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/bprint.h"
23 #include "libavutil/crc.h"
24 #include "libavutil/dict.h"
25 #include "libavutil/intreadwrite.h"
26 #include "libavutil/log.h"
27 #include "libavutil/opt.h"
28 #include "libavutil/avassert.h"
31 #include "avio_internal.h"
36 #define IO_BUFFER_SIZE 32768
39 * Do seeks within this distance ahead of the current buffer by skipping
40 * data instead of calling the protocol seek function, for seekable
43 #define SHORT_SEEK_THRESHOLD 4096
45 static void *ffio_url_child_next(void *obj, void *prev)
48 return prev ? NULL : s->opaque;
51 static const AVClass *ffio_url_child_class_next(const AVClass *prev)
53 return prev ? NULL : &ffurl_context_class;
56 static const AVOption ffio_url_options[] = {
60 const AVClass ffio_url_class = {
61 .class_name = "AVIOContext",
62 .item_name = av_default_item_name,
63 .version = LIBAVUTIL_VERSION_INT,
64 .option = ffio_url_options,
65 .child_next = ffio_url_child_next,
66 .child_class_next = ffio_url_child_class_next,
69 static void fill_buffer(AVIOContext *s);
70 static int url_resetbuf(AVIOContext *s, int flags);
72 int ffio_init_context(AVIOContext *s,
73 unsigned char *buffer,
77 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
78 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
79 int64_t (*seek)(void *opaque, int64_t offset, int whence))
83 s->buffer_size = buffer_size;
88 url_resetbuf(s, write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ);
90 s->write_packet = write_packet;
91 s->read_packet = read_packet;
97 s->seekable = seek ? AVIO_SEEKABLE_NORMAL : 0;
98 s->max_packet_size = 0;
99 s->update_checksum = NULL;
101 if (!read_packet && !write_flag) {
102 s->pos = buffer_size;
103 s->buf_end = s->buffer + buffer_size;
105 s->read_pause = NULL;
111 AVIOContext *avio_alloc_context(
112 unsigned char *buffer,
116 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
117 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
118 int64_t (*seek)(void *opaque, int64_t offset, int whence))
120 AVIOContext *s = av_mallocz(sizeof(AVIOContext));
123 ffio_init_context(s, buffer, buffer_size, write_flag, opaque,
124 read_packet, write_packet, seek);
128 static void writeout(AVIOContext *s, const uint8_t *data, int len)
130 if (s->write_packet && !s->error) {
131 int ret = s->write_packet(s->opaque, (uint8_t *)data, len);
136 s->writeout_count ++;
140 static void flush_buffer(AVIOContext *s)
142 if (s->buf_ptr > s->buffer) {
143 writeout(s, s->buffer, s->buf_ptr - s->buffer);
144 if (s->update_checksum) {
145 s->checksum = s->update_checksum(s->checksum, s->checksum_ptr,
146 s->buf_ptr - s->checksum_ptr);
147 s->checksum_ptr = s->buffer;
150 s->buf_ptr = s->buffer;
153 void avio_w8(AVIOContext *s, int b)
155 av_assert2(b>=-128 && b<=255);
157 if (s->buf_ptr >= s->buf_end)
161 void ffio_fill(AVIOContext *s, int b, int count)
164 int len = FFMIN(s->buf_end - s->buf_ptr, count);
165 memset(s->buf_ptr, b, len);
168 if (s->buf_ptr >= s->buf_end)
175 void avio_write(AVIOContext *s, const unsigned char *buf, int size)
177 if (s->direct && !s->update_checksum) {
179 writeout(s, buf, size);
183 int len = FFMIN(s->buf_end - s->buf_ptr, size);
184 memcpy(s->buf_ptr, buf, len);
187 if (s->buf_ptr >= s->buf_end)
195 void avio_flush(AVIOContext *s)
201 int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
205 int force = whence & AVSEEK_FORCE;
207 whence &= ~AVSEEK_FORCE;
