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
30 #include "libavutil/common.h"
36 * New fields can be added to the end with minor version bumps.
37 * Removal, reordering and changes to existing fields require a major
39 * sizeof(URLContext) must not be used outside libav*.
42 #if LIBAVFORMAT_VERSION_MAJOR >= 53
43 const AVClass *av_class; ///< information for av_log(). Set by url_open().
45 struct URLProtocol *prot;
47 int is_streamed; /**< true if streamed (no seek possible), default = false */
48 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
50 char *filename; /**< specified filename */
53 typedef struct URLContext URLContext;
55 typedef struct URLPollEntry {
65 typedef int URLInterruptCB(void);
67 int url_open_protocol (URLContext **puc, struct URLProtocol *up,
68 const char *filename, int flags);
69 int url_open(URLContext **h, const char *filename, int flags);
70 int url_read(URLContext *h, unsigned char *buf, int size);
71 int url_write(URLContext *h, unsigned char *buf, int size);
72 int64_t url_seek(URLContext *h, int64_t pos, int whence);
73 int url_close(URLContext *h);
74 int url_exist(const char *filename);
75 int64_t url_filesize(URLContext *h);
78 * Return the maximum packet size associated to packetized file
79 * handle. If the file is not packetized (stream like HTTP or file on
80 * disk), then 0 is returned.
82 * @param h file handle
83 * @return maximum packet size in bytes
85 int url_get_max_packet_size(URLContext *h);
86 void url_get_filename(URLContext *h, char *buf, int buf_size);
89 * The callback is called in blocking functions to test regulary if
90 * asynchronous interruption is needed. AVERROR(EINTR) is returned
91 * in this case by the interrupted function. 'NULL' means no interrupt
94 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
97 int url_poll(URLPollEntry *poll_table, int n, int timeout);
100 * Pause and resume playing - only meaningful if using a network streaming
101 * protocol (e.g. MMS).
102 * @param pause 1 for pause, 0 for resume
104 int av_url_read_pause(URLContext *h, int pause);
107 * Seek to a given timestamp relative to some component stream.
108 * Only meaningful if using a network streaming protocol (e.g. MMS.).
109 * @param stream_index The stream index that the timestamp is relative to.
110 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
111 * units from the beginning of the presentation.
112 * If a stream_index >= 0 is used and the protocol does not support
113 * seeking based on component streams, the call will fail with ENOTSUP.
114 * @param timestamp timestamp in AVStream.time_base units
115 * or if there is no stream specified then in AV_TIME_BASE units.
116 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
117 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
118 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
119 * fail with ENOTSUP if used and not supported.
120 * @return >= 0 on success
121 * @see AVInputFormat::read_seek
123 int64_t av_url_read_seek(URLContext *h, int stream_index,
124 int64_t timestamp, int flags);
127 * Passing this as the "whence" parameter to a seek function causes it to
128 * return the filesize without seeking anywhere. Supporting this is optional.
129 * If it is not supported then the seek function will return <0.
131 #define AVSEEK_SIZE 0x10000
133 typedef struct URLProtocol {
135 int (*url_open)(URLContext *h, const char *filename, int flags);
136 int (*url_read)(URLContext *h, unsigned char *buf, int size);
137 int (*url_write)(URLContext *h, unsigned char *buf, int size);
138 int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
139 int (*url_close)(URLContext *h);
140 struct URLProtocol *next;
141 int (*url_read_pause)(URLContext *h, int pause);
142 int64_t (*url_read_seek)(URLContext *h, int stream_index,
143 int64_t timestamp, int flags);
146 #if LIBAVFORMAT_VERSION_MAJOR < 53
147 extern URLProtocol *first_protocol;
150 extern URLInterruptCB *url_interrupt_cb;
153 * If protocol is NULL, returns the first registered protocol,
154 * if protocol is non-NULL, returns the next registered protocol after protocol,
155 * or NULL if protocol is the last one.
157 URLProtocol *av_protocol_next(URLProtocol *p);
159 #if LIBAVFORMAT_VERSION_MAJOR < 53
161 * @deprecated Use av_register_protocol() instead.
163 attribute_deprecated int register_protocol(URLProtocol *protocol);
166 int av_register_protocol(URLProtocol *protocol);
169 * Bytestream IO Context.
170 * New fields can be added to the end with minor version bumps.
171 * Removal, reordering and changes to existing fields require a major
173 * sizeof(ByteIOContext) must not be used outside libav*.
176 unsigned char *buffer;
178 unsigned char *buf_ptr, *buf_end;
180 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
181 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
182 int64_t (*seek)(void *opaque, int64_t offset, int whence);
183 int64_t pos; /**< position in the file of the current buffer */
184 int must_flush; /**< true if the next seek should flush */
185 int eof_reached; /**< true if eof reached */
186 int write_flag; /**< true if open for writing */
189 unsigned long checksum;
190 unsigned char *checksum_ptr;
191 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
192 int error; ///< contains the error code or 0 if no error happened
193 int (*read_pause)(void *opaque, int pause);
194 int64_t (*read_seek)(void *opaque, int stream_index,
195 int64_t timestamp, int flags);
198 int init_put_byte(ByteIOContext *s,
199 unsigned char *buffer,
203 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
204 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
205 int64_t (*seek)(void *opaque, int64_t offset, int whence));
206 ByteIOContext *av_alloc_put_byte(
207 unsigned char *buffer,
211 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
212 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
213 int64_t (*seek)(void *opaque, int64_t offset, int whence));
215 void put_byte(ByteIOContext *s, int b);
216 void put_buffer(ByteIOContext *s, const unsigned char *buf, int size);
217 void put_le64(ByteIOContext *s, uint64_t val);
218 void put_be64(ByteIOContext *s, uint64_t val);
219 void put_le32(ByteIOContext *s, unsigned int val);
220 void put_be32(ByteIOContext *s, unsigned int val);
221 void put_le24(ByteIOContext *s, unsigned int val);
222 void put_be24(ByteIOContext *s, unsigned int val);
223 void put_le16(ByteIOContext *s, unsigned int val);
224 void put_be16(ByteIOContext *s, unsigned int val);
225 void put_tag(ByteIOContext *s, const char *tag);
227 void put_strz(ByteIOContext *s, const char *buf);
230 * fseek() equivalent for ByteIOContext.
