1cbed1d5e7c9090cb6cfe94ee9a3c6946b1e5641
[libav.git] / libavformat / aviobuf.c
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 <stdarg.h>
27
28 #define IO_BUFFER_SIZE 32768
29
30 static void fill_buffer(ByteIOContext *s);
31 #if LIBAVFORMAT_VERSION_MAJOR >= 53
32 static int url_resetbuf(ByteIOContext *s, int flags);
33 #endif
34
35 int init_put_byte(ByteIOContext *s,
36 unsigned char *buffer,
37 int buffer_size,
38 int write_flag,
39 void *opaque,
40 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
41 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
42 int64_t (*seek)(void *opaque, int64_t offset, int whence))
43 {
44 s->buffer = buffer;
45 s->buffer_size = buffer_size;
46 s->buf_ptr = buffer;
47 s->opaque = opaque;
48 url_resetbuf(s, write_flag ? URL_WRONLY : URL_RDONLY);
49 s->write_packet = write_packet;
50 s->read_packet = read_packet;
51 s->seek = seek;
52 s->pos = 0;
53 s->must_flush = 0;
54 s->eof_reached = 0;
55 s->error = 0;
56 s->is_streamed = 0;
57 s->max_packet_size = 0;
58 s->update_checksum= NULL;
59 if(!read_packet && !write_flag){
60 s->pos = buffer_size;
61 s->buf_end = s->buffer + buffer_size;
62 }
63 s->read_pause = NULL;
64 s->read_seek = NULL;
65 return 0;
66 }
67
68 ByteIOContext *av_alloc_put_byte(
69 unsigned char *buffer,
70 int buffer_size,
71 int write_flag,
72 void *opaque,
73 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
74 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
75 int64_t (*seek)(void *opaque, int64_t offset, int whence))
76 {
77 ByteIOContext *s = av_mallocz(sizeof(ByteIOContext));
78 init_put_byte(s, buffer, buffer_size, write_flag, opaque,
79 read_packet, write_packet, seek);
80 return s;
81 }
82
83 static void flush_buffer(ByteIOContext *s)
84 {
85 if (s->buf_ptr > s->buffer) {
86 if (s->write_packet && !s->error){
87 int ret= s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
88 if(ret < 0){
89 s->error = ret;
90 }
91 }
92 if(s->update_checksum){
93 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
94 s->checksum_ptr= s->buffer;
95 }
96 s->pos += s->buf_ptr - s->buffer;
97 }
98 s->buf_ptr = s->buffer;
99 }
100
101 void put_byte(ByteIOContext *s, int b)
102 {
103 *(s->buf_ptr)++ = b;
104 if (s->buf_ptr >= s->buf_end)
105 flush_buffer(s);
106 }
107
108 void put_buffer(ByteIOContext *s, const unsigned char *buf, int size)
109 {
110 while (size > 0) {
111 int len = FFMIN(s->buf_end - s->buf_ptr, size);
112 memcpy(s->buf_ptr, buf, len);
113 s->buf_ptr += len;
114
115 if (s->buf_ptr >= s->buf_end)
116 flush_buffer(s);
117
118 buf += len;
119 size -= len;
120 }
121 }
122
123 void put_flush_packet(ByteIOContext *s)
124 {
125 flush_buffer(s);
126 s->must_flush = 0;
127 }
128
129 int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence)
130 {
131 int64_t offset1;
132 int64_t pos;
133
134 if(!s)
135 return AVERROR(EINVAL);
136
137 pos = s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
138
139 if (whence != SEEK_CUR && whence != SEEK_SET)
140 return AVERROR(EINVAL);
141
142 if (whence == SEEK_CUR) {
143 offset1 = pos + (s->buf_ptr - s->buffer);
144 if (offset == 0)
145 return offset1;
146 offset += offset1;
147 }
148 offset1 = offset - pos;
149 if (!s->must_flush &&
