2 * Buffered I/O for ffmpeg system
3 * Copyright (c) 2000,2001 Fabrice Bellard
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/crc.h"
23 #include "libavutil/intreadwrite.h"
26 #include "avio_internal.h"
31 #define IO_BUFFER_SIZE 32768
34 * Do seeks within this distance ahead of the current buffer by skipping
35 * data instead of calling the protocol seek function, for seekable
38 #define SHORT_SEEK_THRESHOLD 4096
40 static void fill_buffer(AVIOContext *s);
41 static int url_resetbuf(AVIOContext *s, int flags);
43 int ffio_init_context(AVIOContext *s,
44 unsigned char *buffer,
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))
53 s->buffer_size = buffer_size;
56 url_resetbuf(s, write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ);
57 s->write_packet = write_packet;
58 s->read_packet = read_packet;
67 s->seekable = AVIO_SEEKABLE_NORMAL;
68 s->max_packet_size = 0;
69 s->update_checksum= NULL;
70 if(!read_packet && !write_flag){
72 s->buf_end = s->buffer + buffer_size;
80 int init_put_byte(AVIOContext *s,
81 unsigned char *buffer,
85 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
86 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
87 int64_t (*seek)(void *opaque, int64_t offset, int whence))
89 return ffio_init_context(s, buffer, buffer_size, write_flag, opaque,
90 read_packet, write_packet, seek);
92 AVIOContext *av_alloc_put_byte(
93 unsigned char *buffer,
97 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
98 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
99 int64_t (*seek)(void *opaque, int64_t offset, int whence))
101 return avio_alloc_context(buffer, buffer_size, write_flag, opaque,
102 read_packet, write_packet, seek);
106 AVIOContext *avio_alloc_context(
107 unsigned char *buffer,
111 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
112 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
113 int64_t (*seek)(void *opaque, int64_t offset, int whence))
115 AVIOContext *s = av_mallocz(sizeof(AVIOContext));
118 ffio_init_context(s, buffer, buffer_size, write_flag, opaque,
119 read_packet, write_packet, seek);
123 static void flush_buffer(AVIOContext *s)
125 if (s->buf_ptr > s->buffer) {
126 if (s->write_packet && !s->error){
127 int ret= s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
132 if(s->update_checksum){
133 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
134 s->checksum_ptr= s->buffer;
136 s->pos += s->buf_ptr - s->buffer;
138 s->buf_ptr = s->buffer;
141 void avio_w8(AVIOContext *s, int b)
144 if (s->buf_ptr >= s->buf_end)
148 void ffio_fill(AVIOContext *s, int b, int count)
151 int len = FFMIN(s->buf_end - s->buf_ptr, count);
152 memset(s->buf_ptr, b, len);
155 if (s->buf_ptr >= s->buf_end)
162 void avio_write(AVIOContext *s, const unsigned char *buf, int size)
165 int len = FFMIN(s->buf_end - s->buf_ptr, size);
166 memcpy(s->buf_ptr, buf, len);
169 if (s->buf_ptr >= s->buf_end)
177 void avio_flush(AVIOContext *s)
183 int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
187 int force = whence & AVSEEK_FORCE;
188 whence &= ~AVSEEK_FORCE;
191 return AVERROR(EINVAL);
193 pos = s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
195 if (whence != SEEK_CUR && whence != SEEK_SET)
196 return AVERROR(EINVAL);
198 if (whence == SEEK_CUR) {
199 offset1 = pos + (s->buf_ptr - s->buffer);
204 offset1 = offset - pos;
205 if (!s->must_flush &&
206 offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
207 /* can do the seek inside the buffer */
208 s->buf_ptr = s->buffer + offset1;
209 } else if ((!s->seekable ||
210 offset1 <= s->buf_end + SHORT_SEEK_THRESHOLD - s->buffer) &&
211 !s->write_flag && offset1 >= 0 &&
212 (whence != SEEK_END || force)) {
213 while(s->pos < offset && !s->eof_reached)
217 s->buf_ptr = s->buf_end + offset - s->pos;
