Add Cineform HD Decoder
[libav.git] / libavformat / avio.h
CommitLineData
04d7f601 1/*
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2 * copyright (c) 2001 Fabrice Bellard
3 *
2912e87a 4 * This file is part of Libav.
b78e7197 5 *
2912e87a 6 * Libav 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 *
2912e87a 11 * Libav 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
2912e87a 17 * License along with Libav; 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
aafe9b63 23/**
ba87f080 24 * @file
eca06cbe 25 * @ingroup lavf_io
6084ee5d 26 * Buffered I/O operations
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27 */
28
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29#include <stdint.h>
30
30f68128 31#include "libavutil/common.h"
1dee0aca 32#include "libavutil/dict.h"
ed8d5766 33#include "libavutil/log.h"
30f68128 34
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35#include "libavformat/version.h"
36
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37/**
38 * Seeking works like for a local file.
39 */
40#define AVIO_SEEKABLE_NORMAL (1 << 0)
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41
42/**
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43 * Seeking by timestamp with avio_seek_time() is possible.
44 */
45#define AVIO_SEEKABLE_TIME (1 << 1)
46
47/**
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48 * Callback for checking whether to abort blocking functions.
49 * AVERROR_EXIT is returned in this case by the interrupted
50 * function. During blocking operations, callback is called with
51 * opaque as parameter. If the callback returns 1, the
52 * blocking operation will be aborted.
53 *
54 * No members can be added to this struct without a major bump, if
55 * new elements have been added after this struct in AVFormatContext
56 * or AVIOContext.
57 */
0575772f 58typedef struct AVIOInterruptCB {
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59 int (*callback)(void*);
60 void *opaque;
61} AVIOInterruptCB;
62
63/**
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64 * Different data types that can be returned via the AVIO
65 * write_data_type callback.
66 */
67enum AVIODataMarkerType {
68 /**
69 * Header data; this needs to be present for the stream to be decodeable.
70 */
71 AVIO_DATA_MARKER_HEADER,
72 /**
73 * A point in the output bytestream where a decoder can start decoding
74 * (i.e. a keyframe). A demuxer/decoder given the data flagged with
75 * AVIO_DATA_MARKER_HEADER, followed by any AVIO_DATA_MARKER_SYNC_POINT,
76 * should give decodeable results.
77 */
78 AVIO_DATA_MARKER_SYNC_POINT,
79 /**
80 * A point in the output bytestream where a demuxer can start parsing
81 * (for non self synchronizing bytestream formats). That is, any
82 * non-keyframe packet start point.
83 */
84 AVIO_DATA_MARKER_BOUNDARY_POINT,
85 /**
86 * This is any, unlabelled data. It can either be a muxer not marking
87 * any positions at all, it can be an actual boundary/sync point
88 * that the muxer chooses not to mark, or a later part of a packet/fragment
89 * that is cut into multiple write callbacks due to limited IO buffer size.
90 */
91 AVIO_DATA_MARKER_UNKNOWN,
92 /**
93 * Trailer data, which doesn't contain actual content, but only for
94 * finalizing the output file.
95 */
96 AVIO_DATA_MARKER_TRAILER
97};
98
99/**
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100 * Bytestream IO Context.
101 * New fields can be added to the end with minor version bumps.
102 * Removal, reordering and changes to existing fields require a major
103 * version bump.
104 * sizeof(AVIOContext) must not be used outside libav*.
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105 *
106 * @note None of the function pointers in AVIOContext should be called
107 * directly, they should only be set by the client application
108 * when implementing custom I/O. Normally these are set to the
109 * function pointers specified in avio_alloc_context()
fafa7290 110 */
0575772f 111typedef struct AVIOContext {
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112 /**
113 * A class for private options.
114 *
115 * If this AVIOContext is created by avio_open2(), av_class is set and
116 * passes the options down to protocols.
117 *
118 * If this AVIOContext is manually allocated, then av_class may be set by
119 * the caller.
120 *
121 * warning -- this field can be NULL, be sure to not pass this AVIOContext
122 * to any av_opt_* functions in that case.
