2 * This file is part of FFmpeg.
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 * unbuffered private I/O API
24 #ifndef AVFORMAT_URL_H
25 #define AVFORMAT_URL_H
28 #include "libavformat/version.h"
30 #include "libavutil/dict.h"
31 #include "libavutil/log.h"
33 #define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */
34 #define URL_PROTOCOL_FLAG_NETWORK 2 /*< The protocol uses network */
36 extern const AVClass ffurl_context_class;
38 typedef struct URLContext {
39 const AVClass *av_class; /**< information for av_log(). Set by url_open(). */
40 struct URLProtocol *prot;
42 char *filename; /**< specified URL */
44 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
45 int is_streamed; /**< true if streamed (no seek possible), default = false */
47 AVIOInterruptCB interrupt_callback;
48 int64_t rw_timeout; /**< maximum time to wait for (network) read/write operation completion, in mcs */
49 const char *protocol_whitelist;
52 typedef struct URLProtocol {
54 int (*url_open)( URLContext *h, const char *url, int flags);
56 * This callback is to be used by protocols which open further nested
57 * protocols. options are then to be passed to ffurl_open()/ffurl_connect()
58 * for those nested protocols.
60 int (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options);
61 int (*url_accept)(URLContext *s, URLContext **c);
62 int (*url_handshake)(URLContext *c);
65 * Read data from the protocol.
66 * If data is immediately available (even less than size), EOF is
67 * reached or an error occurs (including EINTR), return immediately.
69 * In non-blocking mode, return AVERROR(EAGAIN) immediately.
70 * In blocking mode, wait for data/EOF/error with a short timeout (0.1s),
71 * and return AVERROR(EAGAIN) on timeout.
72 * Checking interrupt_callback, looping on EINTR and EAGAIN and until
73 * enough data has been read is left to the calling function; see
74 * retry_transfer_wrapper in avio.c.
76 int (*url_read)( URLContext *h, unsigned char *buf, int size);
77 int (*url_write)(URLContext *h, const unsigned char *buf, int size);
78 int64_t (*url_seek)( URLContext *h, int64_t pos, int whence);
79 int (*url_close)(URLContext *h);
80 struct URLProtocol *next;
81 int (*url_read_pause)(URLContext *h, int pause);
82 int64_t (*url_read_seek)(URLContext *h, int stream_index,
83 int64_t timestamp, int flags);
84 int (*url_get_file_handle)(URLContext *h);
85 int (*url_get_multi_file_handle)(URLContext *h, int **handles,
87 int (*url_shutdown)(URLContext *h, int flags);
89 const AVClass *priv_data_class;
91 int (*url_check)(URLContext *h, int mask);
92 int (*url_open_dir)(URLContext *h);
93 int (*url_read_dir)(URLContext *h, AVIODirEntry **next);
94 int (*url_close_dir)(URLContext *h);
95 int (*url_delete)(URLContext *h);
96 int (*url_move)(URLContext *h_src, URLContext *h_dst);
97 const char *default_whitelist;
101 * Create a URLContext for accessing to the resource indicated by
102 * url, but do not initiate the connection yet.
104 * @param puc pointer to the location where, in case of success, the
105 * function puts the pointer to the created URLContext
106 * @param flags flags which control how the resource indicated by url
108 * @param int_cb interrupt callback to use for the URLContext, may be
110 * @return >= 0 in case of success, a negative value corresponding to an
111 * AVERROR code in case of failure
113 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
114 const AVIOInterruptCB *int_cb);
117 * Connect an URLContext that has been allocated by ffurl_alloc
119 * @param options A dictionary filled with options for nested protocols,
120 * i.e. it will be passed to url_open2() for protocols implementing it.
121 * This parameter will be destroyed and replaced with a dict containing options
122 * that were not found. May be NULL.
124 int ffurl_connect(URLContext *uc, AVDictionary **options);
127 * Create an URLContext for accessing to the resource indicated by
130 * @param puc pointer to the location where, in case of success, the
131 * function puts the pointer to the created URLContext
132 * @param flags flags which control how the resource indicated by url
134 * @param int_cb interrupt callback to use for the URLContext, may be
136 * @param options A dictionary filled with protocol-private options. On return
137 * this parameter will be destroyed and replaced with a dict containing options
138 * that were not found. May be NULL.
139 * @return >= 0 in case of success, a negative value corresponding to an
140 * AVERROR code in case of failure
142 int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags,
143 const AVIOInterruptCB *int_cb, AVDictionary **options,
144 const char *whitelist);
146 int ffurl_open(URLContext **puc, const char *filename, int flags,
147 const AVIOInterruptCB *int_cb, AVDictionary **options);
150 * Accept an URLContext c on an URLContext s
152 * @param s server context
153 * @param c client context, must be unallocated.
154 * @return >= 0 on success, ff_neterrno() on failure.
