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 const AVClass ffurl_context_class;
39 typedef struct URLContext {
40 const AVClass *av_class; /**< information for av_log(). Set by url_open(). */
41 struct URLProtocol *prot;
43 char *filename; /**< specified URL */
45 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
46 int is_streamed; /**< true if streamed (no seek possible), default = false */
48 AVIOInterruptCB interrupt_callback;
51 typedef struct URLProtocol {
53 int (*url_open)( URLContext *h, const char *url, int flags);
55 * This callback is to be used by protocols which open further nested
56 * protocols. options are then to be passed to ffurl_open()/ffurl_connect()
57 * for those nested protocols.
59 int (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options);
62 * Read data from the protocol.
63 * If data is immediately available (even less than size), EOF is
64 * reached or an error occurs (including EINTR), return immediately.
66 * In non-blocking mode, return AVERROR(EAGAIN) immediately.
67 * In blocking mode, wait for data/EOF/error with a short timeout (0.1s),
68 * and return AVERROR(EAGAIN) on timeout.
69 * Checking interrupt_callback, looping on EINTR and EAGAIN and until
70 * enough data has been read is left to the calling function; see
71 * retry_transfer_wrapper in avio.c.
73 int (*url_read)( URLContext *h, unsigned char *buf, int size);
74 int (*url_write)(URLContext *h, const unsigned char *buf, int size);
75 int64_t (*url_seek)( URLContext *h, int64_t pos, int whence);
76 int (*url_close)(URLContext *h);
77 struct URLProtocol *next;
78 int (*url_read_pause)(URLContext *h, int pause);
79 int64_t (*url_read_seek)(URLContext *h, int stream_index,
80 int64_t timestamp, int flags);
81 int (*url_get_file_handle)(URLContext *h);
82 int (*url_get_multi_file_handle)(URLContext *h, int **handles,
84 int (*url_shutdown)(URLContext *h, int flags);
86 const AVClass *priv_data_class;
88 int (*url_check)(URLContext *h, int mask);
92 * Create a URLContext for accessing to the resource indicated by
93 * url, but do not initiate the connection yet.
95 * @param puc pointer to the location where, in case of success, the
96 * function puts the pointer to the created URLContext
97 * @param flags flags which control how the resource indicated by url
99 * @param int_cb interrupt callback to use for the URLContext, may be
101 * @return 0 in case of success, a negative value corresponding to an
102 * AVERROR code in case of failure
104 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
105 const AVIOInterruptCB *int_cb);
108 * Connect an URLContext that has been allocated by ffurl_alloc
110 * @param options A dictionary filled with options for nested protocols,
111 * i.e. it will be passed to url_open2() for protocols implementing it.
112 * This parameter will be destroyed and replaced with a dict containing options
113 * that were not found. May be NULL.
115 int ffurl_connect(URLContext *uc, AVDictionary **options);
118 * Create an URLContext for accessing to the resource indicated by
121 * @param puc pointer to the location where, in case of success, the
122 * function puts the pointer to the created URLContext
123 * @param flags flags which control how the resource indicated by url
125 * @param int_cb interrupt callback to use for the URLContext, may be
127 * @param options A dictionary filled with protocol-private options. On return
128 * this parameter will be destroyed and replaced with a dict containing options
129 * that were not found. May be NULL.
130 * @return 0 in case of success, a negative value corresponding to an
131 * AVERROR code in case of failure
133 int ffurl_open(URLContext **puc, const char *filename, int flags,
134 const AVIOInterruptCB *int_cb, AVDictionary **options);
137 * Read up to size bytes from the resource accessed by h, and store
138 * the read bytes in buf.
140 * @return The number of bytes actually read, or a negative value
141 * corresponding to an AVERROR code in case of error. A value of zero
142 * indicates that it is not possible to read more from the accessed
143 * resource (except if the value of the size argument is also zero).
145 int ffurl_read(URLContext *h, unsigned char *buf, int size);
148 * Read as many bytes as possible (up to size), calling the
149 * read function multiple times if necessary.
150 * This makes special short-read handling in applications
151 * unnecessary, if the return value is < size then it is
152 * certain there was either an error or the end of file was reached.
154 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
157 * Write size bytes from buf to the resource accessed by h.
159 * @return the number of bytes actually written, or a negative value
160 * corresponding to an AVERROR code in case of failure
162 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
165 * Change the position that will be used by the next read/write
166 * operation on the resource accessed by h.
168 * @param pos specifies the new position to set
169 * @param whence specifies how pos should be interpreted, it must be
170 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
171 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
172 * (return the filesize of the requested resource, pos is ignored).
173 * @return a negative value corresponding to an AVERROR code in case
174 * of failure, or the resulting file position, measured in bytes from
175 * the beginning of the file. You can use this feature together with
176 * SEEK_CUR to read the current file position.
178 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
181 * Close the resource accessed by the URLContext h, and free the
184 * @return a negative value if an error condition occurred, 0
187 int ffurl_close(URLContext *h);
190 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
191 * if the operation is not supported by h, or another negative value
192 * corresponding to an AVERROR error code in case of failure.
194 int64_t ffurl_size(URLContext *h);
197 * Return the file descriptor associated with this URL. For RTP, this
198 * will return only the RTP file descriptor, not the RTCP file descriptor.
200 * @return the file descriptor associated with this URL, or <0 on error.
202 int ffurl_get_file_handle(URLContext *h);
205 * Return the file descriptors associated with this URL.
207 * @return 0 on success or <0 on error.
209 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
212 * Signal the URLContext that we are done reading or writing the stream.
214 * @param h pointer to the resource
215 * @param flags flags which control how the resource indicated by url
218 * @return a negative value if an error condition occurred, 0
221 int ffurl_shutdown(URLContext *h, int flags);
224 * Register the URLProtocol protocol.
226 int ffurl_register_protocol(URLProtocol *protocol);
229 * Check if the user has requested to interrup a blocking function
230 * associated with cb.
232 int ff_check_interrupt(AVIOInterruptCB *cb);
235 * Iterate over all available protocols.
237 * @param prev result of the previous call to this functions or NULL.
239 URLProtocol *ffurl_protocol_next(const URLProtocol *prev);
242 int ff_udp_set_remote_url(URLContext *h, const char *uri);
243 int ff_udp_get_local_port(URLContext *h);
246 * Assemble a URL string from components. This is the reverse operation
249 * Note, this requires networking to be initialized, so the caller must
250 * ensure ff_network_init has been called.
254 * @param str the buffer to fill with the url
255 * @param size the size of the str buffer
256 * @param proto the protocol identifier, if null, the separator
257 * after the identifier is left out, too
258 * @param authorization an optional authorization string, may be null.
259 * An empty string is treated the same as a null string.
260 * @param hostname the host name string
261 * @param port the port number, left out from the string if negative
262 * @param fmt a generic format string for everything to add after the
263 * host/port, may be null
264 * @return the number of characters written to the destination buffer
266 int ff_url_join(char *str, int size, const char *proto,
267 const char *authorization, const char *hostname,
268 int port, const char *fmt, ...) av_printf_format(7, 8);
271 * Convert a relative url into an absolute url, given a base url.
273 * @param buf the buffer where output absolute url is written
274 * @param size the size of buf
275 * @param base the base url, may be equal to buf.
276 * @param rel the new url, which is interpreted relative to base
278 void ff_make_absolute_url(char *buf, int size, const char *base,
282 #endif /* AVFORMAT_URL_H */