150 offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
151 /* can do the seek inside the buffer */
152 s->buf_ptr = s->buffer + offset1;
153 } else if(s->is_streamed && !s->write_flag &&
154 offset1 >= 0 && offset1 < (s->buf_end - s->buffer) + (1<<16)){
155 while(s->pos < offset && !s->eof_reached)
156 fill_buffer(s);
157 if (s->eof_reached)
158 return AVERROR(EPIPE);
159 s->buf_ptr = s->buf_end + offset - s->pos;
160 } else {
161 int64_t res = AVERROR(EPIPE);
162
163 #if CONFIG_MUXERS || CONFIG_NETWORK
164 if (s->write_flag) {
165 flush_buffer(s);
166 s->must_flush = 1;
167 }
168 #endif /* CONFIG_MUXERS || CONFIG_NETWORK */
169 if (!s->seek || (res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
170 return res;
171 if (!s->write_flag)
172 s->buf_end = s->buffer;
173 s->buf_ptr = s->buffer;
174 s->pos = offset;
175 }
176 s->eof_reached = 0;
177 return offset;
178 }
179
180 void url_fskip(ByteIOContext *s, int64_t offset)
181 {
182 url_fseek(s, offset, SEEK_CUR);
183 }
184
185 int64_t url_ftell(ByteIOContext *s)
186 {
187 return url_fseek(s, 0, SEEK_CUR);
188 }
189
190 int64_t url_fsize(ByteIOContext *s)
191 {
192 int64_t size;
193
194 if(!s)
195 return AVERROR(EINVAL);
196
197 if (!s->seek)
198 return AVERROR(EPIPE);
199 size = s->seek(s->opaque, 0, AVSEEK_SIZE);
200 if(size<0){
201 if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
202 return size;
203 size++;
204 s->seek(s->opaque, s->pos, SEEK_SET);
205 }
206 return size;
207 }
208
209 int url_feof(ByteIOContext *s)
210 {
211 if(!s)
212 return 0;
213 return s->eof_reached;
214 }
215
216 int url_ferror(ByteIOContext *s)
217 {
218 if(!s)
219 return 0;
220 return s->error;
221 }
222
223 void put_le32(ByteIOContext *s, unsigned int val)
224 {
225 put_byte(s, val);
226 put_byte(s, val >> 8);
227 put_byte(s, val >> 16);
228 put_byte(s, val >> 24);
229 }
230
231 void put_be32(ByteIOContext *s, unsigned int val)
232 {
233 put_byte(s, val >> 24);
234 put_byte(s, val >> 16);
235 put_byte(s, val >> 8);
236 put_byte(s, val);
237 }
238
239 void put_strz(ByteIOContext *s, const char *str)
240 {
241 if (str)
242 put_buffer(s, (const unsigned char *) str, strlen(str) + 1);
243 else
244 put_byte(s, 0);
245 }
246
247 void put_le64(ByteIOContext *s, uint64_t val)
248 {
249 put_le32(s, (uint32_t)(val & 0xffffffff));
250 put_le32(s, (uint32_t)(val >> 32));
251 }
252
253 void put_be64(ByteIOContext *s, uint64_t val)
254 {
255 put_be32(s, (uint32_t)(val >> 32));
256 put_be32(s, (uint32_t)(val & 0xffffffff));
257 }
258
259 void put_le16(ByteIOContext *s, unsigned int val)
260 {
261 put_byte(s, val);
262 put_byte(s, val >> 8);
263 }
264
265 void put_be16(ByteIOContext *s, unsigned int val)
266 {
267 put_byte(s, val >> 8);
268 put_byte(s, val);
269 }
270
271 void put_le24(ByteIOContext *s, unsigned int val)
272 {
273 put_le16(s, val & 0xffff);
274 put_byte(s, val >> 16);
275 }
276
277 void put_be24(ByteIOContext *s, unsigned int val)
278 {
279 put_be16(s, val >> 8);
280 put_byte(s, val);
281 }
282
283 void put_tag(ByteIOContext *s, const char *tag)
284 {
285 while (*tag) {
286 put_byte(s, *tag++);
287 }
288 }
289
290 /* Input stream */
291
292 static void fill_buffer(ByteIOContext *s)
293 {
