Statistics
| Branch: | Revision:

ffmpeg / libavformat / avio.h @ 468644f6

History | View | Annotate | Download (24.8 KB)

1
/*
2
 * copyright (c) 2001 Fabrice Bellard
3
 *
4
 * This file is part of Libav.
5
 *
6
 * Libav is free software; you can redistribute it and/or
7
 * modify it under the terms of the GNU Lesser General Public
8
 * License as published by the Free Software Foundation; either
9
 * version 2.1 of the License, or (at your option) any later version.
10
 *
11
 * Libav is distributed in the hope that it will be useful,
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
17
 * License along with Libav; if not, write to the Free Software
18
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19
 */
20
#ifndef AVFORMAT_AVIO_H
21
#define AVFORMAT_AVIO_H
22

    
23
/**
24
 * @file
25
 * Buffered I/O operations
26
 */
27

    
28
#include <stdint.h>
29

    
30
#include "libavutil/common.h"
31
#include "libavutil/log.h"
32

    
33
#include "libavformat/version.h"
34

    
35

    
36
#define AVIO_SEEKABLE_NORMAL 0x0001 /**< Seeking works like for a local file */
37

    
38
/**
39
 * Bytestream IO Context.
40
 * New fields can be added to the end with minor version bumps.
41
 * Removal, reordering and changes to existing fields require a major
42
 * version bump.
43
 * sizeof(AVIOContext) must not be used outside libav*.
44
 *
45
 * @note None of the function pointers in AVIOContext should be called
46
 *       directly, they should only be set by the client application
47
 *       when implementing custom I/O. Normally these are set to the
48
 *       function pointers specified in avio_alloc_context()
49
 */
50
typedef struct {
51
    unsigned char *buffer;  /**< Start of the buffer. */
52
    int buffer_size;        /**< Maximum buffer size */
53
    unsigned char *buf_ptr; /**< Current position in the buffer */
54
    unsigned char *buf_end; /**< End of the data, may be less than
55
                                 buffer+buffer_size if the read function returned
56
                                 less data than requested, e.g. for streams where
57
                                 no more data has been received yet. */
58
    void *opaque;           /**< A private pointer, passed to the read/write/seek/...
59
                                 functions. */
60
    int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
61
    int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
62
    int64_t (*seek)(void *opaque, int64_t offset, int whence);
63
    int64_t pos;            /**< position in the file of the current buffer */
64
    int must_flush;         /**< true if the next seek should flush */
65
    int eof_reached;        /**< true if eof reached */
66
    int write_flag;         /**< true if open for writing */
67
#if FF_API_OLD_AVIO
68
    attribute_deprecated int is_streamed;
69
#endif
70
    int max_packet_size;
71
    unsigned long checksum;
72
    unsigned char *checksum_ptr;
73
    unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
74
    int error;              /**< contains the error code or 0 if no error happened */
75
    /**
76
     * Pause or resume playback for network streaming protocols - e.g. MMS.
77
     */
78
    int (*read_pause)(void *opaque, int pause);
79
    /**
80
     * Seek to a given timestamp in stream with the specified stream_index.
81
     * Needed for some network streaming protocols which don't support seeking
82
     * to byte position.
83
     */
84
    int64_t (*read_seek)(void *opaque, int stream_index,
85
                         int64_t timestamp, int flags);
86
    /**
87
     * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
88
     */
89
    int seekable;
90
} AVIOContext;
91

    
92
/* unbuffered I/O */
93

    
94
#if FF_API_OLD_AVIO
95
/**
96
 * URL Context.
97
 * New fields can be added to the end with minor version bumps.
98
 * Removal, reordering and changes to existing fields require a major
99
 * version bump.
100
 * sizeof(URLContext) must not be used outside libav*.
101
 * @deprecated This struct will be made private
102
 */
103
typedef struct URLContext {
104
#if FF_API_URL_CLASS
105
    const AVClass *av_class; ///< information for av_log(). Set by url_open().
106
#endif
107
    struct URLProtocol *prot;
108
    int flags;
109
    int is_streamed;  /**< true if streamed (no seek possible), default = false */
110
    int max_packet_size;  /**< if non zero, the stream is packetized with this max packet size */
111
    void *priv_data;
112
    char *filename; /**< specified URL */
113
    int is_connected;
114
} URLContext;
115