123 */
6208313a 124 const AVClass *av_class;
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125 unsigned char *buffer; /**< Start of the buffer. */
126 int buffer_size; /**< Maximum buffer size */
127 unsigned char *buf_ptr; /**< Current position in the buffer */
128 unsigned char *buf_end; /**< End of the data, may be less than
129 buffer+buffer_size if the read function returned
130 less data than requested, e.g. for streams where
131 no more data has been received yet. */
132 void *opaque; /**< A private pointer, passed to the read/write/seek/...
133 functions. */
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134 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
135 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
136 int64_t (*seek)(void *opaque, int64_t offset, int whence);
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137 int64_t pos; /**< position in the file of the current buffer */
138 int must_flush; /**< true if the next seek should flush */
139 int eof_reached; /**< true if eof reached */
140 int write_flag; /**< true if open for writing */
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141 int max_packet_size;
142 unsigned long checksum;
143 unsigned char *checksum_ptr;
144 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
893816ba 145 int error; /**< contains the error code or 0 if no error happened */
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146 /**
147 * Pause or resume playback for network streaming protocols - e.g. MMS.
148 */
fafa7290 149 int (*read_pause)(void *opaque, int pause);
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150 /**
151 * Seek to a given timestamp in stream with the specified stream_index.
152 * Needed for some network streaming protocols which don't support seeking
153 * to byte position.
154 */
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155 int64_t (*read_seek)(void *opaque, int stream_index,
156 int64_t timestamp, int flags);
157 /**
158 * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
159 */
160 int seekable;
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161
162 /**
163 * A callback that is used instead of write_packet.
164 */
165 int (*write_data_type)(void *opaque, uint8_t *buf, int buf_size,
166 enum AVIODataMarkerType type, int64_t time);
167 /**
168 * If set, don't call write_data_type separately for AVIO_DATA_MARKER_BOUNDARY_POINT,
169 * but ignore them and treat them as AVIO_DATA_MARKER_UNKNOWN (to avoid needlessly
170 * small chunks of data returned from the callback).
171 */
172 int ignore_boundary_point;
173
174 /**
175 * Internal, not meant to be used from outside of AVIOContext.
176 */
177 enum AVIODataMarkerType current_type;
178 int64_t last_time;
3f75e511 179 int64_t written;
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180} AVIOContext;
181
37744e32 182/**
59d96941 183 * Return AVIO_FLAG_* access flags corresponding to the access permissions
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184 * of the resource in url, or a negative value corresponding to an
185 * AVERROR code in case of failure. The returned access flags are
186 * masked by the value in flags.
187 *
188 * @note This function is intrinsically unsafe, in the sense that the
189 * checked resource may change its existence or permission status from
190 * one call to another. Thus you should not trust the returned value,
191 * unless you are sure that no other processes are accessing the
192 * checked resource.
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193 */
194int avio_check(const char *url, int flags);
195
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196/**
197 * Allocate and initialize an AVIOContext for buffered I/O. It must be later
198 * freed with av_free().
199 *
200 * @param buffer Memory block for input/output operations via AVIOContext.
d49051e0 201 * The buffer must be allocated with av_malloc() and friends.
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202 * @param buffer_size The buffer size is very important for performance.
203 * For protocols with fixed blocksize it should be set to this blocksize.
204 * For others a typical size is a cache page, e.g. 4kb.
205 * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.
206 * @param opaque An opaque pointer to user-specific data.
207 * @param read_packet A function for refilling the buffer, may be NULL.
208 * @param write_packet A function for writing the buffer contents, may be NULL.
209 * @param seek A function for seeking to specified byte position, may be NULL.
210 *
211 * @return Allocated AVIOContext or NULL on failure.
212 */
8d9ac969 213AVIOContext *avio_alloc_context(
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214 unsigned char *buffer,
215 int buffer_size,
216 int write_flag,
217 void *opaque,
0c1a9eda 218 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
576ae256 219 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
bc5c918e 220 int64_t (*seek)(void *opaque, int64_t offset, int whence));
de6d9b64 221
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222/**
223 * Free the supplied IO context and everything associated with it.
