8137cb54dc331ae9790fd3cffda6fc61a30dc4f3
[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_protocol (URLContext **puc, struct URLProtocol *up,
66 const char *filename, int flags);
67 int url_open(URLContext **h, const char *filename, int flags);
68 int url_read(URLContext *h, unsigned char *buf, int size);
69 int url_write(URLContext *h, unsigned char *buf, int size);
70 offset_t url_seek(URLContext *h, offset_t pos, int whence);
71 int url_close(URLContext *h);
72 int url_exist(const char *filename);
73 offset_t url_filesize(URLContext *h);
74
75 /**
76 * Return the maximum packet size associated to packetized file
77 * handle. If the file is not packetized (stream like HTTP or file on
78 * disk), then 0 is returned.
79 *
80 * @param h file handle
81 * @return maximum packet size in bytes
82 */
83 int url_get_max_packet_size(URLContext *h);
84 void url_get_filename(URLContext *h, char *buf, int buf_size);
85
86 /**
87 * The callback is called in blocking functions to test regulary if
88 * asynchronous interruption is needed. AVERROR(EINTR) is returned
89 * in this case by the interrupted function. 'NULL' means no interrupt
90 * callback is given.
91 */
92 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
93
94 /* not implemented */
95 int url_poll(URLPollEntry *poll_table, int n, int timeout);
96
97 /**
98 * Pause and resume playing - only meaningful if using a network streaming
99 * protocol (e.g. MMS).
100 * @param pause 1 for pause, 0 for resume
101 */
102 int av_url_read_pause(URLContext *h, int pause);
103
104 /**
105 * Seek to a given timestamp relative to some component stream.
106 * Only meaningful if using a network streaming protocol (e.g. MMS.).
107 * @param stream_index The stream index that the timestamp is relative to.
108 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
109 * units from the beginning of the presentation.
110 * If a stream_index >= 0 is used and the protocol does not support
111 * seeking based on component streams, the call will fail with ENOTSUP.
112 * @param timestamp timestamp in AVStream.time_base units
113 * or if there is no stream specified then in AV_TIME_BASE units.
114 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
115 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
116 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
117 * fail with ENOTSUP if used and not supported.
118 * @return >= 0 on success
119 * @see AVInputFormat::read_seek
120 */
121 offset_t av_url_read_seek(URLContext *h,
122 int stream_index, int64_t timestamp, int flags);
123
124 /**
125 * Passing this as the "whence" parameter to a seek function causes it to
126 * return the filesize without seeking anywhere. Supporting this is optional.
127 * If it is not supported then the seek function will return <0.
128 */
129 #define AVSEEK_SIZE 0x10000
130
131 typedef struct URLProtocol {
132 const char *name;
133 int (*url_open)(URLContext *h, const char *filename, int flags);
134 int (*url_read)(URLContext *h, unsigned char *buf, int size);
135 int (*url_write)(URLContext *h, unsigned char *buf, int size);
136 offset_t (*url_seek)(URLContext *h, offset_t pos, int whence);
137 int (*url_close)(URLContext *h);
138 struct URLProtocol *next;
139 int (*url_read_pause)(URLContext *h, int pause);
140 offset_t (*url_read_seek)(URLContext *h,
141 int stream_index, int64_t timestamp, int flags);
142 } URLProtocol;
143
144 extern URLProtocol *first_protocol;
145 extern URLInterruptCB *url_interrupt_cb;
146
147 URLProtocol *av_protocol_next(URLProtocol *p);
148
149 int register_protocol(URLProtocol *protocol);
150
151 /**
152 * Bytestream IO Context.
153 * New fields can be added to the end with minor version bumps.
154 * Removal, reordering and changes to existing fields require a major
155 * version bump.
156 * sizeof(ByteIOContext) must not be used outside libav*.
157 */
158 typedef struct {
159 unsigned char *buffer;
160 int buffer_size;
161 unsigned char *buf_ptr, *buf_end;
162 void *opaque;
163 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
164 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
165 offset_t (*seek)(void *opaque, offset_t offset, int whence);
166 offset_t pos; /**< position in the file of the current buffer */
167 int must_flush; /**< true if the next seek should flush */
168 int eof_reached; /**< true if eof reached */
169 int write_flag; /**< true if open for writing */
170 int is_streamed;
171 int max_packet_size;
172 unsigned long checksum;
173 unsigned char *checksum_ptr;
174 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
175 int error; ///< contains the error code or 0 if no error happened
176 int (*read_pause)(void *opaque, int pause);
177 offset_t (*read_seek)(void *opaque,
178 int stream_index, int64_t timestamp, int flags);
179 } ByteIOContext;
180
181 int init_put_byte(ByteIOContext *s,
182 unsigned char *buffer,
183 int buffer_size,
184 int write_flag,
185 void *opaque,
186 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
187 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
188 offset_t (*seek)(void *opaque, offset_t offset, int whence));
189 ByteIOContext *av_alloc_put_byte(
190 unsigned char *buffer,
191 int buffer_size,
192 int write_flag,
193 void *opaque,
194 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
195 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
196 offset_t (*seek)(void *opaque, offset_t offset, int whence));
197
198 void put_byte(ByteIOContext *s, int b);
199 void put_buffer(ByteIOContext *s, const unsigned char *buf, int size);
200 void put_le64(ByteIOContext *s, uint64_t val);
201 void put_be64(ByteIOContext *s, uint64_t val);
202 void put_le32(ByteIOContext *s, unsigned int val);
203 void put_be32(ByteIOContext *s, unsigned int val);
204 void put_le24(ByteIOContext *s, unsigned int val);
205 void put_be24(ByteIOContext *s, unsigned int val);
206 void put_le16(ByteIOContext *s, unsigned int val);
207 void put_be16(ByteIOContext *s, unsigned int val);
208 void put_tag(ByteIOContext *s, const char *tag);
209
210 void put_strz(ByteIOContext *s, const char *buf);
211
212 /**
213 * fseek() equivalent for ByteIOContext.
