2 * unbuffered io for ffmpeg system
3 * copyright (c) 2001 Fabrice Bellard
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #ifndef AVFORMAT_AVIO_H
22 #define AVFORMAT_AVIO_H
30 * New fields can be added to the end with minor version bumps.
31 * Removal, reordering and changes to existing fields require a major
33 * sizeof(URLContext) must not be used outside libav*.
36 #if LIBAVFORMAT_VERSION_MAJOR >= 53
37 const AVClass
*av_class
; ///< information for av_log(). Set by url_open().
39 struct URLProtocol
*prot
;
41 int is_streamed
; /**< true if streamed (no seek possible), default = false */
42 int max_packet_size
; /**< if non zero, the stream is packetized with this max packet size */
44 char *filename
; /**< specified filename */
47 typedef struct URLContext URLContext
;
49 typedef struct URLPollEntry
{
59 typedef int URLInterruptCB(void);
61 int url_open_protocol (URLContext
**puc
, struct URLProtocol
*up
,
62 const char *filename
, int flags
);
63 int url_open(URLContext
**h
, const char *filename
, int flags
);
64 int url_read(URLContext
*h
, unsigned char *buf
, int size
);
65 int url_write(URLContext
*h
, unsigned char *buf
, int size
);
66 int64_t url_seek(URLContext
*h
, int64_t pos
, int whence
);
67 int url_close(URLContext
*h
);
68 int url_exist(const char *filename
);
69 int64_t url_filesize(URLContext
*h
);
72 * Return the maximum packet size associated to packetized file
73 * handle. If the file is not packetized (stream like HTTP or file on
74 * disk), then 0 is returned.
76 * @param h file handle
77 * @return maximum packet size in bytes
79 int url_get_max_packet_size(URLContext
*h
);
80 void url_get_filename(URLContext
*h
, char *buf
, int buf_size
);
83 * The callback is called in blocking functions to test regulary if
84 * asynchronous interruption is needed. AVERROR(EINTR) is returned
85 * in this case by the interrupted function. 'NULL' means no interrupt
88 void url_set_interrupt_cb(URLInterruptCB
*interrupt_cb
);
91 int url_poll(URLPollEntry
*poll_table
, int n
, int timeout
);
94 * Pause and resume playing - only meaningful if using a network streaming
95 * protocol (e.g. MMS).
96 * @param pause 1 for pause, 0 for resume
98 int av_url_read_pause(URLContext
*h
, int pause
);
101 * Seek to a given timestamp relative to some component stream.
102 * Only meaningful if using a network streaming protocol (e.g. MMS.).
103 * @param stream_index The stream index that the timestamp is relative to.
104 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
105 * units from the beginning of the presentation.
106 * If a stream_index >= 0 is used and the protocol does not support
107 * seeking based on component streams, the call will fail with ENOTSUP.
108 * @param timestamp timestamp in AVStream.time_base units
109 * or if there is no stream specified then in AV_TIME_BASE units.
110 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
111 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
112 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
113 * fail with ENOTSUP if used and not supported.
114 * @return >= 0 on success
115 * @see AVInputFormat::read_seek
117 int64_t av_url_read_seek(URLContext
*h
, int stream_index
,
118 int64_t timestamp
, int flags
);
121 * Passing this as the "whence" parameter to a seek function causes it to
122 * return the filesize without seeking anywhere. Supporting this is optional.
123 * If it is not supported then the seek function will return <0.
125 #define AVSEEK_SIZE 0x10000
127 typedef struct URLProtocol
{
129 int (*url_open
)(URLContext
*h
, const char *filename
, int flags
);
130 int (*url_read
)(URLContext
*h
, unsigned char *buf
, int size
);
131 int (*url_write
)(URLContext
*h
, unsigned char *buf
, int size
);
132 int64_t (*url_seek
)(URLContext
*h
, int64_t pos
, int whence
);
133 int (*url_close
)(URLContext
*h
);
134 struct URLProtocol
*next
;
135 int (*url_read_pause
)(URLContext
*h
, int pause
);
136 int64_t (*url_read_seek
)(URLContext
*h
, int stream_index
,
137 int64_t timestamp
, int flags
);
140 extern URLProtocol
*first_protocol
;
141 extern URLInterruptCB
*url_interrupt_cb
;
143 URLProtocol
*av_protocol_next(URLProtocol
*p
);
145 int register_protocol(URLProtocol
*protocol
);
148 * Bytestream IO Context.
