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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
36extern const AVClass ffurl_context_class;
37
38typedef 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 */
46 int is_connected;
47 AVIOInterruptCB interrupt_callback;
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
53typedef 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);
62 int (*url_accept)(URLContext *s, URLContext **c);
63 int (*url_handshake)(URLContext *c);
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);
80 int (*url_close)(URLContext *h);
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);
84 int (*url_get_file_handle)(URLContext *h);
85 int (*url_get_multi_file_handle)(URLContext *h, int **handles,
86 int *numhandles);
87 int (*url_get_short_seek)(URLContext *h);
88 int (*url_shutdown)(URLContext *h, int flags);
89 int priv_data_size;
90 const AVClass *priv_data_class;
91 int flags;
92 int (*url_check)(URLContext *h, int mask);
93 int (*url_open_dir)(URLContext *h);
94 int (*url_read_dir)(URLContext *h, AVIODirEntry **next);
95 int (*url_close_dir)(URLContext *h);
96 int (*url_delete)(URLContext *h);
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 */
114int 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 */
125int ffurl_connect(URLContext *uc, AVDictionary **options);
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 */
145int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags,
146 const AVIOInterruptCB *int_cb, AVDictionary **options,
147 const char *whitelist, const char* blacklist,
148 URLContext *parent);
149
150int ffurl_open(URLContext **puc, const char *filename, int flags,
151 const AVIOInterruptCB *int_cb, AVDictionary **options);
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 */
160int ffurl_accept(URLContext *s, URLContext **c);
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 */
174int ffurl_handshake(URLContext *c);
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 */
185int 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 */
194int 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 */
202int 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 */
218int64_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 */
227int ffurl_closep(URLContext **h);
228int 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 */
235int64_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 */
243int ffurl_get_file_handle(URLContext *h);
244
245/**
246 * Return the file descriptors associated with this URL.
247 *
248 * @return 0 on success or <0 on error.
249 */
250int 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 */
257int ffurl_get_short_seek(URLContext *h);
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 */
269int 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 */
275int ff_check_interrupt(AVIOInterruptCB *cb);
276
277/* udp.c */
278int ff_udp_set_remote_url(URLContext *h, const char *uri);
279int ff_udp_get_local_port(URLContext *h);
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 */
302int 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 */
314void 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 */
322AVIODirEntry *ff_alloc_dir_entry(void);
323
324const AVClass *ff_urlcontext_child_class_next(const AVClass *prev);
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 */
339const URLProtocol **ffurl_get_protocols(const char *whitelist,
340 const char *blacklist);
341
342#endif /* AVFORMAT_URL_H */
343
generated by cgit at 2024-05-17 03:43:30 (GMT)