294 uint8_t *dst= !s->max_packet_size && s->buf_end - s->buffer < s->buffer_size ? s->buf_ptr : s->buffer;
295 int len= s->buffer_size - (dst - s->buffer);
296
297 assert(s->buf_ptr == s->buf_end);
298
299 /* no need to do anything if EOF already reached */
300 if (s->eof_reached)
301 return;
302
303 if(s->update_checksum && dst == s->buffer){
304 if(s->buf_end > s->checksum_ptr)
305 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
306 s->checksum_ptr= s->buffer;
307 }
308
309 if(s->read_packet)
310 len = s->read_packet(s->opaque, dst, len);
311 else
312 len = 0;
313 if (len <= 0) {
314 /* do not modify buffer if EOF reached so that a seek back can
315 be done without rereading data */
316 s->eof_reached = 1;
317 if(len<0)
318 s->error= len;
319 } else {
320 s->pos += len;
321 s->buf_ptr = dst;
322 s->buf_end = dst + len;
323 }
324 }
325
326 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
327 unsigned int len)
328 {
329 return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
330 }
331
332 unsigned long get_checksum(ByteIOContext *s)
333 {
334 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
335 s->update_checksum= NULL;
336 return s->checksum;
337 }
338
339 void init_checksum(ByteIOContext *s,
340 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
341 unsigned long checksum)
342 {
343 s->update_checksum= update_checksum;
344 if(s->update_checksum){
345 s->checksum= checksum;
346 s->checksum_ptr= s->buf_ptr;
347 }
348 }
349
350 /* XXX: put an inline version */
351 int get_byte(ByteIOContext *s)
352 {
353 if (s->buf_ptr < s->buf_end) {
354 return *s->buf_ptr++;
355 } else {
356 fill_buffer(s);
357 if (s->buf_ptr < s->buf_end)
358 return *s->buf_ptr++;
359 else
360 return 0;
361 }
362 }
363
364 int url_fgetc(ByteIOContext *s)
365 {
366 if (s->buf_ptr < s->buf_end) {
367 return *s->buf_ptr++;
368 } else {
369 fill_buffer(s);
370 if (s->buf_ptr < s->buf_end)
371 return *s->buf_ptr++;
372 else
373 return URL_EOF;
374 }
375 }
376
377 int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
378 {
379 int len, size1;
380
381 size1 = size;
382 while (size > 0) {
383 len = s->buf_end - s->buf_ptr;
384 if (len > size)
385 len = size;
386 if (len == 0) {
387 if(size > s->buffer_size && !s->update_checksum){
388 if(s->read_packet)
389 len = s->read_packet(s->opaque, buf, size);
390 if (len <= 0) {
391 /* do not modify buffer if EOF reached so that a seek back can
392 be done without rereading data */
393 s->eof_reached = 1;
394 if(len<0)
395 s->error= len;
396 break;
397 } else {
398 s->pos += len;
399 size -= len;
400 buf += len;
401 s->buf_ptr = s->buffer;
402 s->buf_end = s->buffer/* + len*/;
403 }
404 }else{
405 fill_buffer(s);
406 len = s->buf_end - s->buf_ptr;
407 if (len == 0)
408 break;
409 }
410 } else {
411 memcpy(buf, s->buf_ptr, len);
412 buf += len;
413 s->buf_ptr += len;
414 size -= len;
415 }
416 }
417 if (size1 == size) {
418 if (url_ferror(s)) return url_ferror(s);
419 if (url_feof(s)) return AVERROR_EOF;
420 }
421 return size1 - size;
422 }
423
424 int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size)
425 {
426 int len;
427
428 if(size<0)
429 return -1;
430
431 len = s->buf_end - s->buf_ptr;
432 if (len == 0) {
433 fill_buffer(s);
