Statistics
| Branch: | Revision:

ffmpeg / libavformat / avio.h @ 725b3da9

History | View | Annotate | Download (15.1 KB)

1
/*
2
 * copyright (c) 2001 Fabrice Bellard
3
 *
4
 * This file is part of FFmpeg.
5
 *
6
 * FFmpeg 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
 * FFmpeg 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 FFmpeg; 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 libavformat/avio.h
25
 * unbuffered I/O operations
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.
29
 */
30

    
31
#include <stdint.h>
32

    
33
#include "libavutil/common.h"
34

    
35
/* unbuffered I/O */
36

    
37
/**
38
 * URL Context.
39
 * New fields can be added to the end with minor version bumps.
40
 * Removal, reordering and changes to existing fields require a major
41
 * version bump.
42
 * sizeof(URLContext) must not be used outside libav*.
43
 */
44
typedef struct URLContext {
45
#if LIBAVFORMAT_VERSION_MAJOR >= 53
46
    const AVClass *av_class; ///< information for av_log(). Set by url_open().
47
#endif
48
    struct URLProtocol *prot;
49
    int flags;
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 */
52
    void *priv_data;
53
    char *filename; /**< specified URL */
54
} URLContext;
55

    
56
typedef struct URLPollEntry {
57
    URLContext *handle;
58
    int events;
59
    int revents;
60
} URLPollEntry;
61

    
62
#define URL_RDONLY 0
63
#define URL_WRONLY 1
64
#define URL_RDWR   2
65

    
66
typedef int URLInterruptCB(void);
67

    
68
/**
69
 * Creates an URLContext for accessing to the resource indicated by
70
 * url, 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 url
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
 */
79
int url_open_protocol (URLContext **puc, struct URLProtocol *up,
80
                       const char *url, int flags);
81

    
82
int url_open(URLContext **h, const char *url, int flags);
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
 */
93
int url_read(URLContext *h, unsigned char *buf, int size);
94

    
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
 */
103
int url_read_complete(URLContext *h, unsigned char *buf, int size);
104
int url_write(URLContext *h, unsigned char *buf, int size);
105
int64_t url_seek(URLContext *h, int64_t pos, int whence);
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
 */
114
int url_close(URLContext *h);
115

    
116
int url_exist(const char *url);
117
int64_t url_filesize(URLContext *h);
118

    
119
/**
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
 */
126
int url_get_file_handle(URLContext *h);
127

    
128
/**
129
 * Return the maximum packet size associated to packetized file
130
 * handle. If the file is not packetized (stream like HTTP or file on
131
 * disk), then 0 is returned.
132
 *
133
 * @param h file handle
134
 * @return maximum packet size in bytes
135
 */
136
int url_get_max_packet_size(URLContext *h);
137
void url_get_filename(URLContext *h, char *buf, int buf_size);
138

    
139
/**
140
 * The callback is called in blocking functions to test regulary if
141
 * asynchronous interruption is needed. AVERROR(EINTR) is returned
142
 * in this case by the interrupted function. 'NULL' means no interrupt
143
 * callback is given.
144
 */
145
void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
146

    
147
/* not implemented */
148
int url_poll(URLPollEntry *poll_table, int n, int timeout);
149

    
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
 */
155
int av_url_read_pause(URLContext *h, int pause);
156

    
157
/**
158
 * Seek to a given timestamp relative to some component stream.
159
 * Only meaningful if using a network streaming protocol (e.g. MMS.).
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.
165
 * @param timestamp timestamp in AVStream.time_base units
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
 */
174
int64_t av_url_read_seek(URLContext *h, int stream_index,
175
                         int64_t timestamp, int flags);
176

    
177
/**
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.
181
 */
182
#define AVSEEK_SIZE 0x10000
183

    
184
typedef struct URLProtocol {
185
    const char *name;
186
    int (*url_open)(URLContext *h, const char *url, int flags);
187
    int (*url_read)(URLContext *h, unsigned char *buf, int size);
188
    int (*url_write)(URLContext *h, unsigned char *buf, int size);
189
    int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
190
    int (*url_close)(URLContext *h);
191
    struct URLProtocol *next;
192
    int (*url_read_pause)(URLContext *h, int pause);
193
    int64_t (*url_read_seek)(URLContext *h, int stream_index,
194
                             int64_t timestamp, int flags);
195
    int (*url_get_file_handle)(URLContext *h);
196
} URLProtocol;
197

