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 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;
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 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);
91 int (*url_open_dir)(URLContext *h);
92 int (*url_read_dir)(URLContext *h, AVIODirEntry **next);
93 int (*url_close_dir)(URLContext *h);
94 int (*url_delete)(URLContext *h);
95 int (*url_move)(URLContext *h_src, URLContext *h_dst);
96 const char *default_whitelist;
100 * Create a URLContext for accessing to the resource indicated by
101 * url, but do not initiate the connection yet.
103 * @param puc pointer to the location where, in case of success, the
104 * function puts the pointer to the created URLContext
105 * @param flags flags which control how the resource indicated by url
107 * @param int_cb interrupt callback to use for the URLContext, may be
109 * @return >= 0 in case of success, a negative value corresponding to an
110 * AVERROR code in case of failure
112 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
113 const AVIOInterruptCB *int_cb);
116 * Connect an URLContext that has been allocated by ffurl_alloc
118 * @param options A dictionary filled with options for nested protocols,
119 * i.e. it will be passed to url_open2() for protocols implementing it.
120 * This parameter will be destroyed and replaced with a dict containing options
121 * that were not found. May be NULL.
123 int ffurl_connect(URLContext *uc, AVDictionary **options);
126 * Create an URLContext for accessing to the resource indicated by
129 * @param puc pointer to the location where, in case of success, the
130 * function puts the pointer to the created URLContext
131 * @param flags flags which control how the resource indicated by url
133 * @param int_cb interrupt callback to use for the URLContext, may be
135 * @param options A dictionary filled with protocol-private options. On return
136 * this parameter will be destroyed and replaced with a dict containing options
137 * that were not found. May be NULL.
138 * @return >= 0 in case of success, a negative value corresponding to an
139 * AVERROR code in case of failure
141 int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags,
142 const AVIOInterruptCB *int_cb, AVDictionary **options,
143 const char *whitelist);
145 int ffurl_open(URLContext **puc, const char *filename, int flags,
146 const AVIOInterruptCB *int_cb, AVDictionary **options);
149 * Accept an URLContext c on an URLContext s
151 * @param s server context
152 * @param c client context, must be unallocated.
153 * @return >= 0 on success, ff_neterrno() on failure.
155 int ffurl_accept(URLContext *s, URLContext **c);
158 * Perform one step of the protocol handshake to accept a new client.
159 * See avio_handshake() for details.
160 * Implementations should try to return decreasing values.
161 * If the protocol uses an underlying protocol, the underlying handshake is
162 * usually the first step, and the return value can be:
163 * (largest value for this protocol) + (return value from other protocol)
165 * @param c the client context
166 * @return >= 0 on success or a negative value corresponding
167 * to an AVERROR code on failure
169 int ffurl_handshake(URLContext *c);
172 * Read up to size bytes from the resource accessed by h, and store
173 * the read bytes in buf.
175 * @return The number of bytes actually read, or a negative value
176 * corresponding to an AVERROR code in case of error. A value of zero
177 * indicates that it is not possible to read more from the accessed
178 * resource (except if the value of the size argument is also zero).
180 int ffurl_read(URLContext *h, unsigned char *buf, int size);
183 * Read as many bytes as possible (up to size), calling the
184 * read function multiple times if necessary.
185 * This makes special short-read handling in applications
186 * unnecessary, if the return value is < size then it is
187 * certain there was either an error or the end of file was reached.
189 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
192 * Write size bytes from buf to the resource accessed by h.
194 * @return the number of bytes actually written, or a negative value
195 * corresponding to an AVERROR code in case of failure
197 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
200 * Change the position that will be used by the next read/write
201 * operation on the resource accessed by h.
203 * @param pos specifies the new position to set
204 * @param whence specifies how pos should be interpreted, it must be
205 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
206 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
207 * (return the filesize of the requested resource, pos is ignored).
208 * @return a negative value corresponding to an AVERROR code in case
209 * of failure, or the resulting file position, measured in bytes from
210 * the beginning of the file. You can use this feature together with
211 * SEEK_CUR to read the current file position.
213 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
216 * Close the resource accessed by the URLContext h, and free the
217 * memory used by it. Also set the URLContext pointer to NULL.
219 * @return a negative value if an error condition occurred, 0
222 int ffurl_closep(URLContext **h);
223 int ffurl_close(URLContext *h);
226 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
227 * if the operation is not supported by h, or another negative value
228 * corresponding to an AVERROR error code in case of failure.
230 int64_t ffurl_size(URLContext *h);
233 * Return the file descriptor associated with this URL. For RTP, this
234 * will return only the RTP file descriptor, not the RTCP file descriptor.
236 * @return the file descriptor associated with this URL, or <0 on error.
238 int ffurl_get_file_handle(URLContext *h);
241 * Return the file descriptors associated with this URL.
243 * @return 0 on success or <0 on error.
245 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
248 * Signal the URLContext that we are done reading or writing the stream.
250 * @param h pointer to the resource
251 * @param flags flags which control how the resource indicated by url
254 * @return a negative value if an error condition occurred, 0
257 int ffurl_shutdown(URLContext *h, int flags);
260 * Check if the user has requested to interrup a blocking function
261 * associated with cb.
263 int ff_check_interrupt(AVIOInterruptCB *cb);
266 int ff_udp_set_remote_url(URLContext *h, const char *uri);
267 int ff_udp_get_local_port(URLContext *h);
270 * Assemble a URL string from components. This is the reverse operation
273 * Note, this requires networking to be initialized, so the caller must
274 * ensure ff_network_init has been called.
278 * @param str the buffer to fill with the url
279 * @param size the size of the str buffer
280 * @param proto the protocol identifier, if null, the separator
281 * after the identifier is left out, too
282 * @param authorization an optional authorization string, may be null.
283 * An empty string is treated the same as a null string.
284 * @param hostname the host name string
285 * @param port the port number, left out from the string if negative
286 * @param fmt a generic format string for everything to add after the
287 * host/port, may be null
288 * @return the number of characters written to the destination buffer
290 int ff_url_join(char *str, int size, const char *proto,
291 const char *authorization, const char *hostname,
292 int port, const char *fmt, ...) av_printf_format(7, 8);
295 * Convert a relative url into an absolute url, given a base url.
297 * @param buf the buffer where output absolute url is written
298 * @param size the size of buf
299 * @param base the base url, may be equal to buf.
300 * @param rel the new url, which is interpreted relative to base
302 void ff_make_absolute_url(char *buf, int size, const char *base,
306 * Allocate directory entry with default values.
308 * @return entry or NULL on error
310 AVIODirEntry *ff_alloc_dir_entry(void);
312 extern const URLProtocol *ff_url_protocols[];
314 #endif /* AVFORMAT_URL_H */