224 *
225 * @param s Double pointer to the IO context. This function will write NULL
226 * into s.
227 */
228void avio_context_free(AVIOContext **s);
229
77eb5504 230void avio_w8(AVIOContext *s, int b);
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231void avio_write(AVIOContext *s, const unsigned char *buf, int size);
232void avio_wl64(AVIOContext *s, uint64_t val);
233void avio_wb64(AVIOContext *s, uint64_t val);
234void avio_wl32(AVIOContext *s, unsigned int val);
235void avio_wb32(AVIOContext *s, unsigned int val);
236void avio_wl24(AVIOContext *s, unsigned int val);
237void avio_wb24(AVIOContext *s, unsigned int val);
238void avio_wl16(AVIOContext *s, unsigned int val);
239void avio_wb16(AVIOContext *s, unsigned int val);
de6d9b64 240
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241/**
242 * Write a NULL-terminated string.
243 * @return number of bytes written.
244 */
ae628ec1 245int avio_put_str(AVIOContext *s, const char *str);
75bdb984 246
67e21020 247/**
dccbd97d 248 * Convert an UTF-8 string to UTF-16LE and write it.
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249 * @param s the AVIOContext
250 * @param str NULL-terminated UTF-8 string
251 *
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252 * @return number of bytes written.
253 */
ae628ec1 254int avio_put_str16le(AVIOContext *s, const char *str);
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255
256/**
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257 * Convert an UTF-8 string to UTF-16BE and write it.
258 * @param s the AVIOContext
259 * @param str NULL-terminated UTF-8 string
260 *
261 * @return number of bytes written.
262 */
263int avio_put_str16be(AVIOContext *s, const char *str);
264
265/**
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266 * Mark the written bytestream as a specific type.
267 *
268 * Zero-length ranges are omitted from the output.
269 *
270 * @param time the stream time the current bytestream pos corresponds to
271 * (in AV_TIME_BASE units), or AV_NOPTS_VALUE if unknown or not
272 * applicable
273 * @param type the kind of data written starting at the current pos
274 */
275void avio_write_marker(AVIOContext *s, int64_t time, enum AVIODataMarkerType type);
276
277/**
41ed7ab4 278 * ORing this as the "whence" parameter to a seek function causes it to
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279 * return the filesize without seeking anywhere. Supporting this is optional.
280 * If it is not supported then the seek function will return <0.
281 */
282#define AVSEEK_SIZE 0x10000
283
284/**
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285 * Passing this flag as the "whence" parameter to a seek function causes it to
286 * seek by any means (like reopening and linear reading) or other normally unreasonable
287 * means that can be extremely slow.
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288 * This may be ignored by the seek code.
289 */
290#define AVSEEK_FORCE 0x20000
291
292/**
ae628ec1 293 * fseek() equivalent for AVIOContext.
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294 * @return new position or AVERROR.
295 */
6b4aa5da 296int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);
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297
298/**
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299 * Skip given number of bytes forward
300 * @return new position or AVERROR.
301 */
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302static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
303{
304 return avio_seek(s, offset, SEEK_CUR);
305}
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306
307/**
ae628ec1 308 * ftell() equivalent for AVIOContext.
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309 * @return position or AVERROR.
310 */
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311static av_always_inline int64_t avio_tell(AVIOContext *s)
312{
313 return avio_seek(s, 0, SEEK_CUR);
314}
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315
316/**
49bd8e4b 317 * Get the filesize.
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318 * @return filesize or AVERROR
319 */
76aa876e 320int64_t avio_size(AVIOContext *s);
67e21020 321
c3316802 322/** @warning currently size is limited */
9abbe8cc 323int avio_printf(AVIOContext *s, const char *fmt, ...) av_printf_format(2, 3);
a8c5ab27 324
b7f2fdde 325void avio_flush(AVIOContext *s);
de6d9b64 326
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327
328/**
ae628ec1 329 * Read size bytes from AVIOContext into buf.
