3 * Copyright (c) 2000,2001 Fabrice Bellard
5 * This file is part of Libav.
7 * Libav 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.
12 * Libav 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/crc.h"
23 #include "libavutil/dict.h"
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/log.h"
26 #include "libavutil/opt.h"
29 #include "avio_internal.h"
34 #define IO_BUFFER_SIZE 32768
37 * Do seeks within this distance ahead of the current buffer by skipping
38 * data instead of calling the protocol seek function, for seekable
41 #define SHORT_SEEK_THRESHOLD 4096
44 static void *ffio_url_child_next(void *obj, void *prev)
47 return prev ? NULL : s->opaque;
50 static const AVClass *ffio_url_child_class_next(const AVClass *prev)
52 return prev ? NULL : &ffurl_context_class;
55 static const AVOption ffio_url_options[] = {
59 const AVClass ffio_url_class = {
60 .class_name = "AVIOContext",
61 .item_name = av_default_item_name,
62 .version = LIBAVUTIL_VERSION_INT,
63 .option = ffio_url_options,
64 .child_next = ffio_url_child_next,
65 .child_class_next = ffio_url_child_class_next,
68 static void fill_buffer(AVIOContext *s);
69 static int url_resetbuf(AVIOContext *s, int flags);
71 int ffio_init_context(AVIOContext *s,
72 unsigned char *buffer,
76 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
77 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
78 int64_t (*seek)(void *opaque, int64_t offset, int whence))
81 s->buffer_size = buffer_size;
84 url_resetbuf(s, write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ);
85 s->write_packet = write_packet;
86 s->read_packet = read_packet;
95 s->seekable = AVIO_SEEKABLE_NORMAL;
96 s->max_packet_size = 0;
97 s->update_checksum= NULL;
98 if(!read_packet && !write_flag){
100 s->buf_end = s->buffer + buffer_size;
102 s->read_pause = NULL;
108 int init_put_byte(AVIOContext *s,
109 unsigned char *buffer,
113 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
114 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
115 int64_t (*seek)(void *opaque, int64_t offset, int whence))
117 return ffio_init_context(s, buffer, buffer_size, write_flag, opaque,
118 read_packet, write_packet, seek);
120 AVIOContext *av_alloc_put_byte(
121 unsigned char *buffer,
125 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
126 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
127 int64_t (*seek)(void *opaque, int64_t offset, int whence))
129 return avio_alloc_context(buffer, buffer_size, write_flag, opaque,
130 read_packet, write_packet, seek);
134 AVIOContext *avio_alloc_context(
135 unsigned char *buffer,
139 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
140 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
141 int64_t (*seek)(void *opaque, int64_t offset, int whence))
143 AVIOContext *s = av_mallocz(sizeof(AVIOContext));
146 ffio_init_context(s, buffer, buffer_size, write_flag, opaque,
147 read_packet, write_packet, seek);
151 static void flush_buffer(AVIOContext *s)
153 if (s->buf_ptr > s->buffer) {
154 if (s->write_packet && !s->error){
155 int ret= s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
160 if(s->update_checksum){
161 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
162 s->checksum_ptr= s->buffer;
164 s->pos += s->buf_ptr - s->buffer;
166 s->buf_ptr = s->buffer;
169 void avio_w8(AVIOContext *s, int b)
172 if (s->buf_ptr >= s->buf_end)
176 void ffio_fill(AVIOContext *s, int b, int count)
179 int len = FFMIN(s->buf_end - s->buf_ptr, count);
180 memset(s->buf_ptr, b, len);
183 if (s->buf_ptr >= s->buf_end)
190 void avio_write(AVIOContext *s, const unsigned char *buf, int size)
