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
43 typedef struct AVIOInternal {
46 char *protocol_whitelist;
47 char *protocol_blacklist;
50 const URLProtocol **protocols;
53 static void *io_priv_child_next(void *obj, void *prev)
55 AVIOInternal *internal = obj;
56 return prev ? NULL : internal->h;
59 static const AVClass *io_priv_child_class_next(const AVClass *prev)
61 return prev ? NULL : &ffurl_context_class;
64 #define OFFSET(x) offsetof(AVIOInternal, x)
65 static const AVOption io_priv_options[] = {
66 { "protocol_whitelist", "A comma-separated list of allowed protocols",
67 OFFSET(protocol_whitelist), AV_OPT_TYPE_STRING },
68 { "protocol_blacklist", "A comma-separated list of forbidden protocols",
69 OFFSET(protocol_whitelist), AV_OPT_TYPE_STRING },
73 static const AVClass io_priv_class = {
74 .class_name = "AVIOContext",
75 .item_name = av_default_item_name,
76 .version = LIBAVUTIL_VERSION_INT,
77 .option = io_priv_options,
78 .child_next = io_priv_child_next,
79 .child_class_next = io_priv_child_class_next,
82 static void *ff_avio_child_next(void *obj, void *prev)
85 return prev ? NULL : s->opaque;
88 static const AVClass *ff_avio_child_class_next(const AVClass *prev)
90 return prev ? NULL : &io_priv_class;
93 static const AVOption ff_avio_options[] = {
97 const AVClass ff_avio_class = {
98 .class_name = "AVIOContext",
99 .item_name = av_default_item_name,
100 .version = LIBAVUTIL_VERSION_INT,
101 .option = ff_avio_options,
102 .child_next = ff_avio_child_next,
103 .child_class_next = ff_avio_child_class_next,
106 static void fill_buffer(AVIOContext *s);
107 static int url_resetbuf(AVIOContext *s, int flags);
109 int ffio_init_context(AVIOContext *s,
110 unsigned char *buffer,
114 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
115 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
116 int64_t (*seek)(void *opaque, int64_t offset, int whence))
119 s->buffer_size = buffer_size;
123 url_resetbuf(s, write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ);
125 s->write_packet = write_packet;
126 s->read_packet = read_packet;
132 s->seekable = seek ? AVIO_SEEKABLE_NORMAL : 0;
133 s->max_packet_size = 0;
134 s->update_checksum = NULL;
136 if (!read_packet && !write_flag) {
137 s->pos = buffer_size;
138 s->buf_end = s->buffer + buffer_size;
140 s->read_pause = NULL;
143 s->write_data_type = NULL;
144 s->ignore_boundary_point = 0;
145 s->current_type = AVIO_DATA_MARKER_UNKNOWN;
146 s->last_time = AV_NOPTS_VALUE;
151 AVIOContext *avio_alloc_context(
152 unsigned char *buffer,
156 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
157 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
158 int64_t (*seek)(void *opaque, int64_t offset, int whence))
160 AVIOContext *s = av_mallocz(sizeof(AVIOContext));
163 ffio_init_context(s, buffer, buffer_size, write_flag, opaque,
164 read_packet, write_packet, seek);
168 static void flush_buffer(AVIOContext *s)
170 if (s->buf_ptr > s->buffer) {
173 if (s->write_data_type)
174 ret = s->write_data_type(s->opaque, s->buffer,
175 s->buf_ptr - s->buffer,
178 else if (s->write_packet)
179 ret = s->write_packet(s->opaque, s->buffer,
180 s->buf_ptr - s->buffer);
185 if (s->current_type == AVIO_DATA_MARKER_SYNC_POINT ||
186 s->current_type == AVIO_DATA_MARKER_BOUNDARY_POINT) {
187 s->current_type = AVIO_DATA_MARKER_UNKNOWN;
189 s->last_time = AV_NOPTS_VALUE;
190 if (s->update_checksum) {
191 s->checksum = s->update_checksum(s->checksum, s->checksum_ptr,
192 s->buf_ptr - s->checksum_ptr);
193 s->checksum_ptr = s->buffer;
195 s->pos += s->buf_ptr - s->buffer;
197 s->buf_ptr = s->buffer;
200 void avio_w8(AVIOContext *s, int b)
