2 * This file is part of Libav.
4 * Libav 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 * Libav 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 Libav; 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 const struct URLProtocol *prot;
42 * A NULL-terminated list of protocols usable by the child contexts.
44 const struct URLProtocol **protocols;
46 char *filename; /**< specified URL */
48 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
49 int is_streamed; /**< true if streamed (no seek possible), default = false */
51 AVIOInterruptCB interrupt_callback;
54 typedef struct URLProtocol {
56 int (*url_open)( URLContext *h, const char *url, int flags);
58 * This callback is to be used by protocols which open further nested
59 * protocols. options are then to be passed to ffurl_open()/ffurl_connect()
60 * for those nested protocols.
62 int (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options);
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 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 * @param protocols a NULL-terminate list of protocols available for use by
104 * this context and its children. The caller must ensure this
105 * list remains valid until the context is closed.
106 * @return 0 in case of success, a negative value corresponding to an
107 * AVERROR code in case of failure
109 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
110 const AVIOInterruptCB *int_cb,
111 const URLProtocol **protocols);
114 * Connect an URLContext that has been allocated by ffurl_alloc
116 * @param options A dictionary filled with options for nested protocols,
117 * i.e. it will be passed to url_open2() for protocols implementing it.
118 * This parameter will be destroyed and replaced with a dict containing options
119 * that were not found. May be NULL.
121 int ffurl_connect(URLContext *uc, AVDictionary **options);
124 * Create an URLContext for accessing to the resource indicated by
127 * @param puc pointer to the location where, in case of success, the
128 * function puts the pointer to the created URLContext
129 * @param flags flags which control how the resource indicated by url
131 * @param int_cb interrupt callback to use for the URLContext, may be
133 * @param options A dictionary filled with protocol-private options. On return
134 * this parameter will be destroyed and replaced with a dict containing options
135 * that were not found. May be NULL.
136 * @param protocols a NULL-terminate list of protocols available for use by
137 * this context and its children. The caller must ensure this
138 * list remains valid until the context is closed.
139 * @return 0 in case of success, a negative value corresponding to an
140 * AVERROR code in case of failure
142 int ffurl_open(URLContext **puc, const char *filename, int flags,
143 const AVIOInterruptCB *int_cb, AVDictionary **options,
144 const URLProtocol **protocols);
147 * Read up to size bytes from the resource accessed by h, and store
148 * the read bytes in buf.
150 * @return The number of bytes actually read, or a negative value
151 * corresponding to an AVERROR code in case of error. A value of zero
152 * indicates that it is not possible to read more from the accessed
153 * resource (except if the value of the size argument is also zero).
155 int ffurl_read(URLContext *h, unsigned char *buf, int size);
158 * Read as many bytes as possible (up to size), calling the
159 * read function multiple times if necessary.
160 * This makes special short-read handling in applications
161 * unnecessary, if the return value is < size then it is
162 * certain there was either an error or the end of file was reached.
164 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
167 * Write size bytes from buf to the resource accessed by h.
169 * @return the number of bytes actually written, or a negative value
170 * corresponding to an AVERROR code in case of failure
172 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
175 * Change the position that will be used by the next read/write
176 * operation on the resource accessed by h.
178 * @param pos specifies the new position to set
179 * @param whence specifies how pos should be interpreted, it must be
180 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
181 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
182 * (return the filesize of the requested resource, pos is ignored).
183 * @return a negative value corresponding to an AVERROR code in case
184 * of failure, or the resulting file position, measured in bytes from
185 * the beginning of the file. You can use this feature together with
186 * SEEK_CUR to read the current file position.
188 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
191 * Close the resource accessed by the URLContext h, and free the
194 * @return a negative value if an error condition occurred, 0
197 int ffurl_close(URLContext *h);
200 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
201 * if the operation is not supported by h, or another negative value
202 * corresponding to an AVERROR error code in case of failure.
204 int64_t ffurl_size(URLContext *h);
207 * Return the file descriptor associated with this URL. For RTP, this
208 * will return only the RTP file descriptor, not the RTCP file descriptor.
210 * @return the file descriptor associated with this URL, or <0 on error.
212 int ffurl_get_file_handle(URLContext *h);
215 * Return the file descriptors associated with this URL.
217 * @return 0 on success or <0 on error.
219 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
222 * Signal the URLContext that we are done reading or writing the stream.
224 * @param h pointer to the resource
225 * @param flags flags which control how the resource indicated by url
228 * @return a negative value if an error condition occurred, 0
231 int ffurl_shutdown(URLContext *h, int flags);
234 * Check if the user has requested to interrup a blocking function
235 * associated with cb.
237 int ff_check_interrupt(AVIOInterruptCB *cb);
240 int ff_udp_set_remote_url(URLContext *h, const char *uri);
241 int ff_udp_get_local_port(URLContext *h);
244 * Assemble a URL string from components. This is the reverse operation
247 * Note, this requires networking to be initialized, so the caller must
248 * ensure ff_network_init has been called.
252 * @param str the buffer to fill with the url
253 * @param size the size of the str buffer
254 * @param proto the protocol identifier, if null, the separator
255 * after the identifier is left out, too
256 * @param authorization an optional authorization string, may be null.
257 * An empty string is treated the same as a null string.
258 * @param hostname the host name string
259 * @param port the port number, left out from the string if negative
260 * @param fmt a generic format string for everything to add after the
261 * host/port, may be null
262 * @return the number of characters written to the destination buffer
264 int ff_url_join(char *str, int size, const char *proto,
265 const char *authorization, const char *hostname,
266 int port, const char *fmt, ...) av_printf_format(7, 8);
269 * Convert a relative url into an absolute url, given a base url.
271 * @param buf the buffer where output absolute url is written
272 * @param size the size of buf
273 * @param base the base url, may be equal to buf.
274 * @param rel the new url, which is interpreted relative to base
276 void ff_make_absolute_url(char *buf, int size, const char *base,
279 const AVClass *ff_urlcontext_child_class_next(const AVClass *prev);
282 * Construct a list of protocols matching a given whitelist and/or blacklist.
284 * @param whitelist a comma-separated list of allowed protocol names or NULL. If
285 * this is a non-empty string, only protocols in this list will
287 * @param blacklist a comma-separated list of forbidden protocol names or NULL.
288 * If this is a non-empty string, all protocols in this list
291 * @return a NULL-terminated array of matching protocols. The array must be
292 * freed by the caller.
294 const URLProtocol **ffurl_get_protocols(const char *whitelist,
295 const char *blacklist);
297 #endif /* AVFORMAT_URL_H */