FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
url.h
Go to the documentation of this file.
1 /*
2  * This file is part of FFmpeg.
3  *
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.
8  *
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.
13  *
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
17  */
18 
19 /**
20  * @file
21  * unbuffered private I/O API
22  */
23 
24 #ifndef AVFORMAT_URL_H
25 #define AVFORMAT_URL_H
26 
27 #include "avio.h"
28 #include "libavformat/version.h"
29 
30 #include "libavutil/dict.h"
31 #include "libavutil/log.h"
32 
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 */
35 
36 extern const AVClass ffurl_context_class;
37 
38 typedef struct URLContext {
39  const AVClass *av_class; /**< information for av_log(). Set by url_open(). */
40  const struct URLProtocol *prot;
41  void *priv_data;
42  char *filename; /**< specified URL */
43  int flags;
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 */
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 } URLContext;
52 
53 typedef struct URLProtocol {
54  const char *name;
55  int (*url_open)( URLContext *h, const char *url, int flags);
56  /**
57  * This callback is to be used by protocols which open further nested
58  * protocols. options are then to be passed to ffurl_open()/ffurl_connect()
59  * for those nested protocols.
60  */
61  int (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options);
64 
65  /**
66  * Read data from the protocol.
67  * If data is immediately available (even less than size), EOF is
68  * reached or an error occurs (including EINTR), return immediately.
69  * Otherwise:
70  * In non-blocking mode, return AVERROR(EAGAIN) immediately.
71  * In blocking mode, wait for data/EOF/error with a short timeout (0.1s),
72  * and return AVERROR(EAGAIN) on timeout.
73  * Checking interrupt_callback, looping on EINTR and EAGAIN and until
74  * enough data has been read is left to the calling function; see
75  * retry_transfer_wrapper in avio.c.
76  */
77  int (*url_read)( URLContext *h, unsigned char *buf, int size);
78  int (*url_write)(URLContext *h, const unsigned char *buf, int size);
79  int64_t (*url_seek)( URLContext *h, int64_t pos, int whence);
81  int (*url_read_pause)(URLContext *h, int pause);
82  int64_t (*url_read_seek)(URLContext *h, int stream_index,
83  int64_t timestamp, int flags);
85  int (*url_get_multi_file_handle)(URLContext *h, int **handles,
86  int *numhandles);
87  int (*url_shutdown)(URLContext *h, int flags);
90  int flags;
91  int (*url_check)(URLContext *h, int mask);
96  int (*url_move)(URLContext *h_src, URLContext *h_dst);
97  const char *default_whitelist;
98 } URLProtocol;
99 
100 /**
101  * Create a URLContext for accessing to the resource indicated by
102  * url, but do not initiate the connection yet.
103  *
104  * @param puc pointer to the location where, in case of success, the
105  * function puts the pointer to the created URLContext
106  * @param flags flags which control how the resource indicated by url
107  * is to be opened
108  * @param int_cb interrupt callback to use for the URLContext, may be
109  * NULL
110  * @return >= 0 in case of success, a negative value corresponding to an
111  * AVERROR code in case of failure
112  */
113 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
114  const AVIOInterruptCB *int_cb);
115 
116 /**
117  * Connect an URLContext that has been allocated by ffurl_alloc
118  *
119  * @param options A dictionary filled with options for nested protocols,
120  * i.e. it will be passed to url_open2() for protocols implementing it.
121  * This parameter will be destroyed and replaced with a dict containing options
122  * that were not found. May be NULL.
123  */
125 
126 /**
127  * Create an URLContext for accessing to the resource indicated by
128  * url, and open it.
129  *
130  * @param puc pointer to the location where, in case of success, the
131  * function puts the pointer to the created URLContext
132  * @param flags flags which control how the resource indicated by url
133  * is to be opened
134  * @param int_cb interrupt callback to use for the URLContext, may be
135  * NULL
136  * @param options A dictionary filled with protocol-private options. On return
137  * this parameter will be destroyed and replaced with a dict containing options
138  * that were not found. May be NULL.
139  * @param parent An enclosing URLContext, whose generic options should
140  * be applied to this URLContext as well.