214 * @return new position or AVERROR.
215 */
216 offset_t url_fseek(ByteIOContext *s, offset_t offset, int whence);
217
218 /**
219 * Skip given number of bytes forward.
220 * @param offset number of bytes
221 */
222 void url_fskip(ByteIOContext *s, offset_t offset);
223
224 /**
225 * ftell() equivalent for ByteIOContext.
226 * @return position or AVERROR.
227 */
228 offset_t url_ftell(ByteIOContext *s);
229
230 /**
231 * Gets the filesize.
232 * @return filesize or AVERROR
233 */
234 offset_t url_fsize(ByteIOContext *s);
235
236 /**
237 * feof() equivalent for ByteIOContext.
238 * @return non zero if and only if end of file
239 */
240 int url_feof(ByteIOContext *s);
241
242 int url_ferror(ByteIOContext *s);
243
244 int av_url_read_fpause(ByteIOContext *h, int pause);
245 offset_t av_url_read_fseek(ByteIOContext *h,
246 int stream_index, int64_t timestamp, int flags);
247
248 #define URL_EOF (-1)
249 /** @note return URL_EOF (-1) if EOF */
250 int url_fgetc(ByteIOContext *s);
251
252 /** @warning currently size is limited */
253 #ifdef __GNUC__
254 int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
255 #else
256 int url_fprintf(ByteIOContext *s, const char *fmt, ...);
257 #endif
258
259 /** @note unlike fgets, the EOL character is not returned and a whole
260 line is parsed. return NULL if first char read was EOF */
261 char *url_fgets(ByteIOContext *s, char *buf, int buf_size);
262
263 void put_flush_packet(ByteIOContext *s);
264
265
266 /**
267 * Reads size bytes from ByteIOContext into buf.
268 * @returns number of bytes read or AVERROR
269 */
270 int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
271
272 /**
273 * Reads size bytes from ByteIOContext into buf.
274 * This reads at most 1 packet. If that is not enough fewer bytes will be
275 * returned.
276 * @returns number of bytes read or AVERROR
277 */
278 int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
279
280 /** @note return 0 if EOF, so you cannot use it if EOF handling is
281 necessary */
282 int get_byte(ByteIOContext *s);
283 unsigned int get_le24(ByteIOContext *s);
284 unsigned int get_le32(ByteIOContext *s);
285 uint64_t get_le64(ByteIOContext *s);
286 unsigned int get_le16(ByteIOContext *s);
287
288 char *get_strz(ByteIOContext *s, char *buf, int maxlen);
289 unsigned int get_be16(ByteIOContext *s);
290 unsigned int get_be24(ByteIOContext *s);
291 unsigned int get_be32(ByteIOContext *s);
292 uint64_t get_be64(ByteIOContext *s);
293
294 uint64_t ff_get_v(ByteIOContext *bc);
295
296 static inline int url_is_streamed(ByteIOContext *s)
297 {
298 return s->is_streamed;
299 }
300
301 /** @note when opened as read/write, the buffers are only used for
302 writing */
303 int url_fdopen(ByteIOContext **s, URLContext *h);
304
305 /** @warning must be called before any I/O */
306 int url_setbufsize(ByteIOContext *s, int buf_size);
307 /** Reset the buffer for reading or writing.
308 * @note Will drop any data currently in the buffer without transmitting it.
309 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
310 * to set up the buffer for writing. */
311 int url_resetbuf(ByteIOContext *s, int flags);
312
313 /** @note when opened as read/write, the buffers are only used for
314 writing */
315 int url_fopen(ByteIOContext **s, const char *filename, int flags);
316 int url_fclose(ByteIOContext *s);
317 URLContext *url_fileno(ByteIOContext *s);
318
319 /**
320 * Return the maximum packet size associated to packetized buffered file
321 * handle. If the file is not packetized (stream like http or file on
322 * disk), then 0 is returned.
323 *
324 * @param s buffered file handle
325 * @return maximum packet size in bytes
326 */
327 int url_fget_max_packet_size(ByteIOContext *s);
328
329 int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags);
330
331 /** return the written or read size */
332 int url_close_buf(ByteIOContext *s);
333
334 /**
335 * Open a write only memory stream.
336 *
337 * @param s new IO context
338 * @return zero if no error.
339 */
340 int url_open_dyn_buf(ByteIOContext **s);
341
342 /**
343 * Open a write only packetized memory stream with a maximum packet
344 * size of 'max_packet_size'. The stream is stored in a memory buffer
345 * with a big endian 4 byte header giving the packet size in bytes.
346 *
347 * @param s new IO context
348 * @param max_packet_size maximum packet size (must be > 0)
349 * @return zero if no error.
350 */
351 int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size);
352
353 /**
354 * Return the written size and a pointer to the buffer. The buffer
355 * must be freed with av_free().
356 * @param s IO context
357 * @param pbuffer pointer to a byte buffer
358 * @return the length of the byte buffer
359 */
360 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);
361
362 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf, unsigned int len);
363 unsigned long get_checksum(ByteIOContext *s);
364 void init_checksum(ByteIOContext *s, unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), unsigned long checksum);
365
366 /* udp.c */
367 int udp_set_remote_url(URLContext *h, const char *uri);
368 int udp_get_local_port(URLContext *h);
369 int udp_get_file_handle(URLContext *h);
370
371 #endif /* FFMPEG_AVIO_H */