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);
86  int *numhandles);
91  int flags;
97  int (*url_move)(URLContext *h_src, URLContext *h_dst);
98  const char *default_whitelist;
99 } URLProtocol;
100 
101 /**
102  * Create a URLContext for accessing to the resource indicated by
103  * url, but do not initiate the connection yet.
104  *
105  * @param puc pointer to the location where, in case of success, the
106  * function puts the pointer to the created URLContext
107  * @param flags flags which control how the resource indicated by url
108  * is to be opened
109  * @param int_cb interrupt callback to use for the URLContext, may be
110  * NULL
111  * @return >= 0 in case of success, a negative value corresponding to an
112  * AVERROR code in case of failure
113  */
114 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
115  const AVIOInterruptCB *int_cb);
116 
117 /**
118  * Connect an URLContext that has been allocated by ffurl_alloc
119  *
120  * @param options A dictionary filled with options for nested protocols,
121  * i.e. it will be passed to url_open2() for protocols implementing it.
122  * This parameter will be destroyed and replaced with a dict containing options
123  * that were not found. May be NULL.
124  */
126 
127 /**
128  * Create an URLContext for accessing to the resource indicated by
129  * url, and open it.
130  *
131  * @param puc pointer to the location where, in case of success, the
132  * function puts the pointer to the created URLContext
133  * @param flags flags which control how the resource indicated by url
134  * is to be opened
135  * @param int_cb interrupt callback to use for the URLContext, may be
136  * NULL
137  * @param options A dictionary filled with protocol-private options. On return
138  * this parameter will be destroyed and replaced with a dict containing options
139  * that were not found. May be NULL.
140  * @param parent An enclosing URLContext, whose generic options should
141  * be applied to this URLContext as well.
142  * @return >= 0 in case of success, a negative value corresponding to an
143  * AVERROR code in case of failure
144  */
145 int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags,
147  const char *whitelist, const char* blacklist,
148  URLContext *parent);
149 
150 int ffurl_open(URLContext **puc, const char *filename, int flags,
152 
153 /**
154  * Accept an URLContext c on an URLContext s
155  *
156  * @param s server context
157  * @param c client context, must be unallocated.
158  * @return >= 0 on success, ff_neterrno() on failure.
159  */
161 
162 /**
163  * Perform one step of the protocol handshake to accept a new client.
164  * See avio_handshake() for details.
165  * Implementations should try to return decreasing values.
166  * If the protocol uses an underlying protocol, the underlying handshake is
167  * usually the first step, and the return value can be:
168  * (largest value for this protocol) + (return value from other protocol)
169  *
170  * @param c the client context
171  * @return >= 0 on success or a negative value corresponding
172  * to an AVERROR code on failure
173  */
175 
176 /**
177  * Read up to size bytes from the resource accessed by h, and store
178  * the read bytes in buf.
179  *
180  * @return The number of bytes actually read, or a negative value
181  * corresponding to an AVERROR code in case of error. A value of zero
182  * indicates that it is not possible to read more from the accessed
183  * resource (except if the value of the size argument is also zero).
184  */
185 int ffurl_read(URLContext *h, unsigned char *buf, int size);
186 
187 /**
188  * Read as many bytes as possible (up to size), calling the
189  * read function multiple times if necessary.
190  * This makes special short-read handling in applications
191  * unnecessary, if the return value is < size then it is
192  * certain there was either an error or the end of file was reached.
193  */
194 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
195 
196 /**
197  * Write size bytes from buf to the resource accessed by h.
198  *
199  * @return the number of bytes actually written, or a negative value
200  * corresponding to an AVERROR code in case of failure
201  */
202 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
203 
204 /**
205  * Change the position that will be used by the next read/write
206  * operation on the resource accessed by h.
207  *
208  * @param pos specifies the new position to set
209  * @param whence specifies how pos should be interpreted, it must be
210  * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
211  * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
212  * (return the filesize of the requested resource, pos is ignored).
213  * @return a negative value corresponding to an AVERROR code in case
214  * of failure, or the resulting file position, measured in bytes from
215  * the beginning of the file. You can use this feature together with
216  * SEEK_CUR to read the current file position.
217  */
218 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
219 
220 /**
221  * Close the resource accessed by the URLContext h, and free the
222  * memory used by it. Also set the URLContext pointer to NULL.
223  *
224  * @return a negative value if an error condition occurred, 0
225  * otherwise
226  */
227 int ffurl_closep(URLContext **h);
228 int ffurl_close(URLContext *h);
229 
230 /**
231  * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
232  * if the operation is not supported by h, or another negative value
233  * corresponding to an AVERROR error code in case of failure.
