FFmpeg  4.4.4
url.h
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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_whitelist()
60  * or ffurl_connect() 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 /**
152  * Accept an URLContext c on an URLContext s
153  *
154  * @param s server context
155  * @param c client context, must be unallocated.
156  * @return >= 0 on success, ff_neterrno() on failure.
157  */
159 
160 /**
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)
167  *
168  * @param c the client context
169  * @return >= 0 on success or a negative value corresponding
170  * to an AVERROR code on failure
171  */
173 
174 /**
175  * Read up to size bytes from the resource accessed by h, and store
176  * the read bytes in buf.
177  *
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).
182  */
183 int ffurl_read(URLContext *h, unsigned char *buf, int size);
184 
185 /**
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.
191  */
192 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
193 
194 /**
195  * Write size bytes from buf to the resource accessed by h.
196  *
197  * @return the number of bytes actually written, or a negative value
198  * corresponding to an AVERROR code in case of failure
199  */
200 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
201 
202 /**
203  * Change the position that will be used by the next read/write
204  * operation on the resource accessed by h.
205  *
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.
215  */
216 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
217 
218 /**
219  * Close the resource accessed by the URLContext h, and free the
220  * memory used by it. Also set the URLContext pointer to NULL.
221  *
222  * @return a negative value if an error condition occurred, 0
223  * otherwise
224  */
225 int ffurl_closep(URLContext **h);
226 int ffurl_close(URLContext *h);
227 
228 /**
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.
232  */
233 int64_t ffurl_size(URLContext *h);
234 
235 /**
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.
238  *
239  * @return the file descriptor associated with this URL, or <0 on error.
240  */
242 
243 /**
244  * Return the file descriptors associated with this URL.
245  *
246  * @return 0 on success or <0 on error.
247  */
248 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
249 
250 /**
251  * Return the current short seek threshold value for this URL.
252  *
253  * @return threshold (>0) on success or <=0 on error.
254  */
256 
257 /**
258  * Signal the URLContext that we are done reading or writing the stream.
259  *
260  * @param h pointer to the resource
261  * @param flags flags which control how the resource indicated by url
262  * is to be shutdown
263  *
264  * @return a negative value if an error condition occurred, 0
265  * otherwise
266  */
267 int ffurl_shutdown(URLContext *h, int flags);
268 
269 /**
270  * Check if the user has requested to interrupt a blocking function
271  * associated with cb.
272  */
274 
275 /* udp.c */
276 int ff_udp_set_remote_url(URLContext *h, const char *uri);
278 
279 /**
280  * Assemble a URL string from components. This is the reverse operation
281  * of av_url_split.
282  *
283  * Note, this requires networking to be initialized, so the caller must
284  * ensure ff_network_init has been called.
285  *
286  * @see av_url_split
287  *
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
299  */
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);
303 
304 /**
305  * Convert a relative url into an absolute url, given a base url.
306  *
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
311  * @param handle_dos_paths handle DOS paths for file or unspecified protocol
312  */
313 int ff_make_absolute_url2(char *buf, int size, const char *base,
314  const char *rel, int handle_dos_paths);
315 
316 /**
317  * Convert a relative url into an absolute url, given a base url.
318  *
319  * Same as ff_make_absolute_url2 with handle_dos_paths being equal to
320  * HAVE_DOS_PATHS config variable.
321  */
322 int ff_make_absolute_url(char *buf, int size, const char *base,
323  const char *rel);
324 
325 /**
326  * Allocate directory entry with default values.
327  *
328  * @return entry or NULL on error
329  */
331 
332 #if FF_API_CHILD_CLASS_NEXT
333 const AVClass *ff_urlcontext_child_class_next(const AVClass *prev);
334 #endif
335 
336 const AVClass *ff_urlcontext_child_class_iterate(void **iter);
337 
338 /**
339  * Construct a list of protocols matching a given whitelist and/or blacklist.
340  *
341  * @param whitelist a comma-separated list of allowed protocol names or NULL. If
342  * this is a non-empty string, only protocols in this list will
343  * be included.
