2 * Buffered I/O for ffmpeg system
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/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;
241 int url_fskip(AVIOContext *s, int64_t offset)
243 int64_t ret = avio_seek(s, offset, SEEK_CUR);
244 return ret < 0 ? ret : 0;
247 int64_t url_ftell(AVIOContext *s)
249 return avio_seek(s, 0, SEEK_CUR);
253 int64_t avio_size(AVIOContext *s)
258 return AVERROR(EINVAL);
261 return AVERROR(ENOSYS);
262 size = s->seek(s->opaque, 0, AVSEEK_SIZE);
264 if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
267 s->seek(s->opaque, s->pos, SEEK_SET);
273 int url_feof(AVIOContext *s)
277 return s->eof_reached;
280 int url_ferror(AVIOContext *s)
288 void avio_wl32(AVIOContext *s, unsigned int val)
291 avio_w8(s, val >> 8);
292 avio_w8(s, val >> 16);
293 avio_w8(s, val >> 24);
296 void avio_wb32(AVIOContext *s, unsigned int val)
298 avio_w8(s, val >> 24);
299 avio_w8(s, val >> 16);
300 avio_w8(s, val >> 8);
305 void put_strz(AVIOContext *s, const char *str)
307 avio_put_str(s, str);
310 #define GET(name, type) \
311 type get_be ##name(AVIOContext *s) \
313 return avio_rb ##name(s);\
315 type get_le ##name(AVIOContext *s) \
317 return avio_rl ##name(s);\
320 GET(16, unsigned int)
321 GET(24, unsigned int)
322 GET(32, unsigned int)
327 #define PUT(name, type ) \
328 void put_le ##name(AVIOContext *s, type val)\
330 avio_wl ##name(s, val);\
332 void put_be ##name(AVIOContext *s, type val)\
334 avio_wb ##name(s, val);\
337 PUT(16, unsigned int)
338 PUT(24, unsigned int)
339 PUT(32, unsigned int)
343 int get_byte(AVIOContext *s)
347 int get_buffer(AVIOContext *s, unsigned char *buf, int size)
349 return avio_read(s, buf, size);
351 int get_partial_buffer(AVIOContext *s, unsigned char *buf, int size)
353 return ffio_read_partial(s, buf, size);
355 void put_byte(AVIOContext *s, int val)
359 void put_buffer(AVIOContext *s, const unsigned char *buf, int size)
361 avio_write(s, buf, size);
363 void put_nbyte(AVIOContext *s, int b, int count)
365 ffio_fill(s, b, count);
368 int url_fopen(AVIOContext **s, const char *filename, int flags)
370 return avio_open(s, filename, flags);
372 int url_fclose(AVIOContext *s)
374 return avio_close(s);
376 int64_t url_fseek(AVIOContext *s, int64_t offset, int whence)
378 return avio_seek(s, offset, whence);
380 int64_t url_fsize(AVIOContext *s)
384 int url_setbufsize(AVIOContext *s, int buf_size)
386 return ffio_set_buf_size(s, buf_size);
388 int url_fprintf(AVIOContext *s, const char *fmt, ...)
395 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
397 avio_write(s, buf, strlen(buf));
400 void put_flush_packet(AVIOContext *s)
404 int av_url_read_fpause(AVIOContext *s, int pause)
406 return avio_pause(s, pause);
408 int64_t av_url_read_fseek(AVIOContext *s, int stream_index,
409 int64_t timestamp, int flags)
411 return avio_seek_time(s, stream_index, timestamp, flags);
413 void init_checksum(AVIOContext *s,
414 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
415 unsigned long checksum)
417 ffio_init_checksum(s, update_checksum, checksum);
419 unsigned long get_checksum(AVIOContext *s)
421 return ffio_get_checksum(s);
423 int url_open_dyn_buf(AVIOContext **s)
425 return avio_open_dyn_buf(s);
427 int url_open_dyn_packet_buf(AVIOContext **s, int max_packet_size)
429 return ffio_open_dyn_packet_buf(s, max_packet_size);
431 int url_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
433 return avio_close_dyn_buf(s, pbuffer);
435 int url_fdopen(AVIOContext **s, URLContext *h)
437 return ffio_fdopen(s, h);
441 int avio_put_str(AVIOContext *s, const char *str)
446 avio_write(s, (const unsigned char *) str, len);
452 int avio_put_str16le(AVIOContext *s, const char *str)