203 if (s->buf_ptr >= s->buf_end)
207 void ffio_fill(AVIOContext *s, int b, int count)
210 int len = FFMIN(s->buf_end - s->buf_ptr, count);
211 memset(s->buf_ptr, b, len);
214 if (s->buf_ptr >= s->buf_end)
221 void avio_write(AVIOContext *s, const unsigned char *buf, int size)
224 int len = FFMIN(s->buf_end - s->buf_ptr, size);
225 memcpy(s->buf_ptr, buf, len);
228 if (s->buf_ptr >= s->buf_end)
236 void avio_flush(AVIOContext *s)
242 int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
246 int force = whence & AVSEEK_FORCE;
247 whence &= ~AVSEEK_FORCE;
250 return AVERROR(EINVAL);
252 pos = s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
254 if (whence != SEEK_CUR && whence != SEEK_SET)
255 return AVERROR(EINVAL);
257 if (whence == SEEK_CUR) {
258 offset1 = pos + (s->buf_ptr - s->buffer);
263 offset1 = offset - pos;
264 if (!s->must_flush &&
265 offset1 >= 0 && offset1 < (s->buf_end - s->buffer)) {
266 /* can do the seek inside the buffer */
267 s->buf_ptr = s->buffer + offset1;
268 } else if ((!s->seekable ||
269 offset1 <= s->buf_end + SHORT_SEEK_THRESHOLD - s->buffer) &&
270 !s->write_flag && offset1 >= 0 &&
271 (whence != SEEK_END || force)) {
272 while(s->pos < offset && !s->eof_reached)
276 s->buf_ptr = s->buf_end + offset - s->pos;
285 return AVERROR(EPIPE);
286 if ((res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
289 s->buf_end = s->buffer;
290 s->buf_ptr = s->buffer;
297 int64_t avio_size(AVIOContext *s)
302 return AVERROR(EINVAL);
305 return AVERROR(ENOSYS);
306 size = s->seek(s->opaque, 0, AVSEEK_SIZE);
308 if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
311 s->seek(s->opaque, s->pos, SEEK_SET);
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);
332 int avio_put_str(AVIOContext *s, const char *str)
337 avio_write(s, (const unsigned char *) str, len);
343 #define PUT_STR16(type, write) \
344 int avio_put_str16 ## type(AVIOContext * s, const char *str) \
346 const uint8_t *q = str; \
353 GET_UTF8(ch, *q++, break; ) \
354 PUT_UTF16(ch, tmp, write(s, tmp); ret += 2; ) \
361 PUT_STR16(le, avio_wl16)
362 PUT_STR16(be, avio_wb16)
366 int ff_get_v_length(uint64_t val)
376 void ff_put_v(AVIOContext *bc, uint64_t val)
378 int i = ff_get_v_length(val);
381 avio_w8(bc, 128 | (val >> (7 * i)));
383 avio_w8(bc, val & 127);
386 void avio_wl64(AVIOContext *s, uint64_t val)
388 avio_wl32(s, (uint32_t)(val & 0xffffffff));
389 avio_wl32(s, (uint32_t)(val >> 32));
392 void avio_wb64(AVIOContext *s, uint64_t val)
394 avio_wb32(s, (uint32_t)(val >> 32));
395 avio_wb32(s, (uint32_t)(val & 0xffffffff));
398 void avio_wl16(AVIOContext *s, unsigned int val)
401 avio_w8(s, val >> 8);
404 void avio_wb16(AVIOContext *s, unsigned int val)
406 avio_w8(s, val >> 8);
410 void avio_wl24(AVIOContext *s, unsigned int val)
412 avio_wl16(s, val & 0xffff);
413 avio_w8(s, val >> 16);
416 void avio_wb24(AVIOContext *s, unsigned int val)
418 avio_wb16(s, val >> 8);
422 void avio_write_marker(AVIOContext *s, int64_t time, enum AVIODataMarkerType type)
424 if (!s->write_data_type)
426 // If ignoring boundary points, just treat it as unknown
427 if (type == AVIO_DATA_MARKER_BOUNDARY_POINT && s->ignore_boundary_point)
428 type = AVIO_DATA_MARKER_UNKNOWN;
429 // Avoid unnecessary flushes if we are already in non-header/trailer
430 // data and setting the type to unknown
431 if (type == AVIO_DATA_MARKER_UNKNOWN &&
432 (s->current_type != AVIO_DATA_MARKER_HEADER &&
433 s->current_type != AVIO_DATA_MARKER_TRAILER))
437 case AVIO_DATA_MARKER_HEADER:
438 case AVIO_DATA_MARKER_TRAILER:
439 // For header/trailer, ignore a new marker of the same type;
440 // consecutive header/trailer markers can be merged.
