Doxument url_close().
[libav.git] / libavformat / avio.h
CommitLineData
04d7f601 1/*
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2 * copyright (c) 2001 Fabrice Bellard
3 *
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4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
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7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
b78e7197 9 * version 2.1 of the License, or (at your option) any later version.
04d7f601 10 *
b78e7197 11 * FFmpeg is distributed in the hope that it will be useful,
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12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
b78e7197 17 * License along with FFmpeg; if not, write to the Free Software
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18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
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20#ifndef AVFORMAT_AVIO_H
21#define AVFORMAT_AVIO_H
f031df23 22
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23/**
24 * @file libavformat/avio.h
25 * unbuffered I/O operations
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26 *
27 * @warning This file has to be considered an internal but installed
28 * header, so it should not be directly included in your projects.
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29 */
30
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31#include <stdint.h>
32
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33#include "libavutil/common.h"
34
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35/* unbuffered I/O */
36
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37/**
38 * URL Context.
39 * New fields can be added to the end with minor version bumps.
8bfb108b 40 * Removal, reordering and changes to existing fields require a major
1308f273 41 * version bump.
8bfb108b 42 * sizeof(URLContext) must not be used outside libav*.
1308f273 43 */
597b4b3f 44typedef struct URLContext {
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45#if LIBAVFORMAT_VERSION_MAJOR >= 53
46 const AVClass *av_class; ///< information for av_log(). Set by url_open().
47#endif
de6d9b64 48 struct URLProtocol *prot;
115329f1 49 int flags;
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50 int is_streamed; /**< true if streamed (no seek possible), default = false */
51 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
de6d9b64 52 void *priv_data;
c3316802 53 char *filename; /**< specified filename */
597b4b3f 54} URLContext;
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55
56typedef struct URLPollEntry {
57 URLContext *handle;
58 int events;
59 int revents;
60} URLPollEntry;
61
62#define URL_RDONLY 0
63#define URL_WRONLY 1
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64#define URL_RDWR 2
65
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66typedef int URLInterruptCB(void);
67
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68/**
69 * Creates an URLContext for accessing to the resource indicated by
70 * filename, and opens it using the URLProtocol up.
71 *
72 * @param puc pointer to the location where, in case of success, the
73 * function puts the pointer to the created URLContext
74 * @param flags flags which control how the resource indicated by filename
75 * is to be opened
76 * @return 0 in case of success, a negative value corresponding to an
77 * AVERROR code in case of failure
78 */
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79int url_open_protocol (URLContext **puc, struct URLProtocol *up,
80 const char *filename, int flags);
333146dd 81
de6d9b64 82int url_open(URLContext **h, const char *filename, int flags);
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83
84/**
85 * Reads up to size bytes from the resource accessed by h, and stores
86 * the read bytes in buf.
87 *
88 * @return The number of bytes actually read, or a negative value
89 * corresponding to an AVERROR code in case of error. A value of zero
90 * indicates that it is not possible to read more from the accessed
91 * resource (except if the value of the size argument is also zero).
92 */
de6d9b64 93int url_read(URLContext *h, unsigned char *buf, int size);
1f8ad15a 94
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95/**
96 * Read as many bytes as possible (up to size), calling the
97 * read function multiple times if necessary.
98 * Will also retry if the read function returns AVERROR(EAGAIN).
99 * This makes special short-read handling in applications
100 * unnecessary, if the return value is < size then it is
101 * certain there was either an error or the end of file was reached.
102 */
0e848977 103int url_read_complete(URLContext *h, unsigned char *buf, int size);
de6d9b64 104int url_write(URLContext *h, unsigned char *buf, int size);
bc5c918e 105int64_t url_seek(URLContext *h, int64_t pos, int whence);
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106
107/**
108 * Closes the resource accessed by the URLContext h, and frees the
109 * memory used by it.
110 *
111 * @return a negative value if an error condition occurred, 0
112 * otherwise
113 */
de6d9b64 114int url_close(URLContext *h);
f1f78a9d 115
de6d9b64 116int url_exist(const char *filename);
bc5c918e 117int64_t url_filesize(URLContext *h);
c306748c 118
c3316802 119/**
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120 * Return the file descriptor associated with this URL. For RTP, this
121 * will return only the RTP file descriptor, not the RTCP file descriptor.
122 * To get both, use rtp_get_file_handles().
123 *
124 * @return the file descriptor associated with this URL, or <0 on error.
