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
26 /* output byte stream handling */
28 typedef int64_t offset_t
;
34 * New fields can be added to the end with minor version bumps.
35 * Removal, reordering and changes to existing fields require a major
37 * sizeof(URLContext) must not be used outside libav*.
40 #if LIBAVFORMAT_VERSION_MAJOR >= 53
41 const AVClass
*av_class
; ///< information for av_log(). Set by url_open().
43 struct URLProtocol
*prot
;
45 int is_streamed
; /**< true if streamed (no seek possible), default = false */
46 int max_packet_size
; /**< if non zero, the stream is packetized with this max packet size */
48 char *filename
; /**< specified filename */
51 typedef struct URLContext URLContext
;
53 typedef struct URLPollEntry
{
63 typedef int URLInterruptCB(void);
65 int url_open_protocol (URLContext
**puc
, struct URLProtocol
*up
,
66 const char *filename
, int flags
);
67 int url_open(URLContext
**h
, const char *filename
, int flags
);
68 int url_read(URLContext
*h
, unsigned char *buf
, int size
);
69 int url_write(URLContext
*h
, unsigned char *buf
, int size
);
70 offset_t
url_seek(URLContext
*h
, offset_t pos
, int whence
);
71 int url_close(URLContext
*h
);
72 int url_exist(const char *filename
);
73 offset_t
url_filesize(URLContext
*h
);
76 * Return the maximum packet size associated to packetized file
77 * handle. If the file is not packetized (stream like HTTP or file on
78 * disk), then 0 is returned.
80 * @param h file handle
81 * @return maximum packet size in bytes
83 int url_get_max_packet_size(URLContext
*h
);
84 void url_get_filename(URLContext
*h
, char *buf
, int buf_size
);
87 * The callback is called in blocking functions to test regulary if
88 * asynchronous interruption is needed. AVERROR(EINTR) is returned
89 * in this case by the interrupted function. 'NULL' means no interrupt
92 void url_set_interrupt_cb(URLInterruptCB
*interrupt_cb
);
95 int url_poll(URLPollEntry
*poll_table
, int n
, int timeout
);
98 * Pause and resume playing - only meaningful if using a network streaming
99 * protocol (e.g. MMS).
100 * @param pause 1 for pause, 0 for resume
102 int av_url_read_pause(URLContext
*h
, int pause
);
105 * Seek to a given timestamp relative to some component stream.
106 * Only meaningful if using a network streaming protocol (e.g. MMS.).
107 * @param stream_index The stream index that the timestamp is relative to.
108 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
109 * units from the beginning of the presentation.
110 * If a stream_index >= 0 is used and the protocol does not support
111 * seeking based on component streams, the call will fail with ENOTSUP.
112 * @param timestamp timestamp in AVStream.time_base units
113 * or if there is no stream specified then in AV_TIME_BASE units.
114 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
115 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
116 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
117 * fail with ENOTSUP if used and not supported.
118 * @return >= 0 on success
119 * @see AVInputFormat::read_seek
121 offset_t
av_url_read_seek(URLContext
*h
,
122 int stream_index
, int64_t timestamp
, int flags
);
125 * Passing this as the "whence" parameter to a seek function causes it to
126 * return the filesize without seeking anywhere. Supporting this is optional.
127 * If it is not supported then the seek function will return <0.
129 #define AVSEEK_SIZE 0x10000
131 typedef struct URLProtocol
{
133 int (*url_open
)(URLContext
*h
, const char *filename
, int flags
);
134 int (*url_read
)(URLContext
*h
, unsigned char *buf
, int size
);
135 int (*url_write
)(URLContext
*h
, unsigned char *buf
, int size
);
136 offset_t (*url_seek
)(URLContext
*h
, offset_t pos
, int whence
);
137 int (*url_close
)(URLContext
*h
);
138 struct URLProtocol
*next
;
139 int (*url_read_pause
)(URLContext
*h
, int pause
);
140 offset_t (*url_read_seek
)(URLContext
*h
,
141 int stream_index
, int64_t timestamp
, int flags
);
144 extern URLProtocol
*first_protocol
;
145 extern URLInterruptCB
*url_interrupt_cb
;
147 URLProtocol
*av_protocol_next(URLProtocol
*p
);
149 int register_protocol(URLProtocol
*protocol
);
152 * Bytestream IO Context.