193 int len = FFMIN(s->buf_end - s->buf_ptr, size);
194 memcpy(s->buf_ptr, buf, len);
197 if (s->buf_ptr >= s->buf_end)
205 void avio_flush(AVIOContext *s)
211 int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
215 int force = whence & AVSEEK_FORCE;
216 whence &= ~AVSEEK_FORCE;
219 return AVERROR(EINVAL);
221 pos = s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
223 if (whence != SEEK_CUR && whence != SEEK_SET)
224 return AVERROR(EINVAL);
226 if (whence == SEEK_CUR) {
227 offset1 = pos + (s->buf_ptr - s->buffer);
232 offset1 = offset - pos;
233 if (!s->must_flush &&
234 offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
235 /* can do the seek inside the buffer */
236 s->buf_ptr = s->buffer + offset1;
237 } else if ((!s->seekable ||
238 offset1 <= s->buf_end + SHORT_SEEK_THRESHOLD - s->buffer) &&
239 !s->write_flag && offset1 >= 0 &&
240 (whence != SEEK_END || force)) {
241 while(s->pos < offset && !s->eof_reached)
245 s->buf_ptr = s->buf_end + offset - s->pos;
249 #if CONFIG_MUXERS || CONFIG_NETWORK
254 #endif /* CONFIG_MUXERS || CONFIG_NETWORK */
256 return AVERROR(EPIPE);
257 if ((res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
260 s->buf_end = s->buffer;
261 s->buf_ptr = s->buffer;
269 int url_fskip(AVIOContext *s, int64_t offset)
271 int64_t ret = avio_seek(s, offset, SEEK_CUR);
272 return ret < 0 ? ret : 0;
275 int64_t url_ftell(AVIOContext *s)
277 return avio_seek(s, 0, SEEK_CUR);
281 int64_t avio_size(AVIOContext *s)
286 return AVERROR(EINVAL);
289 return AVERROR(ENOSYS);
290 size = s->seek(s->opaque, 0, AVSEEK_SIZE);
292 if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
295 s->seek(s->opaque, s->pos, SEEK_SET);
301 int url_feof(AVIOContext *s)
305 return s->eof_reached;
308 int url_ferror(AVIOContext *s)
316 void avio_wl32(AVIOContext *s, unsigned int val)
319 avio_w8(s, val >> 8);
320 avio_w8(s, val >> 16);
321 avio_w8(s, val >> 24);
324 void avio_wb32(AVIOContext *s, unsigned int val)
326 avio_w8(s, val >> 24);
327 avio_w8(s, val >> 16);
328 avio_w8(s, val >> 8);
333 void put_strz(AVIOContext *s, const char *str)
335 avio_put_str(s, str);
338 #define GET(name, type) \
339 type get_be ##name(AVIOContext *s) \
341 return avio_rb ##name(s);\
343 type get_le ##name(AVIOContext *s) \
345 return avio_rl ##name(s);\
348 GET(16, unsigned int)
349 GET(24, unsigned int)
350 GET(32, unsigned int)
355 #define PUT(name, type ) \
356 void put_le ##name(AVIOContext *s, type val)\
358 avio_wl ##name(s, val);\
360 void put_be ##name(AVIOContext *s, type val)\
362 avio_wb ##name(s, val);\
365 PUT(16, unsigned int)
366 PUT(24, unsigned int)
367 PUT(32, unsigned int)
371 int get_byte(AVIOContext *s)
375 int get_buffer(AVIOContext *s, unsigned char *buf, int size)
377 return avio_read(s, buf, size);
379 int get_partial_buffer(AVIOContext *s, unsigned char *buf, int size)
381 return ffio_read_partial(s, buf, size);
383 void put_byte(AVIOContext *s, int val)
387 void put_buffer(AVIOContext *s, const unsigned char *buf, int size)
389 avio_write(s, buf, size);
391 void put_nbyte(AVIOContext *s, int b, int count)
393 ffio_fill(s, b, count);
396 int url_fopen(AVIOContext **s, const char *filename, int flags)
398 return avio_open(s, filename, flags);
400 int url_fclose(AVIOContext *s)
402 return avio_close(s);
404 int64_t url_fseek(AVIOContext *s, int64_t offset, int whence)
406 return avio_seek(s, offset, whence);
408 int64_t url_fsize(AVIOContext *s)
412 int url_setbufsize(AVIOContext *s, int buf_size)
414 return ffio_set_buf_size(s, buf_size);
416 int url_fprintf(AVIOContext *s, const char *fmt, ...)
