Cosmetics: remove a redundant and misplaced doxy.
[libav.git] / libavformat / avio.h
1 /*
2 * unbuffered io for ffmpeg system
3 * copyright (c) 2001 Fabrice Bellard
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21 #ifndef FFMPEG_AVIO_H
22 #define FFMPEG_AVIO_H
23
24 #include <stdint.h>
25
26 /* output byte stream handling */
27
28 typedef int64_t offset_t;
29
30 /* unbuffered I/O */
31
32 /**
33 * URL Context.
34 * New fields can be added to the end with minor version bumps.
35 * Removal, reordering and changes to existing fields require a major
36 * version bump.
37 * sizeof(URLContext) must not be used outside libav*.
38 */
39 struct URLContext {
40 #if LIBAVFORMAT_VERSION_MAJOR >= 53
41 const AVClass *av_class; ///< information for av_log(). Set by url_open().
42 #endif
43 struct URLProtocol *prot;
44 int flags;
45 int is_streamed; /**< true if streamed (no seek possible), default = false */
46 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
47 void *priv_data;
48 char *filename; /**< specified filename */
49 };
50
51 typedef struct URLContext URLContext;
52
53 typedef struct URLPollEntry {
54 URLContext *handle;
55 int events;
56 int revents;
57 } URLPollEntry;
58
59 #define URL_RDONLY 0
60 #define URL_WRONLY 1
61 #define URL_RDWR 2
62
63 typedef int URLInterruptCB(void);
64
65 int url_open(URLContext **h, const char *filename, int flags);
66 int url_read(URLContext *h, unsigned char *buf, int size);
67 int url_write(URLContext *h, unsigned char *buf, int size);
68 offset_t url_seek(URLContext *h, offset_t pos, int whence);
69 int url_close(URLContext *h);
70 int url_exist(const char *filename);
71 offset_t url_filesize(URLContext *h);
72
73 /**
74 * Return the maximum packet size associated to packetized file
75 * handle. If the file is not packetized (stream like HTTP or file on
76 * disk), then 0 is returned.
77 *
78 * @param h file handle
79 * @return maximum packet size in bytes
80 */
81 int url_get_max_packet_size(URLContext *h);
82 void url_get_filename(URLContext *h, char *buf, int buf_size);
83
84 /**
85 * The callback is called in blocking functions to test regulary if
86 * asynchronous interruption is needed. AVERROR(EINTR) is returned
87 * in this case by the interrupted function. 'NULL' means no interrupt
88 * callback is given.
89 */
90 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
91
92 /* not implemented */
93 int url_poll(URLPollEntry *poll_table, int n, int timeout);
94
95 /**
96 * Pause and resume playing - only meaningful if using a network streaming
97 * protocol (e.g. MMS).
98 * @param pause 1 for pause, 0 for resume
99 */
100 int av_url_read_pause(URLContext *h, int pause);
101
102 /**
103 * Seek to a given timestamp relative to some component stream.
104 * Only meaningful if using a network streaming protocol (e.g. MMS.).
105 * @param stream_index The stream index that the timestamp is relative to.
106 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
107 * units from the beginning of the presentation.
108 * If a stream_index >= 0 is used and the protocol does not support
109 * seeking based on component streams, the call will fail with ENOTSUP.
110 * @param timestamp timestamp in AVStream.time_base units
111 * or if there is no stream specified then in AV_TIME_BASE units.
112 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
113 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
114 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
115 * fail with ENOTSUP if used and not supported.
116 * @return >= 0 on success
117 * @see AVInputFormat::read_seek
118 */
119 offset_t av_url_read_seek(URLContext *h,
120 int stream_index, int64_t timestamp, int flags);
121
122 /**
123 * Passing this as the "whence" parameter to a seek function causes it to
124 * return the filesize without seeking anywhere. Supporting this is optional.
125 * If it is not supported then the seek function will return <0.