    
116
#define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */
117

    
118
/**
119
 * @deprecated This struct is to be made private. Use the higher-level
120
 *             AVIOContext-based API instead.
121
 */
122
typedef struct URLProtocol {
123
    const char *name;
124
    int (*url_open)(URLContext *h, const char *url, int flags);
125
    int (*url_read)(URLContext *h, unsigned char *buf, int size);
126
    int (*url_write)(URLContext *h, const unsigned char *buf, int size);
127
    int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
128
    int (*url_close)(URLContext *h);
129
    struct URLProtocol *next;
130
    int (*url_read_pause)(URLContext *h, int pause);
131
    int64_t (*url_read_seek)(URLContext *h, int stream_index,
132
                             int64_t timestamp, int flags);
133
    int (*url_get_file_handle)(URLContext *h);
134
    int priv_data_size;
135
    const AVClass *priv_data_class;
136
    int flags;
137
    int (*url_check)(URLContext *h, int mask);
138
} URLProtocol;
139

    
140
typedef struct URLPollEntry {
141
    URLContext *handle;
142
    int events;
143
    int revents;
144
} URLPollEntry;
145

    
146
/* not implemented */
147
attribute_deprecated int url_poll(URLPollEntry *poll_table, int n, int timeout);
148

    
149
/**
150
 * @defgroup open_modes URL open modes
151
 * The flags argument to url_open and cosins must be one of the following
152
 * constants, optionally ORed with other flags.
153
 * @{
154
 */
155
#define URL_RDONLY 0  /**< read-only */
156
#define URL_WRONLY 1  /**< write-only */
157
#define URL_RDWR   2  /**< read-write */
158
/**
159
 * @}
160
 */
161

    
162
/**
163
 * Use non-blocking mode.
164
 * If this flag is set, operations on the context will return
165
 * AVERROR(EAGAIN) if they can not be performed immediately.
166
 * If this flag is not set, operations on the context will never return
167
 * AVERROR(EAGAIN).
168
 * Note that this flag does not affect the opening/connecting of the
169
 * context. Connecting a protocol will always block if necessary (e.g. on
170
 * network protocols) but never hang (e.g. on busy devices).
171
 * Warning: non-blocking protocols is work-in-progress; this flag may be
172
 * silently ignored.
173
 */
174
#define URL_FLAG_NONBLOCK 4
175

    
176
typedef int URLInterruptCB(void);
177
extern URLInterruptCB *url_interrupt_cb;
178

    
179
/**
180
 * @defgroup old_url_funcs Old url_* functions
181
 * @deprecated use the buffered API based on AVIOContext instead
182
 * @{
183
 */
184
attribute_deprecated int url_open_protocol (URLContext **puc, struct URLProtocol *up,
185
                                            const char *url, int flags);
186
attribute_deprecated int url_alloc(URLContext **h, const char *url, int flags);
187
attribute_deprecated int url_connect(URLContext *h);
188
attribute_deprecated int url_open(URLContext **h, const char *url, int flags);
189
attribute_deprecated int url_read(URLContext *h, unsigned char *buf, int size);
190
attribute_deprecated int url_read_complete(URLContext *h, unsigned char *buf, int size);
191
attribute_deprecated int url_write(URLContext *h, const unsigned char *buf, int size);
192
attribute_deprecated int64_t url_seek(URLContext *h, int64_t pos, int whence);
193
attribute_deprecated int url_close(URLContext *h);
194
attribute_deprecated int64_t url_filesize(URLContext *h);
195
attribute_deprecated int url_get_file_handle(URLContext *h);
196
attribute_deprecated int url_get_max_packet_size(URLContext *h);
197
attribute_deprecated void url_get_filename(URLContext *h, char *buf, int buf_size);
198
attribute_deprecated int av_url_read_pause(URLContext *h, int pause);
199
attribute_deprecated int64_t av_url_read_seek(URLContext *h, int stream_index,
200
                                              int64_t timestamp, int flags);
201
attribute_deprecated void url_set_interrupt_cb(int (*interrupt_cb)(void));
202
/**
203
 * If protocol is NULL, returns the first registered protocol,
204
 * if protocol is non-NULL, returns the next registered protocol after protocol,
205
 * or NULL if protocol is the last one.
206
 */
207
attribute_deprecated URLProtocol *av_protocol_next(URLProtocol *p);
208
/**
209
 * Register the URLProtocol protocol.
210
 *
211
 * @param size the size of the URLProtocol struct referenced
212
 */
213
attribute_deprecated int av_register_protocol2(URLProtocol *protocol, int size);
214
/**
215
 * @}
216
 */
217