344  * @param blacklist a comma-separated list of forbidden protocol names or NULL.
345  * If this is a non-empty string, all protocols in this list
346  * will be excluded.
347  *
348  * @return a NULL-terminated array of matching protocols. The array must be
349  * freed by the caller.
350  */
351 const URLProtocol **ffurl_get_protocols(const char *whitelist,
352  const char *blacklist);
353 
354 typedef struct URLComponents {
355  const char *url; /**< whole URL, for reference */
356  const char *scheme; /**< possibly including lavf-specific options */
357  const char *authority; /**< "//" if it is a real URL */
358  const char *userinfo; /**< including final '@' if present */
359  const char *host;
360  const char *port; /**< including initial ':' if present */
361  const char *path;
362  const char *query; /**< including initial '?' if present */
363  const char *fragment; /**< including initial '#' if present */
364  const char *end;
365 } URLComponents;
366 
367 #define url_component_end_scheme authority
368 #define url_component_end_authority userinfo
369 #define url_component_end_userinfo host
370 #define url_component_end_host port
371 #define url_component_end_port path
372 #define url_component_end_path query
373 #define url_component_end_query fragment
374 #define url_component_end_fragment end
375 #define url_component_end_authority_full path
376 
377 #define URL_COMPONENT_HAVE(uc, component) \
378  ((uc).url_component_end_##component > (uc).component)
379 
380 /**
381  * Parse an URL to find the components.
382  *
383  * Each component runs until the start of the next component,
384  * possibly including a mandatory delimiter.
385  *
386  * @param uc structure to fill with pointers to the components.
387  * @param url URL to parse.
388  * @param end end of the URL, or NULL to parse to the end of string.
389  *
390  * @return >= 0 for success or an AVERROR code, especially if the URL is
391  * malformed.
392  */
393 int ff_url_decompose(URLComponents *uc, const char *url, const char *end);
394 
395 #endif /* AVFORMAT_URL_H */
#define av_printf_format(fmtpos, attrpos)
Definition: attributes.h:161
Buffered I/O operations.
#define flags(name, subs,...)
Definition: cbs_av1.c:561
#define s(width, name)
Definition: cbs_vp9.c:257
Public dictionary API.
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:513
const OptionDef options[]
int
Libavformat version macros.
static const uint16_t mask[17]
Definition: lzw.c:38
unsigned int pos
Definition: spdifenc.c:412
Describe the class of an AVClass context structure.
Definition: log.h:67
Describes single entry of the directory.
Definition: avio.h:86
Callback for checking whether to abort blocking functions.
Definition: avio.h:58
const char * scheme
possibly including lavf-specific options
Definition: url.h:356
const char * host
Definition: url.h:359
const char * port
including initial ':' if present
Definition: url.h:360
const char * authority
"//" if it is a real URL
Definition: url.h:357
const char * fragment
including initial '#' if present
Definition: url.h:363
const char * end
Definition: url.h:364
const char * path
Definition: url.h:361
const char * userinfo
including final '@' if present
Definition: url.h:358
const char * query
including initial '?' if present
Definition: url.h:362
const char * url
whole URL, for reference
Definition: url.h:355
Definition: url.h:38
void * priv_data
Definition: url.h:41
const char * protocol_whitelist
Definition: url.h:49
int min_packet_size
if non zero, the stream is packetized with this min packet size
Definition: url.h:51
AVIOInterruptCB interrupt_callback
Definition: url.h:47
const struct URLProtocol * prot
Definition: url.h:40
const AVClass * av_class
information for av_log().
Definition: url.h:39
int is_streamed
true if streamed (no seek possible), default = false
Definition: url.h:45
const char * protocol_blacklist
Definition: url.h:50
int is_connected
Definition: url.h:46
int max_packet_size
if non zero, the stream is packetized with this max packet size
Definition: url.h:44
char * filename
specified URL
Definition: url.h:42
int64_t rw_timeout
maximum time to wait for (network) read/write operation completion, in mcs
Definition: url.h:48
int flags
Definition: url.h:43
int(* url_handshake)(URLContext *c)
Definition: url.h:64
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
int64_t(* url_read_seek)(URLContext *h, int stream_index, int64_t timestamp, int flags)
Definition: url.h:83
int(* url_read)(URLContext *h, unsigned char *buf, int size)
Read data from the protocol.