231 * @return new position or AVERROR.
233 int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence);
236 * Skip given number of bytes forward.
237 * @param offset number of bytes
239 void url_fskip(ByteIOContext *s, int64_t offset);
242 * ftell() equivalent for ByteIOContext.
243 * @return position or AVERROR.
245 int64_t url_ftell(ByteIOContext *s);
249 * @return filesize or AVERROR
251 int64_t url_fsize(ByteIOContext *s);
254 * feof() equivalent for ByteIOContext.
255 * @return non zero if and only if end of file
257 int url_feof(ByteIOContext *s);
259 int url_ferror(ByteIOContext *s);
261 int av_url_read_fpause(ByteIOContext *h, int pause);
262 int64_t av_url_read_fseek(ByteIOContext *h, int stream_index,
263 int64_t timestamp, int flags);
266 /** @note return URL_EOF (-1) if EOF */
267 int url_fgetc(ByteIOContext *s);
269 /** @warning currently size is limited */
271 int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
273 int url_fprintf(ByteIOContext *s, const char *fmt, ...);
276 /** @note unlike fgets, the EOL character is not returned and a whole
277 line is parsed. return NULL if first char read was EOF */
278 char *url_fgets(ByteIOContext *s, char *buf, int buf_size);
280 void put_flush_packet(ByteIOContext *s);
284 * Reads size bytes from ByteIOContext into buf.
285 * @returns number of bytes read or AVERROR
287 int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
290 * Reads size bytes from ByteIOContext into buf.
291 * This reads at most 1 packet. If that is not enough fewer bytes will be
293 * @returns number of bytes read or AVERROR
295 int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
297 /** @note return 0 if EOF, so you cannot use it if EOF handling is
299 int get_byte(ByteIOContext *s);
300 unsigned int get_le24(ByteIOContext *s);
301 unsigned int get_le32(ByteIOContext *s);
302 uint64_t get_le64(ByteIOContext *s);
303 unsigned int get_le16(ByteIOContext *s);
305 char *get_strz(ByteIOContext *s, char *buf, int maxlen);
306 unsigned int get_be16(ByteIOContext *s);
307 unsigned int get_be24(ByteIOContext *s);
308 unsigned int get_be32(ByteIOContext *s);
309 uint64_t get_be64(ByteIOContext *s);
311 uint64_t ff_get_v(ByteIOContext *bc);
313 static inline int url_is_streamed(ByteIOContext *s)
315 return s->is_streamed;
318 /** @note when opened as read/write, the buffers are only used for
320 int url_fdopen(ByteIOContext **s, URLContext *h);
322 /** @warning must be called before any I/O */
323 int url_setbufsize(ByteIOContext *s, int buf_size);
324 /** Reset the buffer for reading or writing.
325 * @note Will drop any data currently in the buffer without transmitting it.
326 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
327 * to set up the buffer for writing. */
328 int url_resetbuf(ByteIOContext *s, int flags);
330 /** @note when opened as read/write, the buffers are only used for
332 int url_fopen(ByteIOContext **s, const char *filename, int flags);
333 int url_fclose(ByteIOContext *s);
334 URLContext *url_fileno(ByteIOContext *s);
337 * Return the maximum packet size associated to packetized buffered file
338 * handle. If the file is not packetized (stream like http or file on
339 * disk), then 0 is returned.
341 * @param s buffered file handle
342 * @return maximum packet size in bytes
344 int url_fget_max_packet_size(ByteIOContext *s);
346 int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags);
348 /** return the written or read size */
349 int url_close_buf(ByteIOContext *s);
352 * Open a write only memory stream.
354 * @param s new IO context
355 * @return zero if no error.
357 int url_open_dyn_buf(ByteIOContext **s);
360 * Open a write only packetized memory stream with a maximum packet
361 * size of 'max_packet_size'. The stream is stored in a memory buffer
362 * with a big endian 4 byte header giving the packet size in bytes.
364 * @param s new IO context
365 * @param max_packet_size maximum packet size (must be > 0)
366 * @return zero if no error.
368 int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size);
371 * Return the written size and a pointer to the buffer. The buffer
372 * must be freed with av_free().
373 * @param s IO context
374 * @param pbuffer pointer to a byte buffer
375 * @return the length of the byte buffer
377 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);
379 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
381 unsigned long get_checksum(ByteIOContext *s);
382 void init_checksum(ByteIOContext *s,
383 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
384 unsigned long checksum);
387 int udp_set_remote_url(URLContext *h, const char *uri);
388 int udp_get_local_port(URLContext *h);
389 int udp_get_file_handle(URLContext *h);
391 #endif /* AVFORMAT_AVIO_H */