141  * @return >= 0 in case of success, a negative value corresponding to an
142  * AVERROR code in case of failure
143  */
144 int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags,
146  const char *whitelist, const char* blacklist,
147  URLContext *parent);
148 
149 int ffurl_open(URLContext **puc, const char *filename, int flags,
151 
152 /**
153  * Accept an URLContext c on an URLContext s
154  *
155  * @param s server context
156  * @param c client context, must be unallocated.
157  * @return >= 0 on success, ff_neterrno() on failure.
158  */
160 
161 /**
162  * Perform one step of the protocol handshake to accept a new client.
163  * See avio_handshake() for details.
164  * Implementations should try to return decreasing values.
165  * If the protocol uses an underlying protocol, the underlying handshake is
166  * usually the first step, and the return value can be:
167  * (largest value for this protocol) + (return value from other protocol)
168  *
169  * @param c the client context
170  * @return >= 0 on success or a negative value corresponding
171  * to an AVERROR code on failure
172  */
174 
175 /**
176  * Read up to size bytes from the resource accessed by h, and store
177  * the read bytes in buf.
178  *
179  * @return The number of bytes actually read, or a negative value
180  * corresponding to an AVERROR code in case of error. A value of zero
181  * indicates that it is not possible to read more from the accessed
182  * resource (except if the value of the size argument is also zero).
183  */
184 int ffurl_read(URLContext *h, unsigned char *buf, int size);
185 
186 /**
187  * Read as many bytes as possible (up to size), calling the
188  * read function multiple times if necessary.
189  * This makes special short-read handling in applications
190  * unnecessary, if the return value is < size then it is
191  * certain there was either an error or the end of file was reached.
192  */
193 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
194 
195 /**
196  * Write size bytes from buf to the resource accessed by h.
197  *
198  * @return the number of bytes actually written, or a negative value
199  * corresponding to an AVERROR code in case of failure
200  */
201 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
202 
203 /**
204  * Change the position that will be used by the next read/write
205  * operation on the resource accessed by h.
206  *
207  * @param pos specifies the new position to set
208  * @param whence specifies how pos should be interpreted, it must be
209  * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
210  * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
211  * (return the filesize of the requested resource, pos is ignored).
212  * @return a negative value corresponding to an AVERROR code in case
213  * of failure, or the resulting file position, measured in bytes from
214  * the beginning of the file. You can use this feature together with
215  * SEEK_CUR to read the current file position.
216  */
217 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
218 
219 /**
220  * Close the resource accessed by the URLContext h, and free the
221  * memory used by it. Also set the URLContext pointer to NULL.
222  *
223  * @return a negative value if an error condition occurred, 0
224  * otherwise
225  */
226 int ffurl_closep(URLContext **h);
227 int ffurl_close(URLContext *h);
228 
229 /**
230  * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
231  * if the operation is not supported by h, or another negative value
232  * corresponding to an AVERROR error code in case of failure.
233  */
234 int64_t ffurl_size(URLContext *h);
235 
236 /**
237  * Return the file descriptor associated with this URL. For RTP, this
238  * will return only the RTP file descriptor, not the RTCP file descriptor.
239  *
240  * @return the file descriptor associated with this URL, or <0 on error.
241  */
243 
244 /**
245  * Return the file descriptors associated with this URL.
246  *
247  * @return 0 on success or <0 on error.
248  */
249 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
250 
251 /**
252  * Signal the URLContext that we are done reading or writing the stream.
253  *
254  * @param h pointer to the resource
255  * @param flags flags which control how the resource indicated by url
256  * is to be shutdown
257  *
258  * @return a negative value if an error condition occurred, 0
259  * otherwise
260  */
261 int ffurl_shutdown(URLContext *h, int flags);
262 
263 /**
264  * Check if the user has requested to interrup a blocking function
265  * associated with cb.
266  */
268 
269 /* udp.c */
270 int ff_udp_set_remote_url(URLContext *h, const char *uri);
272 
273 /**
274  * Assemble a URL string from components. This is the reverse operation
275  * of av_url_split.
276  *
277  * Note, this requires networking to be initialized, so the caller must
278  * ensure ff_network_init has been called.
279  *
280  * @see av_url_split
281  *
282  * @param str the buffer to fill with the url
283  * @param size the size of the str buffer
284  * @param proto the protocol identifier, if null, the separator
285  * after the identifier is left out, too
286  * @param authorization an optional authorization string, may be null.
287  * An empty string is treated the same as a null string.
