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ffmpeg / libavformat / aviobuf.c @ 7939d0ed

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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
    assert(s->buf_ptr == s->buf_end);
332

    
333
    /* no need to do anything if EOF already reached */
334
    if (s->eof_reached)
335
        return;
336

    
337
    if(s->update_checksum && dst == s->buffer){
338
        if(s->buf_end > s->checksum_ptr)
339
            s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
340
        s->checksum_ptr= s->buffer;
341
    }
342

    
343
    /* make buffer smaller in case it ended up large after probing */
344
    if (s->buffer_size > max_buffer_size) {
345
        url_setbufsize(s, max_buffer_size);
346

    
347
        s->checksum_ptr = dst = s->buffer;
348
        len = s->buffer_size;
349
    }
350

    
351
    if(s->read_packet)
352
        len = s->read_packet(s->opaque, dst, len);
353
    else
354
        len = 0;
355
    if (len <= 0) {
356
        /* do not modify buffer if EOF reached so that a seek back can
357
           be done without rereading data */
358
        s->eof_reached = 1;
359
        if(len<0)
360
            s->error= len;
361
    } else {
362
        s->pos += len;
363
        s->buf_ptr = dst;
364
        s->buf_end = dst + len;
365
    }
366
}
367

    
368
unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
369
                                    unsigned int len)
370
{
371
    return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
372
}
373

    
374
unsigned long get_checksum(ByteIOContext *s)
375
{
376
    s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
377
    s->update_checksum= NULL;
378
    return s->checksum;
379
}
380

    
381
void init_checksum(ByteIOContext *s,
382
                   unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
383
                   unsigned long checksum)
384
{
385
    s->update_checksum= update_checksum;
386
    if(s->update_checksum){
387
        s->checksum= checksum;
388
        s->checksum_ptr= s->buf_ptr;
389
    }
390
}
391

    
392
/* XXX: put an inline version */
393
int get_byte(ByteIOContext *s)
394
{
395
    if (s->buf_ptr < s->buf_end) {
396
        return *s->buf_ptr++;
397
    } else {
398
        fill_buffer(s);
399
        if (s->buf_ptr < s->buf_end)
400
            return *s->buf_ptr++;
401
        else
402
            return 0;
403
    }
404
}
405

    
406
int url_fgetc(ByteIOContext *s)
407
{
408
    if (s->buf_ptr < s->buf_end) {
409
        return *s->buf_ptr++;
410
    } else {
411
        fill_buffer(s);
412
        if (s->buf_ptr < s->buf_end)
413
            return *s->buf_ptr++;
414
        else
415
            return URL_EOF;
416
    }
417
}
418

    
419
int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
420
{
421
    int len, size1;
422

    
423
    size1 = size;
424
    while (size > 0) {
425
        len = s->buf_end - s->buf_ptr;
426
        if (len > size)
427
            len = size;
428
        if (len == 0) {
429
            if(size > s->buffer_size && !s->update_checksum){
430
                if(s->read_packet)
431
                    len = s->read_packet(s->opaque, buf, size);
432
                if (len <= 0) {
433
                    /* do not modify buffer if EOF reached so that a seek back can
434
                    be done without rereading data */
435
                    s->eof_reached = 1;
436
                    if(len<0)
437
                        s->error= len;
438
                    break;
439
                } else {
440
                    s->pos += len;
441
                    size -= len;
442
                    buf += len;
443
                    s->buf_ptr = s->buffer;
444
                    s->buf_end = s->buffer/* + len*/;
445
                }
446
            }else{
447
                fill_buffer(s);
448
                len = s->buf_end - s->buf_ptr;
449
                if (len == 0)
450
                    break;
451
            }
452
        } else {
453
            memcpy(buf, s->buf_ptr, len);
454
            buf += len;
455
            s->buf_ptr += len;
456
            size -= len;
457
        }
458
    }
459
    if (size1 == size) {
460
        if (url_ferror(s)) return url_ferror(s);
461
        if (url_feof(s))   return AVERROR_EOF;
462
    }
463
    return size1 - size;
464
}
465

    
466
int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size)
467
{
468
    int len;
469

    
470
    if(size<0)
471
        return -1;
472

    
473
    len = s->buf_end - s->buf_ptr;
474
    if (len == 0) {
475
        fill_buffer(s);
476
        len = s->buf_end - s->buf_ptr;
477
    }
478
    if (len > size)
479
        len = size;
480
    memcpy(buf, s->buf_ptr, len);
481
    s->buf_ptr += len;
482
    if (!len) {
483
        if (url_ferror(s)) return url_ferror(s);
484
        if (url_feof(s))   return AVERROR_EOF;
485
    }
486
    return len;
487
}
488

