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url.h
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1 /*
2  *
3  * This file is part of FFmpeg.
4  *
5  * FFmpeg is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * FFmpeg is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * Lesser General Public License for more details.
14  *
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16  * License along with FFmpeg; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18  */
19 
20 /**
21  * @file
22  * unbuffered private I/O API
23  */
24 
25 #ifndef AVFORMAT_URL_H
26 #define AVFORMAT_URL_H
27 
28 #include "avio.h"
29 #include "libavformat/version.h"
30 
31 #include "libavutil/dict.h"
32 #include "libavutil/log.h"
33 
34 #define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */
35 #define URL_PROTOCOL_FLAG_NETWORK 2 /*< The protocol uses network */
36 
37 extern const AVClass ffurl_context_class;
38 
39 typedef struct URLContext {
40  const AVClass *av_class; /**< information for av_log(). Set by url_open(). */
41  struct URLProtocol *prot;
42  void *priv_data;
43  char *filename; /**< specified URL */
44  int flags;
45  int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
46  int is_streamed; /**< true if streamed (no seek possible), default = false */
49  int64_t rw_timeout; /**< maximum time to wait for (network) read/write operation completion, in mcs */
50 } URLContext;
51 
52 typedef struct URLProtocol {
53  const char *name;
54  int (*url_open)( URLContext *h, const char *url, int flags);
55  /**
56  * This callback is to be used by protocols which open further nested
57  * protocols. options are then to be passed to ffurl_open()/ffurl_connect()
58  * for those nested protocols.
59  */
60  int (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options);
63 
64  /**
65  * Read data from the protocol.
66  * If data is immediately available (even less than size), EOF is
67  * reached or an error occurs (including EINTR), return immediately.
68  * Otherwise:
69  * In non-blocking mode, return AVERROR(EAGAIN) immediately.
70  * In blocking mode, wait for data/EOF/error with a short timeout (0.1s),
71  * and return AVERROR(EAGAIN) on timeout.
72  * Checking interrupt_callback, looping on EINTR and EAGAIN and until
73  * enough data has been read is left to the calling function; see
74  * retry_transfer_wrapper in avio.c.
75  */
76  int (*url_read)( URLContext *h, unsigned char *buf, int size);
77  int (*url_write)(URLContext *h, const unsigned char *buf, int size);
78  int64_t (*url_seek)( URLContext *h, int64_t pos, int whence);
80  struct URLProtocol *next;
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 } URLProtocol;
98 
99 /**
100  * Create a URLContext for accessing to the resource indicated by
101  * url, but do not initiate the connection yet.
102  *
103  * @param puc pointer to the location where, in case of success, the
104  * function puts the pointer to the created URLContext
105  * @param flags flags which control how the resource indicated by url
106  * is to be opened
107  * @param int_cb interrupt callback to use for the URLContext, may be
108  * NULL
109  * @return >= 0 in case of success, a negative value corresponding to an
110  * AVERROR code in case of failure
111  */
112 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
113  const AVIOInterruptCB *int_cb);
114 
115 /**
116  * Connect an URLContext that has been allocated by ffurl_alloc
117  *
118  * @param options A dictionary filled with options for nested protocols,
119  * i.e. it will be passed to url_open2() for protocols implementing it.
120  * This parameter will be destroyed and replaced with a dict containing options
121  * that were not found. May be NULL.
122  */
124 
125 /**
126  * Create an URLContext for accessing to the resource indicated by
127  * url, and open it.
128  *
129  * @param puc pointer to the location where, in case of success, the
130  * function puts the pointer to the created URLContext
131  * @param flags flags which control how the resource indicated by url
132  * is to be opened
133  * @param int_cb interrupt callback to use for the URLContext, may be
134  * NULL
135  * @param options A dictionary filled with protocol-private options. On return
136  * this parameter will be destroyed and replaced with a dict containing options
137  * that were not found. May be NULL.
138  * @return >= 0 in case of success, a negative value corresponding to an
139  * AVERROR code in case of failure
140  */
141 int ffurl_open(URLContext **puc, const char *filename, int flags,
143 
144 /**
145  * Accept an URLContext c on an URLContext s
146  *
147  * @param s server context
148  * @param c client context, must be unallocated.