434 len = s->buf_end - s->buf_ptr;
435 }
436 if (len > size)
437 len = size;
438 memcpy(buf, s->buf_ptr, len);
439 s->buf_ptr += len;
440 if (!len) {
441 if (url_ferror(s)) return url_ferror(s);
442 if (url_feof(s)) return AVERROR_EOF;
443 }
444 return len;
445 }
446
447 unsigned int get_le16(ByteIOContext *s)
448 {
449 unsigned int val;
450 val = get_byte(s);
451 val |= get_byte(s) << 8;
452 return val;
453 }
454
455 unsigned int get_le24(ByteIOContext *s)
456 {
457 unsigned int val;
458 val = get_le16(s);
459 val |= get_byte(s) << 16;
460 return val;
461 }
462
463 unsigned int get_le32(ByteIOContext *s)
464 {
465 unsigned int val;
466 val = get_le16(s);
467 val |= get_le16(s) << 16;
468 return val;
469 }
470
471 uint64_t get_le64(ByteIOContext *s)
472 {
473 uint64_t val;
474 val = (uint64_t)get_le32(s);
475 val |= (uint64_t)get_le32(s) << 32;
476 return val;
477 }
478
479 unsigned int get_be16(ByteIOContext *s)
480 {
481 unsigned int val;
482 val = get_byte(s) << 8;
483 val |= get_byte(s);
484 return val;
485 }
486
487 unsigned int get_be24(ByteIOContext *s)
488 {
489 unsigned int val;
490 val = get_be16(s) << 8;
491 val |= get_byte(s);
492 return val;
493 }
494 unsigned int get_be32(ByteIOContext *s)
495 {
496 unsigned int val;
497 val = get_be16(s) << 16;
498 val |= get_be16(s);
499 return val;
500 }
501
502 char *get_strz(ByteIOContext *s, char *buf, int maxlen)
503 {
504 int i = 0;
505 char c;
506
507 while ((c = get_byte(s))) {
508 if (i < maxlen-1)
509 buf[i++] = c;
510 }
511
512 buf[i] = 0; /* Ensure null terminated, but may be truncated */
513
514 return buf;
515 }
516
517 uint64_t get_be64(ByteIOContext *s)
518 {
519 uint64_t val;
520 val = (uint64_t)get_be32(s) << 32;
521 val |= (uint64_t)get_be32(s);
522 return val;
523 }
524
525 uint64_t ff_get_v(ByteIOContext *bc){
526 uint64_t val = 0;
527 int tmp;
528
529 do{
530 tmp = get_byte(bc);
531 val= (val<<7) + (tmp&127);
532 }while(tmp&128);
533 return val;
534 }
535
536 int url_fdopen(ByteIOContext **s, URLContext *h)
537 {
538 uint8_t *buffer;
539 int buffer_size, max_packet_size;
540
541 max_packet_size = url_get_max_packet_size(h);
542 if (max_packet_size) {
543 buffer_size = max_packet_size; /* no need to bufferize more than one packet */
544 } else {
545 buffer_size = IO_BUFFER_SIZE;
546 }
547 buffer = av_malloc(buffer_size);
548 if (!buffer)
549 return AVERROR(ENOMEM);
550
551 *s = av_mallocz(sizeof(ByteIOContext));
552 if(!*s) {
553 av_free(buffer);
554 return AVERROR(ENOMEM);
555 }
556
557 if (init_put_byte(*s, buffer, buffer_size,
558 (h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
559 url_read, url_write, url_seek) < 0) {
560 av_free(buffer);
561 av_freep(s);
562 return AVERROR(EIO);
563 }
564 (*s)->is_streamed = h->is_streamed;
565 (*s)->max_packet_size = max_packet_size;
566 if(h->prot) {
567 (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
568 (*s)->read_seek = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
569 }
570 return 0;
571 }
572
573 int url_setbufsize(ByteIOContext *s, int buf_size)
574 {
575 uint8_t *buffer;
576 buffer = av_malloc(buf_size);
577 if (!buffer)
578 return AVERROR(ENOMEM);
579
580 av_free(s->buffer);
581 s->buffer = buffer;
582 s->buffer_size = buf_size;