454 const uint8_t *q = str;
461 GET_UTF8(ch, *q++, break;)
462 PUT_UTF16(ch, tmp, avio_wl16(s, tmp);ret += 2;)
469 int ff_get_v_length(uint64_t val){
478 void ff_put_v(AVIOContext *bc, uint64_t val){
479 int i= ff_get_v_length(val);
482 avio_w8(bc, 128 | (val>>(7*i)));
484 avio_w8(bc, val&127);
487 void avio_wl64(AVIOContext *s, uint64_t val)
489 avio_wl32(s, (uint32_t)(val & 0xffffffff));
490 avio_wl32(s, (uint32_t)(val >> 32));
493 void avio_wb64(AVIOContext *s, uint64_t val)
495 avio_wb32(s, (uint32_t)(val >> 32));
496 avio_wb32(s, (uint32_t)(val & 0xffffffff));
499 void avio_wl16(AVIOContext *s, unsigned int val)
502 avio_w8(s, val >> 8);
505 void avio_wb16(AVIOContext *s, unsigned int val)
507 avio_w8(s, val >> 8);
511 void avio_wl24(AVIOContext *s, unsigned int val)
513 avio_wl16(s, val & 0xffff);
514 avio_w8(s, val >> 16);
517 void avio_wb24(AVIOContext *s, unsigned int val)
519 avio_wb16(s, val >> 8);
524 void put_tag(AVIOContext *s, const char *tag)
534 static void fill_buffer(AVIOContext *s)
536 uint8_t *dst= !s->max_packet_size && s->buf_end - s->buffer < s->buffer_size ? s->buf_end : s->buffer;
537 int len= s->buffer_size - (dst - s->buffer);
538 int max_buffer_size = s->max_packet_size ? s->max_packet_size : IO_BUFFER_SIZE;
540 /* no need to do anything if EOF already reached */
544 if(s->update_checksum && dst == s->buffer){
545 if(s->buf_end > s->checksum_ptr)
546 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
547 s->checksum_ptr= s->buffer;
550 /* make buffer smaller in case it ended up large after probing */
551 if (s->buffer_size > max_buffer_size) {
552 ffio_set_buf_size(s, max_buffer_size);
554 s->checksum_ptr = dst = s->buffer;
555 len = s->buffer_size;
559 len = s->read_packet(s->opaque, dst, len);
563 /* do not modify buffer if EOF reached so that a seek back can
564 be done without rereading data */
571 s->buf_end = dst + len;
575 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
578 return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
581 unsigned long ffio_get_checksum(AVIOContext *s)
583 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
584 s->update_checksum= NULL;
588 void ffio_init_checksum(AVIOContext *s,
589 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
590 unsigned long checksum)
592 s->update_checksum= update_checksum;
593 if(s->update_checksum){
594 s->checksum= checksum;
595 s->checksum_ptr= s->buf_ptr;
599 /* XXX: put an inline version */
600 int avio_r8(AVIOContext *s)
602 if (s->buf_ptr >= s->buf_end)
604 if (s->buf_ptr < s->buf_end)
605 return *s->buf_ptr++;
610 int url_fgetc(AVIOContext *s)
612 if (s->buf_ptr >= s->buf_end)
614 if (s->buf_ptr < s->buf_end)
615 return *s->buf_ptr++;
620 int avio_read(AVIOContext *s, unsigned char *buf, int size)
626 len = s->buf_end - s->buf_ptr;
630 if(size > s->buffer_size && !s->update_checksum){
632 len = s->read_packet(s->opaque, buf, size);
634 /* do not modify buffer if EOF reached so that a seek back can
635 be done without rereading data */
644 s->buf_ptr = s->buffer;
645 s->buf_end = s->buffer/* + len*/;
649 len = s->buf_end - s->buf_ptr;
654 memcpy(buf, s->buf_ptr, len);
661 if (s->error) return s->error;
662 if (s->eof_reached) return AVERROR_EOF;
667 int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size)
674 len = s->buf_end - s->buf_ptr;
677 len = s->buf_end - s->buf_ptr;
681 memcpy(buf, s->buf_ptr, len);
684 if (s->error) return s->error;
685 if (s->eof_reached) return AVERROR_EOF;
690 unsigned int avio_rl16(AVIOContext *s)
694 val |= avio_r8(s) << 8;
698 unsigned int avio_rl24(AVIOContext *s)
702 val |= avio_r8(s) << 16;
706 unsigned int avio_rl32(AVIOContext *s)
710 val |= avio_rl16(s) << 16;