149  * @return >= 0 on success, ff_neterrno() on failure.
150  */
152 
153 /**
154  * Perform one step of the protocol handshake to accept a new client.
155  * See avio_handshake() for details.
156  * Implementations should try to return decreasing values.
157  * If the protocol uses an underlying protocol, the underlying handshake is
158  * usually the first step, and the return value can be:
159  * (largest value for this protocol) + (return value from other protocol)
160  *
161  * @param c the client context
162  * @return >= 0 on success or a negative value corresponding
163  * to an AVERROR code on failure
164  */
166 
167 /**
168  * Read up to size bytes from the resource accessed by h, and store
169  * the read bytes in buf.
170  *
171  * @return The number of bytes actually read, or a negative value
172  * corresponding to an AVERROR code in case of error. A value of zero
173  * indicates that it is not possible to read more from the accessed
174  * resource (except if the value of the size argument is also zero).
175  */
176 int ffurl_read(URLContext *h, unsigned char *buf, int size);
177 
178 /**
179  * Read as many bytes as possible (up to size), calling the
180  * read function multiple times if necessary.
181  * This makes special short-read handling in applications
182  * unnecessary, if the return value is < size then it is
183  * certain there was either an error or the end of file was reached.
184  */
185 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
186 
187 /**
188  * Write size bytes from buf to the resource accessed by h.
189  *
190  * @return the number of bytes actually written, or a negative value
191  * corresponding to an AVERROR code in case of failure
192  */
193 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
194 
195 /**
196  * Change the position that will be used by the next read/write
197  * operation on the resource accessed by h.
198  *
199  * @param pos specifies the new position to set
200  * @param whence specifies how pos should be interpreted, it must be
201  * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
202  * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
203  * (return the filesize of the requested resource, pos is ignored).
204  * @return a negative value corresponding to an AVERROR code in case
205  * of failure, or the resulting file position, measured in bytes from
206  * the beginning of the file. You can use this feature together with
207  * SEEK_CUR to read the current file position.
208  */
209 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
210 
211 /**
212  * Close the resource accessed by the URLContext h, and free the
213  * memory used by it. Also set the URLContext pointer to NULL.
214  *
215  * @return a negative value if an error condition occurred, 0
216  * otherwise
217  */
218 int ffurl_closep(URLContext **h);
219 int ffurl_close(URLContext *h);
220 
221 /**
222  * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
223  * if the operation is not supported by h, or another negative value
224  * corresponding to an AVERROR error code in case of failure.
225  */
226 int64_t ffurl_size(URLContext *h);
227 
228 /**
229  * Return the file descriptor associated with this URL. For RTP, this
230  * will return only the RTP file descriptor, not the RTCP file descriptor.
231  *
232  * @return the file descriptor associated with this URL, or <0 on error.
233  */
235 
236 /**
237  * Return the file descriptors associated with this URL.
238  *
239  * @return 0 on success or <0 on error.
240  */
241 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
242 
243 /**
244  * Signal the URLContext that we are done reading or writing the stream.
245  *
246  * @param h pointer to the resource
247  * @param flags flags which control how the resource indicated by url
248  * is to be shutdown
249  *
250  * @return a negative value if an error condition occurred, 0
251  * otherwise
252  */
253 int ffurl_shutdown(URLContext *h, int flags);
254 
255 /**
256  * Register the URLProtocol protocol.
257  */
258 int ffurl_register_protocol(URLProtocol *protocol);
259 
260 /**
261  * Check if the user has requested to interrup a blocking function
262  * associated with cb.
263  */
265 
266 /**
267  * Iterate over all available protocols.
268  *
269  * @param prev result of the previous call to this functions or NULL.
270  */
272 
273 /* udp.c */
274 int ff_udp_set_remote_url(URLContext *h, const char *uri);
276 
277 /**
278  * Assemble a URL string from components. This is the reverse operation
279  * of av_url_split.
280  *
281  * Note, this requires networking to be initialized, so the caller must
282  * ensure ff_network_init has been called.
