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);
106 attribute_deprecated int url_connect(URLContext *h);
107 attribute_deprecated int url_open(URLContext **h, const char *url, int flags);
108 attribute_deprecated int url_read(URLContext *h, unsigned char *buf, int size);
109 attribute_deprecated int url_read_complete(URLContext *h, unsigned char *buf, int size);
110 attribute_deprecated int url_write(URLContext *h, const unsigned char *buf, int size);
111 attribute_deprecated int64_t url_seek(URLContext *h, int64_t pos, int whence);
112 attribute_deprecated int url_close(URLContext *h);
113 attribute_deprecated int64_t url_filesize(URLContext *h);
117 * Return a non-zero value if the resource indicated by url
118 * exists, 0 otherwise.
120 int url_exist(const char *url);
123 * Return the file descriptor associated with this URL. For RTP, this
124 * will return only the RTP file descriptor, not the RTCP file descriptor.
126 * @return the file descriptor associated with this URL, or <0 on error.
128 int url_get_file_handle(URLContext *h);
131 * Return the maximum packet size associated to packetized file
132 * handle. If the file is not packetized (stream like HTTP or file on
133 * disk), then 0 is returned.
135 * @param h file handle
136 * @return maximum packet size in bytes
138 int url_get_max_packet_size(URLContext *h);
141 * Copy the filename of the resource accessed by h to buf.
143 * @param buf_size size in bytes of buf
145 void url_get_filename(URLContext *h, char *buf, int buf_size);
148 * The callback is called in blocking functions to test regulary if
149 * asynchronous interruption is needed. AVERROR_EXIT is returned
150 * in this case by the interrupted function. 'NULL' means no interrupt
153 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
156 /* not implemented */
157 attribute_deprecated int url_poll(URLPollEntry *poll_table, int n, int timeout);
161 * Pause and resume playing - only meaningful if using a network streaming
162 * protocol (e.g. MMS).
163 * @param pause 1 for pause, 0 for resume
165 int av_url_read_pause(URLContext *h, int pause);
168 * Seek to a given timestamp relative to some component stream.
169 * Only meaningful if using a network streaming protocol (e.g. MMS.).
170 * @param stream_index The stream index that the timestamp is relative to.
171 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
172 * units from the beginning of the presentation.
173 * If a stream_index >= 0 is used and the protocol does not support
174 * seeking based on component streams, the call will fail with ENOTSUP.
175 * @param timestamp timestamp in AVStream.time_base units
176 * or if there is no stream specified then in AV_TIME_BASE units.
177 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
178 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
179 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
180 * fail with ENOTSUP if used and not supported.
181 * @return >= 0 on success
182 * @see AVInputFormat::read_seek
184 int64_t av_url_read_seek(URLContext *h, int stream_index,
185 int64_t timestamp, int flags);
187 #define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */
189 typedef struct URLProtocol {
191 int (*url_open)(URLContext *h, const char *url, int flags);
192 int (*url_read)(URLContext *h, unsigned char *buf, int size);
193 int (*url_write)(URLContext *h, const unsigned char *buf, int size);
194 int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
195 int (*url_close)(URLContext *h);
196 struct URLProtocol *next;
197 int (*url_read_pause)(URLContext *h, int pause);
198 int64_t (*url_read_seek)(URLContext *h, int stream_index,
199 int64_t timestamp, int flags);
200 int (*url_get_file_handle)(URLContext *h);
202 const AVClass *priv_data_class;
206 #if FF_API_REGISTER_PROTOCOL
207 extern URLProtocol *first_protocol;
210 extern URLInterruptCB *url_interrupt_cb;
213 * If protocol is NULL, returns the first registered protocol,
214 * if protocol is non-NULL, returns the next registered protocol after protocol,
215 * or NULL if protocol is the last one.
217 URLProtocol *av_protocol_next(URLProtocol *p);
219 #if FF_API_REGISTER_PROTOCOL
221 * @deprecated Use av_register_protocol() instead.
223 attribute_deprecated int register_protocol(URLProtocol *protocol);
226 * @deprecated Use av_register_protocol2() instead.
228 attribute_deprecated int av_register_protocol(URLProtocol *protocol);
232 * Register the URLProtocol protocol.