221 #if CONFIG_MUXERS || CONFIG_NETWORK
226 #endif /* CONFIG_MUXERS || CONFIG_NETWORK */
228 return AVERROR(EPIPE);
229 if ((res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
232 s->buf_end = s->buffer;
233 s->buf_ptr = s->buffer;
240 int64_t avio_skip(AVIOContext *s, int64_t offset)
242 return avio_seek(s, offset, SEEK_CUR);
246 int url_fskip(AVIOContext *s, int64_t offset)
248 int64_t ret = avio_seek(s, offset, SEEK_CUR);
249 return ret < 0 ? ret : 0;
252 int64_t url_ftell(AVIOContext *s)
254 return avio_seek(s, 0, SEEK_CUR);
258 int64_t avio_size(AVIOContext *s)
263 return AVERROR(EINVAL);
266 return AVERROR(ENOSYS);
267 size = s->seek(s->opaque, 0, AVSEEK_SIZE);
269 if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
272 s->seek(s->opaque, s->pos, SEEK_SET);
277 int url_feof(AVIOContext *s)
285 return s->eof_reached;
289 int url_ferror(AVIOContext *s)
297 void avio_wl32(AVIOContext *s, unsigned int val)
300 avio_w8(s, val >> 8);
301 avio_w8(s, val >> 16);
302 avio_w8(s, val >> 24);
305 void avio_wb32(AVIOContext *s, unsigned int val)
307 avio_w8(s, val >> 24);
308 avio_w8(s, val >> 16);
309 avio_w8(s, val >> 8);
314 void put_strz(AVIOContext *s, const char *str)
316 avio_put_str(s, str);
319 #define GET(name, type) \
320 type get_be ##name(AVIOContext *s) \
322 return avio_rb ##name(s);\
324 type get_le ##name(AVIOContext *s) \
326 return avio_rl ##name(s);\
329 GET(16, unsigned int)
330 GET(24, unsigned int)
331 GET(32, unsigned int)
336 #define PUT(name, type ) \
337 void put_le ##name(AVIOContext *s, type val)\
339 avio_wl ##name(s, val);\
341 void put_be ##name(AVIOContext *s, type val)\
343 avio_wb ##name(s, val);\
346 PUT(16, unsigned int)
347 PUT(24, unsigned int)
348 PUT(32, unsigned int)
352 int get_byte(AVIOContext *s)
356 int get_buffer(AVIOContext *s, unsigned char *buf, int size)
358 return avio_read(s, buf, size);
360 int get_partial_buffer(AVIOContext *s, unsigned char *buf, int size)
362 return ffio_read_partial(s, buf, size);
364 void put_byte(AVIOContext *s, int val)
368 void put_buffer(AVIOContext *s, const unsigned char *buf, int size)
370 avio_write(s, buf, size);
372 void put_nbyte(AVIOContext *s, int b, int count)
374 ffio_fill(s, b, count);
377 int url_fopen(AVIOContext **s, const char *filename, int flags)
379 return avio_open(s, filename, flags);
381 int url_fclose(AVIOContext *s)
383 return avio_close(s);
385 int64_t url_fseek(AVIOContext *s, int64_t offset, int whence)
387 return avio_seek(s, offset, whence);
389 int64_t url_fsize(AVIOContext *s)
393 int url_setbufsize(AVIOContext *s, int buf_size)
395 return ffio_set_buf_size(s, buf_size);
397 int url_fprintf(AVIOContext *s, const char *fmt, ...)
404 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
406 avio_write(s, buf, strlen(buf));
409 void put_flush_packet(AVIOContext *s)
413 int av_url_read_fpause(AVIOContext *s, int pause)
415 return avio_pause(s, pause);
417 int64_t av_url_read_fseek(AVIOContext *s, int stream_index,
418 int64_t timestamp, int flags)
420 return avio_seek_time(s, stream_index, timestamp, flags);
422 void init_checksum(AVIOContext *s,
423 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
424 unsigned long checksum)
426 ffio_init_checksum(s, update_checksum, checksum);
428 unsigned long get_checksum(AVIOContext *s)
430 return ffio_get_checksum(s);
432 int url_open_dyn_buf(AVIOContext **s)
434 return avio_open_dyn_buf(s);
436 int url_open_dyn_packet_buf(AVIOContext **s, int max_packet_size)
438 return ffio_open_dyn_packet_buf(s, max_packet_size);
440 int url_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
442 return avio_close_dyn_buf(s, pbuffer);
444 int url_fdopen(AVIOContext **s, URLContext *h)
446 return ffio_fdopen(s, h);
450 int avio_put_str(AVIOContext *s, const char *str)