283  *
284  * @see av_url_split
285  *
286  * @param str the buffer to fill with the url
287  * @param size the size of the str buffer
288  * @param proto the protocol identifier, if null, the separator
289  * after the identifier is left out, too
290  * @param authorization an optional authorization string, may be null.
291  * An empty string is treated the same as a null string.
292  * @param hostname the host name string
293  * @param port the port number, left out from the string if negative
294  * @param fmt a generic format string for everything to add after the
295  * host/port, may be null
296  * @return the number of characters written to the destination buffer
297  */
298 int ff_url_join(char *str, int size, const char *proto,
299  const char *authorization, const char *hostname,
300  int port, const char *fmt, ...) av_printf_format(7, 8);
301 
302 /**
303  * Convert a relative url into an absolute url, given a base url.
304  *
305  * @param buf the buffer where output absolute url is written
306  * @param size the size of buf
307  * @param base the base url, may be equal to buf.
308  * @param rel the new url, which is interpreted relative to base
309  */
310 void ff_make_absolute_url(char *buf, int size, const char *base,
311  const char *rel);
312 
313 /**
314  * Allocate directory entry with default values.
315  *
316  * @return entry or NULL on error
317  */
319 
320 
321 #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:593
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:77
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:556
int is_streamed
true if streamed (no seek possible), default = false
Definition: url.h:46
AVIOInterruptCB interrupt_callback
Definition: url.h:48
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:49
struct URLProtocol * prot
Definition: url.h:41
int flags
Definition: url.h:44
int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles)
Return the file descriptors associated with this URL.
Definition: avio.c:578
const AVClass * priv_data_class
Definition: url.h:89
struct URLProtocol * next
Definition: url.h:80
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:367
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:3807
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)
Create an URLContext for accessing to the resource indicated by url, and open it. ...
Definition: avio.c:292
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:60
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:360
static const uint16_t mask[17]
Definition: lzw.c:38
int ff_check_interrupt(AVIOInterruptCB *cb)
Check if the user has requested to interrup a blocking function associated with cb.
Definition: avio.c:600
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:423
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:353
int(* url_open)(URLContext *h, const char *url, int flags)
Definition: url.h:54
#define av_printf_format(fmtpos, attrpos)
Definition: attributes.h:148
int(* url_write)(URLContext *h, const unsigned char *buf, int size)
Definition: url.h:77
int(* url_read)(URLContext *h, unsigned char *buf, int size)
Read data from the protocol.
Definition: url.h:76
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:195
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:78
Libavformat version macros.
int ffurl_get_file_handle(URLContext *h)
Return the file descriptor associated with this URL.
Definition: avio.c:571
int is_connected
Definition: url.h:47
int ff_udp_get_local_port(URLContext *h)
Return the local port used by the UDP connection.
Definition: udp.c:462
int64_t(* url_read_seek)(URLContext *h, int stream_index, int64_t timestamp, int flags)
Definition: url.h:82
void * buf
Definition: avisynth_c.h:553
Definition: url.h:39
Describe the class of an AVClass context structure.
Definition: log.h:67
URLProtocol * ffurl_protocol_next(const URLProtocol *prev)
Iterate over all available protocols.
Definition: avio.c:36
void * priv_data
Definition: url.h:42
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:270
int(* url_handshake)(URLContext *c)
Definition: url.h:62
int(* url_read_dir)(URLContext *h, AVIODirEntry **next)
Definition: url.h:93
const char * name
Definition: url.h:53
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:380
const AVClass * av_class
information for av_log().
Definition: url.h:40
static int flags
Definition: cpu.c:47
int(* url_accept)(URLContext *s, URLContext **c)
Definition: url.h:61
int ffurl_close(URLContext *h)
Definition: avio.c:412
int(* url_delete)(URLContext *h)
Definition: url.h:95
static double c[64]
char * filename
specified URL
Definition: url.h:43
int ffurl_handshake(URLContext *c)
Perform one step of the protocol handshake to accept a new client.
Definition: avio.c:222
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:214
int ffurl_register_protocol(URLProtocol *protocol)
Register the URLProtocol protocol.
Definition: avio.c:98
int max_packet_size
if non zero, the stream is packetized with this max packet size
Definition: url.h:45
int(* url_close)(URLContext *h)
Definition: url.h:79
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:390