Definition: url.h:78
int(* url_get_multi_file_handle)(URLContext *h, int **handles, int *numhandles)
Definition: url.h:86
int(* url_open_dir)(URLContext *h)
Definition: url.h:94
int(* url_open)(URLContext *h, const char *url, int flags)
Definition: url.h:56
int(* url_close_dir)(URLContext *h)
Definition: url.h:96
const AVClass * priv_data_class
Definition: url.h:90
int(* url_delete)(URLContext *h)
Definition: url.h:97
int64_t(* url_seek)(URLContext *h, int64_t pos, int whence)
Definition: url.h:80
int(* url_shutdown)(URLContext *h, int flags)
Definition: url.h:89
int(* url_accept)(URLContext *s, URLContext **c)
Definition: url.h:63
const char * default_whitelist
Definition: url.h:99
int(* url_get_short_seek)(URLContext *h)
Definition: url.h:88
int(* url_read_pause)(URLContext *h, int pause)
Definition: url.h:82
const char * name
Definition: url.h:55
int(* url_close)(URLContext *h)
Definition: url.h:81
int flags
Definition: url.h:92
int(* url_write)(URLContext *h, const unsigned char *buf, int size)
Definition: url.h:79
int priv_data_size
Definition: url.h:91
int(* url_move)(URLContext *h_src, URLContext *h_dst)
Definition: url.h:98
int(* url_read_dir)(URLContext *h, AVIODirEntry **next)
Definition: url.h:95
int(* url_get_file_handle)(URLContext *h)
Definition: url.h:85
int(* url_check)(URLContext *h, int mask)
Definition: url.h:93
int size
int ffurl_shutdown(URLContext *h, int flags)
Signal the URLContext that we are done reading or writing the stream.
Definition: avio.c:654
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 ff_url_decompose(URLComponents *uc, const char *url, const char *end)
Parse an URL to find the components.
Definition: url.c:89
int ffurl_handshake(URLContext *c)
Perform one step of the protocol handshake to accept a new client.
Definition: avio.c:237
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:296
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:404
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:139
int ff_udp_get_local_port(URLContext *h)
Return the local port used by the UDP connection.
Definition: udp.c:445
AVIODirEntry * ff_alloc_dir_entry(void)
Allocate directory entry with default values.
Definition: url.c:325
int ff_check_interrupt(AVIOInterruptCB *cb)
Check if the user has requested to interrupt a blocking function associated with cb.
Definition: avio.c:661
int int ff_make_absolute_url2(char *buf, int size, const char *base, const char *rel, int handle_dos_paths)
Convert a relative url into an absolute url, given a base url.
Definition: url.c:193
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:647
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:431
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:608
int ffurl_closep(URLContext **h)
Close the resource accessed by the URLContext h, and free the memory used by it.
Definition: avio.c:441
int ffurl_accept(URLContext *s, URLContext **c)
Accept an URLContext c on an URLContext s.
Definition: avio.c:229
int ffurl_close(URLContext *h)
Definition: avio.c:464
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:406
int ffurl_connect(URLContext *uc, AVDictionary **options)
Connect an URLContext that has been allocated by ffurl_alloc.
Definition: avio.c:169
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:418
int ffurl_get_file_handle(URLContext *h)
Return the file descriptor associated with this URL.
Definition: avio.c:623
int 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:319
int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles)
Return the file descriptors associated with this URL.
Definition: avio.c:630
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:411
const AVClass * ff_urlcontext_child_class_iterate(void **iter)
Definition: protocols.c:99
const AVClass ffurl_context_class
Definition: avio.c:64
static double cb(void *priv, double x, double y)
Definition: vf_geq.c:215
uint8_t base
Definition: vp3data.h:141
static double c[64]