234  */
235 int64_t ffurl_size(URLContext *h);
236 
237 /**
238  * Return the file descriptor associated with this URL. For RTP, this
239  * will return only the RTP file descriptor, not the RTCP file descriptor.
240  *
241  * @return the file descriptor associated with this URL, or <0 on error.
242  */
244 
245 /**
246  * Return the file descriptors associated with this URL.
247  *
248  * @return 0 on success or <0 on error.
249  */
250 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
251 
252 /**
253  * Return the current short seek threshold value for this URL.
254  *
255  * @return threshold (>0) on success or <=0 on error.
256  */
258 
259 /**
260  * Signal the URLContext that we are done reading or writing the stream.
261  *
262  * @param h pointer to the resource
263  * @param flags flags which control how the resource indicated by url
264  * is to be shutdown
265  *
266  * @return a negative value if an error condition occurred, 0
267  * otherwise
268  */
269 int ffurl_shutdown(URLContext *h, int flags);
270 
271 /**
272  * Check if the user has requested to interrupt a blocking function
273  * associated with cb.
274  */
276 
277 /* udp.c */
278 int ff_udp_set_remote_url(URLContext *h, const char *uri);
280 
281 /**
282  * Assemble a URL string from components. This is the reverse operation
283  * of av_url_split.
284  *
285  * Note, this requires networking to be initialized, so the caller must
286  * ensure ff_network_init has been called.
287  *
288  * @see av_url_split
289  *
290  * @param str the buffer to fill with the url
291  * @param size the size of the str buffer
292  * @param proto the protocol identifier, if null, the separator
293  * after the identifier is left out, too
294  * @param authorization an optional authorization string, may be null.
295  * An empty string is treated the same as a null string.
296  * @param hostname the host name string
297  * @param port the port number, left out from the string if negative
298  * @param fmt a generic format string for everything to add after the
299  * host/port, may be null
300  * @return the number of characters written to the destination buffer
301  */
302 int ff_url_join(char *str, int size, const char *proto,
303  const char *authorization, const char *hostname,
304  int port, const char *fmt, ...) av_printf_format(7, 8);
305 
306 /**
307  * Convert a relative url into an absolute url, given a base url.
308  *
309  * @param buf the buffer where output absolute url is written
310  * @param size the size of buf
311  * @param base the base url, may be equal to buf.
312  * @param rel the new url, which is interpreted relative to base
313  */
314 void ff_make_absolute_url(char *buf, int size, const char *base,
315  const char *rel);
316 
317 /**
318  * Allocate directory entry with default values.
319  *
320  * @return entry or NULL on error
321  */
323 
325 
326 /**
327  * Construct a list of protocols matching a given whitelist and/or blacklist.
328  *
329  * @param whitelist a comma-separated list of allowed protocol names or NULL. If
330  * this is a non-empty string, only protocols in this list will
331  * be included.
332  * @param blacklist a comma-separated list of forbidden protocol names or NULL.
333  * If this is a non-empty string, all protocols in this list
334  * will be excluded.
335  *
336  * @return a NULL-terminated array of matching protocols. The array must be
337  * freed by the caller.
338  */
339 const URLProtocol **ffurl_get_protocols(const char *whitelist,
340  const char *blacklist);
341 
342 #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:93
const char * s
Definition: avisynth_c.h:768
Buffered I/O operations.
int(* url_close_dir)(URLContext *h)
Definition: url.h:95
int(* url_check)(URLContext *h, int mask)
Definition: url.h:92
const char * fmt
Definition: avisynth_c.h:769
int flags
Definition: url.h:91
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:111
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:90
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
static int flags
Definition: log.c:57
ptrdiff_t size
Definition: opengl_enc.c:101
const OptionDef options[]
Definition: ffserver.c:3952
int(* url_move)(URLContext *h_src, URLContext *h_dst)
Definition: url.h:97
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:460
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:55
#define av_printf_format(fmtpos, attrpos)
Definition: attributes.h:155
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 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:82
const char * default_whitelist
Definition: url.h:98
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:292
int(* url_handshake)(URLContext *c)
Definition: url.h:63
int(* url_read_dir)(URLContext *h, AVIODirEntry **next)
Definition: url.h:94
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
int(* url_accept)(URLContext *s, URLContext **c)
Definition: url.h:62
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:96
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_get_short_seek)(URLContext *h)
Definition: url.h:87
int(* url_shutdown)(URLContext *h, int flags)
Definition: url.h:88
int priv_data_size
Definition: url.h:89
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:76