210 return AVERROR(EINVAL);
212 buffer_size = s->buf_end - s->buffer;
213 pos = s->pos - (s->write_flag ? 0 : buffer_size);
215 if (whence != SEEK_CUR && whence != SEEK_SET)
216 return AVERROR(EINVAL);
218 if (whence == SEEK_CUR) {
219 offset1 = pos + (s->buf_ptr - s->buffer);
224 offset1 = offset - pos;
225 if (!s->must_flush && (!s->direct || !s->seek) &&
226 offset1 >= 0 && offset1 <= buffer_size) {
227 /* can do the seek inside the buffer */
228 s->buf_ptr = s->buffer + offset1;
229 } else if ((!s->seekable ||
230 offset1 <= s->buf_end + SHORT_SEEK_THRESHOLD - s->buffer) &&
231 !s->write_flag && offset1 >= 0 &&
232 (!s->direct || !s->seek) &&
233 (whence != SEEK_END || force)) {
234 while(s->pos < offset && !s->eof_reached)
238 s->buf_ptr = s->buf_end + offset - s->pos;
239 } else if(!s->write_flag && offset1 < 0 && -offset1 < buffer_size>>1 && s->seek && offset > 0) {
242 pos -= FFMIN(buffer_size>>1, pos);
243 if ((res = s->seek(s->opaque, pos, SEEK_SET)) < 0)
246 s->buf_ptr = s->buffer;
250 return avio_seek(s, offset, SEEK_SET | force);
258 return AVERROR(EPIPE);
259 if ((res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
263 s->buf_end = s->buffer;
264 s->buf_ptr = s->buffer;
271 int64_t avio_skip(AVIOContext *s, int64_t offset)
273 return avio_seek(s, offset, SEEK_CUR);
276 int64_t avio_size(AVIOContext *s)
281 return AVERROR(EINVAL);
284 return AVERROR(ENOSYS);
285 size = s->seek(s->opaque, 0, AVSEEK_SIZE);
287 if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
290 s->seek(s->opaque, s->pos, SEEK_SET);
295 int avio_feof(AVIOContext *s)
303 return s->eof_reached;
307 int url_feof(AVIOContext *s)
313 void avio_wl32(AVIOContext *s, unsigned int val)
315 avio_w8(s, (uint8_t) val );
316 avio_w8(s, (uint8_t)(val >> 8 ));
317 avio_w8(s, (uint8_t)(val >> 16));
318 avio_w8(s, val >> 24 );
321 void avio_wb32(AVIOContext *s, unsigned int val)
323 avio_w8(s, val >> 24 );
324 avio_w8(s, (uint8_t)(val >> 16));
325 avio_w8(s, (uint8_t)(val >> 8 ));
326 avio_w8(s, (uint8_t) val );
329 int avio_put_str(AVIOContext *s, const char *str)
334 avio_write(s, (const unsigned char *) str, len);
340 int avio_put_str16le(AVIOContext *s, const char *str)
342 const uint8_t *q = str;
350 GET_UTF8(ch, *q++, goto invalid;)
351 PUT_UTF16(ch, tmp, avio_wl16(s, tmp); ret += 2;)
354 av_log(s, AV_LOG_ERROR, "Invaid UTF8 sequence in avio_put_str16le\n");
355 err = AVERROR(EINVAL);
364 int ff_get_v_length(uint64_t val)
374 void ff_put_v(AVIOContext *bc, uint64_t val)
376 int i = ff_get_v_length(val);
379 avio_w8(bc, 128 | (uint8_t)(val >> (7*i)));
381 avio_w8(bc, val & 127);
384 void avio_wl64(AVIOContext *s, uint64_t val)
386 avio_wl32(s, (uint32_t)(val & 0xffffffff));
387 avio_wl32(s, (uint32_t)(val >> 32));
390 void avio_wb64(AVIOContext *s, uint64_t val)
392 avio_wb32(s, (uint32_t)(val >> 32));
393 avio_wb32(s, (uint32_t)(val & 0xffffffff));
396 void avio_wl16(AVIOContext *s, unsigned int val)
398 avio_w8(s, (uint8_t)val);
399 avio_w8(s, (int)val >> 8);
402 void avio_wb16(AVIOContext *s, unsigned int val)
404 avio_w8(s, (int)val >> 8);
405 avio_w8(s, (uint8_t)val);
408 void avio_wl24(AVIOContext *s, unsigned int val)
410 avio_wl16(s, val & 0xffff);
411 avio_w8(s, (int)val >> 16);
414 void avio_wb24(AVIOContext *s, unsigned int val)
416 avio_wb16(s, (int)val >> 8);
417 avio_w8(s, (uint8_t)val);
422 static void fill_buffer(AVIOContext *s)
424 int max_buffer_size = s->max_packet_size ?