441 if (type == s->current_type)
446 // If we've reached here, we have a new, noteworthy marker.
447 // Flush the previous data and mark the start of the new data.
449 s->current_type = type;
455 static void fill_buffer(AVIOContext *s)
457 uint8_t *dst = !s->max_packet_size &&
458 s->buf_end - s->buffer < s->buffer_size ?
459 s->buf_end : s->buffer;
460 int len = s->buffer_size - (dst - s->buffer);
461 int max_buffer_size = s->max_packet_size ?
462 s->max_packet_size : IO_BUFFER_SIZE;
464 /* can't fill the buffer without read_packet, just set EOF if appropriate */
465 if (!s->read_packet && s->buf_ptr >= s->buf_end)
468 /* no need to do anything if EOF already reached */
472 if (s->update_checksum && dst == s->buffer) {
473 if (s->buf_end > s->checksum_ptr)
474 s->checksum = s->update_checksum(s->checksum, s->checksum_ptr,
475 s->buf_end - s->checksum_ptr);
476 s->checksum_ptr = s->buffer;
479 /* make buffer smaller in case it ended up large after probing */
480 if (s->buffer_size > max_buffer_size) {
481 ffio_set_buf_size(s, max_buffer_size);
483 s->checksum_ptr = dst = s->buffer;
484 len = s->buffer_size;
488 len = s->read_packet(s->opaque, dst, len);
492 /* do not modify buffer if EOF reached so that a seek back can
493 be done without rereading data */
500 s->buf_end = dst + len;
504 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
507 return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
510 unsigned long ff_crcA001_update(unsigned long checksum, const uint8_t *buf,
513 return av_crc(av_crc_get_table(AV_CRC_16_ANSI_LE), checksum, buf, len);
516 unsigned long ffio_get_checksum(AVIOContext *s)
518 s->checksum = s->update_checksum(s->checksum, s->checksum_ptr,
519 s->buf_ptr - s->checksum_ptr);
520 s->update_checksum = NULL;
524 void ffio_init_checksum(AVIOContext *s,
525 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
526 unsigned long checksum)
528 s->update_checksum = update_checksum;
529 if (s->update_checksum) {
530 s->checksum = checksum;
531 s->checksum_ptr = s->buf_ptr;
535 /* XXX: put an inline version */
536 int avio_r8(AVIOContext *s)
538 if (s->buf_ptr >= s->buf_end)
540 if (s->buf_ptr < s->buf_end)
541 return *s->buf_ptr++;
545 int avio_read(AVIOContext *s, unsigned char *buf, int size)
551 len = s->buf_end - s->buf_ptr;
554 if (len == 0 || s->write_flag) {
555 if(size > s->buffer_size && !s->update_checksum){
557 len = s->read_packet(s->opaque, buf, size);
559 /* do not modify buffer if EOF reached so that a seek back can
560 be done without rereading data */
569 s->buf_ptr = s->buffer;
570 s->buf_end = s->buffer/* + len*/;
574 len = s->buf_end - s->buf_ptr;
579 memcpy(buf, s->buf_ptr, len);
586 if (s->error) return s->error;
587 if (s->eof_reached) return AVERROR_EOF;
592 int ffio_read_size(AVIOContext *s, unsigned char *buf, int size)
594 int ret = avio_read(s, buf, size);
596 return AVERROR_INVALIDDATA;
600 int ffio_read_indirect(AVIOContext *s, unsigned char *buf, int size, const unsigned char **data)
602 if (s->buf_end - s->buf_ptr >= size && !s->write_flag) {
608 return avio_read(s, buf, size);
612 int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size)
619 if (s->read_packet && s->write_flag) {
620 len = s->read_packet(s->opaque, buf, size);
626 len = s->buf_end - s->buf_ptr;
628 /* Reset the buf_end pointer to the start of the buffer, to make sure
629 * the fill_buffer call tries to read as much data as fits into the
630 * full buffer, instead of just what space is left after buf_end.