583 s->buf_ptr = buffer;
584 url_resetbuf(s, s->write_flag ? URL_WRONLY : URL_RDONLY);
585 return 0;
586 }
587
588 #if LIBAVFORMAT_VERSION_MAJOR < 53
589 int url_resetbuf(ByteIOContext *s, int flags)
590 #else
591 static int url_resetbuf(ByteIOContext *s, int flags)
592 #endif
593 {
594 #if LIBAVFORMAT_VERSION_MAJOR < 53
595 URLContext *h = s->opaque;
596 if ((flags & URL_RDWR) || (h && h->flags != flags && !h->flags & URL_RDWR))
597 return AVERROR(EINVAL);
598 #else
599 assert(flags == URL_WRONLY || flags == URL_RDONLY);
600 #endif
601
602 if (flags & URL_WRONLY) {
603 s->buf_end = s->buffer + s->buffer_size;
604 s->write_flag = 1;
605 } else {
606 s->buf_end = s->buffer;
607 s->write_flag = 0;
608 }
609 return 0;
610 }
611
612 int url_fopen(ByteIOContext **s, const char *filename, int flags)
613 {
614 URLContext *h;
615 int err;
616
617 err = url_open(&h, filename, flags);
618 if (err < 0)
619 return err;
620 err = url_fdopen(s, h);
621 if (err < 0) {
622 url_close(h);
623 return err;
624 }
625 return 0;
626 }
627
628 int url_fclose(ByteIOContext *s)
629 {
630 URLContext *h = s->opaque;
631
632 av_free(s->buffer);
633 av_free(s);
634 return url_close(h);
635 }
636
637 URLContext *url_fileno(ByteIOContext *s)
638 {
639 return s->opaque;
640 }
641
642 #if CONFIG_MUXERS
643 int url_fprintf(ByteIOContext *s, const char *fmt, ...)
644 {
645 va_list ap;
646 char buf[4096];
647 int ret;
648
649 va_start(ap, fmt);
650 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
651 va_end(ap);
652 put_buffer(s, buf, strlen(buf));
653 return ret;
654 }
655 #endif //CONFIG_MUXERS
656
657 char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
658 {
659 int c;
660 char *q;
661
662 c = url_fgetc(s);
663 if (c == EOF)
664 return NULL;
665 q = buf;
666 for(;;) {
667 if (c == EOF || c == '\n')
668 break;
669 if ((q - buf) < buf_size - 1)
670 *q++ = c;
671 c = url_fgetc(s);
672 }
673 if (buf_size > 0)
674 *q = '\0';
675 return buf;
676 }
677
678 int url_fget_max_packet_size(ByteIOContext *s)
679 {
680 return s->max_packet_size;
681 }
682
683 int av_url_read_fpause(ByteIOContext *s, int pause)
684 {
685 if (!s->read_pause)
686 return AVERROR(ENOSYS);
687 return s->read_pause(s->opaque, pause);
688 }
689
690 int64_t av_url_read_fseek(ByteIOContext *s, int stream_index,
691 int64_t timestamp, int flags)
692 {
693 URLContext *h = s->opaque;
694 int64_t ret;
695 if (!s->read_seek)
696 return AVERROR(ENOSYS);
697 ret = s->read_seek(h, stream_index, timestamp, flags);
698 if(ret >= 0) {
699 s->buf_ptr = s->buf_end; // Flush buffer
700 s->pos = s->seek(h, 0, SEEK_CUR);
701 }
702 return ret;
703 }
704
705 /* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
706 * back to the server even if CONFIG_MUXERS is false. */
707 #if CONFIG_MUXERS || CONFIG_NETWORK
708 /* buffer handling */
709 int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags)
710 {
711 int ret;
712 *s = av_mallocz(sizeof(ByteIOContext));
713 if(!*s)
714 return AVERROR(ENOMEM);
715 ret = init_put_byte(*s, buf, buf_size,
716 (flags & URL_WRONLY || flags & URL_RDWR),
717 NULL, NULL, NULL, NULL);
718 if(ret != 0)
719 av_freep(s);
720 return ret;
721 }
722
723 int url_close_buf(ByteIOContext *s)