    
198
#if LIBAVFORMAT_VERSION_MAJOR < 53
199
extern URLProtocol *first_protocol;
200
#endif
201

    
202
extern URLInterruptCB *url_interrupt_cb;
203

    
204
/**
205
 * If protocol is NULL, returns the first registered protocol,
206
 * if protocol is non-NULL, returns the next registered protocol after protocol,
207
 * or NULL if protocol is the last one.
208
 */
209
URLProtocol *av_protocol_next(URLProtocol *p);
210

    
211
#if LIBAVFORMAT_VERSION_MAJOR < 53
212
/**
213
 * @deprecated Use av_register_protocol() instead.
214
 */
215
attribute_deprecated int register_protocol(URLProtocol *protocol);
216
#endif
217

    
218
int av_register_protocol(URLProtocol *protocol);
219

    
220
/**
221
 * Bytestream IO Context.
222
 * New fields can be added to the end with minor version bumps.
223
 * Removal, reordering and changes to existing fields require a major
224
 * version bump.
225
 * sizeof(ByteIOContext) must not be used outside libav*.
226
 */
227
typedef struct {
228
    unsigned char *buffer;
229
    int buffer_size;
230
    unsigned char *buf_ptr, *buf_end;
231
    void *opaque;
232
    int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
233
    int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
234
    int64_t (*seek)(void *opaque, int64_t offset, int whence);
235
    int64_t pos; /**< position in the file of the current buffer */
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 */
239
    int is_streamed;
240
    int max_packet_size;
241
    unsigned long checksum;
242
    unsigned char *checksum_ptr;
243
    unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
244
    int error;         ///< contains the error code or 0 if no error happened
245
    int (*read_pause)(void *opaque, int pause);
246
    int64_t (*read_seek)(void *opaque, int stream_index,
247
                         int64_t timestamp, int flags);
248
} ByteIOContext;
249

    
250
int init_put_byte(ByteIOContext *s,
251
                  unsigned char *buffer,
252
                  int buffer_size,
253
                  int write_flag,
254
                  void *opaque,
255
                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
256
                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
257
                  int64_t (*seek)(void *opaque, int64_t offset, int whence));
258
ByteIOContext *av_alloc_put_byte(
259
                  unsigned char *buffer,
260
                  int buffer_size,
261
                  int write_flag,
262
                  void *opaque,
263
                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
264
                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
265
                  int64_t (*seek)(void *opaque, int64_t offset, int whence));
266

    
267
void put_byte(ByteIOContext *s, int b);
268
void put_buffer(ByteIOContext *s, const unsigned char *buf, int size);
269
void put_le64(ByteIOContext *s, uint64_t val);
270
void put_be64(ByteIOContext *s, uint64_t val);
271
void put_le32(ByteIOContext *s, unsigned int val);
272
void put_be32(ByteIOContext *s, unsigned int val);
273
void put_le24(ByteIOContext *s, unsigned int val);
274
void put_be24(ByteIOContext *s, unsigned int val);
275
void put_le16(ByteIOContext *s, unsigned int val);
276
void put_be16(ByteIOContext *s, unsigned int val);
277
void put_tag(ByteIOContext *s, const char *tag);
278

    
279
void put_strz(ByteIOContext *s, const char *buf);
280

    
281
/**
282
 * fseek() equivalent for ByteIOContext.
283
 * @return new position or AVERROR.
284
 */
285
int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence);
286

    
287
/**
288
 * Skip given number of bytes forward.
289
 * @param offset number of bytes
290
 */
291
void url_fskip(ByteIOContext *s, int64_t offset);
292

    
293
/**
294
 * ftell() equivalent for ByteIOContext.
295
 * @return position or AVERROR.
296
 */
297
int64_t url_ftell(ByteIOContext *s);
298

    
299
/**
300
 * Gets the filesize.
301
 * @return filesize or AVERROR
302
 */
303
int64_t url_fsize(ByteIOContext *s);
304

    
305
/**
306
 * feof() equivalent for ByteIOContext.
307
 * @return non zero if and only if end of file
308
 */
309
int url_feof(ByteIOContext *s);
310