32e543f8 330 * @return number of bytes read or AVERROR
4edfcecc 331 */
b7effd4e 332int avio_read(AVIOContext *s, unsigned char *buf, int size);
4edfcecc 333
72d4405b 334/**
21a19b79 335 * @name Functions for reading from AVIOContext
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336 * @{
337 *
338 * @note return 0 if EOF, so you cannot use it if EOF handling is
339 * necessary
340 */
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341int avio_r8 (AVIOContext *s);
342unsigned int avio_rl16(AVIOContext *s);
343unsigned int avio_rl24(AVIOContext *s);
344unsigned int avio_rl32(AVIOContext *s);
345uint64_t avio_rl64(AVIOContext *s);
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346unsigned int avio_rb16(AVIOContext *s);
347unsigned int avio_rb24(AVIOContext *s);
348unsigned int avio_rb32(AVIOContext *s);
349uint64_t avio_rb64(AVIOContext *s);
350/**
351 * @}
352 */
de6d9b64 353
93b78d12 354/**
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355 * Read a string from pb into buf. The reading will terminate when either
356 * a NULL character was encountered, maxlen bytes have been read, or nothing
357 * more can be read from pb. The result is guaranteed to be NULL-terminated, it
358 * will be truncated if buf is too small.
359 * Note that the string is not interpreted or validated in any way, it
360 * might get truncated in the middle of a sequence for multi-byte encodings.
361 *
362 * @return number of bytes read (is always <= maxlen).
363 * If reading ends on EOF or error, the return value will be one more than
364 * bytes actually read.
365 */
366int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);
367
368/**
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369 * Read a UTF-16 string from pb and convert it to UTF-8.
370 * The reading will terminate when either a null or invalid character was
371 * encountered or maxlen bytes have been read.
372 * @return number of bytes read (is always <= maxlen)
373 */
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374int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);
375int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);
93b78d12 376
de6d9b64 377
fe4fbb58 378/**
21a19b79 379 * @name URL open modes
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380 * The flags argument to avio_open must be one of the following
381 * constants, optionally ORed with other flags.
382 * @{
383 */
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384#define AVIO_FLAG_READ 1 /**< read-only */
385#define AVIO_FLAG_WRITE 2 /**< write-only */
386#define AVIO_FLAG_READ_WRITE (AVIO_FLAG_READ|AVIO_FLAG_WRITE) /**< read-write pseudo flag */
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387/**
388 * @}
389 */
390
391/**
392 * Use non-blocking mode.
393 * If this flag is set, operations on the context will return
394 * AVERROR(EAGAIN) if they can not be performed immediately.
395 * If this flag is not set, operations on the context will never return
396 * AVERROR(EAGAIN).
397 * Note that this flag does not affect the opening/connecting of the
398 * context. Connecting a protocol will always block if necessary (e.g. on
399 * network protocols) but never hang (e.g. on busy devices).
400 * Warning: non-blocking protocols is work-in-progress; this flag may be
401 * silently ignored.
402 */
cbea3ac8 403#define AVIO_FLAG_NONBLOCK 8
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404
405/**
ae628ec1 406 * Create and initialize a AVIOContext for accessing the
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407 * resource indicated by url.
408 * @note When the resource indicated by url has been opened in
ae628ec1 409 * read+write mode, the AVIOContext can be used only for writing.
fe4fbb58 410 *
ae628ec1 411 * @param s Used to return the pointer to the created AVIOContext.
fe4fbb58 412 * In case of failure the pointed to value is set to NULL.
4d7ab5cf 413 * @param url resource to access
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414 * @param flags flags which control how the resource indicated by url
415 * is to be opened
416 * @return 0 in case of success, a negative value corresponding to an
417 * AVERROR code in case of failure
418 */
22a3212e 419int avio_open(AVIOContext **s, const char *url, int flags);
fe4fbb58 420
e782a0c6 421/**
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422 * Create and initialize a AVIOContext for accessing the
423 * resource indicated by url.
424 * @note When the resource indicated by url has been opened in
425 * read+write mode, the AVIOContext can be used only for writing.
