2 * copyright (c) 2001 Fabrice Bellard
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 #ifndef AVFORMAT_AVIO_H
21 #define AVFORMAT_AVIO_H
24 * @file libavformat/avio.h
25 * unbuffered I/O operations
27 * @warning This file has to be considered an internal but installed
28 * header, so it should not be directly included in your projects.
39 * New fields can be added to the end with minor version bumps.
40 * Removal, reordering and changes to existing fields require a major
42 * sizeof(URLContext) must not be used outside libav*.
45 #if LIBAVFORMAT_VERSION_MAJOR >= 53
46 const AVClass *av_class; ///< information for av_log(). Set by url_open().
48 struct URLProtocol *prot;
50 int is_streamed; /**< true if streamed (no seek possible), default = false */
51 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
53 char *filename; /**< specified filename */
56 typedef struct URLContext URLContext;
58 typedef struct URLPollEntry {
68 typedef int URLInterruptCB(void);
70 int url_open_protocol (URLContext **puc, struct URLProtocol *up,
71 const char *filename, int flags);
72 int url_open(URLContext **h, const char *filename, int flags);
73 int url_read(URLContext *h, unsigned char *buf, int size);
74 int url_write(URLContext *h, unsigned char *buf, int size);
75 int64_t url_seek(URLContext *h, int64_t pos, int whence);
76 int url_close(URLContext *h);
77 int url_exist(const char *filename);
78 int64_t url_filesize(URLContext *h);
81 * Return the maximum packet size associated to packetized file
82 * handle. If the file is not packetized (stream like HTTP or file on
83 * disk), then 0 is returned.
85 * @param h file handle
86 * @return maximum packet size in bytes
88 int url_get_max_packet_size(URLContext *h);
89 void url_get_filename(URLContext *h, char *buf, int buf_size);
92 * The callback is called in blocking functions to test regulary if
93 * asynchronous interruption is needed. AVERROR(EINTR) is returned
94 * in this case by the interrupted function. 'NULL' means no interrupt
97 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
100 int url_poll(URLPollEntry *poll_table, int n, int timeout);
103 * Pause and resume playing - only meaningful if using a network streaming
104 * protocol (e.g. MMS).
105 * @param pause 1 for pause, 0 for resume
107 int av_url_read_pause(URLContext *h, int pause);
110 * Seek to a given timestamp relative to some component stream.
111 * Only meaningful if using a network streaming protocol (e.g. MMS.).
112 * @param stream_index The stream index that the timestamp is relative to.
113 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
114 * units from the beginning of the presentation.
115 * If a stream_index >= 0 is used and the protocol does not support
116 * seeking based on component streams, the call will fail with ENOTSUP.
117 * @param timestamp timestamp in AVStream.time_base units
118 * or if there is no stream specified then in AV_TIME_BASE units.
119 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
120 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
121 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
122 * fail with ENOTSUP if used and not supported.
123 * @return >= 0 on success
124 * @see AVInputFormat::read_seek
126 int64_t av_url_read_seek(URLContext *h, int stream_index,
127 int64_t timestamp, int flags);
130 * Passing this as the "whence" parameter to a seek function causes it to
131 * return the filesize without seeking anywhere. Supporting this is optional.
132 * If it is not supported then the seek function will return <0.
134 #define AVSEEK_SIZE 0x10000
136 typedef struct URLProtocol {
138 int (*url_open)(URLContext *h, const char *filename, int flags);
139 int (*url_read)(URLContext *h, unsigned char *buf, int size);
140 int (*url_write)(URLContext *h, unsigned char *buf, int size);
141 int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
142 int (*url_close)(URLContext *h);
143 struct URLProtocol *next;
144 int (*url_read_pause)(URLContext *h, int pause);
145 int64_t (*url_read_seek)(URLContext *h, int stream_index,
146 int64_t timestamp, int flags);
149 #if LIBAVFORMAT_VERSION_MAJOR < 53
150 extern URLProtocol *first_protocol;
153 extern URLInterruptCB *url_interrupt_cb;
156 * If protocol is NULL, returns the first registered protocol,
157 * if protocol is non-NULL, returns the next registered protocol after protocol,
158 * or NULL if protocol is the last one.
160 URLProtocol *av_protocol_next(URLProtocol *p);
162 #if LIBAVFORMAT_VERSION_MAJOR < 53
164 * @deprecated Use av_register_protocol() instead.
166 attribute_deprecated int register_protocol(URLProtocol *protocol);
169 int av_register_protocol(URLProtocol *protocol);
172 * Bytestream IO Context.
173 * New fields can be added to the end with minor version bumps.
174 * Removal, reordering and changes to existing fields require a major
176 * sizeof(ByteIOContext) must not be used outside libav*.