425 s->max_packet_size : IO_BUFFER_SIZE;
426 uint8_t *dst = s->buf_end - s->buffer + max_buffer_size < s->buffer_size ?
427 s->buf_end : s->buffer;
428 int len = s->buffer_size - (dst - s->buffer);
430 /* can't fill the buffer without read_packet, just set EOF if appropriate */
431 if (!s->read_packet && s->buf_ptr >= s->buf_end)
434 /* no need to do anything if EOF already reached */
438 if (s->update_checksum && dst == s->buffer) {
439 if (s->buf_end > s->checksum_ptr)
440 s->checksum = s->update_checksum(s->checksum, s->checksum_ptr,
441 s->buf_end - s->checksum_ptr);
442 s->checksum_ptr = s->buffer;
445 /* make buffer smaller in case it ended up large after probing */
446 if (s->read_packet && s->orig_buffer_size && s->buffer_size > s->orig_buffer_size) {
447 if (dst == s->buffer) {
448 ffio_set_buf_size(s, s->orig_buffer_size);
450 s->checksum_ptr = dst = s->buffer;
452 av_assert0(len >= s->orig_buffer_size);
453 len = s->orig_buffer_size;
457 len = s->read_packet(s->opaque, dst, len);
461 /* do not modify buffer if EOF reached so that a seek back can
462 be done without rereading data */
469 s->buf_end = dst + len;
470 s->bytes_read += len;
474 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
477 return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
480 unsigned long ff_crcA001_update(unsigned long checksum, const uint8_t *buf,
483 return av_crc(av_crc_get_table(AV_CRC_16_ANSI_LE), checksum, buf, len);
486 unsigned long ffio_get_checksum(AVIOContext *s)
488 s->checksum = s->update_checksum(s->checksum, s->checksum_ptr,
489 s->buf_ptr - s->checksum_ptr);
490 s->update_checksum = NULL;
494 void ffio_init_checksum(AVIOContext *s,
495 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
496 unsigned long checksum)
498 s->update_checksum = update_checksum;
499 if (s->update_checksum) {
500 s->checksum = checksum;
501 s->checksum_ptr = s->buf_ptr;
505 /* XXX: put an inline version */
506 int avio_r8(AVIOContext *s)
508 if (s->buf_ptr >= s->buf_end)
510 if (s->buf_ptr < s->buf_end)
511 return *s->buf_ptr++;
515 int avio_read(AVIOContext *s, unsigned char *buf, int size)
521 len = s->buf_end - s->buf_ptr;
524 if (len == 0 || s->write_flag) {
525 if((s->direct || size > s->buffer_size) && !s->update_checksum){
527 len = s->read_packet(s->opaque, buf, size);
529 /* do not modify buffer if EOF reached so that a seek back can
530 be done without rereading data */
537 s->bytes_read += len;
540 s->buf_ptr = s->buffer;
541 s->buf_end = s->buffer/* + len*/;
545 len = s->buf_end - s->buf_ptr;
550 memcpy(buf, s->buf_ptr, len);
557 if (s->error) return s->error;
558 if (avio_feof(s)) return AVERROR_EOF;
563 int ffio_read_indirect(AVIOContext *s, unsigned char *buf, int size, const unsigned char **data)
565 if (s->buf_end - s->buf_ptr >= size && !s->write_flag) {
571 return avio_read(s, buf, size);
575 int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size)
582 if (s->read_packet && s->write_flag) {
583 len = s->read_packet(s->opaque, buf, size);
589 len = s->buf_end - s->buf_ptr;
591 /* Reset the buf_end pointer to the start of the buffer, to make sure
592 * the fill_buffer call tries to read as much data as fits into the
593 * full buffer, instead of just what space is left after buf_end.