149 * New fields can be added to the end with minor version bumps.
150 * Removal, reordering and changes to existing fields require a major
152 * sizeof(ByteIOContext) must not be used outside libav*.
155 unsigned char *buffer
;
157 unsigned char *buf_ptr
, *buf_end
;
159 int (*read_packet
)(void *opaque
, uint8_t *buf
, int buf_size
);
160 int (*write_packet
)(void *opaque
, uint8_t *buf
, int buf_size
);
161 int64_t (*seek
)(void *opaque
, int64_t offset
, int whence
);
162 int64_t pos
; /**< position in the file of the current buffer */
163 int must_flush
; /**< true if the next seek should flush */
164 int eof_reached
; /**< true if eof reached */
165 int write_flag
; /**< true if open for writing */
168 unsigned long checksum
;
169 unsigned char *checksum_ptr
;
170 unsigned long (*update_checksum
)(unsigned long checksum
, const uint8_t *buf
, unsigned int size
);
171 int error
; ///< contains the error code or 0 if no error happened
172 int (*read_pause
)(void *opaque
, int pause
);
173 int64_t (*read_seek
)(void *opaque
, int stream_index
,
174 int64_t timestamp
, int flags
);
177 int init_put_byte(ByteIOContext
*s
,
178 unsigned char *buffer
,
182 int (*read_packet
)(void *opaque
, uint8_t *buf
, int buf_size
),
183 int (*write_packet
)(void *opaque
, uint8_t *buf
, int buf_size
),
184 int64_t (*seek
)(void *opaque
, int64_t offset
, int whence
));
185 ByteIOContext
*av_alloc_put_byte(
186 unsigned char *buffer
,
190 int (*read_packet
)(void *opaque
, uint8_t *buf
, int buf_size
),
191 int (*write_packet
)(void *opaque
, uint8_t *buf
, int buf_size
),
192 int64_t (*seek
)(void *opaque
, int64_t offset
, int whence
));
194 void put_byte(ByteIOContext
*s
, int b
);
195 void put_buffer(ByteIOContext
*s
, const unsigned char *buf
, int size
);
196 void put_le64(ByteIOContext
*s
, uint64_t val
);
197 void put_be64(ByteIOContext
*s
, uint64_t val
);
198 void put_le32(ByteIOContext
*s
, unsigned int val
);
199 void put_be32(ByteIOContext
*s
, unsigned int val
);
200 void put_le24(ByteIOContext
*s
, unsigned int val
);
201 void put_be24(ByteIOContext
*s
, unsigned int val
);
202 void put_le16(ByteIOContext
*s
, unsigned int val
);
203 void put_be16(ByteIOContext
*s
, unsigned int val
);
204 void put_tag(ByteIOContext
*s
, const char *tag
);
206 void put_strz(ByteIOContext
*s
, const char *buf
);
209 * fseek() equivalent for ByteIOContext.
210 * @return new position or AVERROR.
212 int64_t url_fseek(ByteIOContext
*s
, int64_t offset
, int whence
);
215 * Skip given number of bytes forward.
216 * @param offset number of bytes
218 void url_fskip(ByteIOContext
*s
, int64_t offset
);
221 * ftell() equivalent for ByteIOContext.
222 * @return position or AVERROR.
224 int64_t url_ftell(ByteIOContext
*s
);
228 * @return filesize or AVERROR
230 int64_t url_fsize(ByteIOContext
*s
);
233 * feof() equivalent for ByteIOContext.
234 * @return non zero if and only if end of file
236 int url_feof(ByteIOContext
*s
);
238 int url_ferror(ByteIOContext
*s
);
240 int av_url_read_fpause(ByteIOContext
*h
, int pause
);
241 int64_t av_url_read_fseek(ByteIOContext
*h
, int stream_index
,
242 int64_t timestamp
, int flags
);
245 /** @note return URL_EOF (-1) if EOF */
246 int url_fgetc(ByteIOContext
*s
);
248 /** @warning currently size is limited */
250 int url_fprintf(ByteIOContext
*s
, const char *fmt
, ...) __attribute__ ((__format__ (__printf__
, 2, 3)));
252 int url_fprintf(ByteIOContext
*s
, const char *fmt
, ...);
255 /** @note unlike fgets, the EOL character is not returned and a whole
256 line is parsed. return NULL if first char read was EOF */
257 char *url_fgets(ByteIOContext
*s
, char *buf
, int buf_size
);
259 void put_flush_packet(ByteIOContext
*s
);
263 * Reads size bytes from ByteIOContext into buf.