153 * New fields can be added to the end with minor version bumps.
154 * Removal, reordering and changes to existing fields require a major
156 * sizeof(ByteIOContext) must not be used outside libav*.
159 unsigned char *buffer
;
161 unsigned char *buf_ptr
, *buf_end
;
163 int (*read_packet
)(void *opaque
, uint8_t *buf
, int buf_size
);
164 int (*write_packet
)(void *opaque
, uint8_t *buf
, int buf_size
);
165 offset_t (*seek
)(void *opaque
, offset_t offset
, int whence
);
166 offset_t pos
; /**< position in the file of the current buffer */
167 int must_flush
; /**< true if the next seek should flush */
168 int eof_reached
; /**< true if eof reached */
169 int write_flag
; /**< true if open for writing */
172 unsigned long checksum
;
173 unsigned char *checksum_ptr
;
174 unsigned long (*update_checksum
)(unsigned long checksum
, const uint8_t *buf
, unsigned int size
);
175 int error
; ///< contains the error code or 0 if no error happened
176 int (*read_pause
)(void *opaque
, int pause
);
177 offset_t (*read_seek
)(void *opaque
,
178 int stream_index
, int64_t timestamp
, int flags
);
181 int init_put_byte(ByteIOContext
*s
,
182 unsigned char *buffer
,
186 int (*read_packet
)(void *opaque
, uint8_t *buf
, int buf_size
),
187 int (*write_packet
)(void *opaque
, uint8_t *buf
, int buf_size
),
188 offset_t (*seek
)(void *opaque
, offset_t offset
, int whence
));
189 ByteIOContext
*av_alloc_put_byte(
190 unsigned char *buffer
,
194 int (*read_packet
)(void *opaque
, uint8_t *buf
, int buf_size
),
195 int (*write_packet
)(void *opaque
, uint8_t *buf
, int buf_size
),
196 offset_t (*seek
)(void *opaque
, offset_t offset
, int whence
));
198 void put_byte(ByteIOContext
*s
, int b
);
199 void put_buffer(ByteIOContext
*s
, const unsigned char *buf
, int size
);
200 void put_le64(ByteIOContext
*s
, uint64_t val
);
201 void put_be64(ByteIOContext
*s
, uint64_t val
);
202 void put_le32(ByteIOContext
*s
, unsigned int val
);
203 void put_be32(ByteIOContext
*s
, unsigned int val
);
204 void put_le24(ByteIOContext
*s
, unsigned int val
);
205 void put_be24(ByteIOContext
*s
, unsigned int val
);
206 void put_le16(ByteIOContext
*s
, unsigned int val
);
207 void put_be16(ByteIOContext
*s
, unsigned int val
);
208 void put_tag(ByteIOContext
*s
, const char *tag
);
210 void put_strz(ByteIOContext
*s
, const char *buf
);
213 * fseek() equivalent for ByteIOContext.
214 * @return new position or AVERROR.
216 offset_t
url_fseek(ByteIOContext
*s
, offset_t offset
, int whence
);
219 * Skip given number of bytes forward.
220 * @param offset number of bytes
222 void url_fskip(ByteIOContext
*s
, offset_t offset
);
225 * ftell() equivalent for ByteIOContext.
226 * @return position or AVERROR.
228 offset_t
url_ftell(ByteIOContext
*s
);
232 * @return filesize or AVERROR
234 offset_t
url_fsize(ByteIOContext
*s
);
237 * feof() equivalent for ByteIOContext.
238 * @return non zero if and only if end of file
240 int url_feof(ByteIOContext
*s
);
242 int url_ferror(ByteIOContext
*s
);
244 int av_url_read_fpause(ByteIOContext
*h
, int pause
);
245 offset_t
av_url_read_fseek(ByteIOContext
*h
,
246 int stream_index
, int64_t timestamp
, int flags
);
249 /** @note return URL_EOF (-1) if EOF */
250 int url_fgetc(ByteIOContext
*s
);
252 /** @warning currently size is limited */
254 int url_fprintf(ByteIOContext
*s
, const char *fmt
, ...) __attribute__ ((__format__ (__printf__
, 2, 3)));
256 int url_fprintf(ByteIOContext
*s
, const char *fmt
, ...);
259 /** @note unlike fgets, the EOL character is not returned and a whole
260 line is parsed. return NULL if first char read was EOF */
261 char *url_fgets(ByteIOContext
*s
, char *buf
, int buf_size
);
263 void put_flush_packet(ByteIOContext
*s
);
267 * Reads size bytes from ByteIOContext into buf.
