2 * copyright (c) 2001 Fabrice Bellard
4 * This file is part of Libav.
6 * Libav 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 * Libav 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 Libav; 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
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"
34 #include "libavutil/log.h"
36 #include "libavformat/version.h"
42 * New fields can be added to the end with minor version bumps.
43 * Removal, reordering and changes to existing fields require a major
45 * sizeof(URLContext) must not be used outside libav*.
47 typedef struct URLContext {
49 const AVClass *av_class; ///< information for av_log(). Set by url_open().
51 struct URLProtocol *prot;
53 int is_streamed; /**< true if streamed (no seek possible), default = false */
54 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
56 char *filename; /**< specified URL */
61 typedef struct URLPollEntry {
69 * @defgroup open_modes URL open modes
70 * The flags argument to url_open and cosins must be one of the following
71 * constants, optionally ORed with other flags.
74 #define URL_RDONLY 0 /**< read-only */
75 #define URL_WRONLY 1 /**< write-only */
76 #define URL_RDWR 2 /**< read-write */
82 * Use non-blocking mode.
83 * If this flag is set, operations on the context will return
84 * AVERROR(EAGAIN) if they can not be performed immediately.
85 * If this flag is not set, operations on the context will never return
87 * Note that this flag does not affect the opening/connecting of the
88 * context. Connecting a protocol will always block if necessary (e.g. on
89 * network protocols) but never hang (e.g. on busy devices).
90 * Warning: non-blocking protocols is work-in-progress; this flag may be
93 #define URL_FLAG_NONBLOCK 4
95 typedef int URLInterruptCB(void);
99 * @defgroup old_url_funcs Old url_* functions
100 * @deprecated use the buffered API based on AVIOContext instead
103 attribute_deprecated int url_open_protocol (URLContext **puc, struct URLProtocol *up,
104 const char *url, int flags);
105 attribute_deprecated int url_alloc(URLContext **h, const char *url, int flags);
109 * Connect an URLContext that has been allocated by url_alloc
111 int url_connect(URLContext *h);
114 * Create an URLContext for accessing to the resource indicated by
117 * @param puc pointer to the location where, in case of success, the
118 * function puts the pointer to the created URLContext
119 * @param flags flags which control how the resource indicated by url
121 * @return 0 in case of success, a negative value corresponding to an
122 * AVERROR code in case of failure
124 int url_open(URLContext **h, const char *url, int flags);
127 * Read up to size bytes from the resource accessed by h, and store
128 * the read bytes in buf.
130 * @return The number of bytes actually read, or a negative value
131 * corresponding to an AVERROR code in case of error. A value of zero
132 * indicates that it is not possible to read more from the accessed
133 * resource (except if the value of the size argument is also zero).
135 int url_read(URLContext *h, unsigned char *buf, int size);
138 * Read as many bytes as possible (up to size), calling the
139 * read function multiple times if necessary.
140 * This makes special short-read handling in applications
141 * unnecessary, if the return value is < size then it is
142 * certain there was either an error or the end of file was reached.
144 int url_read_complete(URLContext *h, unsigned char *buf, int size);
147 * Write size bytes from buf to the resource accessed by h.
149 * @return the number of bytes actually written, or a negative value
150 * corresponding to an AVERROR code in case of failure
152 int url_write(URLContext *h, const unsigned char *buf, int size);
155 * Passing this as the "whence" parameter to a seek function causes it to
156 * return the filesize without seeking anywhere. Supporting this is optional.
157 * If it is not supported then the seek function will return <0.
159 #define AVSEEK_SIZE 0x10000
162 * Change the position that will be used by the next read/write
163 * operation on the resource accessed by h.
165 * @param pos specifies the new position to set
166 * @param whence specifies how pos should be interpreted, it must be
167 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
168 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
169 * (return the filesize of the requested resource, pos is ignored).
170 * @return a negative value corresponding to an AVERROR code in case
171 * of failure, or the resulting file position, measured in bytes from
172 * the beginning of the file. You can use this feature together with
173 * SEEK_CUR to read the current file position.
