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  int min_packet_size; /**< if non zero, the stream is packetized with this min packet size */
52 } URLContext;
53 
54 typedef struct URLProtocol {
55  const char *name;
56  int (*url_open)( URLContext *h, const char *url, int flags);
57  /**
58  * This callback is to be used by protocols which open further nested
59  * protocols. options are then to be passed to ffurl_open()/ffurl_connect()
60  * for those nested protocols.
61  */
62  int (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options);
65 
66  /**
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.
70  * Otherwise:
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.
77  */
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);
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);
87  int *numhandles);
92  int flags;
98  int (*url_move)(URLContext *h_src, URLContext *h_dst);
99  const char *default_whitelist;
100 } URLProtocol;
101 
102 /**
103  * Create a URLContext for accessing to the resource indicated by
104  * url, but do not initiate the connection yet.
105  *
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
109  * is to be opened
110  * @param int_cb interrupt callback to use for the URLContext, may be
111  * NULL
112  * @return >= 0 in case of success, a negative value corresponding to an
113  * AVERROR code in case of failure
114  */
115 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
116  const AVIOInterruptCB *int_cb);
117 
118 /**
119  * Connect an URLContext that has been allocated by ffurl_alloc
120  *
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.
125  */
127 
128 /**
129  * Create an URLContext for accessing to the resource indicated by
130  * url, and open it.
131  *
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
135  * is to be opened
136  * @param int_cb interrupt callback to use for the URLContext, may be
137  * NULL
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
145  */
146 int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags,
148  const char *whitelist, const char* blacklist,
149  URLContext *parent);
150 
151 int ffurl_open(URLContext **puc, const char *filename, int flags,
153 
154 /**
155  * Accept an URLContext c on an URLContext s
156  *
157  * @param s server context
158  * @param c client context, must be unallocated.
159  * @return >= 0 on success, ff_neterrno() on failure.
160  */
162 
163 /**
164  * Perform one step of the protocol handshake to accept a new client.
165  * See avio_handshake() for details.
166  * Implementations should try to return decreasing values.
167  * If the protocol uses an underlying protocol, the underlying handshake is
168  * usually the first step, and the return value can be:
169  * (largest value for this protocol) + (return value from other protocol)
170  *
171  * @param c the client context
172  * @return >= 0 on success or a negative value corresponding
173  * to an AVERROR code on failure
174  */
176 
177 /**
178  * Read up to size bytes from the resource accessed by h, and store
179  * the read bytes in buf.
180  *
181  * @return The number of bytes actually read, or a negative value
182  * corresponding to an AVERROR code in case of error. A value of zero
183  * indicates that it is not possible to read more from the accessed
184  * resource (except if the value of the size argument is also zero).
185  */
186 int ffurl_read(URLContext *h, unsigned char *buf, int size);
187 
188 /**
189  * Read as many bytes as possible (up to size), calling the
190  * read function multiple times if necessary.
191  * This makes special short-read handling in applications
192  * unnecessary, if the return value is < size then it is
193  * certain there was either an error or the end of file was reached.
194  */
195 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
196 
197 /**
198  * Write size bytes from buf to the resource accessed by h.
199  *
200  * @return the number of bytes actually written, or a negative value
201  * corresponding to an AVERROR code in case of failure
202  */
203 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
204 
205 /**
206  * Change the position that will be used by the next read/write
207  * operation on the resource accessed by h.
208  *
209  * @param pos specifies the new position to set
210  * @param whence specifies how pos should be interpreted, it must be
211  * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
212  * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
213  * (return the filesize of the requested resource, pos is ignored).
214  * @return a negative value corresponding to an AVERROR code in case
215  * of failure, or the resulting file position, measured in bytes from
216  * the beginning of the file. You can use this feature together with
217  * SEEK_CUR to read the current file position.
218  */
219 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
220 
221 /**
222  * Close the resource accessed by the URLContext h, and free the
223  * memory used by it. Also set the URLContext pointer to NULL.
224  *
225  * @return a negative value if an error condition occurred, 0
226  * otherwise
227  */
228 int ffurl_closep(URLContext **h);
229 int ffurl_close(URLContext *h);
230 
231 /**
232  * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
233  * if the operation is not supported by h, or another negative value
234  * corresponding to an AVERROR error code in case of failure.
235  */
236 int64_t ffurl_size(URLContext *h);
237 
238 /**
239  * Return the file descriptor associated with this URL. For RTP, this
240  * will return only the RTP file descriptor, not the RTCP file descriptor.
241  *
242  * @return the file descriptor associated with this URL, or <0 on error.
243  */
245 
246 /**
247  * Return the file descriptors associated with this URL.
248  *
249  * @return 0 on success or <0 on error.
250  */
251 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
252 
253 /**
254  * Return the current short seek threshold value for this URL.
255  *
256  * @return threshold (>0) on success or <=0 on error.
257  */
259 
260 /**
261  * Signal the URLContext that we are done reading or writing the stream.