234 * @param size the size of the URLProtocol struct referenced
236 int av_register_protocol2(URLProtocol *protocol, int size);
238 #define AVIO_SEEKABLE_NORMAL 0x0001 /**< Seeking works like for a local file */
245 * Bytestream IO Context.
246 * New fields can be added to the end with minor version bumps.
247 * Removal, reordering and changes to existing fields require a major
249 * sizeof(AVIOContext) must not be used outside libav*.
252 unsigned char *buffer;
254 unsigned char *buf_ptr, *buf_end;
256 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
257 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
258 int64_t (*seek)(void *opaque, int64_t offset, int whence);
259 int64_t pos; /**< position in the file of the current buffer */
260 int must_flush; /**< true if the next seek should flush */
261 int eof_reached; /**< true if eof reached */
262 int write_flag; /**< true if open for writing */
264 attribute_deprecated int is_streamed;
267 unsigned long checksum;
268 unsigned char *checksum_ptr;
269 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
270 int error; ///< contains the error code or 0 if no error happened
271 int (*read_pause)(void *opaque, int pause);
272 int64_t (*read_seek)(void *opaque, int stream_index,
273 int64_t timestamp, int flags);
275 * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
281 typedef attribute_deprecated AVIOContext ByteIOContext;
283 attribute_deprecated int init_put_byte(AVIOContext *s,
284 unsigned char *buffer,
288 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
289 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
290 int64_t (*seek)(void *opaque, int64_t offset, int whence));
291 attribute_deprecated AVIOContext *av_alloc_put_byte(
292 unsigned char *buffer,
296 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
297 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
298 int64_t (*seek)(void *opaque, int64_t offset, int whence));
301 * @defgroup old_avio_funcs Old put_/get_*() functions
302 * @deprecated use the avio_ -prefixed functions instead.
305 attribute_deprecated int get_buffer(AVIOContext *s, unsigned char *buf, int size);
306 attribute_deprecated int get_partial_buffer(AVIOContext *s, unsigned char *buf, int size);
307 attribute_deprecated int get_byte(AVIOContext *s);
308 attribute_deprecated unsigned int get_le16(AVIOContext *s);
309 attribute_deprecated unsigned int get_le24(AVIOContext *s);
310 attribute_deprecated unsigned int get_le32(AVIOContext *s);
311 attribute_deprecated uint64_t get_le64(AVIOContext *s);
312 attribute_deprecated unsigned int get_be16(AVIOContext *s);
313 attribute_deprecated unsigned int get_be24(AVIOContext *s);
314 attribute_deprecated unsigned int get_be32(AVIOContext *s);
315 attribute_deprecated uint64_t get_be64(AVIOContext *s);
317 attribute_deprecated void put_byte(AVIOContext *s, int b);
318 attribute_deprecated void put_nbyte(AVIOContext *s, int b, int count);
319 attribute_deprecated void put_buffer(AVIOContext *s, const unsigned char *buf, int size);
320 attribute_deprecated void put_le64(AVIOContext *s, uint64_t val);
321 attribute_deprecated void put_be64(AVIOContext *s, uint64_t val);
322 attribute_deprecated void put_le32(AVIOContext *s, unsigned int val);
323 attribute_deprecated void put_be32(AVIOContext *s, unsigned int val);
324 attribute_deprecated void put_le24(AVIOContext *s, unsigned int val);
325 attribute_deprecated void put_be24(AVIOContext *s, unsigned int val);
326 attribute_deprecated void put_le16(AVIOContext *s, unsigned int val);
327 attribute_deprecated void put_be16(AVIOContext *s, unsigned int val);
328 attribute_deprecated void put_tag(AVIOContext *s, const char *tag);
333 attribute_deprecated int av_url_read_fpause(AVIOContext *h, int pause);
334 attribute_deprecated int64_t av_url_read_fseek (AVIOContext *h, int stream_index,
335 int64_t timestamp, int flags);
338 * @defgroup old_url_f_funcs Old url_f* functions
339 * @deprecated use the avio_ -prefixed functions instead.