455 avio_write(s, (const unsigned char *) str, len);
461 int avio_put_str16le(AVIOContext *s, const char *str)
463 const uint8_t *q = str;
470 GET_UTF8(ch, *q++, break;)
471 PUT_UTF16(ch, tmp, avio_wl16(s, tmp);ret += 2;)
478 int ff_get_v_length(uint64_t val){
487 void ff_put_v(AVIOContext *bc, uint64_t val){
488 int i= ff_get_v_length(val);
491 avio_w8(bc, 128 | (val>>(7*i)));
493 avio_w8(bc, val&127);
496 void avio_wl64(AVIOContext *s, uint64_t val)
498 avio_wl32(s, (uint32_t)(val & 0xffffffff));
499 avio_wl32(s, (uint32_t)(val >> 32));
502 void avio_wb64(AVIOContext *s, uint64_t val)
504 avio_wb32(s, (uint32_t)(val >> 32));
505 avio_wb32(s, (uint32_t)(val & 0xffffffff));
508 void avio_wl16(AVIOContext *s, unsigned int val)
511 avio_w8(s, val >> 8);
514 void avio_wb16(AVIOContext *s, unsigned int val)
516 avio_w8(s, val >> 8);
520 void avio_wl24(AVIOContext *s, unsigned int val)
522 avio_wl16(s, val & 0xffff);
523 avio_w8(s, val >> 16);
526 void avio_wb24(AVIOContext *s, unsigned int val)
528 avio_wb16(s, val >> 8);
533 void put_tag(AVIOContext *s, const char *tag)
543 static void fill_buffer(AVIOContext *s)
545 uint8_t *dst= !s->max_packet_size && s->buf_end - s->buffer < s->buffer_size ? s->buf_end : s->buffer;
546 int len= s->buffer_size - (dst - s->buffer);
547 int max_buffer_size = s->max_packet_size ? s->max_packet_size : IO_BUFFER_SIZE;
549 /* no need to do anything if EOF already reached */
553 if(s->update_checksum && dst == s->buffer){
554 if(s->buf_end > s->checksum_ptr)
555 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
556 s->checksum_ptr= s->buffer;
559 /* make buffer smaller in case it ended up large after probing */
560 if (s->read_packet && s->buffer_size > max_buffer_size) {
561 ffio_set_buf_size(s, max_buffer_size);
563 s->checksum_ptr = dst = s->buffer;
564 len = s->buffer_size;
568 len = s->read_packet(s->opaque, dst, len);
572 /* do not modify buffer if EOF reached so that a seek back can
573 be done without rereading data */
580 s->buf_end = dst + len;
584 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
587 return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
590 unsigned long ffio_get_checksum(AVIOContext *s)
592 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
593 s->update_checksum= NULL;
597 void ffio_init_checksum(AVIOContext *s,
598 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
599 unsigned long checksum)
601 s->update_checksum= update_checksum;
602 if(s->update_checksum){
603 s->checksum= checksum;
604 s->checksum_ptr= s->buf_ptr;
608 /* XXX: put an inline version */
609 int avio_r8(AVIOContext *s)
611 if (s->buf_ptr >= s->buf_end)
613 if (s->buf_ptr < s->buf_end)
614 return *s->buf_ptr++;
619 int url_fgetc(AVIOContext *s)
621 if (s->buf_ptr >= s->buf_end)
623 if (s->buf_ptr < s->buf_end)
624 return *s->buf_ptr++;
629 int avio_read(AVIOContext *s, unsigned char *buf, int size)
635 len = s->buf_end - s->buf_ptr;
639 if(size > s->buffer_size && !s->update_checksum){
641 len = s->read_packet(s->opaque, buf, size);
643 /* do not modify buffer if EOF reached so that a seek back can
644 be done without rereading data */
653 s->buf_ptr = s->buffer;
654 s->buf_end = s->buffer/* + len*/;
658 len = s->buf_end - s->buf_ptr;
663 memcpy(buf, s->buf_ptr, len);
670 if (s->error) return s->error;
671 if (url_feof(s)) return AVERROR_EOF;
676 int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size)
683 len = s->buf_end - s->buf_ptr;
686 len = s->buf_end - s->buf_ptr;
690 memcpy(buf, s->buf_ptr, len);
693 if (s->error) return s->error;
694 if (url_feof(s)) return AVERROR_EOF;
699 unsigned int avio_rl16(AVIOContext *s)
703 val |= avio_r8(s) << 8;
707 unsigned int avio_rl24(AVIOContext *s)
711 val |= avio_r8(s) << 16;
715 unsigned int avio_rl32(AVIOContext *s)
