3 * This file is part of Libav.
5 * Libav is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
10 * Libav is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with Libav; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 * unbuffered private I/O API
25 #ifndef AVFORMAT_URL_H
26 #define AVFORMAT_URL_H
29 #include "libavformat/version.h"
31 #include "libavutil/dict.h"
32 #include "libavutil/log.h"
34 #define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */
35 #define URL_PROTOCOL_FLAG_NETWORK 2 /*< The protocol uses network */
37 extern int (*url_interrupt_cb)(void);
39 extern const AVClass ffurl_context_class;
41 typedef struct URLContext {
42 const AVClass *av_class; /**< information for av_log(). Set by url_open(). */
43 struct URLProtocol *prot;
45 char *filename; /**< specified URL */
47 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
48 int is_streamed; /**< true if streamed (no seek possible), default = false */
50 AVIOInterruptCB interrupt_callback;
53 typedef struct URLProtocol {
55 int (*url_open)( URLContext *h, const char *url, int flags);
57 * This callback is to be used by protocols which open further nested
58 * protocols. options are then to be passed to ffurl_open()/ffurl_connect()
59 * for those nested protocols.
61 int (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options);
64 * Read data from the protocol.
65 * If data is immediately available (even less than size), EOF is
66 * reached or an error occurs (including EINTR), return immediately.
68 * In non-blocking mode, return AVERROR(EAGAIN) immediately.
69 * In blocking mode, wait for data/EOF/error with a short timeout (0.1s),
70 * and return AVERROR(EAGAIN) on timeout.
71 * Checking interrupt_callback, looping on EINTR and EAGAIN and until
72 * enough data has been read is left to the calling function; see
73 * retry_transfer_wrapper in avio.c.
75 int (*url_read)( URLContext *h, unsigned char *buf, int size);
76 int (*url_write)(URLContext *h, const unsigned char *buf, int size);
77 int64_t (*url_seek)( URLContext *h, int64_t pos, int whence);
78 int (*url_close)(URLContext *h);
79 struct URLProtocol *next;
80 int (*url_read_pause)(URLContext *h, int pause);
81 int64_t (*url_read_seek)(URLContext *h, int stream_index,
82 int64_t timestamp, int flags);
83 int (*url_get_file_handle)(URLContext *h);
84 int (*url_get_multi_file_handle)(URLContext *h, int **handles,
86 int (*url_shutdown)(URLContext *h, int flags);
88 const AVClass *priv_data_class;
90 int (*url_check)(URLContext *h, int mask);
94 * Create a URLContext for accessing to the resource indicated by
95 * url, but do not initiate the connection yet.
97 * @param puc pointer to the location where, in case of success, the
98 * function puts the pointer to the created URLContext
99 * @param flags flags which control how the resource indicated by url
101 * @param int_cb interrupt callback to use for the URLContext, may be
103 * @return 0 in case of success, a negative value corresponding to an
104 * AVERROR code in case of failure
106 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
107 const AVIOInterruptCB *int_cb);
110 * Connect an URLContext that has been allocated by ffurl_alloc
112 * @param options A dictionary filled with options for nested protocols,
113 * i.e. it will be passed to url_open2() for protocols implementing it.
114 * This parameter will be destroyed and replaced with a dict containing options
115 * that were not found. May be NULL.
117 int ffurl_connect(URLContext *uc, AVDictionary **options);
120 * Create an URLContext for accessing to the resource indicated by
123 * @param puc pointer to the location where, in case of success, the
124 * function puts the pointer to the created URLContext
125 * @param flags flags which control how the resource indicated by url
127 * @param int_cb interrupt callback to use for the URLContext, may be
129 * @param options A dictionary filled with protocol-private options. On return
130 * this parameter will be destroyed and replaced with a dict containing options
131 * that were not found. May be NULL.
132 * @return 0 in case of success, a negative value corresponding to an
133 * AVERROR code in case of failure
135 int ffurl_open(URLContext **puc, const char *filename, int flags,
136 const AVIOInterruptCB *int_cb, AVDictionary **options);
139 * Read up to size bytes from the resource accessed by h, and store
140 * the read bytes in buf.