125 */
126int url_get_file_handle(URLContext *h);
127
128/**
c306748c 129 * Return the maximum packet size associated to packetized file
8bfb108b 130 * handle. If the file is not packetized (stream like HTTP or file on
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131 * disk), then 0 is returned.
132 *
133 * @param h file handle
134 * @return maximum packet size in bytes
135 */
f031df23 136int url_get_max_packet_size(URLContext *h);
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137void url_get_filename(URLContext *h, char *buf, int buf_size);
138
c3316802 139/**
8bfb108b 140 * The callback is called in blocking functions to test regulary if
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141 * asynchronous interruption is needed. AVERROR(EINTR) is returned
142 * in this case by the interrupted function. 'NULL' means no interrupt
8bfb108b 143 * callback is given.
c3316802 144 */
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145void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
146
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147/* not implemented */
148int url_poll(URLPollEntry *poll_table, int n, int timeout);
149
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150/**
151 * Pause and resume playing - only meaningful if using a network streaming
152 * protocol (e.g. MMS).
153 * @param pause 1 for pause, 0 for resume
154 */
155int av_url_read_pause(URLContext *h, int pause);
8bfb108b 156
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157/**
158 * Seek to a given timestamp relative to some component stream.
8bfb108b 159 * Only meaningful if using a network streaming protocol (e.g. MMS.).
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160 * @param stream_index The stream index that the timestamp is relative to.
161 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
162 * units from the beginning of the presentation.
163 * If a stream_index >= 0 is used and the protocol does not support
164 * seeking based on component streams, the call will fail with ENOTSUP.
00ef4f58 165 * @param timestamp timestamp in AVStream.time_base units
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166 * or if there is no stream specified then in AV_TIME_BASE units.
167 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
168 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
169 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
170 * fail with ENOTSUP if used and not supported.
171 * @return >= 0 on success
172 * @see AVInputFormat::read_seek
173 */
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174int64_t av_url_read_seek(URLContext *h, int stream_index,
175 int64_t timestamp, int flags);
536333a0 176
aa38b097 177/**
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178 * Passing this as the "whence" parameter to a seek function causes it to
179 * return the filesize without seeking anywhere. Supporting this is optional.
180 * If it is not supported then the seek function will return <0.
aa38b097 181 */
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182#define AVSEEK_SIZE 0x10000
183
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184typedef struct URLProtocol {
185 const char *name;
186 int (*url_open)(URLContext *h, const char *filename, int flags);
187 int (*url_read)(URLContext *h, unsigned char *buf, int size);
188 int (*url_write)(URLContext *h, unsigned char *buf, int size);
bc5c918e 189 int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
de6d9b64 190 int (*url_close)(URLContext *h);
de6d9b64 191 struct URLProtocol *next;
502bdf68 192 int (*url_read_pause)(URLContext *h, int pause);
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193 int64_t (*url_read_seek)(URLContext *h, int stream_index,
194 int64_t timestamp, int flags);
f0a80394 195 int (*url_get_file_handle)(URLContext *h);
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196} URLProtocol;
197
d1037c12 198#if LIBAVFORMAT_VERSION_MAJOR < 53
de6d9b64 199extern URLProtocol *first_protocol;
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200#endif
201
019ac05a 202extern URLInterruptCB *url_interrupt_cb;
de6d9b64 203
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204/**
205 * If protocol is NULL, returns the first registered protocol,
c1b02101 206 * if protocol is non-NULL, returns the next registered protocol after protocol,
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207 * or NULL if protocol is the last one.
208 */
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209URLProtocol *av_protocol_next(URLProtocol *p);
210
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211#if LIBAVFORMAT_VERSION_MAJOR < 53
212/**
213 * @deprecated Use av_register_protocol() instead.
214 */
215attribute_deprecated int register_protocol(URLProtocol *protocol);
216#endif
217
218int av_register_protocol(URLProtocol *protocol);
de6d9b64 219
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220/**
221 * Bytestream IO Context.
222 * New fields can be added to the end with minor version bumps.
8bfb108b 223 * Removal, reordering and changes to existing fields require a major
1308f273 224 * version bump.
8bfb108b 225 * sizeof(ByteIOContext) must not be used outside libav*.