    
218

    
219
typedef attribute_deprecated AVIOContext ByteIOContext;
220

    
221
attribute_deprecated int init_put_byte(AVIOContext *s,
222
                  unsigned char *buffer,
223
                  int buffer_size,
224
                  int write_flag,
225
                  void *opaque,
226
                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
227
                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
228
                  int64_t (*seek)(void *opaque, int64_t offset, int whence));
229
attribute_deprecated AVIOContext *av_alloc_put_byte(
230
                  unsigned char *buffer,
231
                  int buffer_size,
232
                  int write_flag,
233
                  void *opaque,
234
                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
235
                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
236
                  int64_t (*seek)(void *opaque, int64_t offset, int whence));
237

    
238
/**
239
 * @defgroup old_avio_funcs Old put_/get_*() functions
240
 * @deprecated use the avio_ -prefixed functions instead.
241
 * @{
242
 */
243
attribute_deprecated int          get_buffer(AVIOContext *s, unsigned char *buf, int size);
244
attribute_deprecated int          get_partial_buffer(AVIOContext *s, unsigned char *buf, int size);
245
attribute_deprecated int          get_byte(AVIOContext *s);
246
attribute_deprecated unsigned int get_le16(AVIOContext *s);
247
attribute_deprecated unsigned int get_le24(AVIOContext *s);
248
attribute_deprecated unsigned int get_le32(AVIOContext *s);
249
attribute_deprecated uint64_t     get_le64(AVIOContext *s);
250
attribute_deprecated unsigned int get_be16(AVIOContext *s);
251
attribute_deprecated unsigned int get_be24(AVIOContext *s);
252
attribute_deprecated unsigned int get_be32(AVIOContext *s);
253
attribute_deprecated uint64_t     get_be64(AVIOContext *s);
254

    
255
attribute_deprecated void         put_byte(AVIOContext *s, int b);
256
attribute_deprecated void         put_nbyte(AVIOContext *s, int b, int count);
257
attribute_deprecated void         put_buffer(AVIOContext *s, const unsigned char *buf, int size);
258
attribute_deprecated void         put_le64(AVIOContext *s, uint64_t val);
259
attribute_deprecated void         put_be64(AVIOContext *s, uint64_t val);
260
attribute_deprecated void         put_le32(AVIOContext *s, unsigned int val);
261
attribute_deprecated void         put_be32(AVIOContext *s, unsigned int val);
262
attribute_deprecated void         put_le24(AVIOContext *s, unsigned int val);
263
attribute_deprecated void         put_be24(AVIOContext *s, unsigned int val);
264
attribute_deprecated void         put_le16(AVIOContext *s, unsigned int val);
265
attribute_deprecated void         put_be16(AVIOContext *s, unsigned int val);
266
attribute_deprecated void         put_tag(AVIOContext *s, const char *tag);
267
/**
268
 * @}
269
 */
270

    
271
attribute_deprecated int     av_url_read_fpause(AVIOContext *h,    int pause);
272
attribute_deprecated int64_t av_url_read_fseek (AVIOContext *h,    int stream_index,
273
                                                int64_t timestamp, int flags);
274