179 unsigned char *buffer;
181 unsigned char *buf_ptr, *buf_end;
183 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
184 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
185 int64_t (*seek)(void *opaque, int64_t offset, int whence);
186 int64_t pos; /**< position in the file of the current buffer */
187 int must_flush; /**< true if the next seek should flush */
188 int eof_reached; /**< true if eof reached */
189 int write_flag; /**< true if open for writing */
192 unsigned long checksum;
193 unsigned char *checksum_ptr;
194 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
195 int error; ///< contains the error code or 0 if no error happened
196 int (*read_pause)(void *opaque, int pause);
197 int64_t (*read_seek)(void *opaque, int stream_index,
198 int64_t timestamp, int flags);
201 int init_put_byte(ByteIOContext *s,
202 unsigned char *buffer,
206 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
207 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
208 int64_t (*seek)(void *opaque, int64_t offset, int whence));
209 ByteIOContext *av_alloc_put_byte(
210 unsigned char *buffer,
214 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
215 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
216 int64_t (*seek)(void *opaque, int64_t offset, int whence));
218 void put_byte(ByteIOContext *s, int b);
219 void put_buffer(ByteIOContext *s, const unsigned char *buf, int size);
220 void put_le64(ByteIOContext *s, uint64_t val);
221 void put_be64(ByteIOContext *s, uint64_t val);
222 void put_le32(ByteIOContext *s, unsigned int val);
223 void put_be32(ByteIOContext *s, unsigned int val);
224 void put_le24(ByteIOContext *s, unsigned int val);
225 void put_be24(ByteIOContext *s, unsigned int val);
226 void put_le16(ByteIOContext *s, unsigned int val);
227 void put_be16(ByteIOContext *s, unsigned int val);
228 void put_tag(ByteIOContext *s, const char *tag);
230 void put_strz(ByteIOContext *s, const char *buf);
233 * fseek() equivalent for ByteIOContext.
234 * @return new position or AVERROR.
236 int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence);
239 * Skip given number of bytes forward.
240 * @param offset number of bytes
242 void url_fskip(ByteIOContext *s, int64_t offset);
245 * ftell() equivalent for ByteIOContext.
246 * @return position or AVERROR.
248 int64_t url_ftell(ByteIOContext *s);
252 * @return filesize or AVERROR
254 int64_t url_fsize(ByteIOContext *s);
257 * feof() equivalent for ByteIOContext.
258 * @return non zero if and only if end of file
260 int url_feof(ByteIOContext *s);
262 int url_ferror(ByteIOContext *s);
264 int av_url_read_fpause(ByteIOContext *h, int pause);
265 int64_t av_url_read_fseek(ByteIOContext *h, int stream_index,
266 int64_t timestamp, int flags);
269 /** @note return URL_EOF (-1) if EOF */
270 int url_fgetc(ByteIOContext *s);
272 /** @warning currently size is limited */
274 int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
276 int url_fprintf(ByteIOContext *s, const char *fmt, ...);
279 /** @note unlike fgets, the EOL character is not returned and a whole
280 line is parsed. return NULL if first char read was EOF */
281 char *url_fgets(ByteIOContext *s, char *buf, int buf_size);
283 void put_flush_packet(ByteIOContext *s);
287 * Reads size bytes from ByteIOContext into buf.
288 * @returns number of bytes read or AVERROR
290 int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
293 * Reads size bytes from ByteIOContext into buf.
294 * This reads at most 1 packet. If that is not enough fewer bytes will be
296 * @returns number of bytes read or AVERROR
298 int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
300 /** @note return 0 if EOF, so you cannot use it if EOF handling is
302 int get_byte(ByteIOContext *s);
303 unsigned int get_le24(ByteIOContext *s);
304 unsigned int get_le32(ByteIOContext *s);
305 uint64_t get_le64(ByteIOContext *s);
306 unsigned int get_le16(ByteIOContext *s);
308 char *get_strz(ByteIOContext *s, char *buf, int maxlen);
309 unsigned int get_be16(ByteIOContext *s);
310 unsigned int get_be24(ByteIOContext *s);
311 unsigned int get_be32(ByteIOContext *s);
312 uint64_t get_be64(ByteIOContext *s);
314 uint64_t ff_get_v(ByteIOContext *bc);
316 static inline int url_is_streamed(ByteIOContext *s)
318 return s->is_streamed;
321 /** @note when opened as read/write, the buffers are only used for
323 int url_fdopen(ByteIOContext **s, URLContext *h);
325 /** @warning must be called before any I/O */
326 int url_setbufsize(ByteIOContext *s, int buf_size);
327 /** Reset the buffer for reading or writing.
328 * @note Will drop any data currently in the buffer without transmitting it.
329 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
330 * to set up the buffer for writing. */
331 int url_resetbuf(ByteIOContext *s, int flags);
333 /** @note when opened as read/write, the buffers are only used for
335 int url_fopen(ByteIOContext **s, const char *filename, int flags);
336 int url_fclose(ByteIOContext *s);
337 URLContext *url_fileno(ByteIOContext *s);
340 * Return the maximum packet size associated to packetized buffered file
341 * handle. If the file is not packetized (stream like http or file on
342 * disk), then 0 is returned.
344 * @param s buffered file handle
345 * @return maximum packet size in bytes
347 int url_fget_max_packet_size(ByteIOContext *s);
349 int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags);
351 /** return the written or read size */
352 int url_close_buf(ByteIOContext *s);
355 * Open a write only memory stream.
357 * @param s new IO context
358 * @return zero if no error.
360 int url_open_dyn_buf(ByteIOContext **s);
363 * Open a write only packetized memory stream with a maximum packet
364 * size of 'max_packet_size'. The stream is stored in a memory buffer
365 * with a big endian 4 byte header giving the packet size in bytes.
367 * @param s new IO context
368 * @param max_packet_size maximum packet size (must be > 0)
369 * @return zero if no error.
371 int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size);
374 * Return the written size and a pointer to the buffer. The buffer
375 * must be freed with av_free().
376 * @param s IO context
377 * @param pbuffer pointer to a byte buffer
378 * @return the length of the byte buffer
380 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);
382 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
384 unsigned long get_checksum(ByteIOContext *s);
385 void init_checksum(ByteIOContext *s,
386 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
387 unsigned long checksum);
390 int udp_set_remote_url(URLContext *h, const char *uri);
391 int udp_get_local_port(URLContext *h);
392 int udp_get_file_handle(URLContext *h);
394 #endif /* AVFORMAT_AVIO_H */