714 uint64_t avio_rl64(AVIOContext *s)
717 val = (uint64_t)avio_rl32(s);
718 val |= (uint64_t)avio_rl32(s) << 32;
722 unsigned int avio_rb16(AVIOContext *s)
725 val = avio_r8(s) << 8;
730 unsigned int avio_rb24(AVIOContext *s)
733 val = avio_rb16(s) << 8;
737 unsigned int avio_rb32(AVIOContext *s)
740 val = avio_rb16(s) << 16;
746 char *get_strz(AVIOContext *s, char *buf, int maxlen)
748 avio_get_str(s, INT_MAX, buf, maxlen);
753 int ff_get_line(AVIOContext *s, char *buf, int maxlen)
760 if (c && i < maxlen-1)
762 } while (c != '\n' && c);
768 int avio_get_str(AVIOContext *s, int maxlen, char *buf, int buflen)
772 // reserve 1 byte for terminating 0
773 buflen = FFMIN(buflen - 1, maxlen);
774 for (i = 0; i < buflen; i++)
775 if (!(buf[i] = avio_r8(s)))
779 for (; i < maxlen; i++)
785 #define GET_STR16(type, read) \
786 int avio_get_str16 ##type(AVIOContext *pb, int maxlen, char *buf, int buflen)\
790 while (ret + 1 < maxlen) {\
793 GET_UTF16(ch, (ret += 2) <= maxlen ? read(pb) : 0, break;)\
796 PUT_UTF8(ch, tmp, if (q - buf < buflen - 1) *q++ = tmp;)\
802 GET_STR16(le, avio_rl16)
803 GET_STR16(be, avio_rb16)
807 uint64_t avio_rb64(AVIOContext *s)
810 val = (uint64_t)avio_rb32(s) << 32;
811 val |= (uint64_t)avio_rb32(s);
815 uint64_t ffio_read_varlen(AVIOContext *bc){
821 val= (val<<7) + (tmp&127);
826 int ffio_fdopen(AVIOContext **s, URLContext *h)
829 int buffer_size, max_packet_size;
831 max_packet_size = h->max_packet_size;
832 if (max_packet_size) {
833 buffer_size = max_packet_size; /* no need to bufferize more than one packet */
835 buffer_size = IO_BUFFER_SIZE;
837 buffer = av_malloc(buffer_size);
839 return AVERROR(ENOMEM);
841 *s = avio_alloc_context(buffer, buffer_size, h->flags & AVIO_FLAG_WRITE, h,
842 ffurl_read, ffurl_write, ffurl_seek);
845 return AVERROR(ENOMEM);
848 (*s)->is_streamed = h->is_streamed;
850 (*s)->seekable = h->is_streamed ? 0 : AVIO_SEEKABLE_NORMAL;
851 (*s)->max_packet_size = max_packet_size;
853 (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
854 (*s)->read_seek = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
859 int ffio_set_buf_size(AVIOContext *s, int buf_size)
862 buffer = av_malloc(buf_size);
864 return AVERROR(ENOMEM);
868 s->buffer_size = buf_size;
870 url_resetbuf(s, s->write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ);
874 static int url_resetbuf(AVIOContext *s, int flags)
876 assert(flags == AVIO_FLAG_WRITE || flags == AVIO_FLAG_READ);
878 if (flags & AVIO_FLAG_WRITE) {
879 s->buf_end = s->buffer + s->buffer_size;
882 s->buf_end = s->buffer;
888 int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char *buf, int buf_size)
890 int64_t buffer_start;
892 int overlap, new_size, alloc_size;
895 return AVERROR(EINVAL);
897 buffer_size = s->buf_end - s->buffer;
899 /* the buffers must touch or overlap */
900 if ((buffer_start = s->pos - buffer_size) > buf_size)
901 return AVERROR(EINVAL);
903 overlap = buf_size - buffer_start;
904 new_size = buf_size + buffer_size - overlap;
906 alloc_size = FFMAX(s->buffer_size, new_size);
907 if (alloc_size > buf_size)
908 if (!(buf = av_realloc(buf, alloc_size)))
909 return AVERROR(ENOMEM);
911 if (new_size > buf_size) {
912 memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
917 s->buf_ptr = s->buffer = buf;
918 s->buffer_size = alloc_size;
920 s->buf_end = s->buf_ptr + buf_size;
927 int avio_open(AVIOContext **s, const char *filename, int flags)
932 err = ffurl_open(&h, filename, flags);
935 err = ffio_fdopen(s, h);
943 int avio_close(AVIOContext *s)
945 URLContext *h = s->opaque;
949 return ffurl_close(h);
953 URLContext *url_fileno(AVIOContext *s)
959 int avio_printf(AVIOContext *s, const char *fmt, ...)
