_freep(s);
616
        return AVERROR(EIO);
617
    }
618
    (*s)->is_streamed = h->is_streamed;
619
    (*s)->max_packet_size = max_packet_size;
620
    if(h->prot) {
621
        (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
622
        (*s)->read_seek  = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
623
    }
624
    return 0;
625
}
626

    
627
int url_setbufsize(ByteIOContext *s, int buf_size)
628
{
629
    uint8_t *buffer;
630
    buffer = av_malloc(buf_size);
631
    if (!buffer)
632
        return AVERROR(ENOMEM);
633

    
634
    av_free(s->buffer);
635
    s->buffer = buffer;
636
    s->buffer_size = buf_size;
637
    s->buf_ptr = buffer;
638
    url_resetbuf(s, s->write_flag ? URL_WRONLY : URL_RDONLY);
639
    return 0;
640
}
641

    
642
#if LIBAVFORMAT_VERSION_MAJOR < 53
643
int url_resetbuf(ByteIOContext *s, int flags)
644
#else
645
static int url_resetbuf(ByteIOContext *s, int flags)
646
#endif
647
{
648
#if LIBAVFORMAT_VERSION_MAJOR < 53
649
    if (flags & URL_RDWR)
650
        return AVERROR(EINVAL);
651
#else
652
    assert(flags == URL_WRONLY || flags == URL_RDONLY);
653
#endif
654

    
655
    if (flags & URL_WRONLY) {
656
        s->buf_end = s->buffer + s->buffer_size;
657
        s->write_flag = 1;
658
    } else {
659
        s->buf_end = s->buffer;
660
        s->write_flag = 0;
661
    }
662
    return 0;
663
}
664

    
665
int ff_rewind_with_probe_data(ByteIOContext *s, unsigned char *buf, int buf_size)
666
{
667
    int64_t buffer_start;
668
    int buffer_size;
669
    int overlap, new_size;
670

    
671
    if (s->write_flag)
672
        return AVERROR(EINVAL);
673

    
674
    buffer_size = s->buf_end - s->buffer;
675

    
676
    /* the buffers must touch or overlap */
677
    if ((buffer_start = s->pos - buffer_size) > buf_size)
678
        return AVERROR(EINVAL);
679

    
680
    overlap = buf_size - buffer_start;
681
    new_size = buf_size + buffer_size - overlap;
682

    
683
    if (new_size > buf_size) {
684
        if (!(buf = av_realloc(buf, new_size)))
685
            return AVERROR(ENOMEM);
686

    
687
        memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
688
        buf_size = new_size;
689
    }
690

    
691
    av_free(s->buffer);
692
    s->buf_ptr = s->buffer = buf;
693
    s->pos = s->buffer_size = buf_size;
694
    s->buf_end = s->buf_ptr + buf_size;
695
    s->eof_reached = 0;
696
    s->must_flush = 0;
697

    
698
    return 0;
699
}
700

    
701
int url_fopen(ByteIOContext **s, const char *filename, int flags)
702
{
703
    URLContext *h;
704
    int err;
705

    
706
    err = url_open(&h, filename, flags);
707
    if (err < 0)
708
        return err;
709
    err = url_fdopen(s, h);
710
    if (err < 0) {
711
        url_close(h);
712
        return err;
713
    }
714
    return 0;
715
}
716

    
717
int url_fclose(ByteIOContext *s)
718
{
719
    URLContext *h = s->opaque;
720

    
721
    av_free(s->buffer);
722
    av_free(s);
723
    return url_close(h);
724
}
725

    
726
URLContext *url_fileno(ByteIOContext *s)
727
{
728
    return s->opaque;
729
}
730

    
731
#if CONFIG_MUXERS
732
int url_fprintf(ByteIOContext *s, const char *fmt, ...)
733
{
734
    va_list ap;
735
    char buf[4096];
736
    int ret;
737

    
738
    va_start(ap, fmt);
739
    ret = vsnprintf(buf, sizeof(buf), fmt, ap);
740
    va_end(ap);
741
    put_buffer(s, buf, strlen(buf));
742
    return ret;
743
}
744
#endif //CONFIG_MUXERS
745

    
746
char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
747
{
748
    int c;
749
    char *q;
750

    
751
    c = url_fgetc(s);
752
    if (c == EOF)
753
        return NULL;
754
    q = buf;
755
    for(;;) {
756
        if (c == EOF || c == '\n')
757
            break;
758
        if ((q - buf) < buf_size - 1)
759
            *q++ = c;
760
        c = url_fgetc(s);
761
    }
762
    if (buf_size > 0)
763
        *q = '\0';
764
    return buf;
765
}
766

    
767
int url_fget_max_packet_size(ByteIOContext *s)
768
{
769
    return s->max_packet_size;
770
}
771

    
772
int av_url_read_fpause(ByteIOContext *s, int pause)
773
{
774
    if (!s->read_pause)
775
        return AVERROR(ENOSYS);
776
    return s->read_pause(s->opaque, pause);
777
}
778

