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 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;
50 typedef struct URLProtocol {
52 int (*url_open)( URLContext *h, const char *url, int flags);
54 * This callback is to be used by protocols which open further nested
55 * protocols. options are then to be passed to ffurl_open()/ffurl_connect()
56 * for those nested protocols.
58 int (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options);
61 * Read data from the protocol.
62 * If data is immediately available (even less than size), EOF is
63 * reached or an error occurs (including EINTR), return immediately.
65 * In non-blocking mode, return AVERROR(EAGAIN) immediately.
66 * In blocking mode, wait for data/EOF/error with a short timeout (0.1s),
67 * and return AVERROR(EAGAIN) on timeout.
68 * Checking interrupt_callback, looping on EINTR and EAGAIN and until
69 * enough data has been read is left to the calling function; see
70 * retry_transfer_wrapper in avio.c.
72 int (*url_read)( URLContext *h, unsigned char *buf, int size);
73 int (*url_write)(URLContext *h, const unsigned char *buf, int size);
74 int64_t (*url_seek)( URLContext *h, int64_t pos, int whence);
75 int (*url_close)(URLContext *h);
76 int (*url_read_pause)(URLContext *h, int pause);
77 int64_t (*url_read_seek)(URLContext *h, int stream_index,
78 int64_t timestamp, int flags);
79 int (*url_get_file_handle)(URLContext *h);
80 int (*url_get_multi_file_handle)(URLContext *h, int **handles,
82 int (*url_shutdown)(URLContext *h, int flags);
84 const AVClass *priv_data_class;
86 int (*url_check)(URLContext *h, int mask);
90 * Create a URLContext for accessing to the resource indicated by
91 * url, but do not initiate the connection yet.
93 * @param puc pointer to the location where, in case of success, the
94 * function puts the pointer to the created URLContext
95 * @param flags flags which control how the resource indicated by url
97 * @param int_cb interrupt callback to use for the URLContext, may be
99 * @return 0 in case of success, a negative value corresponding to an
100 * AVERROR code in case of failure
102 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
103 const AVIOInterruptCB *int_cb);
106 * Connect an URLContext that has been allocated by ffurl_alloc
108 * @param options A dictionary filled with options for nested protocols,
109 * i.e. it will be passed to url_open2() for protocols implementing it.
110 * This parameter will be destroyed and replaced with a dict containing options
111 * that were not found. May be NULL.
113 int ffurl_connect(URLContext *uc, AVDictionary **options);
116 * Create an URLContext for accessing to the resource indicated by
119 * @param puc pointer to the location where, in case of success, the
120 * function puts the pointer to the created URLContext
121 * @param flags flags which control how the resource indicated by url
123 * @param int_cb interrupt callback to use for the URLContext, may be
125 * @param options A dictionary filled with protocol-private options. On return
126 * this parameter will be destroyed and replaced with a dict containing options
127 * that were not found. May be NULL.
128 * @return 0 in case of success, a negative value corresponding to an
129 * AVERROR code in case of failure
131 int ffurl_open(URLContext **puc, const char *filename, int flags,
132 const AVIOInterruptCB *int_cb, AVDictionary **options);
135 * Read up to size bytes from the resource accessed by h, and store
136 * the read bytes in buf.
138 * @return The number of bytes actually read, or a negative value
139 * corresponding to an AVERROR code in case of error. A value of zero
140 * indicates that it is not possible to read more from the accessed
141 * resource (except if the value of the size argument is also zero).
143 int ffurl_read(URLContext *h, unsigned char *buf, int size);
146 * Read as many bytes as possible (up to size), calling the
147 * read function multiple times if necessary.
148 * This makes special short-read handling in applications
149 * unnecessary, if the return value is < size then it is
150 * certain there was either an error or the end of file was reached.
152 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
155 * Write size bytes from buf to the resource accessed by h.
157 * @return the number of bytes actually written, or a negative value
158 * corresponding to an AVERROR code in case of failure
160 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
163 * Change the position that will be used by the next read/write
164 * operation on the resource accessed by h.
166 * @param pos specifies the new position to set
167 * @param whence specifies how pos should be interpreted, it must be
168 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
169 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
170 * (return the filesize of the requested resource, pos is ignored).
171 * @return a negative value corresponding to an AVERROR code in case
172 * of failure, or the resulting file position, measured in bytes from
173 * the beginning of the file. You can use this feature together with
174 * SEEK_CUR to read the current file position.
176 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
179 * Close the resource accessed by the URLContext h, and free the
182 * @return a negative value if an error condition occurred, 0
185 int ffurl_close(URLContext *h);
188 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
189 * if the operation is not supported by h, or another negative value
190 * corresponding to an AVERROR error code in case of failure.
192 int64_t ffurl_size(URLContext *h);
195 * Return the file descriptor associated with this URL. For RTP, this
196 * will return only the RTP file descriptor, not the RTCP file descriptor.
198 * @return the file descriptor associated with this URL, or <0 on error.
200 int ffurl_get_file_handle(URLContext *h);
203 * Return the file descriptors associated with this URL.
205 * @return 0 on success or <0 on error.
207 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
210 * Signal the URLContext that we are done reading or writing the stream.
212 * @param h pointer to the resource
213 * @param flags flags which control how the resource indicated by url
216 * @return a negative value if an error condition occurred, 0
219 int ffurl_shutdown(URLContext *h, int flags);
222 * Check if the user has requested to interrup a blocking function
223 * associated with cb.
225 int ff_check_interrupt(AVIOInterruptCB *cb);
228 int ff_udp_set_remote_url(URLContext *h, const char *uri);
229 int ff_udp_get_local_port(URLContext *h);
232 * Assemble a URL string from components. This is the reverse operation
235 * Note, this requires networking to be initialized, so the caller must
236 * ensure ff_network_init has been called.
240 * @param str the buffer to fill with the url
241 * @param size the size of the str buffer
242 * @param proto the protocol identifier, if null, the separator
243 * after the identifier is left out, too
244 * @param authorization an optional authorization string, may be null.
245 * An empty string is treated the same as a null string.
246 * @param hostname the host name string
247 * @param port the port number, left out from the string if negative
248 * @param fmt a generic format string for everything to add after the
249 * host/port, may be null
250 * @return the number of characters written to the destination buffer
252 int ff_url_join(char *str, int size, const char *proto,
253 const char *authorization, const char *hostname,
254 int port, const char *fmt, ...) av_printf_format(7, 8);
257 * Convert a relative url into an absolute url, given a base url.
259 * @param buf the buffer where output absolute url is written
260 * @param size the size of buf
261 * @param base the base url, may be equal to buf.
262 * @param rel the new url, which is interpreted relative to base
264 void ff_make_absolute_url(char *buf, int size, const char *base,
267 const AVClass *ff_urlcontext_child_class_next(const AVClass *prev);
269 extern const URLProtocol *ff_url_protocols[];
271 #endif /* AVFORMAT_URL_H */