    
275
/**
276
 * @defgroup old_url_f_funcs Old url_f* functions
277
 * @deprecated use the avio_ -prefixed functions instead.
278
 * @{
279
 */
280
attribute_deprecated int url_fopen( AVIOContext **s, const char *url, int flags);
281
attribute_deprecated int url_fclose(AVIOContext *s);
282
attribute_deprecated int64_t url_fseek(AVIOContext *s, int64_t offset, int whence);
283
attribute_deprecated int url_fskip(AVIOContext *s, int64_t offset);
284
attribute_deprecated int64_t url_ftell(AVIOContext *s);
285
attribute_deprecated int64_t url_fsize(AVIOContext *s);
286
#define URL_EOF (-1)
287
attribute_deprecated int url_fgetc(AVIOContext *s);
288
attribute_deprecated int url_setbufsize(AVIOContext *s, int buf_size);
289
#ifdef __GNUC__
290
attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
291
#else
292
attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...);
293
#endif
294
attribute_deprecated void put_flush_packet(AVIOContext *s);
295
attribute_deprecated int url_open_dyn_buf(AVIOContext **s);
296
attribute_deprecated int url_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
297
attribute_deprecated int url_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
298
attribute_deprecated int url_fdopen(AVIOContext **s, URLContext *h);
299
/**
300
 * @}
301
 */
302

    
303
/**
304
 * @deprecated use AVIOContext.eof_reached
305
 */
306
attribute_deprecated int url_feof(AVIOContext *s);
307
attribute_deprecated int url_ferror(AVIOContext *s);
308

    
309
attribute_deprecated int udp_set_remote_url(URLContext *h, const char *uri);
310
attribute_deprecated int udp_get_local_port(URLContext *h);
311

    
312
attribute_deprecated void init_checksum(AVIOContext *s,
313
                   unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
314
                   unsigned long checksum);
315
attribute_deprecated unsigned long get_checksum(AVIOContext *s);
316
attribute_deprecated void put_strz(AVIOContext *s, const char *buf);
317
/** @note unlike fgets, the EOL character is not returned and a whole
318
    line is parsed. return NULL if first char read was EOF */
319
attribute_deprecated char *url_fgets(AVIOContext *s, char *buf, int buf_size);
320
/**
321
 * @deprecated use avio_get_str instead
322
 */
323
attribute_deprecated char *get_strz(AVIOContext *s, char *buf, int maxlen);
324
/**
325
 * @deprecated Use AVIOContext.seekable field directly.
326
 */
327
attribute_deprecated static inline int url_is_streamed(AVIOContext *s)
328
{
329
    return !s->seekable;
330
}
331
attribute_deprecated URLContext *url_fileno(AVIOContext *s);
332

    
333
/**
334
 * @deprecated use AVIOContext.max_packet_size directly.
335
 */
336
attribute_deprecated int url_fget_max_packet_size(AVIOContext *s);
337

    
338
attribute_deprecated int url_open_buf(AVIOContext **s, uint8_t *buf, int buf_size, int flags);
339

    
340
/** return the written or read size */
341
attribute_deprecated int url_close_buf(AVIOContext *s);
342

    
343
/**
344
 * Return a non-zero value if the resource indicated by url
345
 * exists, 0 otherwise.
346
 * @deprecated Use avio_check instead.
347
 */
348
attribute_deprecated int url_exist(const char *url);
349
#endif // FF_API_OLD_AVIO
350

    
351
/**
352
 * Return AVIO_* access flags corresponding to the access permissions
353
 * of the resource in url, or a negative value corresponding to an
354
 * AVERROR code in case of failure. The returned access flags are
355
 * masked by the value in flags.
356
 *
357
 * @note This function is intrinsically unsafe, in the sense that the
358
 * checked resource may change its existence or permission status from
359
 * one call to another. Thus you should not trust the returned value,
360
 * unless you are sure that no other processes are accessing the
361
 * checked resource.
362
 *
363
 * @note This function is slightly broken until next major bump
364
 *       because of AVIO_RDONLY == 0. Don't use it until then.
365
 */
366
int avio_check(const char *url, int flags);
367