719 val |= avio_rl16(s) << 16;
723 uint64_t avio_rl64(AVIOContext *s)
726 val = (uint64_t)avio_rl32(s);
727 val |= (uint64_t)avio_rl32(s) << 32;
731 unsigned int avio_rb16(AVIOContext *s)
734 val = avio_r8(s) << 8;
739 unsigned int avio_rb24(AVIOContext *s)
742 val = avio_rb16(s) << 8;
746 unsigned int avio_rb32(AVIOContext *s)
749 val = avio_rb16(s) << 16;
755 char *get_strz(AVIOContext *s, char *buf, int maxlen)
757 avio_get_str(s, INT_MAX, buf, maxlen);
762 int ff_get_line(AVIOContext *s, char *buf, int maxlen)
769 if (c && i < maxlen-1)
771 } while (c != '\n' && c);
777 int avio_get_str(AVIOContext *s, int maxlen, char *buf, int buflen)
782 return AVERROR(EINVAL);
783 // reserve 1 byte for terminating 0
784 buflen = FFMIN(buflen - 1, maxlen);
785 for (i = 0; i < buflen; i++)
786 if (!(buf[i] = avio_r8(s)))
789 for (; i < maxlen; i++)
795 #define GET_STR16(type, read) \
796 int avio_get_str16 ##type(AVIOContext *pb, int maxlen, char *buf, int buflen)\
801 return AVERROR(EINVAL); \
802 while (ret + 1 < maxlen) {\
805 GET_UTF16(ch, (ret += 2) <= maxlen ? read(pb) : 0, break;)\
808 PUT_UTF8(ch, tmp, if (q - buf < buflen - 1) *q++ = tmp;)\
814 GET_STR16(le, avio_rl16)
815 GET_STR16(be, avio_rb16)
819 uint64_t avio_rb64(AVIOContext *s)
822 val = (uint64_t)avio_rb32(s) << 32;
823 val |= (uint64_t)avio_rb32(s);
827 uint64_t ffio_read_varlen(AVIOContext *bc){
833 val= (val<<7) + (tmp&127);
838 int ffio_fdopen(AVIOContext **s, URLContext *h)
841 int buffer_size, max_packet_size;
843 max_packet_size = h->max_packet_size;
844 if (max_packet_size) {
845 buffer_size = max_packet_size; /* no need to bufferize more than one packet */
847 buffer_size = IO_BUFFER_SIZE;
849 buffer = av_malloc(buffer_size);
851 return AVERROR(ENOMEM);
853 *s = avio_alloc_context(buffer, buffer_size, h->flags & AVIO_FLAG_WRITE, h,
854 ffurl_read, ffurl_write, ffurl_seek);
857 return AVERROR(ENOMEM);
861 (*s)->is_streamed = h->is_streamed;
863 (*s)->seekable = h->is_streamed ? 0 : AVIO_SEEKABLE_NORMAL;
864 (*s)->max_packet_size = max_packet_size;
866 (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
867 (*s)->read_seek = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
872 int ffio_set_buf_size(AVIOContext *s, int buf_size)
875 buffer = av_malloc(buf_size);
877 return AVERROR(ENOMEM);
881 s->buffer_size = buf_size;
883 url_resetbuf(s, s->write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ);
887 static int url_resetbuf(AVIOContext *s, int flags)
889 assert(flags == AVIO_FLAG_WRITE || flags == AVIO_FLAG_READ);
891 if (flags & AVIO_FLAG_WRITE) {
892 s->buf_end = s->buffer + s->buffer_size;
895 s->buf_end = s->buffer;
901 int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char *buf, int buf_size)
903 int64_t buffer_start;
905 int overlap, new_size, alloc_size;
908 return AVERROR(EINVAL);
910 buffer_size = s->buf_end - s->buffer;
912 /* the buffers must touch or overlap */
913 if ((buffer_start = s->pos - buffer_size) > buf_size)
914 return AVERROR(EINVAL);
916 overlap = buf_size - buffer_start;
917 new_size = buf_size + buffer_size - overlap;
919 alloc_size = FFMAX(s->buffer_size, new_size);
920 if (alloc_size > buf_size)
921 if (!(buf = av_realloc_f(buf, 1, alloc_size)))
922 return AVERROR(ENOMEM);
924 if (new_size > buf_size) {
925 memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
930 s->buf_ptr = s->buffer = buf;
931 s->buffer_size = alloc_size;
933 s->buf_end = s->buf_ptr + buf_size;
940 int avio_open(AVIOContext **s, const char *filename, int flags)
945 err = ffurl_open(&h, filename, flags);
948 err = ffio_fdopen(s, h);
956 int avio_close(AVIOContext *s)
958 URLContext *h = s->opaque;
962 return ffurl_close(h);
966 URLContext *url_fileno(AVIOContext *s)
972 int avio_printf(AVIOContext *s, const char *fmt, ...)