631 * This avoids returning partial packets at the end of the buffer,
632 * for packet based inputs.
634 s->buf_end = s->buf_ptr = s->buffer;
636 len = s->buf_end - s->buf_ptr;
640 memcpy(buf, s->buf_ptr, len);
643 if (s->error) return s->error;
644 if (s->eof_reached) return AVERROR_EOF;
649 unsigned int avio_rl16(AVIOContext *s)
653 val |= avio_r8(s) << 8;
657 unsigned int avio_rl24(AVIOContext *s)
661 val |= avio_r8(s) << 16;
665 unsigned int avio_rl32(AVIOContext *s)
669 val |= avio_rl16(s) << 16;
673 uint64_t avio_rl64(AVIOContext *s)
676 val = (uint64_t)avio_rl32(s);
677 val |= (uint64_t)avio_rl32(s) << 32;
681 unsigned int avio_rb16(AVIOContext *s)
684 val = avio_r8(s) << 8;
689 unsigned int avio_rb24(AVIOContext *s)
692 val = avio_rb16(s) << 8;
696 unsigned int avio_rb32(AVIOContext *s)
699 val = avio_rb16(s) << 16;
704 int ff_get_line(AVIOContext *s, char *buf, int maxlen)
711 if (c && i < maxlen-1)
713 } while (c != '\n' && c);
719 int avio_get_str(AVIOContext *s, int maxlen, char *buf, int buflen)
724 return AVERROR(EINVAL);
725 // reserve 1 byte for terminating 0
726 buflen = FFMIN(buflen - 1, maxlen);
727 for (i = 0; i < buflen; i++)
728 if (!(buf[i] = avio_r8(s)))
731 for (; i < maxlen; i++)
737 #define GET_STR16(type, read) \
738 int avio_get_str16 ##type(AVIOContext *pb, int maxlen, char *buf, int buflen)\
743 return AVERROR(EINVAL); \
744 while (ret + 1 < maxlen) {\
747 GET_UTF16(ch, (ret += 2) <= maxlen ? read(pb) : 0, break;)\
750 PUT_UTF8(ch, tmp, if (q - buf < buflen - 1) *q++ = tmp;)\
756 GET_STR16(le, avio_rl16)
757 GET_STR16(be, avio_rb16)
761 uint64_t avio_rb64(AVIOContext *s)
764 val = (uint64_t)avio_rb32(s) << 32;
765 val |= (uint64_t)avio_rb32(s);
769 uint64_t ffio_read_varlen(AVIOContext *bc){
775 val= (val<<7) + (tmp&127);
780 static int io_read_packet(void *opaque, uint8_t *buf, int buf_size)
782 AVIOInternal *internal = opaque;
783 return ffurl_read(internal->h, buf, buf_size);
786 static int io_write_packet(void *opaque, uint8_t *buf, int buf_size)
788 AVIOInternal *internal = opaque;
789 return ffurl_write(internal->h, buf, buf_size);
792 static int64_t io_seek(void *opaque, int64_t offset, int whence)
794 AVIOInternal *internal = opaque;
795 return ffurl_seek(internal->h, offset, whence);
798 static int io_read_pause(void *opaque, int pause)
800 AVIOInternal *internal = opaque;
801 if (!internal->h->prot->url_read_pause)
802 return AVERROR(ENOSYS);
803 return internal->h->prot->url_read_pause(internal->h, pause);
806 static int64_t io_read_seek(void *opaque, int stream_index, int64_t timestamp, int flags)
808 AVIOInternal *internal = opaque;
809 if (!internal->h->prot->url_read_seek)
810 return AVERROR(ENOSYS);
811 return internal->h->prot->url_read_seek(internal->h, stream_index, timestamp, flags);
814 int ffio_fdopen(AVIOContext **s, URLContext *h)
816 AVIOInternal *internal = NULL;
817 uint8_t *buffer = NULL;
818 int buffer_size, max_packet_size;
820 max_packet_size = h->max_packet_size;
821 if (max_packet_size) {
822 buffer_size = max_packet_size; /* no need to bufferize more than one packet */
824 buffer_size = IO_BUFFER_SIZE;
826 buffer = av_malloc(buffer_size);