    
368
/**
369
 * The callback is called in blocking functions to test regulary if
370
 * asynchronous interruption is needed. AVERROR_EXIT is returned
371
 * in this case by the interrupted function. 'NULL' means no interrupt
372
 * callback is given.
373
 */
374
void avio_set_interrupt_cb(int (*interrupt_cb)(void));
375

    
376
#if FF_API_REGISTER_PROTOCOL
377
extern URLProtocol *first_protocol;
378
#endif
379

    
380
#if FF_API_REGISTER_PROTOCOL
381
/**
382
 * @deprecated Use av_register_protocol() instead.
383
 */
384
attribute_deprecated int register_protocol(URLProtocol *protocol);
385

    
386
/**
387
 * @deprecated Use av_register_protocol2() instead.
388
 */
389
attribute_deprecated int av_register_protocol(URLProtocol *protocol);
390
#endif
391

    
392
/**
393
 * Allocate and initialize an AVIOContext for buffered I/O. It must be later
394
 * freed with av_free().
395
 *
396
 * @param buffer Memory block for input/output operations via AVIOContext.
397
 * @param buffer_size The buffer size is very important for performance.
398
 *        For protocols with fixed blocksize it should be set to this blocksize.
399
 *        For others a typical size is a cache page, e.g. 4kb.
400
 * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.
401
 * @param opaque An opaque pointer to user-specific data.
402
 * @param read_packet  A function for refilling the buffer, may be NULL.
403
 * @param write_packet A function for writing the buffer contents, may be NULL.
404
 * @param seek A function for seeking to specified byte position, may be NULL.
405
 *
406
 * @return Allocated AVIOContext or NULL on failure.
407
 */
408
AVIOContext *avio_alloc_context(
409
                  unsigned char *buffer,
410
                  int buffer_size,
411
                  int write_flag,
412
                  void *opaque,
413
                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
414
                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
415
                  int64_t (*seek)(void *opaque, int64_t offset, int whence));
416

    
417
void avio_w8(AVIOContext *s, int b);
418
void avio_write(AVIOContext *s, const unsigned char *buf, int size);
419
void avio_wl64(AVIOContext *s, uint64_t val);
420
void avio_wb64(AVIOContext *s, uint64_t val);
421
void avio_wl32(AVIOContext *s, unsigned int val);
422
void avio_wb32(AVIOContext *s, unsigned int val);
423
void avio_wl24(AVIOContext *s, unsigned int val);
424
void avio_wb24(AVIOContext *s, unsigned int val);
425
void avio_wl16(AVIOContext *s, unsigned int val);
426
void avio_wb16(AVIOContext *s, unsigned int val);
427

    
428
/**
429
 * Write a NULL-terminated string.
430
 * @return number of bytes written.
431
 */
432
int avio_put_str(AVIOContext *s, const char *str);
433

    
434
/**
435
 * Convert an UTF-8 string to UTF-16LE and write it.
436
 * @return number of bytes written.
437
 */
438
int avio_put_str16le(AVIOContext *s, const char *str);
439

    
440
/**
441
 * Passing this as the "whence" parameter to a seek function causes it to
442
 * return the filesize without seeking anywhere. Supporting this is optional.
443
 * If it is not supported then the seek function will return <0.
444
 */
445
#define AVSEEK_SIZE 0x10000
446

    
447
/**
448
 * Oring this flag as into the "whence" parameter to a seek function causes it to
449
 * seek by any means (like reopening and linear reading) or other normally unreasonble
450
 * means that can be extreemly slow.
451
 * This may be ignored by the seek code.
452
 */
453
#define AVSEEK_FORCE 0x20000
454

    
455
/**
456
 * fseek() equivalent for AVIOContext.
457
 * @return new position or AVERROR.
458
 */
459
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);
460