423 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
425 avio_write(s, buf, strlen(buf));
428 void put_flush_packet(AVIOContext *s)
432 int av_url_read_fpause(AVIOContext *s, int pause)
434 return avio_pause(s, pause);
436 int64_t av_url_read_fseek(AVIOContext *s, int stream_index,
437 int64_t timestamp, int flags)
439 return avio_seek_time(s, stream_index, timestamp, flags);
441 void init_checksum(AVIOContext *s,
442 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
443 unsigned long checksum)
445 ffio_init_checksum(s, update_checksum, checksum);
447 unsigned long get_checksum(AVIOContext *s)
449 return ffio_get_checksum(s);
451 int url_open_dyn_buf(AVIOContext **s)
453 return avio_open_dyn_buf(s);
455 int url_open_dyn_packet_buf(AVIOContext **s, int max_packet_size)
457 return ffio_open_dyn_packet_buf(s, max_packet_size);
459 int url_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
461 return avio_close_dyn_buf(s, pbuffer);
463 int url_fdopen(AVIOContext **s, URLContext *h)
465 return ffio_fdopen(s, h);
469 int avio_put_str(AVIOContext *s, const char *str)
474 avio_write(s, (const unsigned char *) str, len);
480 int avio_put_str16le(AVIOContext *s, const char *str)
482 const uint8_t *q = str;
489 GET_UTF8(ch, *q++, break;)
490 PUT_UTF16(ch, tmp, avio_wl16(s, tmp);ret += 2;)
497 int ff_get_v_length(uint64_t val){
506 void ff_put_v(AVIOContext *bc, uint64_t val){
507 int i= ff_get_v_length(val);
510 avio_w8(bc, 128 | (val>>(7*i)));
512 avio_w8(bc, val&127);
515 void avio_wl64(AVIOContext *s, uint64_t val)
517 avio_wl32(s, (uint32_t)(val & 0xffffffff));
518 avio_wl32(s, (uint32_t)(val >> 32));
521 void avio_wb64(AVIOContext *s, uint64_t val)
523 avio_wb32(s, (uint32_t)(val >> 32));
524 avio_wb32(s, (uint32_t)(val & 0xffffffff));
527 void avio_wl16(AVIOContext *s, unsigned int val)
530 avio_w8(s, val >> 8);
533 void avio_wb16(AVIOContext *s, unsigned int val)
535 avio_w8(s, val >> 8);
539 void avio_wl24(AVIOContext *s, unsigned int val)
541 avio_wl16(s, val & 0xffff);
542 avio_w8(s, val >> 16);
545 void avio_wb24(AVIOContext *s, unsigned int val)
547 avio_wb16(s, val >> 8);
552 void put_tag(AVIOContext *s, const char *tag)
562 static void fill_buffer(AVIOContext *s)
564 uint8_t *dst= !s->max_packet_size && s->buf_end - s->buffer < s->buffer_size ? s->buf_end : s->buffer;
565 int len= s->buffer_size - (dst - s->buffer);
566 int max_buffer_size = s->max_packet_size ? s->max_packet_size : IO_BUFFER_SIZE;
568 /* no need to do anything if EOF already reached */
572 if(s->update_checksum && dst == s->buffer){
573 if(s->buf_end > s->checksum_ptr)
574 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
575 s->checksum_ptr= s->buffer;
578 /* make buffer smaller in case it ended up large after probing */
579 if (s->buffer_size > max_buffer_size) {
580 ffio_set_buf_size(s, max_buffer_size);
582 s->checksum_ptr = dst = s->buffer;
583 len = s->buffer_size;
587 len = s->read_packet(s->opaque, dst, len);