175 int64_t url_seek(URLContext *h, int64_t pos, int whence);
178 * Close the resource accessed by the URLContext h, and free the
181 * @return a negative value if an error condition occurred, 0
184 int url_close(URLContext *h);
187 * Return a non-zero value if the resource indicated by url
188 * exists, 0 otherwise.
190 int url_exist(const char *url);
193 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
194 * if the operation is not supported by h, or another negative value
195 * corresponding to an AVERROR error code in case of failure.
197 int64_t url_filesize(URLContext *h);
200 * Return the file descriptor associated with this URL. For RTP, this
201 * will return only the RTP file descriptor, not the RTCP file descriptor.
203 * @return the file descriptor associated with this URL, or <0 on error.
205 int url_get_file_handle(URLContext *h);
208 * Return the maximum packet size associated to packetized file
209 * handle. If the file is not packetized (stream like HTTP or file on
210 * disk), then 0 is returned.
212 * @param h file handle
213 * @return maximum packet size in bytes
215 int url_get_max_packet_size(URLContext *h);
218 * Copy the filename of the resource accessed by h to buf.
220 * @param buf_size size in bytes of buf
222 void url_get_filename(URLContext *h, char *buf, int buf_size);
225 * The callback is called in blocking functions to test regulary if
226 * asynchronous interruption is needed. AVERROR_EXIT is returned
227 * in this case by the interrupted function. 'NULL' means no interrupt
230 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
233 /* not implemented */
234 attribute_deprecated int url_poll(URLPollEntry *poll_table, int n, int timeout);
238 * Pause and resume playing - only meaningful if using a network streaming
239 * protocol (e.g. MMS).
240 * @param pause 1 for pause, 0 for resume
242 int av_url_read_pause(URLContext *h, int pause);
245 * Seek to a given timestamp relative to some component stream.
246 * Only meaningful if using a network streaming protocol (e.g. MMS.).
247 * @param stream_index The stream index that the timestamp is relative to.
248 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
249 * units from the beginning of the presentation.
250 * If a stream_index >= 0 is used and the protocol does not support
251 * seeking based on component streams, the call will fail with ENOTSUP.
252 * @param timestamp timestamp in AVStream.time_base units
253 * or if there is no stream specified then in AV_TIME_BASE units.
254 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
255 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
256 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
257 * fail with ENOTSUP if used and not supported.
258 * @return >= 0 on success
259 * @see AVInputFormat::read_seek
261 int64_t av_url_read_seek(URLContext *h, int stream_index,
262 int64_t timestamp, int flags);
265 * Oring this flag as into the "whence" parameter to a seek function causes it to
266 * seek by any means (like reopening and linear reading) or other normally unreasonble
267 * means that can be extreemly slow.
268 * This may be ignored by the seek code.
270 #define AVSEEK_FORCE 0x20000
272 #define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */
274 typedef struct URLProtocol {
276 int (*url_open)(URLContext *h, const char *url, int flags);
277 int (*url_read)(URLContext *h, unsigned char *buf, int size);
278 int (*url_write)(URLContext *h, const unsigned char *buf, int size);
279 int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
280 int (*url_close)(URLContext *h);
281 struct URLProtocol *next;
282 int (*url_read_pause)(URLContext *h, int pause);
283 int64_t (*url_read_seek)(URLContext *h, int stream_index,
284 int64_t timestamp, int flags);
285 int (*url_get_file_handle)(URLContext *h);
287 const AVClass *priv_data_class;
291 #if FF_API_REGISTER_PROTOCOL
292 extern URLProtocol *first_protocol;
295 extern URLInterruptCB *url_interrupt_cb;
298 * If protocol is NULL, returns the first registered protocol,
299 * if protocol is non-NULL, returns the next registered protocol after protocol,
300 * or NULL if protocol is the last one.
302 URLProtocol *av_protocol_next(URLProtocol *p);
304 #if FF_API_REGISTER_PROTOCOL
306 * @deprecated Use av_register_protocol() instead.
308 attribute_deprecated int register_protocol(URLProtocol *protocol);
311 * @deprecated Use av_register_protocol2() instead.
313 attribute_deprecated int av_register_protocol(URLProtocol *protocol);
317 * Register the URLProtocol protocol.
