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;
50 const char *protocol_blacklist;
51 int min_packet_size; /**< if non zero, the stream is packetized with this min packet size */
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_whitelist()
60 * or ffurl_connect() for those nested protocols.
62 int (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options);
63 int (*url_accept)(URLContext *s, URLContext **c);
64 int (*url_handshake)(URLContext *c);
67 * Read data from the protocol.
68 * If data is immediately available (even less than size), EOF is
69 * reached or an error occurs (including EINTR), return immediately.
71 * In non-blocking mode, return AVERROR(EAGAIN) immediately.
72 * In blocking mode, wait for data/EOF/error with a short timeout (0.1s),
73 * and return AVERROR(EAGAIN) on timeout.
74 * Checking interrupt_callback, looping on EINTR and EAGAIN and until
75 * enough data has been read is left to the calling function; see
76 * retry_transfer_wrapper in avio.c.
78 int (*url_read)( URLContext *h, unsigned char *buf, int size);
79 int (*url_write)(URLContext *h, const unsigned char *buf, int size);
80 int64_t (*url_seek)( URLContext *h, int64_t pos, int whence);
81 int (*url_close)(URLContext *h);
82 int (*url_read_pause)(URLContext *h, int pause);
83 int64_t (*url_read_seek)(URLContext *h, int stream_index,
84 int64_t timestamp, int flags);
85 int (*url_get_file_handle)(URLContext *h);
86 int (*url_get_multi_file_handle)(URLContext *h, int **handles,
88 int (*url_get_short_seek)(URLContext *h);
89 int (*url_shutdown)(URLContext *h, int flags);
90 const AVClass *priv_data_class;
93 int (*url_check)(URLContext *h, int mask);
94 int (*url_open_dir)(URLContext *h);
95 int (*url_read_dir)(URLContext *h, AVIODirEntry **next);
96 int (*url_close_dir)(URLContext *h);
97 int (*url_delete)(URLContext *h);
98 int (*url_move)(URLContext *h_src, URLContext *h_dst);
99 const char *default_whitelist;
103 * Create a URLContext for accessing to the resource indicated by
104 * url, but do not initiate the connection yet.
106 * @param puc pointer to the location where, in case of success, the
107 * function puts the pointer to the created URLContext
108 * @param flags flags which control how the resource indicated by url
110 * @param int_cb interrupt callback to use for the URLContext, may be
112 * @return >= 0 in case of success, a negative value corresponding to an
113 * AVERROR code in case of failure
115 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
116 const AVIOInterruptCB *int_cb);
119 * Connect an URLContext that has been allocated by ffurl_alloc
121 * @param options A dictionary filled with options for nested protocols,
122 * i.e. it will be passed to url_open2() for protocols implementing it.
123 * This parameter will be destroyed and replaced with a dict containing options
124 * that were not found. May be NULL.
126 int ffurl_connect(URLContext *uc, AVDictionary **options);
129 * Create an URLContext for accessing to the resource indicated by
132 * @param puc pointer to the location where, in case of success, the
133 * function puts the pointer to the created URLContext
134 * @param flags flags which control how the resource indicated by url
136 * @param int_cb interrupt callback to use for the URLContext, may be
138 * @param options A dictionary filled with protocol-private options. On return
139 * this parameter will be destroyed and replaced with a dict containing options
140 * that were not found. May be NULL.
141 * @param parent An enclosing URLContext, whose generic options should
142 * be applied to this URLContext as well.
143 * @return >= 0 in case of success, a negative value corresponding to an
144 * AVERROR code in case of failure
146 int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags,
147 const AVIOInterruptCB *int_cb, AVDictionary **options,
148 const char *whitelist, const char* blacklist,
152 * Accept an URLContext c on an URLContext s
154 * @param s server context
155 * @param c client context, must be unallocated.
156 * @return >= 0 on success, ff_neterrno() on failure.
158 int ffurl_accept(URLContext *s, URLContext **c);
161 * Perform one step of the protocol handshake to accept a new client.
162 * See avio_handshake() for details.
163 * Implementations should try to return decreasing values.
164 * If the protocol uses an underlying protocol, the underlying handshake is
165 * usually the first step, and the return value can be:
166 * (largest value for this protocol) + (return value from other protocol)
168 * @param c the client context
169 * @return >= 0 on success or a negative value corresponding
170 * to an AVERROR code on failure
172 int ffurl_handshake(URLContext *c);
175 * Read up to size bytes from the resource accessed by h, and store
176 * the read bytes in buf.
178 * @return The number of bytes actually read, or a negative value
179 * corresponding to an AVERROR code in case of error. A value of zero
180 * indicates that it is not possible to read more from the accessed
181 * resource (except if the value of the size argument is also zero).
183 int ffurl_read(URLContext *h, unsigned char *buf, int size);
186 * Read as many bytes as possible (up to size), calling the
187 * read function multiple times if necessary.
188 * This makes special short-read handling in applications
189 * unnecessary, if the return value is < size then it is
190 * certain there was either an error or the end of file was reached.
192 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
195 * Write size bytes from buf to the resource accessed by h.
197 * @return the number of bytes actually written, or a negative value
198 * corresponding to an AVERROR code in case of failure
200 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
203 * Change the position that will be used by the next read/write
204 * operation on the resource accessed by h.