126 */
127 #define AVSEEK_SIZE 0x10000
128
129 typedef struct URLProtocol {
130 const char *name;
131 int (*url_open)(URLContext *h, const char *filename, int flags);
132 int (*url_read)(URLContext *h, unsigned char *buf, int size);
133 int (*url_write)(URLContext *h, unsigned char *buf, int size);
134 offset_t (*url_seek)(URLContext *h, offset_t pos, int whence);
135 int (*url_close)(URLContext *h);
136 struct URLProtocol *next;
137 int (*url_read_pause)(URLContext *h, int pause);
138 offset_t (*url_read_seek)(URLContext *h,
139 int stream_index, int64_t timestamp, int flags);
140 } URLProtocol;
141
142 extern URLProtocol *first_protocol;
143 extern URLInterruptCB *url_interrupt_cb;
144
145 URLProtocol *av_protocol_next(URLProtocol *p);
146
147 int register_protocol(URLProtocol *protocol);
148
149 /**
150 * Bytestream IO Context.
151 * New fields can be added to the end with minor version bumps.
152 * Removal, reordering and changes to existing fields require a major
153 * version bump.
154 * sizeof(ByteIOContext) must not be used outside libav*.
155 */
156 typedef struct {
157 unsigned char *buffer;
158 int buffer_size;
159 unsigned char *buf_ptr, *buf_end;
160 void *opaque;
161 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
162 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
163 offset_t (*seek)(void *opaque, offset_t offset, int whence);
164 offset_t pos; /**< position in the file of the current buffer */
165 int must_flush; /**< true if the next seek should flush */
166 int eof_reached; /**< true if eof reached */
167 int write_flag; /**< true if open for writing */
168 int is_streamed;
169 int max_packet_size;
170 unsigned long checksum;
171 unsigned char *checksum_ptr;
172 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
173 int error; ///< contains the error code or 0 if no error happened
174 int (*read_pause)(void *opaque, int pause);
175 offset_t (*read_seek)(void *opaque,
176 int stream_index, int64_t timestamp, int flags);
177 } ByteIOContext;
178
179 int init_put_byte(ByteIOContext *s,
180 unsigned char *buffer,
181 int buffer_size,
182 int write_flag,
183 void *opaque,
184 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
185 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
186 offset_t (*seek)(void *opaque, offset_t offset, int whence));
187 ByteIOContext *av_alloc_put_byte(
188 unsigned char *buffer,
189 int buffer_size,
190 int write_flag,
191 void *opaque,
192 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
193 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
194 offset_t (*seek)(void *opaque, offset_t offset, int whence));
195
196 void put_byte(ByteIOContext *s, int b);
197 void put_buffer(ByteIOContext *s, const unsigned char *buf, int size);
198 void put_le64(ByteIOContext *s, uint64_t val);
199 void put_be64(ByteIOContext *s, uint64_t val);
200 void put_le32(ByteIOContext *s, unsigned int val);
201 void put_be32(ByteIOContext *s, unsigned int val);
202 void put_le24(ByteIOContext *s, unsigned int val);
203 void put_be24(ByteIOContext *s, unsigned int val);
204 void put_le16(ByteIOContext *s, unsigned int val);
205 void put_be16(ByteIOContext *s, unsigned int val);
206 void put_tag(ByteIOContext *s, const char *tag);
207
208 void put_strz(ByteIOContext *s, const char *buf);
209
210 /**
211 * fseek() equivalent for ByteIOContext.
212 * @return new position or AVERROR.
213 */
214 offset_t url_fseek(ByteIOContext *s, offset_t offset, int whence);
215
216 /**
217 * Skip given number of bytes forward.
218 * @param offset number of bytes
219 */
220 void url_fskip(ByteIOContext *s, offset_t offset);
221
222 /**
223 * ftell() equivalent for ByteIOContext.
224 * @return position or AVERROR.
225 */
226 offset_t url_ftell(ByteIOContext *s);
227
228 /**
229 * Gets the filesize.
230 * @return filesize or AVERROR
231 */
232 offset_t url_fsize(ByteIOContext *s);
233
234 /**
235 * feof() equivalent for ByteIOContext.