319 * @param size the size of the URLProtocol struct referenced
321 int av_register_protocol2(URLProtocol *protocol, int size);
323 #define AVIO_SEEKABLE_NORMAL 0x0001 /**< Seeking works like for a local file */
330 * Bytestream IO Context.
331 * New fields can be added to the end with minor version bumps.
332 * Removal, reordering and changes to existing fields require a major
334 * sizeof(AVIOContext) must not be used outside libav*.
337 unsigned char *buffer;
339 unsigned char *buf_ptr, *buf_end;
341 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
342 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
343 int64_t (*seek)(void *opaque, int64_t offset, int whence);
344 int64_t pos; /**< position in the file of the current buffer */
345 int must_flush; /**< true if the next seek should flush */
346 int eof_reached; /**< true if eof reached */
347 int write_flag; /**< true if open for writing */
349 attribute_deprecated int is_streamed;
352 unsigned long checksum;
353 unsigned char *checksum_ptr;
354 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
355 int error; ///< contains the error code or 0 if no error happened
356 int (*read_pause)(void *opaque, int pause);
357 int64_t (*read_seek)(void *opaque, int stream_index,
358 int64_t timestamp, int flags);
360 * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
366 typedef attribute_deprecated AVIOContext ByteIOContext;
368 attribute_deprecated int init_put_byte(AVIOContext *s,
369 unsigned char *buffer,
373 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
374 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
375 int64_t (*seek)(void *opaque, int64_t offset, int whence));
376 attribute_deprecated AVIOContext *av_alloc_put_byte(
377 unsigned char *buffer,
381 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
382 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
383 int64_t (*seek)(void *opaque, int64_t offset, int whence));
386 * @defgroup old_avio_funcs Old put_/get_*() functions
387 * @deprecated use the avio_ -prefixed functions instead.
390 attribute_deprecated int get_buffer(AVIOContext *s, unsigned char *buf, int size);
391 attribute_deprecated int get_partial_buffer(AVIOContext *s, unsigned char *buf, int size);
392 attribute_deprecated int get_byte(AVIOContext *s);
393 attribute_deprecated unsigned int get_le16(AVIOContext *s);
394 attribute_deprecated unsigned int get_le24(AVIOContext *s);
395 attribute_deprecated unsigned int get_le32(AVIOContext *s);
396 attribute_deprecated uint64_t get_le64(AVIOContext *s);
397 attribute_deprecated unsigned int get_be16(AVIOContext *s);
398 attribute_deprecated unsigned int get_be24(AVIOContext *s);
399 attribute_deprecated unsigned int get_be32(AVIOContext *s);
400 attribute_deprecated uint64_t get_be64(AVIOContext *s);
402 attribute_deprecated void put_byte(AVIOContext *s, int b);
403 attribute_deprecated void put_nbyte(AVIOContext *s, int b, int count);
404 attribute_deprecated void put_buffer(AVIOContext *s, const unsigned char *buf, int size);
405 attribute_deprecated void put_le64(AVIOContext *s, uint64_t val);
406 attribute_deprecated void put_be64(AVIOContext *s, uint64_t val);
407 attribute_deprecated void put_le32(AVIOContext *s, unsigned int val);
408 attribute_deprecated void put_be32(AVIOContext *s, unsigned int val);
409 attribute_deprecated void put_le24(AVIOContext *s, unsigned int val);
410 attribute_deprecated void put_be24(AVIOContext *s, unsigned int val);
411 attribute_deprecated void put_le16(AVIOContext *s, unsigned int val);
412 attribute_deprecated void put_be16(AVIOContext *s, unsigned int val);
413 attribute_deprecated void put_tag(AVIOContext *s, const char *tag);
418 attribute_deprecated int av_url_read_fpause(AVIOContext *h, int pause);
419 attribute_deprecated int64_t av_url_read_fseek (AVIOContext *h, int stream_index,
420 int64_t timestamp, int flags);
423 * @defgroup old_url_f_funcs Old url_f* functions
424 * @deprecated use the avio_ -prefixed functions instead.
