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avio.h
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1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
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.
10  *
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.
15  *
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
19  */
20 #ifndef AVFORMAT_AVIO_H
21 #define AVFORMAT_AVIO_H
22 
23 /**
24  * @file
25  * @ingroup lavf_io
26  * Buffered I/O operations
27  */
28 
29 #include <stdint.h>
30 
31 #include "libavutil/common.h"
32 #include "libavutil/dict.h"
33 #include "libavutil/log.h"
34 
35 #include "libavformat/version.h"
36 
37 #define AVIO_SEEKABLE_NORMAL 0x0001 /**< Seeking works like for a local file */
38 
39 /**
40  * Callback for checking whether to abort blocking functions.
41  * AVERROR_EXIT is returned in this case by the interrupted
42  * function. During blocking operations, callback is called with
43  * opaque as parameter. If the callback returns 1, the
44  * blocking operation will be aborted.
45  *
46  * No members can be added to this struct without a major bump, if
47  * new elements have been added after this struct in AVFormatContext
48  * or AVIOContext.
49  */
50 typedef struct AVIOInterruptCB {
51  int (*callback)(void*);
52  void *opaque;
54 
55 /**
56  * Directory entry types.
57  */
70 };
71 
72 /**
73  * Describes single entry of the directory.
74  *
75  * Only name and type fields are guaranteed be set.
76  * Rest of fields are protocol or/and platform dependent and might be unknown.
77  */
78 typedef struct AVIODirEntry {
79  char *name; /**< Filename */
80  int type; /**< Type of the entry */
81  int utf8; /**< Set to 1 when name is encoded with UTF-8, 0 otherwise.
82  Name can be encoded with UTF-8 even though 0 is set. */
83  int64_t size; /**< File size in bytes, -1 if unknown. */
84  int64_t modification_timestamp; /**< Time of last modification in microseconds since unix
85  epoch, -1 if unknown. */
86  int64_t access_timestamp; /**< Time of last access in microseconds since unix epoch,
87  -1 if unknown. */
88  int64_t status_change_timestamp; /**< Time of last status change in microseconds since unix
89  epoch, -1 if unknown. */
90  int64_t user_id; /**< User ID of owner, -1 if unknown. */
91  int64_t group_id; /**< Group ID of owner, -1 if unknown. */
92  int64_t filemode; /**< Unix file mode, -1 if unknown. */
93 } AVIODirEntry;
94 
95 typedef struct AVIODirContext {
98 
99 /**
100  * Different data types that can be returned via the AVIO
101  * write_data_type callback.
102  */
104  /**
105  * Header data; this needs to be present for the stream to be decodeable.
106  */
108  /**
109  * A point in the output bytestream where a decoder can start decoding
110  * (i.e. a keyframe). A demuxer/decoder given the data flagged with
111  * AVIO_DATA_MARKER_HEADER, followed by any AVIO_DATA_MARKER_SYNC_POINT,
112  * should give decodeable results.
113  */
115  /**
116  * A point in the output bytestream where a demuxer can start parsing
117  * (for non self synchronizing bytestream formats). That is, any
118  * non-keyframe packet start point.
119  */
121  /**
122  * This is any, unlabelled data. It can either be a muxer not marking
123  * any positions at all, it can be an actual boundary/sync point
124  * that the muxer chooses not to mark, or a later part of a packet/fragment
125  * that is cut into multiple write callbacks due to limited IO buffer size.
126  */
128  /**
129  * Trailer data, which doesn't contain actual content, but only for
130  * finalizing the output file.
131  */
133 };
134 
135 /**
136  * Bytestream IO Context.
137  * New fields can be added to the end with minor version bumps.
138  * Removal, reordering and changes to existing fields require a major
139  * version bump.
140  * sizeof(AVIOContext) must not be used outside libav*.
141  *
142  * @note None of the function pointers in AVIOContext should be called
143  * directly, they should only be set by the client application
144  * when implementing custom I/O. Normally these are set to the
145  * function pointers specified in avio_alloc_context()
146  */
147 typedef struct AVIOContext {
148  /**
149  * A class for private options.
150  *
151  * If this AVIOContext is created by avio_open2(), av_class is set and
152  * passes the options down to protocols.
153  *
154  * If this AVIOContext is manually allocated, then av_class may be set by
155  * the caller.
156  *
157  * warning -- this field can be NULL, be sure to not pass this AVIOContext
158  * to any av_opt_* functions in that case.
159  */
161 
162  /*
163  * The following shows the relationship between buffer, buf_ptr, buf_end, buf_size,
164  * and pos, when reading and when writing (since AVIOContext is used for both):
165  *
166  **********************************************************************************
167  * READING
168  **********************************************************************************
169  *
170  * | buffer_size |
171  * |---------------------------------------|
172  * | |
173  *
174  * buffer buf_ptr buf_end
175  * +---------------+-----------------------+
176  * |/ / / / / / / /|/ / / / / / /| |
177  * read buffer: |/ / consumed / | to be read /| |
178  * |/ / / / / / / /|/ / / / / / /| |
179  * +---------------+-----------------------+
180  *
181  * pos
182  * +-------------------------------------------+-----------------+
183  * input file: | | |
184  * +-------------------------------------------+-----------------+
185  *
186  *
187  **********************************************************************************
188  * WRITING
189  **********************************************************************************
190  *
191  * | buffer_size |
192  * |-------------------------------|
193  * | |
194  *
195  * buffer buf_ptr buf_end
196  * +-------------------+-----------+
197  * |/ / / / / / / / / /| |
198  * write buffer: | / to be flushed / | |
199  * |/ / / / / / / / / /| |
200  * +-------------------+-----------+
201  *
202  * pos
203  * +--------------------------+-----------------------------------+
204  * output file: | | |
205  * +--------------------------+-----------------------------------+
206  *
207  */
208  unsigned char *buffer; /**< Start of the buffer. */
209  int buffer_size; /**< Maximum buffer size */
210  unsigned char *buf_ptr; /**< Current position in the buffer */
211  unsigned char *buf_end; /**< End of the data, may be less than
212  buffer+buffer_size if the read function returned
213  less data than requested, e.g. for streams where
214  no more data has been received yet. */
215  void *opaque; /**< A private pointer, passed to the read/write/seek/...