262  *
263  * @param h pointer to the resource
264  * @param flags flags which control how the resource indicated by url
265  * is to be shutdown
266  *
267  * @return a negative value if an error condition occurred, 0
268  * otherwise
269  */
270 int ffurl_shutdown(URLContext *h, int flags);
271 
272 /**
273  * Check if the user has requested to interrupt a blocking function
274  * associated with cb.
275  */
277 
278 /* udp.c */
279 int ff_udp_set_remote_url(URLContext *h, const char *uri);
281 
282 /**
283  * Assemble a URL string from components. This is the reverse operation
284  * of av_url_split.
285  *
286  * Note, this requires networking to be initialized, so the caller must
287  * ensure ff_network_init has been called.
288  *
289  * @see av_url_split
290  *
291  * @param str the buffer to fill with the url
292  * @param size the size of the str buffer
293  * @param proto the protocol identifier, if null, the separator
294  * after the identifier is left out, too
295  * @param authorization an optional authorization string, may be null.
296  * An empty string is treated the same as a null string.
297  * @param hostname the host name string
298  * @param port the port number, left out from the string if negative
299  * @param fmt a generic format string for everything to add after the
300  * host/port, may be null
301  * @return the number of characters written to the destination buffer
302  */
303 int ff_url_join(char *str, int size, const char *proto,
304  const char *authorization, const char *hostname,
305  int port, const char *fmt, ...) av_printf_format(7, 8);
306 
307 /**
308  * Convert a relative url into an absolute url, given a base url.
309  *
310  * @param buf the buffer where output absolute url is written
311  * @param size the size of buf
312  * @param base the base url, may be equal to buf.
313  * @param rel the new url, which is interpreted relative to base
314  */
315 void ff_make_absolute_url(char *buf, int size, const char *base,
316  const char *rel);
317 
318 /**
319  * Allocate directory entry with default values.
320  *
321  * @return entry or NULL on error
322  */
324 
326 
327 /**
328  * Construct a list of protocols matching a given whitelist and/or blacklist.
329  *
330  * @param whitelist a comma-separated list of allowed protocol names or NULL. If
331  * this is a non-empty string, only protocols in this list will
332  * be included.
333  * @param blacklist a comma-separated list of forbidden protocol names or NULL.
334  * If this is a non-empty string, all protocols in this list
335  * will be excluded.
336  *
337  * @return a NULL-terminated array of matching protocols. The array must be
338  * freed by the caller.
339  */
340 const URLProtocol **ffurl_get_protocols(const char *whitelist,
341  const char *blacklist);
342 
343 #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:655
int(* url_open_dir)(URLContext *h)
Definition: url.h:94
const char * s
Definition: avisynth_c.h:768
Buffered I/O operations.
int(* url_close_dir)(URLContext *h)
Definition: url.h:96
int(* url_check)(URLContext *h, int mask)
Definition: url.h:93
const char * fmt
Definition: avisynth_c.h:769
int flags
Definition: url.h:92
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:86
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:108
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:91
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:106
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:85
int(* url_get_multi_file_handle)(URLContext *h, int **handles, int *numhandles)
Definition: url.h:86
static int flags
Definition: log.c:57
ptrdiff_t size
Definition: opengl_enc.c:101
const OptionDef options[]
Definition: ffserver.c:3948
int(* url_move)(URLContext *h_src, URLContext *h_dst)
Definition: url.h:98
Callback for checking whether to abort blocking functions.
Definition: avio.h:58
int ffurl_open(URLContext **puc, const char *filename, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Definition: avio.c:355
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:62
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:464
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 interrupt a blocking function associated with cb.
Definition: avio.c:662
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:442
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:56
#define av_printf_format(fmtpos, attrpos)
Definition: attributes.h:155
int(* url_write)(URLContext *h, const unsigned char *buf, int size)
Definition: url.h:79
int(* url_read)(URLContext *h, unsigned char *buf, int size)
Read data from the protocol.
Definition: url.h:78
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:82
int64_t(* url_seek)(URLContext *h, int64_t pos, int whence)
Definition: url.h:80
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:307
int ffurl_get_short_seek(URLContext *h)
Return the current short seek threshold value for this URL.
Definition: avio.c:648
int ff_udp_get_local_port(URLContext *h)
Return the local port used by the UDP connection.
Definition: udp.c:481
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:83
const char * default_whitelist
Definition: url.h:99
void * buf
Definition: avisynth_c.h:690
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:290
int(* url_handshake)(URLContext *c)
Definition: url.h:64
int(* url_read_dir)(URLContext *h, AVIODirEntry **next)
Definition: url.h:95
const char * name
Definition: url.h:55
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
int(* url_accept)(URLContext *s, URLContext **c)
Definition: url.h:63
int ffurl_close(URLContext *h)
Definition: avio.c:467
int
const struct URLProtocol * prot
Definition: url.h:40
int(* url_delete)(URLContext *h)
Definition: url.h:97
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:81
int(* url_get_short_seek)(URLContext *h)
Definition: url.h:88
int(* url_shutdown)(URLContext *h, int flags)
Definition: url.h:89
int min_packet_size
if non zero, the stream is packetized with this min packet size
Definition: url.h:51
int priv_data_size
Definition: url.h:90
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:73