    
461
/**
462
 * Skip given number of bytes forward
463
 * @return new position or AVERROR.
464
 */
465
static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
466
{
467
    return avio_seek(s, offset, SEEK_CUR);
468
}
469

    
470
/**
471
 * ftell() equivalent for AVIOContext.
472
 * @return position or AVERROR.
473
 */
474
static av_always_inline int64_t avio_tell(AVIOContext *s)
475
{
476
    return avio_seek(s, 0, SEEK_CUR);
477
}
478

    
479
/**
480
 * Get the filesize.
481
 * @return filesize or AVERROR
482
 */
483
int64_t avio_size(AVIOContext *s);
484

    
485
/** @warning currently size is limited */
486
#ifdef __GNUC__
487
int avio_printf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
488
#else
489
int avio_printf(AVIOContext *s, const char *fmt, ...);
490
#endif
491

    
492
void avio_flush(AVIOContext *s);
493

    
494

    
495
/**
496
 * Read size bytes from AVIOContext into buf.
497
 * @return number of bytes read or AVERROR
498
 */
499
int avio_read(AVIOContext *s, unsigned char *buf, int size);
500

    
501
/**
502
 * @defgroup avio_read Functions for reading from AVIOContext.
503
 * @{
504
 *
505
 * @note return 0 if EOF, so you cannot use it if EOF handling is
506
 *       necessary
507
 */
508
int          avio_r8  (AVIOContext *s);
509
unsigned int avio_rl16(AVIOContext *s);
510
unsigned int avio_rl24(AVIOContext *s);
511
unsigned int avio_rl32(AVIOContext *s);
512
uint64_t     avio_rl64(AVIOContext *s);
513
unsigned int avio_rb16(AVIOContext *s);
514
unsigned int avio_rb24(AVIOContext *s);
515
unsigned int avio_rb32(AVIOContext *s);
516
uint64_t     avio_rb64(AVIOContext *s);
517
/**
518
 * @}
519
 */
520

    
521
/**
522
 * Read a string from pb into buf. The reading will terminate when either
523
 * a NULL character was encountered, maxlen bytes have been read, or nothing
524
 * more can be read from pb. The result is guaranteed to be NULL-terminated, it
525
 * will be truncated if buf is too small.
526
 * Note that the string is not interpreted or validated in any way, it
527
 * might get truncated in the middle of a sequence for multi-byte encodings.
528
 *
529
 * @return number of bytes read (is always <= maxlen).
530
 * If reading ends on EOF or error, the return value will be one more than
531
 * bytes actually read.
532
 */
533
int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);
534

    
535
/**
536
 * Read a UTF-16 string from pb and convert it to UTF-8.
537
 * The reading will terminate when either a null or invalid character was
538
 * encountered or maxlen bytes have been read.
539
 * @return number of bytes read (is always <= maxlen)
540
 */
541
int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);
542
int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);
543

    
544

    
545
/**
546
 * @defgroup open_modes URL open modes
547
 * The flags argument to avio_open must be one of the following
548
 * constants, optionally ORed with other flags.
549
 * @{
550
 */
551
#if LIBAVFORMAT_VERSION_MAJOR < 53
552
#define AVIO_RDONLY 0  /**< read-only */
553
#define AVIO_WRONLY 1  /**< write-only */
554
#define AVIO_RDWR   2  /**< read-write */
555
#else
556
#define AVIO_RDONLY 1  /**< read-only */
557
#define AVIO_WRONLY 2  /**< write-only */
558
#define AVIO_RDWR   4  /**< read-write */
559
#endif
560
/**
561
 * @}
562
 */
563