1308f273 226 */
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227typedef struct {
228 unsigned char *buffer;
229 int buffer_size;
230 unsigned char *buf_ptr, *buf_end;
231 void *opaque;
0c1a9eda 232 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
576ae256 233 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
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234 int64_t (*seek)(void *opaque, int64_t offset, int whence);
235 int64_t pos; /**< position in the file of the current buffer */
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236 int must_flush; /**< true if the next seek should flush */
237 int eof_reached; /**< true if eof reached */
238 int write_flag; /**< true if open for writing */
de6d9b64 239 int is_streamed;
f031df23 240 int max_packet_size;
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241 unsigned long checksum;
242 unsigned char *checksum_ptr;
243 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
576ae256 244 int error; ///< contains the error code or 0 if no error happened
502bdf68 245 int (*read_pause)(void *opaque, int pause);
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246 int64_t (*read_seek)(void *opaque, int stream_index,
247 int64_t timestamp, int flags);
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248} ByteIOContext;
249
250int init_put_byte(ByteIOContext *s,
251 unsigned char *buffer,
252 int buffer_size,
253 int write_flag,
254 void *opaque,
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255 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
256 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
bc5c918e 257 int64_t (*seek)(void *opaque, int64_t offset, int whence));
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258ByteIOContext *av_alloc_put_byte(
259 unsigned char *buffer,
260 int buffer_size,
261 int write_flag,
262 void *opaque,
0c1a9eda 263 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
576ae256 264 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
bc5c918e 265 int64_t (*seek)(void *opaque, int64_t offset, int whence));
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266
267void put_byte(ByteIOContext *s, int b);
75bdb984 268void put_buffer(ByteIOContext *s, const unsigned char *buf, int size);
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269void put_le64(ByteIOContext *s, uint64_t val);
270void put_be64(ByteIOContext *s, uint64_t val);
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271void put_le32(ByteIOContext *s, unsigned int val);
272void put_be32(ByteIOContext *s, unsigned int val);
ea395e8c 273void put_le24(ByteIOContext *s, unsigned int val);
a254c574 274void put_be24(ByteIOContext *s, unsigned int val);
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275void put_le16(ByteIOContext *s, unsigned int val);
276void put_be16(ByteIOContext *s, unsigned int val);
0570bf06 277void put_tag(ByteIOContext *s, const char *tag);
de6d9b64 278
3b4b29dc 279void put_strz(ByteIOContext *s, const char *buf);
75bdb984 280
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281/**
282 * fseek() equivalent for ByteIOContext.
283 * @return new position or AVERROR.
284 */
bc5c918e 285int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence);
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286
287/**
288 * Skip given number of bytes forward.
289 * @param offset number of bytes
290 */
bc5c918e 291void url_fskip(ByteIOContext *s, int64_t offset);
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292
293/**
294 * ftell() equivalent for ByteIOContext.
295 * @return position or AVERROR.
296 */
bc5c918e 297int64_t url_ftell(ByteIOContext *s);
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298
299/**
300 * Gets the filesize.
301 * @return filesize or AVERROR
302 */
bc5c918e 303int64_t url_fsize(ByteIOContext *s);
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304
305/**
306 * feof() equivalent for ByteIOContext.
307 * @return non zero if and only if end of file
308 */
de6d9b64 309int url_feof(ByteIOContext *s);
67e21020 310
576ae256 311int url_ferror(ByteIOContext *s);
de6d9b64 312
502bdf68 313int av_url_read_fpause(ByteIOContext *h, int pause);
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314int64_t av_url_read_fseek(ByteIOContext *h, int stream_index,
315 int64_t timestamp, int flags);
e7e4810a 316
f031df23 317#define URL_EOF (-1)
c3316802 318/** @note return URL_EOF (-1) if EOF */
f031df23 319int url_fgetc(ByteIOContext *s);
a8c5ab27 320
c3316802 321/** @warning currently size is limited */
572f992e 322#ifdef __GNUC__
08f29f82 323int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
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324#else
325int url_fprintf(ByteIOContext *s, const char *fmt, ...);
326#endif
a8c5ab27 327
c3316802 328/** @note unlike fgets, the EOL character is not returned and a whole
7f37f568 329 line is parsed. return NULL if first char read was EOF */
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330char *url_fgets(ByteIOContext *s, char *buf, int buf_size);
331
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332void put_flush_packet(ByteIOContext *s);
333
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334
335/**
336 * Reads size bytes from ByteIOContext into buf.
337 * @returns number of bytes read or AVERROR
338 */
de6d9b64 339int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
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340
341/**
342 * Reads size bytes from ByteIOContext into buf.
4477dedc 343 * This reads at most 1 packet. If that is not enough fewer bytes will be
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344 * returned.