236 * @return non zero if and only if end of file
237 */
238 int url_feof(ByteIOContext *s);
239
240 int url_ferror(ByteIOContext *s);
241
242 int av_url_read_fpause(ByteIOContext *h, int pause);
243 offset_t av_url_read_fseek(ByteIOContext *h,
244 int stream_index, int64_t timestamp, int flags);
245
246 #define URL_EOF (-1)
247 /** @note return URL_EOF (-1) if EOF */
248 int url_fgetc(ByteIOContext *s);
249
250 /** @warning currently size is limited */
251 #ifdef __GNUC__
252 int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
253 #else
254 int url_fprintf(ByteIOContext *s, const char *fmt, ...);
255 #endif
256
257 /** @note unlike fgets, the EOL character is not returned and a whole
258 line is parsed. return NULL if first char read was EOF */
259 char *url_fgets(ByteIOContext *s, char *buf, int buf_size);
260
261 void put_flush_packet(ByteIOContext *s);
262
263
264 /**
265 * Reads size bytes from ByteIOContext into buf.
266 * @returns number of bytes read or AVERROR
267 */
268 int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
269
270 /**
271 * Reads size bytes from ByteIOContext into buf.
272 * This reads at most 1 packet. If that is not enough fewer bytes will be
273 * returned.
274 * @returns number of bytes read or AVERROR
275 */
276 int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
277
278 /** @note return 0 if EOF, so you cannot use it if EOF handling is
279 necessary */
280 int get_byte(ByteIOContext *s);
281 unsigned int get_le24(ByteIOContext *s);
282 unsigned int get_le32(ByteIOContext *s);
283 uint64_t get_le64(ByteIOContext *s);
284 unsigned int get_le16(ByteIOContext *s);
285
286 char *get_strz(ByteIOContext *s, char *buf, int maxlen);
287 unsigned int get_be16(ByteIOContext *s);
288 unsigned int get_be24(ByteIOContext *s);
289 unsigned int get_be32(ByteIOContext *s);
290 uint64_t get_be64(ByteIOContext *s);
291
292 uint64_t ff_get_v(ByteIOContext *bc);
293
294 static inline int url_is_streamed(ByteIOContext *s)
295 {
296 return s->is_streamed;
297 }
298
299 /** @note when opened as read/write, the buffers are only used for
300 writing */
301 int url_fdopen(ByteIOContext **s, URLContext *h);
302
303 /** @warning must be called before any I/O */
304 int url_setbufsize(ByteIOContext *s, int buf_size);
305 /** Reset the buffer for reading or writing.
306 * @note Will drop any data currently in the buffer without transmitting it.
307 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
308 * to set up the buffer for writing. */
309 int url_resetbuf(ByteIOContext *s, int flags);
310
311 /** @note when opened as read/write, the buffers are only used for
312 writing */
313 int url_fopen(ByteIOContext **s, const char *filename, int flags);
314 int url_fclose(ByteIOContext *s);
315 URLContext *url_fileno(ByteIOContext *s);
316
317 /**
318 * Return the maximum packet size associated to packetized buffered file
319 * handle. If the file is not packetized (stream like http or file on
320 * disk), then 0 is returned.
321 *
322 * @param s buffered file handle
323 * @return maximum packet size in bytes
324 */
325 int url_fget_max_packet_size(ByteIOContext *s);
326
327 int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags);
328
329 /** return the written or read size */
330 int url_close_buf(ByteIOContext *s);
331
332 /**
333 * Open a write only memory stream.
334 *
335 * @param s new IO context
336 * @return zero if no error.
337 */
338 int url_open_dyn_buf(ByteIOContext **s);
339
340 /**
341 * Open a write only packetized memory stream with a maximum packet
342 * size of 'max_packet_size'. The stream is stored in a memory buffer
343 * with a big endian 4 byte header giving the packet size in bytes.
344 *
345 * @param s new IO context
346 * @param max_packet_size maximum packet size (must be > 0)
347 * @return zero if no error.
348 */
349 int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size);
350
351 /**
352 * Return the written size and a pointer to the buffer. The buffer
353 * must be freed with av_free().
354 * @param s IO context
355 * @param pbuffer pointer to a byte buffer
356 * @return the length of the byte buffer
357 */
358 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);
359
360 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf, unsigned int len);
361 unsigned long get_checksum(ByteIOContext *s);
362 void init_checksum(ByteIOContext *s, unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), unsigned long checksum);
363
364 /* udp.c */
365 int udp_set_remote_url(URLContext *h, const char *uri);
366 int udp_get_local_port(URLContext *h);
367 int udp_get_file_handle(URLContext *h);
368
369 #endif /* FFMPEG_AVIO_H */