591 /* do not modify buffer if EOF reached so that a seek back can
592 be done without rereading data */
599 s->buf_end = dst + len;
603 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
606 return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
609 unsigned long ffio_get_checksum(AVIOContext *s)
611 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
612 s->update_checksum= NULL;
616 void ffio_init_checksum(AVIOContext *s,
617 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
618 unsigned long checksum)
620 s->update_checksum= update_checksum;
621 if(s->update_checksum){
622 s->checksum= checksum;
623 s->checksum_ptr= s->buf_ptr;
627 /* XXX: put an inline version */
628 int avio_r8(AVIOContext *s)
630 if (s->buf_ptr >= s->buf_end)
632 if (s->buf_ptr < s->buf_end)
633 return *s->buf_ptr++;
638 int url_fgetc(AVIOContext *s)
640 if (s->buf_ptr >= s->buf_end)
642 if (s->buf_ptr < s->buf_end)
643 return *s->buf_ptr++;
648 int avio_read(AVIOContext *s, unsigned char *buf, int size)
654 len = s->buf_end - s->buf_ptr;
658 if(size > s->buffer_size && !s->update_checksum){
660 len = s->read_packet(s->opaque, buf, size);
662 /* do not modify buffer if EOF reached so that a seek back can
663 be done without rereading data */
672 s->buf_ptr = s->buffer;
673 s->buf_end = s->buffer/* + len*/;
677 len = s->buf_end - s->buf_ptr;
682 memcpy(buf, s->buf_ptr, len);
689 if (s->error) return s->error;
690 if (s->eof_reached) return AVERROR_EOF;
695 int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size)
702 len = s->buf_end - s->buf_ptr;
705 len = s->buf_end - s->buf_ptr;
709 memcpy(buf, s->buf_ptr, len);
712 if (s->error) return s->error;
713 if (s->eof_reached) return AVERROR_EOF;
718 unsigned int avio_rl16(AVIOContext *s)
722 val |= avio_r8(s) << 8;
726 unsigned int avio_rl24(AVIOContext *s)
730 val |= avio_r8(s) << 16;
734 unsigned int avio_rl32(AVIOContext *s)
738 val |= avio_rl16(s) << 16;
742 uint64_t avio_rl64(AVIOContext *s)
745 val = (uint64_t)avio_rl32(s);
746 val |= (uint64_t)avio_rl32(s) << 32;
750 unsigned int avio_rb16(AVIOContext *s)
753 val = avio_r8(s) << 8;
758 unsigned int avio_rb24(AVIOContext *s)
761 val = avio_rb16(s) << 8;
765 unsigned int avio_rb32(AVIOContext *s)
768 val = avio_rb16(s) << 16;
774 char *get_strz(AVIOContext *s, char *buf, int maxlen)
776 avio_get_str(s, INT_MAX, buf, maxlen);
781 int ff_get_line(AVIOContext *s, char *buf, int maxlen)
788 if (c && i < maxlen-1)
790 } while (c != '\n' && c);
796 int avio_get_str(AVIOContext *s, int maxlen, char *buf, int buflen)
801 return AVERROR(EINVAL);
802 // reserve 1 byte for terminating 0
803 buflen = FFMIN(buflen - 1, maxlen);
804 for (i = 0; i < buflen; i++)
805 if (!(buf[i] = avio_r8(s)))
808 for (; i < maxlen; i++)
814 #define GET_STR16(type, read) \
815 int avio_get_str16 ##type(AVIOContext *pb, int maxlen, char *buf, int buflen)\
820 return AVERROR(EINVAL); \
821 while (ret + 1 < maxlen) {\