    
564
/**
565
 * Use non-blocking mode.
566
 * If this flag is set, operations on the context will return
567
 * AVERROR(EAGAIN) if they can not be performed immediately.
568
 * If this flag is not set, operations on the context will never return
569
 * AVERROR(EAGAIN).
570
 * Note that this flag does not affect the opening/connecting of the
571
 * context. Connecting a protocol will always block if necessary (e.g. on
572
 * network protocols) but never hang (e.g. on busy devices).
573
 * Warning: non-blocking protocols is work-in-progress; this flag may be
574
 * silently ignored.
575
 */
576
#if LIBAVFORMAT_VERSION_MAJOR < 53
577
#define AVIO_FLAG_NONBLOCK 4
578
#else
579
#define AVIO_FLAG_NONBLOCK 8
580
#endif
581

    
582
/**
583
 * Create and initialize a AVIOContext for accessing the
584
 * resource indicated by url.
585
 * @note When the resource indicated by url has been opened in
586
 * read+write mode, the AVIOContext can be used only for writing.
587
 *
588
 * @param s Used to return the pointer to the created AVIOContext.
589
 * In case of failure the pointed to value is set to NULL.
590
 * @param flags flags which control how the resource indicated by url
591
 * is to be opened
592
 * @return 0 in case of success, a negative value corresponding to an
593
 * AVERROR code in case of failure
594
 */
595
int avio_open(AVIOContext **s, const char *url, int flags);
596

    
597
/**
598
 * Close the resource accessed by the AVIOContext s and free it.
599
 * This function can only be used if s was opened by avio_open().
600
 *
601
 * @return 0 on success, an AVERROR < 0 on error.
602
 */
603
int avio_close(AVIOContext *s);
604

    
605
/**
606
 * Open a write only memory stream.
607
 *
608
 * @param s new IO context
609
 * @return zero if no error.
610
 */
611
int avio_open_dyn_buf(AVIOContext **s);
612

    
613
/**
614
 * Return the written size and a pointer to the buffer. The buffer
615
 * must be freed with av_free().
616
 * Padding of FF_INPUT_BUFFER_PADDING_SIZE is added to the buffer.
617
 *
618
 * @param s IO context
619
 * @param pbuffer pointer to a byte buffer
620
 * @return the length of the byte buffer
621
 */
622
int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
623

    
624
#if FF_API_UDP_GET_FILE
625
int udp_get_file_handle(URLContext *h);
626
#endif
627

    
628
/**
629
 * Iterate through names of available protocols.
630
 *
631
 * @param opaque A private pointer representing current protocol.
632
 *        It must be a pointer to NULL on first iteration and will
633
 *        be updated by successive calls to avio_enum_protocols.
634
 * @param output If set to 1, iterate over output protocols,
635
 *               otherwise over input protocols.
636
 *
637
 * @return A static string containing the name of current protocol or NULL
638
 */
639
const char *avio_enum_protocols(void **opaque, int output);
640

    
641
/**
642
 * Pause and resume playing - only meaningful if using a network streaming
643
 * protocol (e.g. MMS).
644
 * @param pause 1 for pause, 0 for resume
645
 */
646
int     avio_pause(AVIOContext *h, int pause);
647

    
648
/**
649
 * Seek to a given timestamp relative to some component stream.
650
 * Only meaningful if using a network streaming protocol (e.g. MMS.).
651
 * @param stream_index The stream index that the timestamp is relative to.
652
 *        If stream_index is (-1) the timestamp should be in AV_TIME_BASE
653
 *        units from the beginning of the presentation.
654
 *        If a stream_index >= 0 is used and the protocol does not support
655
 *        seeking based on component streams, the call will fail with ENOTSUP.
656
 * @param timestamp timestamp in AVStream.time_base units
657
 *        or if there is no stream specified then in AV_TIME_BASE units.
658
 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
659
 *        and AVSEEK_FLAG_ANY. The protocol may silently ignore
660
 *        AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
661
 *        fail with ENOTSUP if used and not supported.
662
 * @return >= 0 on success
663
 * @see AVInputFormat::read_seek
664
 */
665
int64_t avio_seek_time(AVIOContext *h, int stream_index,
666
                       int64_t timestamp, int flags);
667

    
668
#endif /* AVFORMAT_AVIO_H */