966 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
968 avio_write(s, buf, strlen(buf));
973 char *url_fgets(AVIOContext *s, char *buf, int buf_size)
983 if (s->eof_reached || c == '\n')
985 if ((q - buf) < buf_size - 1)
994 int url_fget_max_packet_size(AVIOContext *s)
996 return s->max_packet_size;
1000 int avio_pause(AVIOContext *s, int pause)
1003 return AVERROR(ENOSYS);
1004 return s->read_pause(s->opaque, pause);
1007 int64_t avio_seek_time(AVIOContext *s, int stream_index,
1008 int64_t timestamp, int flags)
1010 URLContext *h = s->opaque;
1013 return AVERROR(ENOSYS);
1014 ret = s->read_seek(h, stream_index, timestamp, flags);
1017 s->buf_ptr = s->buf_end; // Flush buffer
1018 pos = s->seek(h, 0, SEEK_CUR);
1021 else if (pos != AVERROR(ENOSYS))
1027 /* buffer handling */
1029 int url_open_buf(AVIOContext **s, uint8_t *buf, int buf_size, int flags)
1032 *s = av_mallocz(sizeof(AVIOContext));
1034 return AVERROR(ENOMEM);
1035 ret = ffio_init_context(*s, buf, buf_size,
1036 flags & AVIO_FLAG_WRITE,
1037 NULL, NULL, NULL, NULL);
1043 int url_close_buf(AVIOContext *s)
1046 return s->buf_ptr - s->buffer;
1050 /* output in a dynamic buffer */
1052 typedef struct DynBuffer {
1053 int pos, size, allocated_size;
1056 uint8_t io_buffer[1];
1059 static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
1061 DynBuffer *d = opaque;
1062 unsigned new_size, new_allocated_size;
1064 /* reallocate buffer if needed */
1065 new_size = d->pos + buf_size;
1066 new_allocated_size = d->allocated_size;
1067 if(new_size < d->pos || new_size > INT_MAX/2)
1069 while (new_size > new_allocated_size) {
1070 if (!new_allocated_size)
1071 new_allocated_size = new_size;
1073 new_allocated_size += new_allocated_size / 2 + 1;
1076 if (new_allocated_size > d->allocated_size) {
1077 d->buffer = av_realloc(d->buffer, new_allocated_size);
1078 if(d->buffer == NULL)
1079 return AVERROR(ENOMEM);
1080 d->allocated_size = new_allocated_size;
1082 memcpy(d->buffer + d->pos, buf, buf_size);
1084 if (d->pos > d->size)
1089 static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
1091 unsigned char buf1[4];
1094 /* packetized write: output the header */
1095 AV_WB32(buf1, buf_size);
1096 ret= dyn_buf_write(opaque, buf1, 4);
1101 return dyn_buf_write(opaque, buf, buf_size);
1104 static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
1106 DynBuffer *d = opaque;
1108 if (whence == SEEK_CUR)
1110 else if (whence == SEEK_END)
1112 if (offset < 0 || offset > 0x7fffffffLL)
1118 static int url_open_dyn_buf_internal(AVIOContext **s, int max_packet_size)
1121 unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
1123 if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
1125 d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
1127 return AVERROR(ENOMEM);
1128 d->io_buffer_size = io_buffer_size;
1129 *s = avio_alloc_context(d->io_buffer, d->io_buffer_size, 1, d, NULL,
1130 max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
1131 max_packet_size ? NULL : dyn_buf_seek);
1134 return AVERROR(ENOMEM);
1136 (*s)->max_packet_size = max_packet_size;
1140 int avio_open_dyn_buf(AVIOContext **s)
1142 return url_open_dyn_buf_internal(s, 0);
1145 int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size)
1147 if (max_packet_size <= 0)
1149 return url_open_dyn_buf_internal(s, max_packet_size);
1152 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
1154 DynBuffer *d = s->opaque;
1156 static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
1159 /* don't attempt to pad fixed-size packet buffers */
1160 if (!s->max_packet_size) {
1161 avio_write(s, padbuf, sizeof(padbuf));
1162 padding = FF_INPUT_BUFFER_PADDING_SIZE;
1167 *pbuffer = d->buffer;
1171 return size - padding;