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.
33 #include "libavutil/common.h"
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 {
69 typedef int URLInterruptCB(void);
71 int url_open_protocol (URLContext **puc, struct URLProtocol *up,
72 const char *filename, int flags);
73 int url_open(URLContext **h, const char *filename, int flags);
74 int url_read(URLContext *h, unsigned char *buf, int size);
75 int url_write(URLContext *h, unsigned char *buf, int size);
76 int64_t url_seek(URLContext *h, int64_t pos, int whence);
77 int url_close(URLContext *h);
78 int url_exist(const char *filename);
79 int64_t url_filesize(URLContext *h);
82 * Return the file descriptor associated with this URL. For RTP, this
83 * will return only the RTP file descriptor, not the RTCP file descriptor.
84 * To get both, use rtp_get_file_handles().
86 * @return the file descriptor associated with this URL, or <0 on error.
88 int url_get_file_handle(URLContext *h);
91 * Return the maximum packet size associated to packetized file
92 * handle. If the file is not packetized (stream like HTTP or file on
93 * disk), then 0 is returned.
95 * @param h file handle
96 * @return maximum packet size in bytes
98 int url_get_max_packet_size(URLContext *h);
99 void url_get_filename(URLContext *h, char *buf, int buf_size);
102 * The callback is called in blocking functions to test regulary if
103 * asynchronous interruption is needed. AVERROR(EINTR) is returned
104 * in this case by the interrupted function. 'NULL' means no interrupt
107 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
109 /* not implemented */
110 int url_poll(URLPollEntry *poll_table, int n, int timeout);
113 * Pause and resume playing - only meaningful if using a network streaming
114 * protocol (e.g. MMS).
115 * @param pause 1 for pause, 0 for resume
117 int av_url_read_pause(URLContext *h, int pause);
120 * Seek to a given timestamp relative to some component stream.
121 * Only meaningful if using a network streaming protocol (e.g. MMS.).
122 * @param stream_index The stream index that the timestamp is relative to.
123 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
124 * units from the beginning of the presentation.
125 * If a stream_index >= 0 is used and the protocol does not support
126 * seeking based on component streams, the call will fail with ENOTSUP.
127 * @param timestamp timestamp in AVStream.time_base units
128 * or if there is no stream specified then in AV_TIME_BASE units.
129 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
130 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
131 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
132 * fail with ENOTSUP if used and not supported.
133 * @return >= 0 on success
134 * @see AVInputFormat::read_seek
136 int64_t av_url_read_seek(URLContext *h, int stream_index,
137 int64_t timestamp, int flags);
140 * Passing this as the "whence" parameter to a seek function causes it to
141 * return the filesize without seeking anywhere. Supporting this is optional.
142 * If it is not supported then the seek function will return <0.
144 #define AVSEEK_SIZE 0x10000
146 typedef struct URLProtocol {
148 int (*url_open)(URLContext *h, const char *filename, int flags);
149 int (*url_read)(URLContext *h, unsigned char *buf, int size);
150 int (*url_write)(URLContext *h, unsigned char *buf, int size);
151 int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
152 int (*url_close)(URLContext *h);
153 struct URLProtocol *next;
154 int (*url_read_pause)(URLContext *h, int pause);
155 int64_t (*url_read_seek)(URLContext *h, int stream_index,
156 int64_t timestamp, int flags);
157 int (*url_get_file_handle)(URLContext *h);
160 #if LIBAVFORMAT_VERSION_MAJOR < 53
161 extern URLProtocol *first_protocol;
164 extern URLInterruptCB *url_interrupt_cb;
167 * If protocol is NULL, returns the first registered protocol,
168 * if protocol is non-NULL, returns the next registered protocol after protocol,
169 * or NULL if protocol is the last one.
171 URLProtocol *av_protocol_next(URLProtocol *p);
173 #if LIBAVFORMAT_VERSION_MAJOR < 53
175 * @deprecated Use av_register_protocol() instead.
177 attribute_deprecated int register_protocol(URLProtocol *protocol);
180 int av_register_protocol(URLProtocol *protocol);
183 * Bytestream IO Context.
184 * New fields can be added to the end with minor version bumps.
185 * Removal, reordering and changes to existing fields require a major
187 * sizeof(ByteIOContext) must not be used outside libav*.
190 unsigned char *buffer;
192 unsigned char *buf_ptr, *buf_end;
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 int64_t (*seek)(void *opaque, int64_t offset, int whence);
197 int64_t pos; /**< position in the file of the current buffer */
198 int must_flush; /**< true if the next seek should flush */
199 int eof_reached; /**< true if eof reached */
200 int write_flag; /**< true if open for writing */
201 int o_direct_flag; /**< true if the underlaying file is open with O_DIRECT */
204 unsigned long checksum;
205 unsigned char *checksum_ptr;
206 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
207 int error; ///< contains the error code or 0 if no error happened
208 int (*read_pause)(void *opaque, int pause);
209 int64_t (*read_seek)(void *opaque, int stream_index,
210 int64_t timestamp, int flags);
213 int init_put_byte(ByteIOContext *s,
214 unsigned char *buffer,
218 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
219 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
220 int64_t (*seek)(void *opaque, int64_t offset, int whence));
221 ByteIOContext *av_alloc_put_byte(
222 unsigned char *buffer,
226 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
227 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
228 int64_t (*seek)(void *opaque, int64_t offset, int whence));
230 void put_byte(ByteIOContext *s, int b);
231 void put_buffer(ByteIOContext *s, const unsigned char *buf, int size);
232 void put_le64(ByteIOContext *s, uint64_t val);
233 void put_be64(ByteIOContext *s, uint64_t val);
234 void put_le32(ByteIOContext *s, unsigned int val);
235 void put_be32(ByteIOContext *s, unsigned int val);
236 void put_le24(ByteIOContext *s, unsigned int val);
237 void put_be24(ByteIOContext *s, unsigned int val);
238 void put_le16(ByteIOContext *s, unsigned int val);
239 void put_be16(ByteIOContext *s, unsigned int val);
240 void put_tag(ByteIOContext *s, const char *tag);
242 void put_strz(ByteIOContext *s, const char *buf);
245 * fseek() equivalent for ByteIOContext.