979 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
981 avio_write(s, buf, strlen(buf));
986 char *url_fgets(AVIOContext *s, char *buf, int buf_size)
996 if (url_feof(s) || c == '\n')
998 if ((q - buf) < buf_size - 1)
1007 int url_fget_max_packet_size(AVIOContext *s)
1009 return s->max_packet_size;
1013 int avio_pause(AVIOContext *s, int pause)
1016 return AVERROR(ENOSYS);
1017 return s->read_pause(s->opaque, pause);
1020 int64_t avio_seek_time(AVIOContext *s, int stream_index,
1021 int64_t timestamp, int flags)
1023 URLContext *h = s->opaque;
1026 return AVERROR(ENOSYS);
1027 ret = s->read_seek(h, stream_index, timestamp, flags);
1030 s->buf_ptr = s->buf_end; // Flush buffer
1031 pos = s->seek(h, 0, SEEK_CUR);
1034 else if (pos != AVERROR(ENOSYS))
1040 /* buffer handling */
1042 int url_open_buf(AVIOContext **s, uint8_t *buf, int buf_size, int flags)
1045 *s = av_mallocz(sizeof(AVIOContext));
1047 return AVERROR(ENOMEM);
1048 ret = ffio_init_context(*s, buf, buf_size,
1049 flags & AVIO_FLAG_WRITE,
1050 NULL, NULL, NULL, NULL);
1056 int url_close_buf(AVIOContext *s)
1059 return s->buf_ptr - s->buffer;
1063 /* output in a dynamic buffer */
1065 typedef struct DynBuffer {
1066 int pos, size, allocated_size;
1069 uint8_t io_buffer[1];
1072 static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
1074 DynBuffer *d = opaque;
1075 unsigned new_size, new_allocated_size;
1077 /* reallocate buffer if needed */
1078 new_size = d->pos + buf_size;
1079 new_allocated_size = d->allocated_size;
1080 if(new_size < d->pos || new_size > INT_MAX/2)
1082 while (new_size > new_allocated_size) {
1083 if (!new_allocated_size)
1084 new_allocated_size = new_size;
1086 new_allocated_size += new_allocated_size / 2 + 1;
1089 if (new_allocated_size > d->allocated_size) {
1090 d->buffer = av_realloc_f(d->buffer, 1, new_allocated_size);
1091 if(d->buffer == NULL)
1092 return AVERROR(ENOMEM);
1093 d->allocated_size = new_allocated_size;
1095 memcpy(d->buffer + d->pos, buf, buf_size);
1097 if (d->pos > d->size)
1102 static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
1104 unsigned char buf1[4];
1107 /* packetized write: output the header */
1108 AV_WB32(buf1, buf_size);
1109 ret= dyn_buf_write(opaque, buf1, 4);
1114 return dyn_buf_write(opaque, buf, buf_size);
1117 static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
1119 DynBuffer *d = opaque;
1121 if (whence == SEEK_CUR)
1123 else if (whence == SEEK_END)
1125 if (offset < 0 || offset > 0x7fffffffLL)
1131 static int url_open_dyn_buf_internal(AVIOContext **s, int max_packet_size)
1134 unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
1136 if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
1138 d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
1140 return AVERROR(ENOMEM);
1141 d->io_buffer_size = io_buffer_size;
1142 *s = avio_alloc_context(d->io_buffer, d->io_buffer_size, 1, d, NULL,
1143 max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
1144 max_packet_size ? NULL : dyn_buf_seek);
1147 return AVERROR(ENOMEM);
1149 (*s)->max_packet_size = max_packet_size;
1153 int avio_open_dyn_buf(AVIOContext **s)
1155 return url_open_dyn_buf_internal(s, 0);
1158 int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size)
1160 if (max_packet_size <= 0)
1162 return url_open_dyn_buf_internal(s, max_packet_size);
1165 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
1167 DynBuffer *d = s->opaque;
1169 static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
1172 /* don't attempt to pad fixed-size packet buffers */
1173 if (!s->max_packet_size) {
1174 avio_write(s, padbuf, sizeof(padbuf));
1175 padding = FF_INPUT_BUFFER_PADDING_SIZE;
1180 *pbuffer = d->buffer;
1184 return size - padding;