    
489
unsigned int get_le16(ByteIOContext *s)
490
{
491
    unsigned int val;
492
    val = get_byte(s);
493
    val |= get_byte(s) << 8;
494
    return val;
495
}
496

    
497
unsigned int get_le24(ByteIOContext *s)
498
{
499
    unsigned int val;
500
    val = get_le16(s);
501
    val |= get_byte(s) << 16;
502
    return val;
503
}
504

    
505
unsigned int get_le32(ByteIOContext *s)
506
{
507
    unsigned int val;
508
    val = get_le16(s);
509
    val |= get_le16(s) << 16;
510
    return val;
511
}
512

    
513
uint64_t get_le64(ByteIOContext *s)
514
{
515
    uint64_t val;
516
    val = (uint64_t)get_le32(s);
517
    val |= (uint64_t)get_le32(s) << 32;
518
    return val;
519
}
520

    
521
unsigned int get_be16(ByteIOContext *s)
522
{
523
    unsigned int val;
524
    val = get_byte(s) << 8;
525
    val |= get_byte(s);
526
    return val;
527
}
528

    
529
unsigned int get_be24(ByteIOContext *s)
530
{
531
    unsigned int val;
532
    val = get_be16(s) << 8;
533
    val |= get_byte(s);
534
    return val;
535
}
536
unsigned int get_be32(ByteIOContext *s)
537
{
538
    unsigned int val;
539
    val = get_be16(s) << 16;
540
    val |= get_be16(s);
541
    return val;
542
}
543

    
544
char *get_strz(ByteIOContext *s, char *buf, int maxlen)
545
{
546
    int i = 0;
547
    char c;
548

    
549
    while ((c = get_byte(s))) {
550
        if (i < maxlen-1)
551
            buf[i++] = c;
552
    }
553

    
554
    buf[i] = 0; /* Ensure null terminated, but may be truncated */
555

    
556
    return buf;
557
}
558

    
559
uint64_t get_be64(ByteIOContext *s)
560
{
561
    uint64_t val;
562
    val = (uint64_t)get_be32(s) << 32;
563
    val |= (uint64_t)get_be32(s);
564
    return val;
565
}
566

    
567
uint64_t ff_get_v(ByteIOContext *bc){
568
    uint64_t val = 0;
569
    int tmp;
570

    
571
    do{
572
        tmp = get_byte(bc);
573
        val= (val<<7) + (tmp&127);
574
    }while(tmp&128);
575
    return val;
576
}
577

    
578
int url_fdopen(ByteIOContext **s, URLContext *h)
579
{
580
    uint8_t *buffer;
581
    int buffer_size, max_packet_size;
582

    
583
    max_packet_size = url_get_max_packet_size(h);
584
    if (max_packet_size) {
585
        buffer_size = max_packet_size; /* no need to bufferize more than one packet */
586
    } else {
587
        buffer_size = IO_BUFFER_SIZE;
588
    }
589
    buffer = av_malloc(buffer_size);
590
    if (!buffer)
591
        return AVERROR(ENOMEM);
592

    
593
    *s = av_mallocz(sizeof(ByteIOContext));
594
    if(!*s) {
595
        av_free(buffer);
596
        return AVERROR(ENOMEM);
597
    }
598

    
599
    if (init_put_byte(*s, buffer, buffer_size,
600
                      (h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
601
                      url_read, url_write, url_seek) < 0) {
602
        av_free(buffer);
603
        av_freep(s);
604
        return AVERROR(EIO);
605
    }
606
    (*s)->is_streamed = h->is_streamed;
607
    (*s)->max_packet_size = max_packet_size;
608
    if(h->prot) {
609
        (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
610
        (*s)->read_seek  = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
611
    }
612
    return 0;
613
}
614

    
615
int url_setbufsize(ByteIOContext *s, int buf_size)
616
{
617
    uint8_t *buffer;
618
    buffer = av_malloc(buf_size);
619
    if (!buffer)
620
        return AVERROR(ENOMEM);
621

    
622
    av_free(s->buffer);
623
    s->buffer = buffer;
624
    s->buffer_size = buf_size;
625
    s->buf_ptr = buffer;
626
    url_resetbuf(s, s->write_flag ? URL_WRONLY : URL_RDONLY);
627
    return 0;
628
}
629

    
630
#if LIBAVFORMAT_VERSION_MAJOR < 53
631
int url_resetbuf(ByteIOContext *s, int flags)
632
#else
633
static int url_resetbuf(ByteIOContext *s, int flags)
634
#endif
635
{
636
#if LIBAVFORMAT_VERSION_MAJOR < 53
637
    if (flags & URL_RDWR)
638
        return AVERROR(EINVAL);
639
#else
640
    assert(flags == URL_WRONLY || flags == URL_RDONLY);
641
#endif
642