246 * @return new position or AVERROR.
248 int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence);
251 * Skip given number of bytes forward.
252 * @param offset number of bytes
254 void url_fskip(ByteIOContext *s, int64_t offset);
257 * ftell() equivalent for ByteIOContext.
258 * @return position or AVERROR.
260 int64_t url_ftell(ByteIOContext *s);
264 * @return filesize or AVERROR
266 int64_t url_fsize(ByteIOContext *s);
269 * feof() equivalent for ByteIOContext.
270 * @return non zero if and only if end of file
272 int url_feof(ByteIOContext *s);
274 int url_ferror(ByteIOContext *s);
276 int av_url_read_fpause(ByteIOContext *h, int pause);
277 int64_t av_url_read_fseek(ByteIOContext *h, int stream_index,
278 int64_t timestamp, int flags);
281 /** @note return URL_EOF (-1) if EOF */
282 int url_fgetc(ByteIOContext *s);
284 /** @warning currently size is limited */
286 int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
288 int url_fprintf(ByteIOContext *s, const char *fmt, ...);
291 /** @note unlike fgets, the EOL character is not returned and a whole
292 line is parsed. return NULL if first char read was EOF */
293 char *url_fgets(ByteIOContext *s, char *buf, int buf_size);
295 void put_flush_packet(ByteIOContext *s);
299 * Reads size bytes from ByteIOContext into buf.
300 * @returns number of bytes read or AVERROR
302 int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
305 * Reads size bytes from ByteIOContext into buf.
306 * This reads at most 1 packet. If that is not enough fewer bytes will be
308 * @returns number of bytes read or AVERROR
310 int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
312 /** @note return 0 if EOF, so you cannot use it if EOF handling is
314 int get_byte(ByteIOContext *s);
315 unsigned int get_le24(ByteIOContext *s);
316 unsigned int get_le32(ByteIOContext *s);
317 uint64_t get_le64(ByteIOContext *s);
318 unsigned int get_le16(ByteIOContext *s);
320 char *get_strz(ByteIOContext *s, char *buf, int maxlen);
321 unsigned int get_be16(ByteIOContext *s);
322 unsigned int get_be24(ByteIOContext *s);
323 unsigned int get_be32(ByteIOContext *s);
324 uint64_t get_be64(ByteIOContext *s);
326 uint64_t ff_get_v(ByteIOContext *bc);
328 static inline int url_is_streamed(ByteIOContext *s)
330 return s->is_streamed;
333 /** @note when opened as read/write, the buffers are only used for
335 int url_fdopen(ByteIOContext **s, URLContext *h);
337 /** @warning must be called before any I/O */
338 int url_setbufsize(ByteIOContext *s, int buf_size);
339 /** Reset the buffer for reading or writing.
340 * @note Will drop any data currently in the buffer without transmitting it.
341 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
342 * to set up the buffer for writing. */
343 int url_resetbuf(ByteIOContext *s, int flags);
345 /** @note when opened as read/write, the buffers are only used for
347 int url_fopen(ByteIOContext **s, const char *filename, int flags);
348 int url_fclose(ByteIOContext *s);
349 URLContext *url_fileno(ByteIOContext *s);
352 * Return the maximum packet size associated to packetized buffered file
353 * handle. If the file is not packetized (stream like http or file on
354 * disk), then 0 is returned.
356 * @param s buffered file handle
357 * @return maximum packet size in bytes
359 int url_fget_max_packet_size(ByteIOContext *s);
361 int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags);
363 /** return the written or read size */
364 int url_close_buf(ByteIOContext *s);
367 * Open a write only memory stream.
369 * @param s new IO context
370 * @return zero if no error.
372 int url_open_dyn_buf(ByteIOContext **s);
375 * Open a write only packetized memory stream with a maximum packet
376 * size of 'max_packet_size'. The stream is stored in a memory buffer
377 * with a big endian 4 byte header giving the packet size in bytes.
379 * @param s new IO context
380 * @param max_packet_size maximum packet size (must be > 0)
381 * @return zero if no error.
383 int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size);
386 * Return the written size and a pointer to the buffer. The buffer
387 * must be freed with av_free().
388 * @param s IO context
389 * @param pbuffer pointer to a byte buffer
390 * @return the length of the byte buffer
392 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);
394 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
396 unsigned long get_checksum(ByteIOContext *s);
397 void init_checksum(ByteIOContext *s,
398 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
399 unsigned long checksum);
402 int udp_set_remote_url(URLContext *h, const char *uri);
403 int udp_get_local_port(URLContext *h);
404 #if (LIBAVFORMAT_VERSION_MAJOR <= 52)
405 int udp_get_file_handle(URLContext *h);
408 #endif /* AVFORMAT_AVIO_H */