288  * @param hostname the host name string
289  * @param port the port number, left out from the string if negative
290  * @param fmt a generic format string for everything to add after the
291  * host/port, may be null
292  * @return the number of characters written to the destination buffer
293  */
294 int ff_url_join(char *str, int size, const char *proto,
295  const char *authorization, const char *hostname,
296  int port, const char *fmt, ...) av_printf_format(7, 8);
297 
298 /**
299  * Convert a relative url into an absolute url, given a base url.
300  *
301  * @param buf the buffer where output absolute url is written
302  * @param size the size of buf
303  * @param base the base url, may be equal to buf.
304  * @param rel the new url, which is interpreted relative to base
305  */
306 void ff_make_absolute_url(char *buf, int size, const char *base,
307  const char *rel);
308 
309 /**
310  * Allocate directory entry with default values.
311  *
312  * @return entry or NULL on error
313  */
315 
317 
318 /**
319  * Construct a list of protocols matching a given whitelist and/or blacklist.
320  *
321  * @param whitelist a comma-separated list of allowed protocol names or NULL. If
322  * this is a non-empty string, only protocols in this list will
323  * be included.
324  * @param blacklist a comma-separated list of forbidden protocol names or NULL.
325  * If this is a non-empty string, all protocols in this list
326  * will be excluded.
327  *
328  * @return a NULL-terminated array of matching protocols. The array must be
329  * freed by the caller.
330  */
331 const URLProtocol **ffurl_get_protocols(const char *whitelist,
332  const char *blacklist);
333 
334 #endif /* AVFORMAT_URL_H */
int ffurl_shutdown(URLContext *h, int flags)
Signal the URLContext that we are done reading or writing the stream.
Definition: avio.c:648
int(* url_open_dir)(URLContext *h)
Definition: url.h:92
const char * s
Definition: avisynth_c.h:631
Buffered I/O operations.
int(* url_close_dir)(URLContext *h)
Definition: url.h:94
int(* url_check)(URLContext *h, int mask)
Definition: url.h:91
const char * fmt
Definition: avisynth_c.h:632
int flags
Definition: url.h:90
const AVClass ffurl_context_class
Definition: avio.c:63
int64_t ffurl_size(URLContext *h)
Return the filesize of the resource accessed by h, AVERROR(ENOSYS) if the operation is not supported ...
Definition: avio.c:611
int is_streamed
true if streamed (no seek possible), default = false
Definition: url.h:45
AVIOInterruptCB interrupt_callback
Definition: url.h:47
Describes single entry of the directory.
Definition: avio.h:78
int64_t rw_timeout
maximum time to wait for (network) read/write operation completion, in mcs
Definition: url.h:48
const URLProtocol ** ffurl_get_protocols(const char *whitelist, const char *blacklist)
Construct a list of protocols matching a given whitelist and/or blacklist.
Definition: protocols.c:109
int flags
Definition: url.h:43
int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles)
Return the file descriptors associated with this URL.
Definition: avio.c:633
const AVClass * priv_data_class
Definition: url.h:89
int ffurl_write(URLContext *h, const unsigned char *buf, int size)
Write size bytes from buf to the resource accessed by h.
Definition: avio.c:421
Public dictionary API.
static double cb(void *priv, double x, double y)
Definition: vf_geq.c:97
int ff_url_join(char *str, int size, const char *proto, const char *authorization, const char *hostname, int port, const char *fmt,...) av_printf_format(7
Assemble a URL string from components.
int(* url_get_file_handle)(URLContext *h)
Definition: url.h:84
int(* url_get_multi_file_handle)(URLContext *h, int **handles, int *numhandles)
Definition: url.h:85
ptrdiff_t size
Definition: opengl_enc.c:101
const OptionDef options[]
Definition: ffserver.c:3969
int(* url_move)(URLContext *h_src, URLContext *h_dst)
Definition: url.h:96
Callback for checking whether to abort blocking functions.
Definition: avio.h:50
int ffurl_open(URLContext **puc, const char *filename, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Definition: avio.c:357
int(* url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options)
This callback is to be used by protocols which open further nested protocols.
Definition: url.h:61
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:457
int ffurl_read_complete(URLContext *h, unsigned char *buf, int size)
Read as many bytes as possible (up to size), calling the read function multiple times if necessary...