427 attribute_deprecated int url_fopen( AVIOContext **s, const char *url, int flags);
428 attribute_deprecated int url_fclose(AVIOContext *s);
429 attribute_deprecated int64_t url_fseek(AVIOContext *s, int64_t offset, int whence);
430 attribute_deprecated int url_fskip(AVIOContext *s, int64_t offset);
431 attribute_deprecated int64_t url_ftell(AVIOContext *s);
432 attribute_deprecated int64_t url_fsize(AVIOContext *s);
434 attribute_deprecated int url_fgetc(AVIOContext *s);
435 attribute_deprecated int url_setbufsize(AVIOContext *s, int buf_size);
437 attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
439 attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...);
441 attribute_deprecated void put_flush_packet(AVIOContext *s);
442 attribute_deprecated int url_open_dyn_buf(AVIOContext **s);
443 attribute_deprecated int url_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
444 attribute_deprecated int url_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
445 attribute_deprecated int url_fdopen(AVIOContext **s, URLContext *h);
451 * @deprecated use AVIOContext.eof_reached
453 attribute_deprecated int url_feof(AVIOContext *s);
454 attribute_deprecated int url_ferror(AVIOContext *s);
456 attribute_deprecated int udp_set_remote_url(URLContext *h, const char *uri);
457 attribute_deprecated int udp_get_local_port(URLContext *h);
459 attribute_deprecated void init_checksum(AVIOContext *s,
460 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
461 unsigned long checksum);
462 attribute_deprecated unsigned long get_checksum(AVIOContext *s);
466 * Allocate and initialize an AVIOContext for buffered I/O. It must be later
467 * freed with av_free().
469 * @param buffer Memory block for input/output operations via AVIOContext.
470 * @param buffer_size The buffer size is very important for performance.
471 * For protocols with fixed blocksize it should be set to this blocksize.
472 * For others a typical size is a cache page, e.g. 4kb.
473 * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.
474 * @param opaque An opaque pointer to user-specific data.
475 * @param read_packet A function for refilling the buffer, may be NULL.
476 * @param write_packet A function for writing the buffer contents, may be NULL.
477 * @param seek A function for seeking to specified byte position, may be NULL.
479 * @return Allocated AVIOContext or NULL on failure.
481 AVIOContext *avio_alloc_context(
482 unsigned char *buffer,
486 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
487 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
488 int64_t (*seek)(void *opaque, int64_t offset, int whence));
490 void avio_w8(AVIOContext *s, int b);
491 void avio_write(AVIOContext *s, const unsigned char *buf, int size);
492 void avio_wl64(AVIOContext *s, uint64_t val);
493 void avio_wb64(AVIOContext *s, uint64_t val);
494 void avio_wl32(AVIOContext *s, unsigned int val);
495 void avio_wb32(AVIOContext *s, unsigned int val);
496 void avio_wl24(AVIOContext *s, unsigned int val);
497 void avio_wb24(AVIOContext *s, unsigned int val);
498 void avio_wl16(AVIOContext *s, unsigned int val);
499 void avio_wb16(AVIOContext *s, unsigned int val);
502 attribute_deprecated void put_strz(AVIOContext *s, const char *buf);
506 * Write a NULL-terminated string.
507 * @return number of bytes written.
509 int avio_put_str(AVIOContext *s, const char *str);
512 * Convert an UTF-8 string to UTF-16LE and write it.
513 * @return number of bytes written.
515 int avio_put_str16le(AVIOContext *s, const char *str);
518 * fseek() equivalent for AVIOContext.
519 * @return new position or AVERROR.
521 int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);
524 * Skip given number of bytes forward
525 * @return new position or AVERROR.
527 static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
529 return avio_seek(s, offset, SEEK_CUR);
533 * ftell() equivalent for AVIOContext.
534 * @return position or AVERROR.