142 * @return The number of bytes actually read, or a negative value
143 * corresponding to an AVERROR code in case of error. A value of zero
144 * indicates that it is not possible to read more from the accessed
145 * resource (except if the value of the size argument is also zero).
147 int ffurl_read(URLContext *h, unsigned char *buf, int size);
150 * Read as many bytes as possible (up to size), calling the
151 * read function multiple times if necessary.
152 * This makes special short-read handling in applications
153 * unnecessary, if the return value is < size then it is
154 * certain there was either an error or the end of file was reached.
156 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
159 * Write size bytes from buf to the resource accessed by h.
161 * @return the number of bytes actually written, or a negative value
162 * corresponding to an AVERROR code in case of failure
164 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
167 * Change the position that will be used by the next read/write
168 * operation on the resource accessed by h.
170 * @param pos specifies the new position to set
171 * @param whence specifies how pos should be interpreted, it must be
172 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
173 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
174 * (return the filesize of the requested resource, pos is ignored).
175 * @return a negative value corresponding to an AVERROR code in case
176 * of failure, or the resulting file position, measured in bytes from
177 * the beginning of the file. You can use this feature together with
178 * SEEK_CUR to read the current file position.
180 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
183 * Close the resource accessed by the URLContext h, and free the
186 * @return a negative value if an error condition occurred, 0
189 int ffurl_close(URLContext *h);
192 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
193 * if the operation is not supported by h, or another negative value
194 * corresponding to an AVERROR error code in case of failure.
196 int64_t ffurl_size(URLContext *h);
199 * Return the file descriptor associated with this URL. For RTP, this
200 * will return only the RTP file descriptor, not the RTCP file descriptor.
202 * @return the file descriptor associated with this URL, or <0 on error.
204 int ffurl_get_file_handle(URLContext *h);
207 * Return the file descriptors associated with this URL.
209 * @return 0 on success or <0 on error.
211 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
214 * Signal the URLContext that we are done reading or writing the stream.
216 * @param h pointer to the resource
217 * @param flags flags which control how the resource indicated by url
220 * @return a negative value if an error condition occurred, 0
223 int ffurl_shutdown(URLContext *h, int flags);
226 * Register the URLProtocol protocol.
228 * @param size the size of the URLProtocol struct referenced
230 int ffurl_register_protocol(URLProtocol *protocol, int size);
233 * Check if the user has requested to interrup a blocking function
234 * associated with cb.
236 int ff_check_interrupt(AVIOInterruptCB *cb);
239 * Iterate over all available protocols.
241 * @param prev result of the previous call to this functions or NULL.
243 URLProtocol *ffurl_protocol_next(URLProtocol *prev);
246 int ff_udp_set_remote_url(URLContext *h, const char *uri);
247 int ff_udp_get_local_port(URLContext *h);
250 * Assemble a URL string from components. This is the reverse operation
253 * Note, this requires networking to be initialized, so the caller must
254 * ensure ff_network_init has been called.
258 * @param str the buffer to fill with the url
259 * @param size the size of the str buffer
260 * @param proto the protocol identifier, if null, the separator
261 * after the identifier is left out, too
262 * @param authorization an optional authorization string, may be null.
263 * An empty string is treated the same as a null string.
264 * @param hostname the host name string
265 * @param port the port number, left out from the string if negative
266 * @param fmt a generic format string for everything to add after the
267 * host/port, may be null
268 * @return the number of characters written to the destination buffer
270 int ff_url_join(char *str, int size, const char *proto,
271 const char *authorization, const char *hostname,
272 int port, const char *fmt, ...) av_printf_format(7, 8);
275 * Convert a relative url into an absolute url, given a base url.
277 * @param buf the buffer where output absolute url is written
278 * @param size the size of buf
279 * @param base the base url, may be equal to buf.
280 * @param rel the new url, which is interpreted relative to base
282 void ff_make_absolute_url(char *buf, int size, const char *base,
286 #endif /* AVFORMAT_URL_H */