824 GET_UTF16(ch, (ret += 2) <= maxlen ? read(pb) : 0, break;)\
827 PUT_UTF8(ch, tmp, if (q - buf < buflen - 1) *q++ = tmp;)\
833 GET_STR16(le, avio_rl16)
834 GET_STR16(be, avio_rb16)
838 uint64_t avio_rb64(AVIOContext *s)
841 val = (uint64_t)avio_rb32(s) << 32;
842 val |= (uint64_t)avio_rb32(s);
846 uint64_t ffio_read_varlen(AVIOContext *bc){
852 val= (val<<7) + (tmp&127);
857 int ffio_fdopen(AVIOContext **s, URLContext *h)
860 int buffer_size, max_packet_size;
862 max_packet_size = h->max_packet_size;
863 if (max_packet_size) {
864 buffer_size = max_packet_size; /* no need to bufferize more than one packet */
866 buffer_size = IO_BUFFER_SIZE;
868 buffer = av_malloc(buffer_size);
870 return AVERROR(ENOMEM);
872 *s = avio_alloc_context(buffer, buffer_size, h->flags & AVIO_FLAG_WRITE, h,
873 ffurl_read, ffurl_write, ffurl_seek);
876 return AVERROR(ENOMEM);
879 (*s)->is_streamed = h->is_streamed;
881 (*s)->seekable = h->is_streamed ? 0 : AVIO_SEEKABLE_NORMAL;
882 (*s)->max_packet_size = max_packet_size;
884 (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
885 (*s)->read_seek = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
888 (*s)->av_class = &ffio_url_class;
893 int ffio_set_buf_size(AVIOContext *s, int buf_size)
896 buffer = av_malloc(buf_size);
898 return AVERROR(ENOMEM);
902 s->buffer_size = buf_size;
904 url_resetbuf(s, s->write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ);
908 static int url_resetbuf(AVIOContext *s, int flags)
910 assert(flags == AVIO_FLAG_WRITE || flags == AVIO_FLAG_READ);
912 if (flags & AVIO_FLAG_WRITE) {
913 s->buf_end = s->buffer + s->buffer_size;
916 s->buf_end = s->buffer;
922 int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char *buf, int buf_size)
924 int64_t buffer_start;
926 int overlap, new_size, alloc_size;
929 return AVERROR(EINVAL);
931 buffer_size = s->buf_end - s->buffer;
933 /* the buffers must touch or overlap */
934 if ((buffer_start = s->pos - buffer_size) > buf_size)
935 return AVERROR(EINVAL);
937 overlap = buf_size - buffer_start;
938 new_size = buf_size + buffer_size - overlap;
940 alloc_size = FFMAX(s->buffer_size, new_size);
941 if (alloc_size > buf_size)
942 if (!(buf = av_realloc(buf, alloc_size)))
943 return AVERROR(ENOMEM);
945 if (new_size > buf_size) {
946 memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
951 s->buf_ptr = s->buffer = buf;
952 s->buffer_size = alloc_size;
954 s->buf_end = s->buf_ptr + buf_size;
961 int avio_open(AVIOContext **s, const char *filename, int flags)
963 return avio_open2(s, filename, flags, NULL, NULL);
966 int avio_open2(AVIOContext **s, const char *filename, int flags,
967 const AVIOInterruptCB *int_cb, AVDictionary **options)
972 err = ffurl_open(&h, filename, flags, int_cb, options);
975 err = ffio_fdopen(s, h);
983 int avio_close(AVIOContext *s)
985 URLContext *h = s->opaque;
989 return ffurl_close(h);
993 URLContext *url_fileno(AVIOContext *s)
999 int avio_printf(AVIOContext *s, const char *fmt, ...)