264 * @returns number of bytes read or AVERROR
266 int get_buffer(ByteIOContext
*s
, unsigned char *buf
, int size
);
269 * Reads size bytes from ByteIOContext into buf.
270 * This reads at most 1 packet. If that is not enough fewer bytes will be
272 * @returns number of bytes read or AVERROR
274 int get_partial_buffer(ByteIOContext
*s
, unsigned char *buf
, int size
);
276 /** @note return 0 if EOF, so you cannot use it if EOF handling is
278 int get_byte(ByteIOContext
*s
);
279 unsigned int get_le24(ByteIOContext
*s
);
280 unsigned int get_le32(ByteIOContext
*s
);
281 uint64_t get_le64(ByteIOContext
*s
);
282 unsigned int get_le16(ByteIOContext
*s
);
284 char *get_strz(ByteIOContext
*s
, char *buf
, int maxlen
);
285 unsigned int get_be16(ByteIOContext
*s
);
286 unsigned int get_be24(ByteIOContext
*s
);
287 unsigned int get_be32(ByteIOContext
*s
);
288 uint64_t get_be64(ByteIOContext
*s
);
290 uint64_t ff_get_v(ByteIOContext
*bc
);
292 static inline int url_is_streamed(ByteIOContext
*s
)
294 return s
->is_streamed
;
297 /** @note when opened as read/write, the buffers are only used for
299 int url_fdopen(ByteIOContext
**s
, URLContext
*h
);
301 /** @warning must be called before any I/O */
302 int url_setbufsize(ByteIOContext
*s
, int buf_size
);
303 /** Reset the buffer for reading or writing.
304 * @note Will drop any data currently in the buffer without transmitting it.
305 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
306 * to set up the buffer for writing. */
307 int url_resetbuf(ByteIOContext
*s
, int flags
);
309 /** @note when opened as read/write, the buffers are only used for
311 int url_fopen(ByteIOContext
**s
, const char *filename
, int flags
);
312 int url_fclose(ByteIOContext
*s
);
313 URLContext
*url_fileno(ByteIOContext
*s
);
316 * Return the maximum packet size associated to packetized buffered file
317 * handle. If the file is not packetized (stream like http or file on
318 * disk), then 0 is returned.
320 * @param s buffered file handle
321 * @return maximum packet size in bytes
323 int url_fget_max_packet_size(ByteIOContext
*s
);
325 int url_open_buf(ByteIOContext
**s
, uint8_t *buf
, int buf_size
, int flags
);
327 /** return the written or read size */
328 int url_close_buf(ByteIOContext
*s
);
331 * Open a write only memory stream.
333 * @param s new IO context
334 * @return zero if no error.
336 int url_open_dyn_buf(ByteIOContext
**s
);
339 * Open a write only packetized memory stream with a maximum packet
340 * size of 'max_packet_size'. The stream is stored in a memory buffer
341 * with a big endian 4 byte header giving the packet size in bytes.
343 * @param s new IO context
344 * @param max_packet_size maximum packet size (must be > 0)
345 * @return zero if no error.
347 int url_open_dyn_packet_buf(ByteIOContext
**s
, int max_packet_size
);
350 * Return the written size and a pointer to the buffer. The buffer
351 * must be freed with av_free().
352 * @param s IO context
353 * @param pbuffer pointer to a byte buffer
354 * @return the length of the byte buffer
356 int url_close_dyn_buf(ByteIOContext
*s
, uint8_t **pbuffer
);
358 unsigned long ff_crc04C11DB7_update(unsigned long checksum
, const uint8_t *buf
,
360 unsigned long get_checksum(ByteIOContext
*s
);
361 void init_checksum(ByteIOContext
*s
,
362 unsigned long (*update_checksum
)(unsigned long c
, const uint8_t *p
, unsigned int len
),
363 unsigned long checksum
);
366 int udp_set_remote_url(URLContext
*h
, const char *uri
);
367 int udp_get_local_port(URLContext
*h
);
368 int udp_get_file_handle(URLContext
*h
);
370 #endif /* AVFORMAT_AVIO_H */