342 attribute_deprecated int url_fopen( AVIOContext **s, const char *url, int flags);
343 attribute_deprecated int url_fclose(AVIOContext *s);
344 attribute_deprecated int64_t url_fseek(AVIOContext *s, int64_t offset, int whence);
345 attribute_deprecated int url_fskip(AVIOContext *s, int64_t offset);
346 attribute_deprecated int64_t url_ftell(AVIOContext *s);
347 attribute_deprecated int64_t url_fsize(AVIOContext *s);
349 attribute_deprecated int url_fgetc(AVIOContext *s);
350 attribute_deprecated int url_setbufsize(AVIOContext *s, int buf_size);
352 attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
354 attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...);
356 attribute_deprecated void put_flush_packet(AVIOContext *s);
357 attribute_deprecated int url_open_dyn_buf(AVIOContext **s);
358 attribute_deprecated int url_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
359 attribute_deprecated int url_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
360 attribute_deprecated int url_fdopen(AVIOContext **s, URLContext *h);
366 * @deprecated use AVIOContext.eof_reached
368 attribute_deprecated int url_feof(AVIOContext *s);
369 attribute_deprecated int url_ferror(AVIOContext *s);
371 attribute_deprecated int udp_set_remote_url(URLContext *h, const char *uri);
372 attribute_deprecated int udp_get_local_port(URLContext *h);
374 attribute_deprecated void init_checksum(AVIOContext *s,
375 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
376 unsigned long checksum);
377 attribute_deprecated unsigned long get_checksum(AVIOContext *s);
381 * Allocate and initialize an AVIOContext for buffered I/O. It must be later
382 * freed with av_free().
384 * @param buffer Memory block for input/output operations via AVIOContext.
385 * @param buffer_size The buffer size is very important for performance.
386 * For protocols with fixed blocksize it should be set to this blocksize.
387 * For others a typical size is a cache page, e.g. 4kb.
388 * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.
389 * @param opaque An opaque pointer to user-specific data.
390 * @param read_packet A function for refilling the buffer, may be NULL.
391 * @param write_packet A function for writing the buffer contents, may be NULL.
392 * @param seek A function for seeking to specified byte position, may be NULL.
394 * @return Allocated AVIOContext or NULL on failure.
396 AVIOContext *avio_alloc_context(
397 unsigned char *buffer,
401 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
402 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
403 int64_t (*seek)(void *opaque, int64_t offset, int whence));
405 void avio_w8(AVIOContext *s, int b);
406 void avio_write(AVIOContext *s, const unsigned char *buf, int size);
407 void avio_wl64(AVIOContext *s, uint64_t val);
408 void avio_wb64(AVIOContext *s, uint64_t val);
409 void avio_wl32(AVIOContext *s, unsigned int val);
410 void avio_wb32(AVIOContext *s, unsigned int val);
411 void avio_wl24(AVIOContext *s, unsigned int val);
412 void avio_wb24(AVIOContext *s, unsigned int val);
413 void avio_wl16(AVIOContext *s, unsigned int val);
414 void avio_wb16(AVIOContext *s, unsigned int val);
417 attribute_deprecated void put_strz(AVIOContext *s, const char *buf);
421 * Write a NULL-terminated string.
422 * @return number of bytes written.
424 int avio_put_str(AVIOContext *s, const char *str);
427 * Convert an UTF-8 string to UTF-16LE and write it.
428 * @return number of bytes written.
430 int avio_put_str16le(AVIOContext *s, const char *str);
433 * Passing this as the "whence" parameter to a seek function causes it to
434 * return the filesize without seeking anywhere. Supporting this is optional.
435 * If it is not supported then the seek function will return <0.
437 #define AVSEEK_SIZE 0x10000
440 * Oring this flag as into the "whence" parameter to a seek function causes it to
441 * seek by any means (like reopening and linear reading) or other normally unreasonble
442 * means that can be extreemly slow.
443 * This may be ignored by the seek code.
445 #define AVSEEK_FORCE 0x20000
448 * fseek() equivalent for AVIOContext.
449 * @return new position or AVERROR.
451 int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);
454 * Skip given number of bytes forward
455 * @return new position or AVERROR.
457 static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
459 return avio_seek(s, offset, SEEK_CUR);
463 * ftell() equivalent for AVIOContext.
464 * @return position or AVERROR.