536 static av_always_inline int64_t avio_tell(AVIOContext *s)
538 return avio_seek(s, 0, SEEK_CUR);
543 * @return filesize or AVERROR
545 int64_t avio_size(AVIOContext *s);
547 /** @warning currently size is limited */
549 int avio_printf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
551 int avio_printf(AVIOContext *s, const char *fmt, ...);
555 /** @note unlike fgets, the EOL character is not returned and a whole
556 line is parsed. return NULL if first char read was EOF */
557 attribute_deprecated char *url_fgets(AVIOContext *s, char *buf, int buf_size);
560 void avio_flush(AVIOContext *s);
564 * Read size bytes from AVIOContext into buf.
565 * @return number of bytes read or AVERROR
567 int avio_read(AVIOContext *s, unsigned char *buf, int size);
569 /** @note return 0 if EOF, so you cannot use it if EOF handling is
571 int avio_r8 (AVIOContext *s);
572 unsigned int avio_rl16(AVIOContext *s);
573 unsigned int avio_rl24(AVIOContext *s);
574 unsigned int avio_rl32(AVIOContext *s);
575 uint64_t avio_rl64(AVIOContext *s);
578 * Read a string from pb into buf. The reading will terminate when either
579 * a NULL character was encountered, maxlen bytes have been read, or nothing
580 * more can be read from pb. The result is guaranteed to be NULL-terminated, it
581 * will be truncated if buf is too small.
582 * Note that the string is not interpreted or validated in any way, it
583 * might get truncated in the middle of a sequence for multi-byte encodings.
585 * @return number of bytes read (is always <= maxlen).
586 * If reading ends on EOF or error, the return value will be one more than
587 * bytes actually read.
589 int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);
592 * Read a UTF-16 string from pb and convert it to UTF-8.
593 * The reading will terminate when either a null or invalid character was
594 * encountered or maxlen bytes have been read.
595 * @return number of bytes read (is always <= maxlen)
597 int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);
598 int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);
602 * @deprecated use avio_get_str instead
604 attribute_deprecated char *get_strz(AVIOContext *s, char *buf, int maxlen);
606 unsigned int avio_rb16(AVIOContext *s);
607 unsigned int avio_rb24(AVIOContext *s);
608 unsigned int avio_rb32(AVIOContext *s);
609 uint64_t avio_rb64(AVIOContext *s);
613 * @deprecated Use AVIOContext.seekable field directly.
615 attribute_deprecated static inline int url_is_streamed(AVIOContext *s)
621 #if FF_API_URL_RESETBUF
622 /** Reset the buffer for reading or writing.
623 * @note Will drop any data currently in the buffer without transmitting it.
624 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
625 * to set up the buffer for writing. */
626 int url_resetbuf(AVIOContext *s, int flags);
630 * Create and initialize a AVIOContext for accessing the
631 * resource indicated by url.
632 * @note When the resource indicated by url has been opened in
633 * read+write mode, the AVIOContext can be used only for writing.
635 * @param s Used to return the pointer to the created AVIOContext.
636 * In case of failure the pointed to value is set to NULL.
637 * @param flags flags which control how the resource indicated by url
639 * @return 0 in case of success, a negative value corresponding to an
640 * AVERROR code in case of failure
642 int avio_open(AVIOContext **s, const char *url, int flags);
644 int avio_close(AVIOContext *s);
647 attribute_deprecated URLContext *url_fileno(AVIOContext *s);
650 * @deprecated use AVIOContext.max_packet_size directly.
652 attribute_deprecated int url_fget_max_packet_size(AVIOContext *s);
654 attribute_deprecated int url_open_buf(AVIOContext **s, uint8_t *buf, int buf_size, int flags);
656 /** return the written or read size */
657 attribute_deprecated int url_close_buf(AVIOContext *s);
661 * Open a write only memory stream.
663 * @param s new IO context
664 * @return zero if no error.
666 int avio_open_dyn_buf(AVIOContext **s);
669 * Return the written size and a pointer to the buffer. The buffer
670 * must be freed with av_free().
671 * Padding of FF_INPUT_BUFFER_PADDING_SIZE is added to the buffer.
673 * @param s IO context
674 * @param pbuffer pointer to a byte buffer
675 * @return the length of the byte buffer
677 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
679 #if FF_API_UDP_GET_FILE
680 int udp_get_file_handle(URLContext *h);
683 #endif /* AVFORMAT_AVIO_H */