828 return AVERROR(ENOMEM);
830 internal = av_mallocz(sizeof(*internal));
834 internal->class = &io_priv_class;
837 av_opt_set_defaults(internal);
839 *s = avio_alloc_context(buffer, buffer_size, h->flags & AVIO_FLAG_WRITE,
840 internal, io_read_packet, io_write_packet, io_seek);
844 (*s)->seekable = h->is_streamed ? 0 : AVIO_SEEKABLE_NORMAL;
845 (*s)->max_packet_size = max_packet_size;
847 (*s)->read_pause = io_read_pause;
848 (*s)->read_seek = io_read_seek;
850 (*s)->av_class = &ff_avio_class;
854 av_opt_free(internal);
857 return AVERROR(ENOMEM);
860 int ffio_set_buf_size(AVIOContext *s, int buf_size)
863 buffer = av_malloc(buf_size);
865 return AVERROR(ENOMEM);
869 s->buffer_size = buf_size;
871 url_resetbuf(s, s->write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ);
875 static int url_resetbuf(AVIOContext *s, int flags)
877 assert(flags == AVIO_FLAG_WRITE || flags == AVIO_FLAG_READ);
879 if (flags & AVIO_FLAG_WRITE) {
880 s->buf_end = s->buffer + s->buffer_size;
883 s->buf_end = s->buffer;
889 int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char *buf, int buf_size)
891 int64_t buffer_start;
893 int overlap, new_size, alloc_size;
896 return AVERROR(EINVAL);
898 buffer_size = s->buf_end - s->buffer;
900 /* the buffers must touch or overlap */
901 if ((buffer_start = s->pos - buffer_size) > buf_size)
902 return AVERROR(EINVAL);
904 overlap = buf_size - buffer_start;
905 new_size = buf_size + buffer_size - overlap;
907 alloc_size = FFMAX(s->buffer_size, new_size);
908 if (alloc_size > buf_size)
909 if (!(buf = av_realloc(buf, alloc_size)))
910 return AVERROR(ENOMEM);
912 if (new_size > buf_size) {
913 memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
918 s->buf_ptr = s->buffer = buf;
919 s->buffer_size = alloc_size;
921 s->buf_end = s->buf_ptr + buf_size;
928 int avio_open(AVIOContext **s, const char *filename, int flags)
930 return avio_open2(s, filename, flags, NULL, NULL);
933 int avio_open2(AVIOContext **s, const char *filename, int flags,
934 const AVIOInterruptCB *int_cb, AVDictionary **options)
936 AVIOInternal *internal;
937 const URLProtocol **protocols;
938 char *proto_whitelist = NULL, *proto_blacklist = NULL;
939 AVDictionaryEntry *e;
944 e = av_dict_get(*options, "protocol_whitelist", NULL, 0);
946 proto_whitelist = e->value;
947 e = av_dict_get(*options, "protocol_blacklist", NULL, 0);
949 proto_blacklist = e->value;
952 protocols = ffurl_get_protocols(proto_whitelist, proto_blacklist);
954 return AVERROR(ENOMEM);
956 err = ffurl_open(&h, filename, flags, int_cb, options, protocols, NULL);
958 av_freep(&protocols);
962 err = ffio_fdopen(s, h);
965 av_freep(&protocols);
969 internal = (*s)->opaque;
970 internal->protocols = protocols;
973 err = av_opt_set_dict(internal, options);
983 int avio_close(AVIOContext *s)
985 AVIOInternal *internal;
992 internal = s->opaque;
995 av_opt_free(internal);
997 av_freep(&internal->protocols);
998 av_freep(&s->opaque);
999 av_freep(&s->buffer);
1001 return ffurl_close(h);
1004 int avio_closep(AVIOContext **s)
1006 int ret = avio_close(*s);
1011 int avio_printf(AVIOContext *s, const char *fmt, ...)