466 static av_always_inline int64_t avio_tell(AVIOContext *s)
468 return avio_seek(s, 0, SEEK_CUR);
473 * @return filesize or AVERROR
475 int64_t avio_size(AVIOContext *s);
477 /** @warning currently size is limited */
479 int avio_printf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
481 int avio_printf(AVIOContext *s, const char *fmt, ...);
485 /** @note unlike fgets, the EOL character is not returned and a whole
486 line is parsed. return NULL if first char read was EOF */
487 attribute_deprecated char *url_fgets(AVIOContext *s, char *buf, int buf_size);
490 void avio_flush(AVIOContext *s);
494 * Read size bytes from AVIOContext into buf.
495 * @return number of bytes read or AVERROR
497 int avio_read(AVIOContext *s, unsigned char *buf, int size);
499 /** @note return 0 if EOF, so you cannot use it if EOF handling is
501 int avio_r8 (AVIOContext *s);
502 unsigned int avio_rl16(AVIOContext *s);
503 unsigned int avio_rl24(AVIOContext *s);
504 unsigned int avio_rl32(AVIOContext *s);
505 uint64_t avio_rl64(AVIOContext *s);
508 * Read a string from pb into buf. The reading will terminate when either
509 * a NULL character was encountered, maxlen bytes have been read, or nothing
510 * more can be read from pb. The result is guaranteed to be NULL-terminated, it
511 * will be truncated if buf is too small.
512 * Note that the string is not interpreted or validated in any way, it
513 * might get truncated in the middle of a sequence for multi-byte encodings.
515 * @return number of bytes read (is always <= maxlen).
516 * If reading ends on EOF or error, the return value will be one more than
517 * bytes actually read.
519 int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);
522 * Read a UTF-16 string from pb and convert it to UTF-8.
523 * The reading will terminate when either a null or invalid character was
524 * encountered or maxlen bytes have been read.
525 * @return number of bytes read (is always <= maxlen)
527 int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);
528 int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);
532 * @deprecated use avio_get_str instead
534 attribute_deprecated char *get_strz(AVIOContext *s, char *buf, int maxlen);
536 unsigned int avio_rb16(AVIOContext *s);
537 unsigned int avio_rb24(AVIOContext *s);
538 unsigned int avio_rb32(AVIOContext *s);
539 uint64_t avio_rb64(AVIOContext *s);
543 * @deprecated Use AVIOContext.seekable field directly.
545 attribute_deprecated static inline int url_is_streamed(AVIOContext *s)
551 #if FF_API_URL_RESETBUF
552 /** Reset the buffer for reading or writing.
553 * @note Will drop any data currently in the buffer without transmitting it.
554 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
555 * to set up the buffer for writing. */
556 int url_resetbuf(AVIOContext *s, int flags);
560 * Create and initialize a AVIOContext for accessing the
561 * resource indicated by url.
562 * @note When the resource indicated by url has been opened in
563 * read+write mode, the AVIOContext can be used only for writing.
565 * @param s Used to return the pointer to the created AVIOContext.
566 * In case of failure the pointed to value is set to NULL.
567 * @param flags flags which control how the resource indicated by url
569 * @return 0 in case of success, a negative value corresponding to an
570 * AVERROR code in case of failure
572 int avio_open(AVIOContext **s, const char *url, int flags);
574 int avio_close(AVIOContext *s);
577 attribute_deprecated URLContext *url_fileno(AVIOContext *s);
580 * @deprecated use AVIOContext.max_packet_size directly.
582 attribute_deprecated int url_fget_max_packet_size(AVIOContext *s);
584 attribute_deprecated int url_open_buf(AVIOContext **s, uint8_t *buf, int buf_size, int flags);
586 /** return the written or read size */
587 attribute_deprecated int url_close_buf(AVIOContext *s);
591 * Open a write only memory stream.
593 * @param s new IO context
594 * @return zero if no error.
596 int avio_open_dyn_buf(AVIOContext **s);
599 * Return the written size and a pointer to the buffer. The buffer
600 * must be freed with av_free().
601 * Padding of FF_INPUT_BUFFER_PADDING_SIZE is added to the buffer.
603 * @param s IO context
604 * @param pbuffer pointer to a byte buffer
605 * @return the length of the byte buffer
607 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
609 #if FF_API_UDP_GET_FILE
610 int udp_get_file_handle(URLContext *h);
613 #endif /* AVFORMAT_AVIO_H */