Definition: avio.c:414
static const uint16_t mask[17]
Definition: lzw.c:38
const char * protocol_whitelist
Definition: url.h:49
int ff_check_interrupt(AVIOInterruptCB *cb)
Check if the user has requested to interrup a blocking function associated with cb.
Definition: avio.c:655
int ff_udp_set_remote_url(URLContext *h, const char *uri)
If no filename is given to av_open_input_file because you want to get the local port first...
Definition: udp.c:436
int ffurl_read(URLContext *h, unsigned char *buf, int size)
Read up to size bytes from the resource accessed by h, and store the read bytes in buf...
Definition: avio.c:407
int(* url_open)(URLContext *h, const char *url, int flags)
Definition: url.h:55
#define av_printf_format(fmtpos, attrpos)
Definition: attributes.h:156
int(* url_write)(URLContext *h, const unsigned char *buf, int size)
Definition: url.h:78
int(* url_read)(URLContext *h, unsigned char *buf, int size)
Read data from the protocol.
Definition: url.h:77
AVIODirEntry * ff_alloc_dir_entry(void)
Allocate directory entry with default values.
Definition: url.c:149
int ffurl_connect(URLContext *uc, AVDictionary **options)
Connect an URLContext that has been allocated by ffurl_alloc.
Definition: avio.c:166
int(* url_read_pause)(URLContext *h, int pause)
Definition: url.h:81
int64_t(* url_seek)(URLContext *h, int64_t pos, int whence)
Definition: url.h:79
Libavformat version macros.
int ffurl_get_file_handle(URLContext *h)
Return the file descriptor associated with this URL.
Definition: avio.c:626
int is_connected
Definition: url.h:46
int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options, const char *whitelist, const char *blacklist, URLContext *parent)
Create an URLContext for accessing to the resource indicated by url, and open it. ...
Definition: avio.c:309
int ff_udp_get_local_port(URLContext *h)
Return the local port used by the UDP connection.
Definition: udp.c:475
const char * protocol_blacklist
Definition: url.h:50
int64_t(* url_read_seek)(URLContext *h, int stream_index, int64_t timestamp, int flags)
Definition: url.h:82
const char * default_whitelist
Definition: url.h:97
void * buf
Definition: avisynth_c.h:553
Definition: url.h:38
Describe the class of an AVClass context structure.
Definition: log.h:67
void * priv_data
Definition: url.h:41
int ffurl_alloc(URLContext **puc, const char *filename, int flags, const AVIOInterruptCB *int_cb)
Create a URLContext for accessing to the resource indicated by url, but do not initiate the connectio...
Definition: avio.c:292
int(* url_handshake)(URLContext *c)
Definition: url.h:63
int(* url_read_dir)(URLContext *h, AVIODirEntry **next)
Definition: url.h:93
const char * name
Definition: url.h:54
int64_t ffurl_seek(URLContext *h, int64_t pos, int whence)
Change the position that will be used by the next read/write operation on the resource accessed by h...
Definition: avio.c:434
const AVClass * av_class
information for av_log().
Definition: url.h:39
static int flags
Definition: cpu.c:47
int(* url_accept)(URLContext *s, URLContext **c)
Definition: url.h:62
int ffurl_close(URLContext *h)
Definition: avio.c:467
const struct URLProtocol * prot
Definition: url.h:40
int(* url_delete)(URLContext *h)
Definition: url.h:95
static double c[64]
char * filename
specified URL
Definition: url.h:42
int ffurl_handshake(URLContext *c)
Perform one step of the protocol handshake to accept a new client.
Definition: avio.c:234
int void ff_make_absolute_url(char *buf, int size, const char *base, const char *rel)
Convert a relative url into an absolute url, given a base url.
Definition: url.c:80
int ffurl_accept(URLContext *s, URLContext **c)
Accept an URLContext c on an URLContext s.
Definition: avio.c:226
int max_packet_size
if non zero, the stream is packetized with this max packet size
Definition: url.h:44
int(* url_close)(URLContext *h)
Definition: url.h:80
int(* url_shutdown)(URLContext *h, int flags)
Definition: url.h:87
int priv_data_size
Definition: url.h:88
int ffurl_closep(URLContext **h)
Close the resource accessed by the URLContext h, and free the memory used by it.
Definition: avio.c:444
const AVClass * ff_urlcontext_child_class_next(const AVClass *prev)
Definition: protocols.c:74