345 * @returns number of bytes read or AVERROR
346 */
e15dec10 347int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
a8c5ab27 348
c3316802 349/** @note return 0 if EOF, so you cannot use it if EOF handling is
7f37f568 350 necessary */
de6d9b64 351int get_byte(ByteIOContext *s);
ea395e8c 352unsigned int get_le24(ByteIOContext *s);
de6d9b64 353unsigned int get_le32(ByteIOContext *s);
0c1a9eda 354uint64_t get_le64(ByteIOContext *s);
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355unsigned int get_le16(ByteIOContext *s);
356
3b4b29dc 357char *get_strz(ByteIOContext *s, char *buf, int maxlen);
de6d9b64 358unsigned int get_be16(ByteIOContext *s);
a254c574 359unsigned int get_be24(ByteIOContext *s);
de6d9b64 360unsigned int get_be32(ByteIOContext *s);
0c1a9eda 361uint64_t get_be64(ByteIOContext *s);
de6d9b64 362
7798b42d 363uint64_t ff_get_v(ByteIOContext *bc);
897d3eef 364
7ac13f0c 365static inline int url_is_streamed(ByteIOContext *s)
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366{
367 return s->is_streamed;
368}
de6d9b64 369
3576f9c6 370/** @note when opened as read/write, the buffers are only used for
7f37f568 371 writing */
899681cd 372int url_fdopen(ByteIOContext **s, URLContext *h);
a8c5ab27 373
c3316802 374/** @warning must be called before any I/O */
de6d9b64 375int url_setbufsize(ByteIOContext *s, int buf_size);
08580cb0 376#if LIBAVFORMAT_VERSION_MAJOR < 53
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377/** Reset the buffer for reading or writing.
378 * @note Will drop any data currently in the buffer without transmitting it.
379 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
380 * to set up the buffer for writing. */
381int url_resetbuf(ByteIOContext *s, int flags);
08580cb0 382#endif
a8c5ab27 383
c3316802 384/** @note when opened as read/write, the buffers are only used for
7f37f568 385 writing */
899681cd 386int url_fopen(ByteIOContext **s, const char *filename, int flags);
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387int url_fclose(ByteIOContext *s);
388URLContext *url_fileno(ByteIOContext *s);
a8c5ab27 389
c3316802 390/**
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391 * Return the maximum packet size associated to packetized buffered file
392 * handle. If the file is not packetized (stream like http or file on
393 * disk), then 0 is returned.
394 *
abfe87d4 395 * @param s buffered file handle
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396 * @return maximum packet size in bytes
397 */
f031df23 398int url_fget_max_packet_size(ByteIOContext *s);
de6d9b64 399
899681cd 400int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags);
a8c5ab27 401
c3316802 402/** return the written or read size */
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403int url_close_buf(ByteIOContext *s);
404
c3316802 405/**
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406 * Open a write only memory stream.
407 *
408 * @param s new IO context
409 * @return zero if no error.
410 */
899681cd 411int url_open_dyn_buf(ByteIOContext **s);
a8c5ab27 412
c3316802 413/**
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414 * Open a write only packetized memory stream with a maximum packet
415 * size of 'max_packet_size'. The stream is stored in a memory buffer
416 * with a big endian 4 byte header giving the packet size in bytes.
417 *
418 * @param s new IO context
419 * @param max_packet_size maximum packet size (must be > 0)
420 * @return zero if no error.
421 */
899681cd 422int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size);
a8c5ab27 423
c3316802 424/**
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425 * Return the written size and a pointer to the buffer. The buffer
426 * must be freed with av_free().
427 * @param s IO context
e8b7c70f 428 * @param pbuffer pointer to a byte buffer
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429 * @return the length of the byte buffer
430 */
0c1a9eda 431int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);
f031df23 432
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433unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
434 unsigned int len);
ee9f36a8 435unsigned long get_checksum(ByteIOContext *s);
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436void init_checksum(ByteIOContext *s,
437 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
438 unsigned long checksum);
ee9f36a8 439
de6d9b64 440/* udp.c */
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441int udp_set_remote_url(URLContext *h, const char *uri);
442int udp_get_local_port(URLContext *h);
f0a80394 443#if (LIBAVFORMAT_VERSION_MAJOR <= 52)
f031df23 444int udp_get_file_handle(URLContext *h);
f0a80394 445#endif
f031df23 446
98790382 447#endif /* AVFORMAT_AVIO_H */