724 {
725 put_flush_packet(s);
726 return s->buf_ptr - s->buffer;
727 }
728
729 /* output in a dynamic buffer */
730
731 typedef struct DynBuffer {
732 int pos, size, allocated_size;
733 uint8_t *buffer;
734 int io_buffer_size;
735 uint8_t io_buffer[1];
736 } DynBuffer;
737
738 static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
739 {
740 DynBuffer *d = opaque;
741 unsigned new_size, new_allocated_size;
742
743 /* reallocate buffer if needed */
744 new_size = d->pos + buf_size;
745 new_allocated_size = d->allocated_size;
746 if(new_size < d->pos || new_size > INT_MAX/2)
747 return -1;
748 while (new_size > new_allocated_size) {
749 if (!new_allocated_size)
750 new_allocated_size = new_size;
751 else
752 new_allocated_size += new_allocated_size / 2 + 1;
753 }
754
755 if (new_allocated_size > d->allocated_size) {
756 d->buffer = av_realloc(d->buffer, new_allocated_size);
757 if(d->buffer == NULL)
758 return AVERROR(ENOMEM);
759 d->allocated_size = new_allocated_size;
760 }
761 memcpy(d->buffer + d->pos, buf, buf_size);
762 d->pos = new_size;
763 if (d->pos > d->size)
764 d->size = d->pos;
765 return buf_size;
766 }
767
768 static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
769 {
770 unsigned char buf1[4];
771 int ret;
772
773 /* packetized write: output the header */
774 AV_WB32(buf1, buf_size);
775 ret= dyn_buf_write(opaque, buf1, 4);
776 if(ret < 0)
777 return ret;
778
779 /* then the data */
780 return dyn_buf_write(opaque, buf, buf_size);
781 }
782
783 static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
784 {
785 DynBuffer *d = opaque;
786
787 if (whence == SEEK_CUR)
788 offset += d->pos;
789 else if (whence == SEEK_END)
790 offset += d->size;
791 if (offset < 0 || offset > 0x7fffffffLL)
792 return -1;
793 d->pos = offset;
794 return 0;
795 }
796
797 static int url_open_dyn_buf_internal(ByteIOContext **s, int max_packet_size)
798 {
799 DynBuffer *d;
800 int ret;
801 unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
802
803 if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
804 return -1;
805 d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
806 if (!d)
807 return AVERROR(ENOMEM);
808 *s = av_mallocz(sizeof(ByteIOContext));
809 if(!*s) {
810 av_free(d);
811 return AVERROR(ENOMEM);
812 }
813 d->io_buffer_size = io_buffer_size;
814 ret = init_put_byte(*s, d->io_buffer, io_buffer_size,
815 1, d, NULL,
816 max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
817 max_packet_size ? NULL : dyn_buf_seek);
818 if (ret == 0) {
819 (*s)->max_packet_size = max_packet_size;
820 } else {
821 av_free(d);
822 av_freep(s);
823 }
824 return ret;
825 }
826
827 int url_open_dyn_buf(ByteIOContext **s)
828 {
829 return url_open_dyn_buf_internal(s, 0);
830 }
831
832 int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size)
833 {
834 if (max_packet_size <= 0)
835 return -1;
836 return url_open_dyn_buf_internal(s, max_packet_size);
837 }
838
839 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
840 {
841 DynBuffer *d = s->opaque;
842 int size;
843
844 put_flush_packet(s);
845
846 *pbuffer = d->buffer;
847 size = d->size;
848 av_free(d);
849 av_free(s);
850 return size;
851 }
852 #endif /* CONFIG_MUXERS || CONFIG_NETWORK */