    
311
int url_ferror(ByteIOContext *s);
312

    
313
int av_url_read_fpause(ByteIOContext *h, int pause);
314
int64_t av_url_read_fseek(ByteIOContext *h, int stream_index,
315
                          int64_t timestamp, int flags);
316

    
317
#define URL_EOF (-1)
318
/** @note return URL_EOF (-1) if EOF */
319
int url_fgetc(ByteIOContext *s);
320

    
321
/** @warning currently size is limited */
322
#ifdef __GNUC__
323
int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
324
#else
325
int url_fprintf(ByteIOContext *s, const char *fmt, ...);
326
#endif
327

    
328
/** @note unlike fgets, the EOL character is not returned and a whole
329
    line is parsed. return NULL if first char read was EOF */
330
char *url_fgets(ByteIOContext *s, char *buf, int buf_size);
331

    
332
void put_flush_packet(ByteIOContext *s);
333

    
334

    
335
/**
336
 * Reads size bytes from ByteIOContext into buf.
337
 * @returns number of bytes read or AVERROR
338
 */
339
int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
340

    
341
/**
342
 * Reads size bytes from ByteIOContext into buf.
343
 * This reads at most 1 packet. If that is not enough fewer bytes will be
344
 * returned.
345
 * @returns number of bytes read or AVERROR
346
 */
347
int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
348

    
349
/** @note return 0 if EOF, so you cannot use it if EOF handling is
350
    necessary */
351
int get_byte(ByteIOContext *s);
352
unsigned int get_le24(ByteIOContext *s);
353
unsigned int get_le32(ByteIOContext *s);
354
uint64_t get_le64(ByteIOContext *s);
355
unsigned int get_le16(ByteIOContext *s);
356

    
357
char *get_strz(ByteIOContext *s, char *buf, int maxlen);
358
unsigned int get_be16(ByteIOContext *s);
359
unsigned int get_be24(ByteIOContext *s);
360
unsigned int get_be32(ByteIOContext *s);
361
uint64_t get_be64(ByteIOContext *s);
362

    
363
uint64_t ff_get_v(ByteIOContext *bc);
364

    
365
static inline int url_is_streamed(ByteIOContext *s)
366
{
367
    return s->is_streamed;
368
}
369

    
370
/** @note when opened as read/write, the buffers are only used for
371
    writing */
372
int url_fdopen(ByteIOContext **s, URLContext *h);
373

    
374
/** @warning must be called before any I/O */
375
int url_setbufsize(ByteIOContext *s, int buf_size);
376
#if LIBAVFORMAT_VERSION_MAJOR < 53
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. */
381
int url_resetbuf(ByteIOContext *s, int flags);
382
#endif
383

    
384
/** @note when opened as read/write, the buffers are only used for
385
    writing */
386
int url_fopen(ByteIOContext **s, const char *url, int flags);
387
int url_fclose(ByteIOContext *s);
388
URLContext *url_fileno(ByteIOContext *s);
389

    
390
/**
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
 *
395
 * @param s buffered file handle
396
 * @return maximum packet size in bytes
397
 */
398
int url_fget_max_packet_size(ByteIOContext *s);
399

    
400
int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags);
401

    
402
/** return the written or read size */
403
int url_close_buf(ByteIOContext *s);
404

    
405
/**
406
 * Open a write only memory stream.
407
 *
408
 * @param s new IO context
409
 * @return zero if no error.
410
 */
411
int url_open_dyn_buf(ByteIOContext **s);
412

    
413
/**
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
 */
422
int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size);
423

    
424
/**
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
428
 * @param pbuffer pointer to a byte buffer
429
 * @return the length of the byte buffer
430
 */
431
int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);
432

    
433
unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
434
                                    unsigned int len);
435
unsigned long get_checksum(ByteIOContext *s);
436
void init_checksum(ByteIOContext *s,
437
                   unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
438
                   unsigned long checksum);
439

    
440
/* udp.c */
441
int udp_set_remote_url(URLContext *h, const char *uri);
442
int udp_get_local_port(URLContext *h);
443
#if (LIBAVFORMAT_VERSION_MAJOR <= 52)
444
int udp_get_file_handle(URLContext *h);
445
#endif
446

    
447
#endif /* AVFORMAT_AVIO_H */