156 int ffurl_accept(URLContext *s, URLContext **c);
159 * Perform one step of the protocol handshake to accept a new client.
160 * See avio_handshake() for details.
161 * Implementations should try to return decreasing values.
162 * If the protocol uses an underlying protocol, the underlying handshake is
163 * usually the first step, and the return value can be:
164 * (largest value for this protocol) + (return value from other protocol)
166 * @param c the client context
167 * @return >= 0 on success or a negative value corresponding
168 * to an AVERROR code on failure
170 int ffurl_handshake(URLContext *c);
173 * Read up to size bytes from the resource accessed by h, and store
174 * the read bytes in buf.
176 * @return The number of bytes actually read, or a negative value
177 * corresponding to an AVERROR code in case of error. A value of zero
178 * indicates that it is not possible to read more from the accessed
179 * resource (except if the value of the size argument is also zero).
181 int ffurl_read(URLContext *h, unsigned char *buf, int size);
184 * Read as many bytes as possible (up to size), calling the
185 * read function multiple times if necessary.
186 * This makes special short-read handling in applications
187 * unnecessary, if the return value is < size then it is
188 * certain there was either an error or the end of file was reached.
190 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
193 * Write size bytes from buf to the resource accessed by h.
195 * @return the number of bytes actually written, or a negative value
196 * corresponding to an AVERROR code in case of failure
198 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
201 * Change the position that will be used by the next read/write
202 * operation on the resource accessed by h.
204 * @param pos specifies the new position to set
205 * @param whence specifies how pos should be interpreted, it must be
206 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
207 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
208 * (return the filesize of the requested resource, pos is ignored).
209 * @return a negative value corresponding to an AVERROR code in case
210 * of failure, or the resulting file position, measured in bytes from
211 * the beginning of the file. You can use this feature together with
212 * SEEK_CUR to read the current file position.
214 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
217 * Close the resource accessed by the URLContext h, and free the
218 * memory used by it. Also set the URLContext pointer to NULL.
220 * @return a negative value if an error condition occurred, 0
223 int ffurl_closep(URLContext **h);
224 int ffurl_close(URLContext *h);
227 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
228 * if the operation is not supported by h, or another negative value
229 * corresponding to an AVERROR error code in case of failure.
231 int64_t ffurl_size(URLContext *h);
234 * Return the file descriptor associated with this URL. For RTP, this
235 * will return only the RTP file descriptor, not the RTCP file descriptor.
237 * @return the file descriptor associated with this URL, or <0 on error.
239 int ffurl_get_file_handle(URLContext *h);
242 * Return the file descriptors associated with this URL.
244 * @return 0 on success or <0 on error.
246 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
249 * Signal the URLContext that we are done reading or writing the stream.
251 * @param h pointer to the resource
252 * @param flags flags which control how the resource indicated by url
255 * @return a negative value if an error condition occurred, 0
258 int ffurl_shutdown(URLContext *h, int flags);
261 * Register the URLProtocol protocol.
263 int ffurl_register_protocol(URLProtocol *protocol);
266 * Check if the user has requested to interrup a blocking function
267 * associated with cb.
269 int ff_check_interrupt(AVIOInterruptCB *cb);
272 * Iterate over all available protocols.
274 * @param prev result of the previous call to this functions or NULL.
276 URLProtocol *ffurl_protocol_next(const URLProtocol *prev);
279 int ff_udp_set_remote_url(URLContext *h, const char *uri);
280 int ff_udp_get_local_port(URLContext *h);
283 * Assemble a URL string from components. This is the reverse operation
286 * Note, this requires networking to be initialized, so the caller must
287 * ensure ff_network_init has been called.
291 * @param str the buffer to fill with the url
292 * @param size the size of the str buffer
293 * @param proto the protocol identifier, if null, the separator
294 * after the identifier is left out, too
295 * @param authorization an optional authorization string, may be null.
296 * An empty string is treated the same as a null string.
297 * @param hostname the host name string
298 * @param port the port number, left out from the string if negative
299 * @param fmt a generic format string for everything to add after the
300 * host/port, may be null
301 * @return the number of characters written to the destination buffer
303 int ff_url_join(char *str, int size, const char *proto,
304 const char *authorization, const char *hostname,
305 int port, const char *fmt, ...) av_printf_format(7, 8);
308 * Convert a relative url into an absolute url, given a base url.
310 * @param buf the buffer where output absolute url is written
311 * @param size the size of buf
312 * @param base the base url, may be equal to buf.
313 * @param rel the new url, which is interpreted relative to base
315 void ff_make_absolute_url(char *buf, int size, const char *base,
319 * Allocate directory entry with default values.
321 * @return entry or NULL on error
323 AVIODirEntry *ff_alloc_dir_entry(void);
326 #endif /* AVFORMAT_URL_H */