594 * This avoids returning partial packets at the end of the buffer,
595 * for packet based inputs.
597 s->buf_end = s->buf_ptr = s->buffer;
599 len = s->buf_end - s->buf_ptr;
603 memcpy(buf, s->buf_ptr, len);
606 if (s->error) return s->error;
607 if (avio_feof(s)) return AVERROR_EOF;
612 unsigned int avio_rl16(AVIOContext *s)
616 val |= avio_r8(s) << 8;
620 unsigned int avio_rl24(AVIOContext *s)
624 val |= avio_r8(s) << 16;
628 unsigned int avio_rl32(AVIOContext *s)
632 val |= avio_rl16(s) << 16;
636 uint64_t avio_rl64(AVIOContext *s)
639 val = (uint64_t)avio_rl32(s);
640 val |= (uint64_t)avio_rl32(s) << 32;
644 unsigned int avio_rb16(AVIOContext *s)
647 val = avio_r8(s) << 8;
652 unsigned int avio_rb24(AVIOContext *s)
655 val = avio_rb16(s) << 8;
659 unsigned int avio_rb32(AVIOContext *s)
662 val = avio_rb16(s) << 16;
667 int ff_get_line(AVIOContext *s, char *buf, int maxlen)
674 if (c && i < maxlen-1)
676 } while (c != '\n' && c != '\r' && c);
677 if (c == '\r' && avio_r8(s) != '\n')
684 int avio_get_str(AVIOContext *s, int maxlen, char *buf, int buflen)
689 return AVERROR(EINVAL);
690 // reserve 1 byte for terminating 0
691 buflen = FFMIN(buflen - 1, maxlen);
692 for (i = 0; i < buflen; i++)
693 if (!(buf[i] = avio_r8(s)))
696 for (; i < maxlen; i++)
702 #define GET_STR16(type, read) \
703 int avio_get_str16 ##type(AVIOContext *pb, int maxlen, char *buf, int buflen)\
708 return AVERROR(EINVAL); \
709 while (ret + 1 < maxlen) {\
712 GET_UTF16(ch, (ret += 2) <= maxlen ? read(pb) : 0, break;)\
715 PUT_UTF8(ch, tmp, if (q - buf < buflen - 1) *q++ = tmp;)\
721 GET_STR16(le, avio_rl16)
722 GET_STR16(be, avio_rb16)
726 uint64_t avio_rb64(AVIOContext *s)
729 val = (uint64_t)avio_rb32(s) << 32;
730 val |= (uint64_t)avio_rb32(s);
734 uint64_t ffio_read_varlen(AVIOContext *bc){
740 val= (val<<7) + (tmp&127);
745 int ffio_fdopen(AVIOContext **s, URLContext *h)
748 int buffer_size, max_packet_size;
750 max_packet_size = h->max_packet_size;
751 if (max_packet_size) {
752 buffer_size = max_packet_size; /* no need to bufferize more than one packet */
754 buffer_size = IO_BUFFER_SIZE;
756 buffer = av_malloc(buffer_size);
758 return AVERROR(ENOMEM);
760 *s = avio_alloc_context(buffer, buffer_size, h->flags & AVIO_FLAG_WRITE, h,
761 (void*)ffurl_read, (void*)ffurl_write, (void*)ffurl_seek);
764 return AVERROR(ENOMEM);
766 (*s)->direct = h->flags & AVIO_FLAG_DIRECT;
767 (*s)->seekable = h->is_streamed ? 0 : AVIO_SEEKABLE_NORMAL;
768 (*s)->max_packet_size = max_packet_size;
770 (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
771 (*s)->read_seek = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
773 (*s)->av_class = &ffio_url_class;
777 int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size)
780 int max_buffer_size = s->max_packet_size ?