    
643
    if (flags & URL_WRONLY) {
644
        s->buf_end = s->buffer + s->buffer_size;
645
        s->write_flag = 1;
646
    } else {
647
        s->buf_end = s->buffer;
648
        s->write_flag = 0;
649
    }
650
    return 0;
651
}
652

    
653
int ff_rewind_with_probe_data(ByteIOContext *s, unsigned char *buf, int buf_size)
654
{
655
    int64_t buffer_start;
656
    int buffer_size;
657
    int overlap, new_size;
658

    
659
    if (s->write_flag)
660
        return AVERROR(EINVAL);
661

    
662
    buffer_size = s->buf_end - s->buffer;
663

    
664
    /* the buffers must touch or overlap */
665
    if ((buffer_start = s->pos - buffer_size) > buf_size)
666
        return AVERROR(EINVAL);
667

    
668
    overlap = buf_size - buffer_start;
669
    new_size = buf_size + buffer_size - overlap;
670

    
671
    if (new_size > buf_size) {
672
        if (!(buf = av_realloc(buf, new_size)))
673
            return AVERROR(ENOMEM);
674

    
675
        memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
676
        buf_size = new_size;
677
    }
678

    
679
    av_free(s->buffer);
680
    s->buf_ptr = s->buffer = buf;
681
    s->pos = s->buffer_size = buf_size;
682
    s->buf_end = s->buf_ptr + buf_size;
683
    s->eof_reached = 0;
684
    s->must_flush = 0;
685

    
686
    return 0;
687
}
688

    
689
int url_fopen(ByteIOContext **s, const char *filename, int flags)
690
{
691
    URLContext *h;
692
    int err;
693

    
694
    err = url_open(&h, filename, flags);
695
    if (err < 0)
696
        return err;
697
    err = url_fdopen(s, h);
698
    if (err < 0) {
699
        url_close(h);
700
        return err;
701
    }
702
    return 0;
703
}
704

    
705
int url_fclose(ByteIOContext *s)
706
{
707
    URLContext *h = s->opaque;
708

    
709
    av_free(s->buffer);
710
    av_free(s);
711
    return url_close(h);
712
}
713

    
714
URLContext *url_fileno(ByteIOContext *s)
715
{
716
    return s->opaque;
717
}
718

    
719
#if CONFIG_MUXERS
720
int url_fprintf(ByteIOContext *s, const char *fmt, ...)
721
{
722
    va_list ap;
723
    char buf[4096];
724
    int ret;
725

    
726
    va_start(ap, fmt);
727
    ret = vsnprintf(buf, sizeof(buf), fmt, ap);
728
    va_end(ap);
729
    put_buffer(s, buf, strlen(buf));
730
    return ret;
731
}
732
#endif //CONFIG_MUXERS
733

    
734
char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
735
{
736
    int c;
737
    char *q;
738

    
739
    c = url_fgetc(s);
740
    if (c == EOF)
741
        return NULL;
742
    q = buf;
743
    for(;;) {
744
        if (c == EOF || c == '\n')
745
            break;
746
        if ((q - buf) < buf_size - 1)
747
            *q++ = c;
748
        c = url_fgetc(s);
749
    }
750
    if (buf_size > 0)
751
        *q = '\0';
752
    return buf;
753
}
754

    
755
int url_fget_max_packet_size(ByteIOContext *s)
756
{
757
    return s->max_packet_size;
758
}
759

    
760
int av_url_read_fpause(ByteIOContext *s, int pause)
761
{
762
    if (!s->read_pause)
763
        return AVERROR(ENOSYS);
764
    return s->read_pause(s->opaque, pause);
765
}
766

    
767
int64_t av_url_read_fseek(ByteIOContext *s, int stream_index,
768
                          int64_t timestamp, int flags)
769
{
770
    URLContext *h = s->opaque;
771
    int64_t ret;
772
    if (!s->read_seek)
773
        return AVERROR(ENOSYS);
774
    ret = s->read_seek(h, stream_index, timestamp, flags);
775
    if(ret >= 0) {
776
        int64_t pos;
777
        s->buf_ptr = s->buf_end; // Flush buffer
778
        pos = s->seek(h, 0, SEEK_CUR);
779
        if (pos >= 0)
780
            s->pos = pos;
781
        else if (pos != AVERROR(ENOSYS))
782
            ret = pos;
783
    }
784
    return ret;
785
}
786