426 *
427 * @param s Used to return the pointer to the created AVIOContext.
428 * In case of failure the pointed to value is set to NULL.
4d7ab5cf 429 * @param url resource to access
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430 * @param flags flags which control how the resource indicated by url
431 * is to be opened
432 * @param int_cb an interrupt callback to be used at the protocols level
433 * @param options A dictionary filled with protocol-private options. On return
434 * this parameter will be destroyed and replaced with a dict containing options
435 * that were not found. May be NULL.
436 * @return 0 in case of success, a negative value corresponding to an
437 * AVERROR code in case of failure
438 */
439int avio_open2(AVIOContext **s, const char *url, int flags,
440 const AVIOInterruptCB *int_cb, AVDictionary **options);
441
442/**
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443 * Close the resource accessed by the AVIOContext s and free it.
444 * This function can only be used if s was opened by avio_open().
445 *
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446 * The internal buffer is automatically flushed before closing the
447 * resource.
448 *
e782a0c6 449 * @return 0 on success, an AVERROR < 0 on error.
b522000e 450 * @see avio_closep
e782a0c6 451 */
22a3212e 452int avio_close(AVIOContext *s);
a8c5ab27 453
c3316802 454/**
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455 * Close the resource accessed by the AVIOContext *s, free it
456 * and set the pointer pointing to it to NULL.
457 * This function can only be used if s was opened by avio_open().
458 *
459 * The internal buffer is automatically flushed before closing the
460 * resource.
461 *
462 * @return 0 on success, an AVERROR < 0 on error.
463 * @see avio_close
464 */
465int avio_closep(AVIOContext **s);
466
467
468/**
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469 * Open a write only memory stream.
470 *
471 * @param s new IO context
472 * @return zero if no error.
473 */
b92c5452 474int avio_open_dyn_buf(AVIOContext **s);
a8c5ab27 475
c3316802 476/**
a8c5ab27 477 * Return the written size and a pointer to the buffer. The buffer
403ee835 478 * must be freed with av_free().
059a9348 479 * Padding of AV_INPUT_BUFFER_PADDING_SIZE is added to the buffer.
de1807bb 480 *
a8c5ab27 481 * @param s IO context
e8b7c70f 482 * @param pbuffer pointer to a byte buffer
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483 * @return the length of the byte buffer
484 */
6dc7d80d 485int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
f031df23 486
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487/**
488 * Iterate through names of available protocols.
489 *
490 * @param opaque A private pointer representing current protocol.
491 * It must be a pointer to NULL on first iteration and will
492 * be updated by successive calls to avio_enum_protocols.
493 * @param output If set to 1, iterate over output protocols,
494 * otherwise over input protocols.
495 *
496 * @return A static string containing the name of current protocol or NULL
497 */
498const char *avio_enum_protocols(void **opaque, int output);
499
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500/**
501 * Pause and resume playing - only meaningful if using a network streaming
502 * protocol (e.g. MMS).
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503 *
504 * @param h IO context from which to call the read_pause function pointer
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505 * @param pause 1 for pause, 0 for resume
506 */
507int avio_pause(AVIOContext *h, int pause);
508
509/**
510 * Seek to a given timestamp relative to some component stream.
511 * Only meaningful if using a network streaming protocol (e.g. MMS.).
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512 *
513 * @param h IO context from which to call the seek function pointers
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514 * @param stream_index The stream index that the timestamp is relative to.
515 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
516 * units from the beginning of the presentation.
517 * If a stream_index >= 0 is used and the protocol does not support
518 * seeking based on component streams, the call will fail with ENOTSUP.
519 * @param timestamp timestamp in AVStream.time_base units
520 * or if there is no stream specified then in AV_TIME_BASE units.
521 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
522 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
523 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
524 * fail with ENOTSUP if used and not supported.
525 * @return >= 0 on success
526 * @see AVInputFormat::read_seek
527 */
528int64_t avio_seek_time(AVIOContext *h, int stream_index,
529 int64_t timestamp, int flags);
530
98790382 531#endif /* AVFORMAT_AVIO_H */