781 s->max_packet_size : IO_BUFFER_SIZE;
782 int filled = s->buf_end - s->buffer;
784 buf_size += s->buf_ptr - s->buffer + max_buffer_size;
786 if (buf_size < filled || s->seekable)
788 av_assert0(!s->write_flag);
790 buffer = av_malloc(buf_size);
792 return AVERROR(ENOMEM);
794 memcpy(buffer, s->buffer, filled);
796 s->buf_ptr = buffer + (s->buf_ptr - s->buffer);
797 s->buf_end = buffer + (s->buf_end - s->buffer);
799 s->buffer_size = buf_size;
803 int ffio_set_buf_size(AVIOContext *s, int buf_size)
806 buffer = av_malloc(buf_size);
808 return AVERROR(ENOMEM);
812 s->orig_buffer_size =
813 s->buffer_size = buf_size;
815 url_resetbuf(s, s->write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ);
819 static int url_resetbuf(AVIOContext *s, int flags)
821 av_assert1(flags == AVIO_FLAG_WRITE || flags == AVIO_FLAG_READ);
823 if (flags & AVIO_FLAG_WRITE) {
824 s->buf_end = s->buffer + s->buffer_size;
827 s->buf_end = s->buffer;
833 int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char **bufp, int buf_size)
835 int64_t buffer_start;
837 int overlap, new_size, alloc_size;
838 uint8_t *buf = *bufp;
842 return AVERROR(EINVAL);
845 buffer_size = s->buf_end - s->buffer;
847 /* the buffers must touch or overlap */
848 if ((buffer_start = s->pos - buffer_size) > buf_size) {
850 return AVERROR(EINVAL);
853 overlap = buf_size - buffer_start;
854 new_size = buf_size + buffer_size - overlap;
856 alloc_size = FFMAX(s->buffer_size, new_size);
857 if (alloc_size > buf_size)
858 if (!(buf = (*bufp) = av_realloc_f(buf, 1, alloc_size)))
859 return AVERROR(ENOMEM);
861 if (new_size > buf_size) {
862 memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
867 s->buf_ptr = s->buffer = buf;
868 s->buffer_size = alloc_size;
870 s->buf_end = s->buf_ptr + buf_size;
877 int avio_open(AVIOContext **s, const char *filename, int flags)
879 return avio_open2(s, filename, flags, NULL, NULL);
882 int avio_open2(AVIOContext **s, const char *filename, int flags,
883 const AVIOInterruptCB *int_cb, AVDictionary **options)
888 err = ffurl_open(&h, filename, flags, int_cb, options);
891 err = ffio_fdopen(s, h);
899 int avio_close(AVIOContext *s)
908 av_freep(&s->buffer);
910 av_log(s, AV_LOG_DEBUG, "Statistics: %d seeks, %d writeouts\n", s->seek_count, s->writeout_count);
912 av_log(s, AV_LOG_DEBUG, "Statistics: %"PRId64" bytes read, %d seeks\n", s->bytes_read, s->seek_count);
914 return ffurl_close(h);
917 int avio_closep(AVIOContext **s)
919 int ret = avio_close(*s);
924 int avio_printf(AVIOContext *s, const char *fmt, ...)