268 * @returns number of bytes read or AVERROR
270 int get_buffer(ByteIOContext
*s
, unsigned char *buf
, int size
);
273 * Reads size bytes from ByteIOContext into buf.
274 * This reads at most 1 packet. If that is not enough fewer bytes will be
276 * @returns number of bytes read or AVERROR
278 int get_partial_buffer(ByteIOContext
*s
, unsigned char *buf
, int size
);
280 /** @note return 0 if EOF, so you cannot use it if EOF handling is
282 int get_byte(ByteIOContext
*s
);
283 unsigned int get_le24(ByteIOContext
*s
);
284 unsigned int get_le32(ByteIOContext
*s
);
285 uint64_t get_le64(ByteIOContext
*s
);
286 unsigned int get_le16(ByteIOContext
*s
);
288 char *get_strz(ByteIOContext
*s
, char *buf
, int maxlen
);
289 unsigned int get_be16(ByteIOContext
*s
);
290 unsigned int get_be24(ByteIOContext
*s
);
291 unsigned int get_be32(ByteIOContext
*s
);
292 uint64_t get_be64(ByteIOContext
*s
);
294 uint64_t ff_get_v(ByteIOContext
*bc
);
296 static inline int url_is_streamed(ByteIOContext
*s
)
298 return s
->is_streamed
;
301 /** @note when opened as read/write, the buffers are only used for
303 int url_fdopen(ByteIOContext
**s
, URLContext
*h
);
305 /** @warning must be called before any I/O */
306 int url_setbufsize(ByteIOContext
*s
, int buf_size
);
307 /** Reset the buffer for reading or writing.
308 * @note Will drop any data currently in the buffer without transmitting it.
309 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
310 * to set up the buffer for writing. */
311 int url_resetbuf(ByteIOContext
*s
, int flags
);
313 /** @note when opened as read/write, the buffers are only used for
315 int url_fopen(ByteIOContext
**s
, const char *filename
, int flags
);
316 int url_fclose(ByteIOContext
*s
);
317 URLContext
*url_fileno(ByteIOContext
*s
);
320 * Return the maximum packet size associated to packetized buffered file
321 * handle. If the file is not packetized (stream like http or file on
322 * disk), then 0 is returned.
324 * @param s buffered file handle
325 * @return maximum packet size in bytes
327 int url_fget_max_packet_size(ByteIOContext
*s
);
329 int url_open_buf(ByteIOContext
**s
, uint8_t *buf
, int buf_size
, int flags
);
331 /** return the written or read size */
332 int url_close_buf(ByteIOContext
*s
);
335 * Open a write only memory stream.
337 * @param s new IO context
338 * @return zero if no error.
340 int url_open_dyn_buf(ByteIOContext
**s
);
343 * Open a write only packetized memory stream with a maximum packet
344 * size of 'max_packet_size'. The stream is stored in a memory buffer
345 * with a big endian 4 byte header giving the packet size in bytes.
347 * @param s new IO context
348 * @param max_packet_size maximum packet size (must be > 0)
349 * @return zero if no error.
351 int url_open_dyn_packet_buf(ByteIOContext
**s
, int max_packet_size
);
354 * Return the written size and a pointer to the buffer. The buffer
355 * must be freed with av_free().
356 * @param s IO context
357 * @param pbuffer pointer to a byte buffer
358 * @return the length of the byte buffer
360 int url_close_dyn_buf(ByteIOContext
*s
, uint8_t **pbuffer
);
362 unsigned long ff_crc04C11DB7_update(unsigned long checksum
, const uint8_t *buf
, unsigned int len
);
363 unsigned long get_checksum(ByteIOContext
*s
);
364 void init_checksum(ByteIOContext
*s
, unsigned long (*update_checksum
)(unsigned long c
, const uint8_t *p
, unsigned int len
), unsigned long checksum
);
367 int udp_set_remote_url(URLContext
*h
, const char *uri
);
368 int udp_get_local_port(URLContext
*h
);
369 int udp_get_file_handle(URLContext
*h
);
371 #endif /* AVFORMAT_AVIO_H */