    
779
int64_t av_url_read_fseek(ByteIOContext *s, int stream_index,
780
                          int64_t timestamp, int flags)
781
{
782
    URLContext *h = s->opaque;
783
    int64_t ret;
784
    if (!s->read_seek)
785
        return AVERROR(ENOSYS);
786
    ret = s->read_seek(h, stream_index, timestamp, flags);
787
    if(ret >= 0) {
788
        int64_t pos;
789
        s->buf_ptr = s->buf_end; // Flush buffer
790
        pos = s->seek(h, 0, SEEK_CUR);
791
        if (pos >= 0)
792
            s->pos = pos;
793
        else if (pos != AVERROR(ENOSYS))
794
            ret = pos;
795
    }
796
    return ret;
797
}
798

    
799
/* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
800
 * back to the server even if CONFIG_MUXERS is false. */
801
#if CONFIG_MUXERS || CONFIG_NETWORK
802
/* buffer handling */
803
int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags)
804
{
805
    int ret;
806
    *s = av_mallocz(sizeof(ByteIOContext));
807
    if(!*s)
808
        return AVERROR(ENOMEM);
809
    ret = init_put_byte(*s, buf, buf_size,
810
                        (flags & URL_WRONLY || flags & URL_RDWR),
811
                        NULL, NULL, NULL, NULL);
812
    if(ret != 0)
813
        av_freep(s);
814
    return ret;
815
}
816

    
817
int url_close_buf(ByteIOContext *s)
818
{
819
    put_flush_packet(s);
820
    return s->buf_ptr - s->buffer;
821
}
822

    
823
/* output in a dynamic buffer */
824

    
825
typedef struct DynBuffer {
826
    int pos, size, allocated_size;
827
    uint8_t *buffer;
828
    int io_buffer_size;
829
    uint8_t io_buffer[1];
830
} DynBuffer;
831

    
832
static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
833
{
834
    DynBuffer *d = opaque;
835
    unsigned new_size, new_allocated_size;
836

    
837
    /* reallocate buffer if needed */
838
    new_size = d->pos + buf_size;
839
    new_allocated_size = d->allocated_size;
840
    if(new_size < d->pos || new_size > INT_MAX/2)
841
        return -1;
842
    while (new_size > new_allocated_size) {
843
        if (!new_allocated_size)
844
            new_allocated_size = new_size;
845
        else
846
            new_allocated_size += new_allocated_size / 2 + 1;
847
    }
848

    
849
    if (new_allocated_size > d->allocated_size) {
850
        d->buffer = av_realloc(d->buffer, new_allocated_size);
851
        if(d->buffer == NULL)
852
             return AVERROR(ENOMEM);
853
        d->allocated_size = new_allocated_size;
854
    }
855
    memcpy(d->buffer + d->pos, buf, buf_size);
856
    d->pos = new_size;
857
    if (d->pos > d->size)
858
        d->size = d->pos;
859
    return buf_size;
860
}
861

    
862
static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
863
{
864
    unsigned char buf1[4];
865
    int ret;
866

    
867
    /* packetized write: output the header */
868
    AV_WB32(buf1, buf_size);
869
    ret= dyn_buf_write(opaque, buf1, 4);
870
    if(ret < 0)
871
        return ret;
872

    
873
    /* then the data */
874
    return dyn_buf_write(opaque, buf, buf_size);
875
}
876

    
877
static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
878
{
879
    DynBuffer *d = opaque;
880

    
881
    if (whence == SEEK_CUR)
882
        offset += d->pos;
883
    else if (whence == SEEK_END)
884
        offset += d->size;
885
    if (offset < 0 || offset > 0x7fffffffLL)
886
        return -1;
887
    d->pos = offset;
888
    return 0;
889
}
890

    
891
static int url_open_dyn_buf_internal(ByteIOContext **s, int max_packet_size)
892
{
893
    DynBuffer *d;
894
    int ret;
895
    unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
896

    
897
    if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
898
        return -1;
899
    d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
900
    if (!d)
901
        return AVERROR(ENOMEM);
902
    *s = av_mallocz(sizeof(ByteIOContext));
903
    if(!*s) {
904
        av_free(d);
905
        return AVERROR(ENOMEM);
906
    }
907
    d->io_buffer_size = io_buffer_size;
908
    ret = init_put_byte(*s, d->io_buffer, io_buffer_size,
909
                        1, d, NULL,
910
                        max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
911
                        max_packet_size ? NULL : dyn_buf_seek);
912
    if (ret == 0) {
913
        (*s)->max_packet_size = max_packet_size;
914
    } else {
915
        av_free(d);
916
        av_freep(s);
917
    }
918
    return ret;
919
}
920

    
921
int url_open_dyn_buf(ByteIOContext **s)
922
{
923
    return url_open_dyn_buf_internal(s, 0);
924
}
925

    
926
int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size)
927
{
928
    if (max_packet_size <= 0)
929
        return -1;
930
    return url_open_dyn_buf_internal(s, max_packet_size);
931
}
932

    
933
int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
934
{
935
    DynBuffer *d = s->opaque;
936
    int size;
937
    static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
938
    int padding = 0;
939

    
940
    /* don't attempt to pad fixed-size packet buffers */
941
    if (!s->max_packet_size) {
942
        put_buffer(s, padbuf, sizeof(padbuf));
943
        padding = FF_INPUT_BUFFER_PADDING_SIZE;
944
    }
945

    
946
    put_flush_packet(s);
947

    
948
    *pbuffer = d->buffer;
949
    size = d->size;
950
    av_free(d);
951
    av_free(s);
952
    return size - padding;
953
}
954
#endif /* CONFIG_MUXERS || CONFIG_NETWORK */