    
787
/* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
788
 * back to the server even if CONFIG_MUXERS is false. */
789
#if CONFIG_MUXERS || CONFIG_NETWORK
790
/* buffer handling */
791
int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags)
792
{
793
    int ret;
794
    *s = av_mallocz(sizeof(ByteIOContext));
795
    if(!*s)
796
        return AVERROR(ENOMEM);
797
    ret = init_put_byte(*s, buf, buf_size,
798
                        (flags & URL_WRONLY || flags & URL_RDWR),
799
                        NULL, NULL, NULL, NULL);
800
    if(ret != 0)
801
        av_freep(s);
802
    return ret;
803
}
804

    
805
int url_close_buf(ByteIOContext *s)
806
{
807
    put_flush_packet(s);
808
    return s->buf_ptr - s->buffer;
809
}
810

    
811
/* output in a dynamic buffer */
812

    
813
typedef struct DynBuffer {
814
    int pos, size, allocated_size;
815
    uint8_t *buffer;
816
    int io_buffer_size;
817
    uint8_t io_buffer[1];
818
} DynBuffer;
819

    
820
static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
821
{
822
    DynBuffer *d = opaque;
823
    unsigned new_size, new_allocated_size;
824

    
825
    /* reallocate buffer if needed */
826
    new_size = d->pos + buf_size;
827
    new_allocated_size = d->allocated_size;
828
    if(new_size < d->pos || new_size > INT_MAX/2)
829
        return -1;
830
    while (new_size > new_allocated_size) {
831
        if (!new_allocated_size)
832
            new_allocated_size = new_size;
833
        else
834
            new_allocated_size += new_allocated_size / 2 + 1;
835
    }
836

    
837
    if (new_allocated_size > d->allocated_size) {
838
        d->buffer = av_realloc(d->buffer, new_allocated_size);
839
        if(d->buffer == NULL)
840
             return AVERROR(ENOMEM);
841
        d->allocated_size = new_allocated_size;
842
    }
843
    memcpy(d->buffer + d->pos, buf, buf_size);
844
    d->pos = new_size;
845
    if (d->pos > d->size)
846
        d->size = d->pos;
847
    return buf_size;
848
}
849

    
850
static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
851
{
852
    unsigned char buf1[4];
853
    int ret;
854

    
855
    /* packetized write: output the header */
856
    AV_WB32(buf1, buf_size);
857
    ret= dyn_buf_write(opaque, buf1, 4);
858
    if(ret < 0)
859
        return ret;
860

    
861
    /* then the data */
862
    return dyn_buf_write(opaque, buf, buf_size);
863
}
864

    
865
static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
866
{
867
    DynBuffer *d = opaque;
868

    
869
    if (whence == SEEK_CUR)
870
        offset += d->pos;
871
    else if (whence == SEEK_END)
872
        offset += d->size;
873
    if (offset < 0 || offset > 0x7fffffffLL)
874
        return -1;
875
    d->pos = offset;
876
    return 0;
877
}
878

    
879
static int url_open_dyn_buf_internal(ByteIOContext **s, int max_packet_size)
880
{
881
    DynBuffer *d;
882
    int ret;
883
    unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
884

    
885
    if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
886
        return -1;
887
    d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
888
    if (!d)
889
        return AVERROR(ENOMEM);
890
    *s = av_mallocz(sizeof(ByteIOContext));
891
    if(!*s) {
892
        av_free(d);
893
        return AVERROR(ENOMEM);
894
    }
895
    d->io_buffer_size = io_buffer_size;
896
    ret = init_put_byte(*s, d->io_buffer, io_buffer_size,
897
                        1, d, NULL,
898
                        max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
899
                        max_packet_size ? NULL : dyn_buf_seek);
900
    if (ret == 0) {
901
        (*s)->max_packet_size = max_packet_size;
902
    } else {
903
        av_free(d);
904
        av_freep(s);
905
    }
906
    return ret;
907
}
908

    
909
int url_open_dyn_buf(ByteIOContext **s)
910
{
911
    return url_open_dyn_buf_internal(s, 0);
912
}
913

    
914
int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size)
915
{
916
    if (max_packet_size <= 0)
917
        return -1;
918
    return url_open_dyn_buf_internal(s, max_packet_size);
919
}
920

    
921
int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
922
{
923
    DynBuffer *d = s->opaque;
924
    int size;
925
    static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
926
    int padding = 0;
927

    
928
    /* don't attempt to pad fixed-size packet buffers */
929
    if (!s->max_packet_size) {
930
        put_buffer(s, padbuf, sizeof(padbuf));
931
        padding = FF_INPUT_BUFFER_PADDING_SIZE;
932
    }
933

    
934
    put_flush_packet(s);
935

    
936
    *pbuffer = d->buffer;
937
    size = d->size;
938
    av_free(d);
939
    av_free(s);
940
    return size - padding;
941
}
942
#endif /* CONFIG_MUXERS || CONFIG_NETWORK */