206 * @param pos specifies the new position to set
207 * @param whence specifies how pos should be interpreted, it must be
208 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
209 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
210 * (return the filesize of the requested resource, pos is ignored).
211 * @return a negative value corresponding to an AVERROR code in case
212 * of failure, or the resulting file position, measured in bytes from
213 * the beginning of the file. You can use this feature together with
214 * SEEK_CUR to read the current file position.
216 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
219 * Close the resource accessed by the URLContext h, and free the
220 * memory used by it. Also set the URLContext pointer to NULL.
222 * @return a negative value if an error condition occurred, 0
225 int ffurl_closep(URLContext **h);
226 int ffurl_close(URLContext *h);
229 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
230 * if the operation is not supported by h, or another negative value
231 * corresponding to an AVERROR error code in case of failure.
233 int64_t ffurl_size(URLContext *h);
236 * Return the file descriptor associated with this URL. For RTP, this
237 * will return only the RTP file descriptor, not the RTCP file descriptor.
239 * @return the file descriptor associated with this URL, or <0 on error.
241 int ffurl_get_file_handle(URLContext *h);
244 * Return the file descriptors associated with this URL.
246 * @return 0 on success or <0 on error.
248 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
251 * Return the current short seek threshold value for this URL.
253 * @return threshold (>0) on success or <=0 on error.
255 int ffurl_get_short_seek(URLContext *h);
258 * Signal the URLContext that we are done reading or writing the stream.
260 * @param h pointer to the resource
261 * @param flags flags which control how the resource indicated by url
264 * @return a negative value if an error condition occurred, 0
267 int ffurl_shutdown(URLContext *h, int flags);
270 * Check if the user has requested to interrupt a blocking function
271 * associated with cb.
273 int ff_check_interrupt(AVIOInterruptCB *cb);
276 int ff_udp_set_remote_url(URLContext *h, const char *uri);
277 int ff_udp_get_local_port(URLContext *h);
280 * Assemble a URL string from components. This is the reverse operation
283 * Note, this requires networking to be initialized, so the caller must
284 * ensure ff_network_init has been called.
288 * @param str the buffer to fill with the url
289 * @param size the size of the str buffer
290 * @param proto the protocol identifier, if null, the separator
291 * after the identifier is left out, too
292 * @param authorization an optional authorization string, may be null.
293 * An empty string is treated the same as a null string.
294 * @param hostname the host name string
295 * @param port the port number, left out from the string if negative
296 * @param fmt a generic format string for everything to add after the
297 * host/port, may be null
298 * @return the number of characters written to the destination buffer
300 int ff_url_join(char *str, int size, const char *proto,
301 const char *authorization, const char *hostname,
302 int port, const char *fmt, ...) av_printf_format(7, 8);
305 * Convert a relative url into an absolute url, given a base url.
307 * @param buf the buffer where output absolute url is written
308 * @param size the size of buf
309 * @param base the base url, may be equal to buf.
310 * @param rel the new url, which is interpreted relative to base
312 int ff_make_absolute_url(char *buf, int size, const char *base,
316 * Allocate directory entry with default values.
318 * @return entry or NULL on error
320 AVIODirEntry *ff_alloc_dir_entry(void);
322 #if FF_API_CHILD_CLASS_NEXT
323 const AVClass *ff_urlcontext_child_class_next(const AVClass *prev);
326 const AVClass *ff_urlcontext_child_class_iterate(void **iter);
329 * Construct a list of protocols matching a given whitelist and/or blacklist.
331 * @param whitelist a comma-separated list of allowed protocol names or NULL. If
332 * this is a non-empty string, only protocols in this list will
334 * @param blacklist a comma-separated list of forbidden protocol names or NULL.
335 * If this is a non-empty string, all protocols in this list
338 * @return a NULL-terminated array of matching protocols. The array must be
339 * freed by the caller.
341 const URLProtocol **ffurl_get_protocols(const char *whitelist,
342 const char *blacklist);
344 typedef struct URLComponents {
345 const char *url; /**< whole URL, for reference */
346 const char *scheme; /**< possibly including lavf-specific options */
347 const char *authority; /**< "//" if it is a real URL */
348 const char *userinfo; /**< including final '@' if present */
350 const char *port; /**< including initial ':' if present */
352 const char *query; /**< including initial '?' if present */
353 const char *fragment; /**< including initial '#' if present */
357 #define url_component_end_scheme authority
358 #define url_component_end_authority userinfo
359 #define url_component_end_userinfo host
360 #define url_component_end_host port
361 #define url_component_end_port path
362 #define url_component_end_path query
363 #define url_component_end_query fragment
364 #define url_component_end_fragment end
365 #define url_component_end_authority_full path
367 #define URL_COMPONENT_HAVE(uc, component) \
368 ((uc).url_component_end_##component > (uc).component)
371 * Parse an URL to find the components.
373 * Each component runs until the start of the next component,
374 * possibly including a mandatory delimiter.
376 * @param uc structure to fill with pointers to the components.
377 * @param url URL to parse.
378 * @param end end of the URL, or NULL to parse to the end of string.
380 * @return >= 0 for success or an AVERROR code, especially if the URL is
383 int ff_url_decompose(URLComponents *uc, const char *url, const char *end);
385 #endif /* AVFORMAT_URL_H */