1006 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
1008 avio_write(s, buf, strlen(buf));
1013 char *url_fgets(AVIOContext *s, char *buf, int buf_size)
1023 if (s->eof_reached || c == '\n')
1025 if ((q - buf) < buf_size - 1)
1034 int url_fget_max_packet_size(AVIOContext *s)
1036 return s->max_packet_size;
1040 int avio_pause(AVIOContext *s, int pause)
1043 return AVERROR(ENOSYS);
1044 return s->read_pause(s->opaque, pause);
1047 int64_t avio_seek_time(AVIOContext *s, int stream_index,
1048 int64_t timestamp, int flags)
1050 URLContext *h = s->opaque;
1053 return AVERROR(ENOSYS);
1054 ret = s->read_seek(h, stream_index, timestamp, flags);
1057 s->buf_ptr = s->buf_end; // Flush buffer
1058 pos = s->seek(h, 0, SEEK_CUR);
1061 else if (pos != AVERROR(ENOSYS))
1067 /* buffer handling */
1069 int url_open_buf(AVIOContext **s, uint8_t *buf, int buf_size, int flags)
1072 *s = av_mallocz(sizeof(AVIOContext));
1074 return AVERROR(ENOMEM);
1075 ret = ffio_init_context(*s, buf, buf_size,
1076 flags & AVIO_FLAG_WRITE,
1077 NULL, NULL, NULL, NULL);
1083 int url_close_buf(AVIOContext *s)
1086 return s->buf_ptr - s->buffer;
1090 /* output in a dynamic buffer */
1092 typedef struct DynBuffer {
1093 int pos, size, allocated_size;
1096 uint8_t io_buffer[1];
1099 static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
1101 DynBuffer *d = opaque;
1102 unsigned new_size, new_allocated_size;
1104 /* reallocate buffer if needed */
1105 new_size = d->pos + buf_size;
1106 new_allocated_size = d->allocated_size;
1107 if(new_size < d->pos || new_size > INT_MAX/2)
1109 while (new_size > new_allocated_size) {
1110 if (!new_allocated_size)
1111 new_allocated_size = new_size;
1113 new_allocated_size += new_allocated_size / 2 + 1;
1116 if (new_allocated_size > d->allocated_size) {
1117 d->buffer = av_realloc(d->buffer, new_allocated_size);
1118 if(d->buffer == NULL)
1119 return AVERROR(ENOMEM);
1120 d->allocated_size = new_allocated_size;
1122 memcpy(d->buffer + d->pos, buf, buf_size);
1124 if (d->pos > d->size)
1129 static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
1131 unsigned char buf1[4];
1134 /* packetized write: output the header */
1135 AV_WB32(buf1, buf_size);
1136 ret= dyn_buf_write(opaque, buf1, 4);
1141 return dyn_buf_write(opaque, buf, buf_size);
1144 static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
1146 DynBuffer *d = opaque;
1148 if (whence == SEEK_CUR)
1150 else if (whence == SEEK_END)
1152 if (offset < 0 || offset > 0x7fffffffLL)
1158 static int url_open_dyn_buf_internal(AVIOContext **s, int max_packet_size)
1161 unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
1163 if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
1165 d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
1167 return AVERROR(ENOMEM);
1168 d->io_buffer_size = io_buffer_size;
1169 *s = avio_alloc_context(d->io_buffer, d->io_buffer_size, 1, d, NULL,
1170 max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
1171 max_packet_size ? NULL : dyn_buf_seek);
1174 return AVERROR(ENOMEM);
1176 (*s)->max_packet_size = max_packet_size;
1180 int avio_open_dyn_buf(AVIOContext **s)
1182 return url_open_dyn_buf_internal(s, 0);
1185 int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size)
1187 if (max_packet_size <= 0)
1189 return url_open_dyn_buf_internal(s, max_packet_size);
1192 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
1194 DynBuffer *d = s->opaque;
1196 static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
1199 /* don't attempt to pad fixed-size packet buffers */
1200 if (!s->max_packet_size) {
1201 avio_write(s, padbuf, sizeof(padbuf));
1202 padding = FF_INPUT_BUFFER_PADDING_SIZE;
1207 *pbuffer = d->buffer;
1211 return size - padding;