1018 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
1020 avio_write(s, buf, strlen(buf));
1024 int avio_pause(AVIOContext *s, int pause)
1027 return AVERROR(ENOSYS);
1028 return s->read_pause(s->opaque, pause);
1031 int64_t avio_seek_time(AVIOContext *s, int stream_index,
1032 int64_t timestamp, int flags)
1036 return AVERROR(ENOSYS);
1037 ret = s->read_seek(s->opaque, stream_index, timestamp, flags);
1040 s->buf_ptr = s->buf_end; // Flush buffer
1041 pos = s->seek(s->opaque, 0, SEEK_CUR);
1044 else if (pos != AVERROR(ENOSYS))
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) {
1078 if ((err = av_reallocp(&d->buffer, new_allocated_size)) < 0) {
1079 d->allocated_size = 0;
1083 d->allocated_size = new_allocated_size;
1085 memcpy(d->buffer + d->pos, buf, buf_size);
1087 if (d->pos > d->size)
1092 static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
1094 unsigned char buf1[4];
1097 /* packetized write: output the header */
1098 AV_WB32(buf1, buf_size);
1099 ret = dyn_buf_write(opaque, buf1, 4);
1104 return dyn_buf_write(opaque, buf, buf_size);
1107 static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
1109 DynBuffer *d = opaque;
1111 if (whence == SEEK_CUR)
1113 else if (whence == SEEK_END)
1115 if (offset < 0 || offset > 0x7fffffffLL)
1121 static int url_open_dyn_buf_internal(AVIOContext **s, int max_packet_size)
1124 unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
1126 if (sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
1128 d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
1130 return AVERROR(ENOMEM);
1131 d->io_buffer_size = io_buffer_size;
1132 *s = avio_alloc_context(d->io_buffer, d->io_buffer_size, 1, d, NULL,
1133 max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
1134 max_packet_size ? NULL : dyn_buf_seek);
1137 return AVERROR(ENOMEM);
1139 (*s)->max_packet_size = max_packet_size;
1143 int avio_open_dyn_buf(AVIOContext **s)
1145 return url_open_dyn_buf_internal(s, 0);
1148 int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size)
1150 if (max_packet_size <= 0)
1152 return url_open_dyn_buf_internal(s, max_packet_size);
1155 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
1159 static const char padbuf[AV_INPUT_BUFFER_PADDING_SIZE] = {0};
1167 /* don't attempt to pad fixed-size packet buffers */
1168 if (!s->max_packet_size) {
1169 avio_write(s, padbuf, sizeof(padbuf));
1170 padding = AV_INPUT_BUFFER_PADDING_SIZE;
1176 *pbuffer = d->buffer;
1180 return size - padding;
1183 void ffio_free_dyn_buf(AVIOContext **s)
1188 avio_close_dyn_buf(*s, &tmp);
1193 static int null_buf_write(void *opaque, uint8_t *buf, int buf_size)
1195 DynBuffer *d = opaque;
1198 if (d->pos > d->size)
1203 int ffio_open_null_buf(AVIOContext **s)
1205 int ret = url_open_dyn_buf_internal(s, 0);
1207 AVIOContext *pb = *s;
1208 pb->write_packet = null_buf_write;
1213 int ffio_close_null_buf(AVIOContext *s)
1215 DynBuffer *d = s->opaque;