931 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
933 avio_write(s, buf, strlen(buf));
937 int avio_pause(AVIOContext *s, int pause)
940 return AVERROR(ENOSYS);
941 return s->read_pause(s->opaque, pause);
944 int64_t avio_seek_time(AVIOContext *s, int stream_index,
945 int64_t timestamp, int flags)
947 URLContext *h = s->opaque;
950 return AVERROR(ENOSYS);
951 ret = s->read_seek(h, stream_index, timestamp, flags);
954 s->buf_ptr = s->buf_end; // Flush buffer
955 pos = s->seek(h, 0, SEEK_CUR);
958 else if (pos != AVERROR(ENOSYS))
964 int avio_read_to_bprint(AVIOContext *h, AVBPrint *pb, size_t max_size)
969 ret = avio_read(h, buf, FFMIN(max_size, sizeof(buf)));
970 if (ret == AVERROR_EOF)
974 av_bprint_append_data(pb, buf, ret);
975 if (!av_bprint_is_complete(pb))
976 return AVERROR(ENOMEM);
982 /* output in a dynamic buffer */
984 typedef struct DynBuffer {
985 int pos, size, allocated_size;
988 uint8_t io_buffer[1];
991 static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
993 DynBuffer *d = opaque;
994 unsigned new_size, new_allocated_size;
996 /* reallocate buffer if needed */
997 new_size = d->pos + buf_size;
998 new_allocated_size = d->allocated_size;
999 if (new_size < d->pos || new_size > INT_MAX/2)
1001 while (new_size > new_allocated_size) {
1002 if (!new_allocated_size)
1003 new_allocated_size = new_size;
1005 new_allocated_size += new_allocated_size / 2 + 1;
1008 if (new_allocated_size > d->allocated_size) {
1010 if ((err = av_reallocp(&d->buffer, new_allocated_size)) < 0) {
1011 d->allocated_size = 0;
1015 d->allocated_size = new_allocated_size;
1017 memcpy(d->buffer + d->pos, buf, buf_size);
1019 if (d->pos > d->size)
1024 static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
1026 unsigned char buf1[4];
1029 /* packetized write: output the header */
1030 AV_WB32(buf1, buf_size);
1031 ret = dyn_buf_write(opaque, buf1, 4);
1036 return dyn_buf_write(opaque, buf, buf_size);
1039 static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
1041 DynBuffer *d = opaque;
1043 if (whence == SEEK_CUR)
1045 else if (whence == SEEK_END)
1047 if (offset < 0 || offset > 0x7fffffffLL)
1053 static int url_open_dyn_buf_internal(AVIOContext **s, int max_packet_size)
1056 unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
1058 if (sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
1060 d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
1062 return AVERROR(ENOMEM);
1063 d->io_buffer_size = io_buffer_size;
1064 *s = avio_alloc_context(d->io_buffer, d->io_buffer_size, 1, d, NULL,
1065 max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
1066 max_packet_size ? NULL : dyn_buf_seek);
1069 return AVERROR(ENOMEM);
1071 (*s)->max_packet_size = max_packet_size;
1075 int avio_open_dyn_buf(AVIOContext **s)
1077 return url_open_dyn_buf_internal(s, 0);
1080 int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size)
1082 if (max_packet_size <= 0)
1084 return url_open_dyn_buf_internal(s, max_packet_size);
1087 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
1091 static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
1100 /* don't attempt to pad fixed-size packet buffers */
1101 if (!s->max_packet_size) {
1102 avio_write(s, padbuf, sizeof(padbuf));
1103 padding = FF_INPUT_BUFFER_PADDING_SIZE;
1108 *pbuffer = d->buffer;
1112 return size - padding;
1115 static int null_buf_write(void *opaque, uint8_t *buf, int buf_size)
1117 DynBuffer *d = opaque;
1120 if (d->pos > d->size)
1125 int ffio_open_null_buf(AVIOContext **s)
1127 int ret = url_open_dyn_buf_internal(s, 0);
1129 AVIOContext *pb = *s;
1130 pb->write_packet = null_buf_write;
1135 int ffio_close_null_buf(AVIOContext *s)
1137 DynBuffer *d = s->opaque;