216  functions. */
217  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
218  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
219  int64_t (*seek)(void *opaque, int64_t offset, int whence);
220  int64_t pos; /**< position in the file of the current buffer */
221  int must_flush; /**< true if the next seek should flush */
222  int eof_reached; /**< true if eof reached */
223  int write_flag; /**< true if open for writing */
225  unsigned long checksum;
226  unsigned char *checksum_ptr;
227  unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
228  int error; /**< contains the error code or 0 if no error happened */
229  /**
230  * Pause or resume playback for network streaming protocols - e.g. MMS.
231  */
232  int (*read_pause)(void *opaque, int pause);
233  /**
234  * Seek to a given timestamp in stream with the specified stream_index.
235  * Needed for some network streaming protocols which don't support seeking
236  * to byte position.
237  */
238  int64_t (*read_seek)(void *opaque, int stream_index,
239  int64_t timestamp, int flags);
240  /**
241  * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
242  */
243  int seekable;
244 
245  /**
246  * max filesize, used to limit allocations
247  * This field is internal to libavformat and access from outside is not allowed.
248  */
249  int64_t maxsize;
250 
251  /**
252  * avio_read and avio_write should if possible be satisfied directly
253  * instead of going through a buffer, and avio_seek will always
254  * call the underlying seek function directly.
255  */
256  int direct;
257 
258  /**
259  * Bytes read statistic
260  * This field is internal to libavformat and access from outside is not allowed.
261  */
262  int64_t bytes_read;
263 
264  /**
265  * seek statistic
266  * This field is internal to libavformat and access from outside is not allowed.
267  */
269 
270  /**
271  * writeout statistic
272  * This field is internal to libavformat and access from outside is not allowed.
273  */
275 
276  /**
277  * Original buffer size
278  * used internally after probing and ensure seekback to reset the buffer size
279  * This field is internal to libavformat and access from outside is not allowed.
280  */
282 
283  /**
284  * Threshold to favor readahead over seek.
285  * This is current internal only, do not use from outside.
286  */
288 
289  /**
290  * ',' separated list of allowed protocols.
291  */
292  const char *protocol_whitelist;
293 
294  /**
295  * ',' separated list of disallowed protocols.
296  */
297  const char *protocol_blacklist;
298 
299  /**
300  * A callback that is used instead of write_packet.
301  */
302  int (*write_data_type)(void *opaque, uint8_t *buf, int buf_size,
303  enum AVIODataMarkerType type, int64_t time);
304  /**
305  * If set, don't call write_data_type separately for AVIO_DATA_MARKER_BOUNDARY_POINT,
306  * but ignore them and treat them as AVIO_DATA_MARKER_UNKNOWN (to avoid needlessly
307  * small chunks of data returned from the callback).
308  */
310 
311  /**
312  * Internal, not meant to be used from outside of AVIOContext.
313  */
315  int64_t last_time;
316 } AVIOContext;
317 
318 /**
319  * Return the name of the protocol that will handle the passed URL.
320  *
321  * NULL is returned if no protocol could be found for the given URL.
322  *
323  * @return Name of the protocol or NULL.
324  */
325 const char *avio_find_protocol_name(const char *url);
326 
327 /**
328  * Return AVIO_FLAG_* access flags corresponding to the access permissions
329  * of the resource in url, or a negative value corresponding to an
330  * AVERROR code in case of failure. The returned access flags are
331  * masked by the value in flags.
332  *
333  * @note This function is intrinsically unsafe, in the sense that the
334  * checked resource may change its existence or permission status from
335  * one call to another. Thus you should not trust the returned value,
336  * unless you are sure that no other processes are accessing the
337  * checked resource.
338  */
339 int avio_check(const char *url, int flags);
340 
341 /**
342  * Move or rename a resource.
343  *
344  * @note url_src and url_dst should share the same protocol and authority.
345  *
346  * @param url_src url to resource to be moved
347  * @param url_dst new url to resource if the operation succeeded
348  * @return >=0 on success or negative on error.
349  */
350 int avpriv_io_move(const char *url_src, const char *url_dst);
351 
352 /**
353  * Delete a resource.
354  *
355  * @param url resource to be deleted.
356  * @return >=0 on success or negative on error.
357  */
358 int avpriv_io_delete(const char *url);
359 
360 /**
361  * Open directory for reading.
362  *
363  * @param s directory read context. Pointer to a NULL pointer must be passed.
364  * @param url directory to be listed.
365  * @param options A dictionary filled with protocol-private options. On return
366  * this parameter will be destroyed and replaced with a dictionary
367  * containing options that were not found. May be NULL.
368  * @return >=0 on success or negative on error.
369  */
370 int avio_open_dir(AVIODirContext **s, const char *url, AVDictionary **options);
371 
372 /**
373  * Get next directory entry.
374  *
375  * Returned entry must be freed with avio_free_directory_entry(). In particular
376  * it may outlive AVIODirContext.
377  *
378  * @param s directory read context.
379  * @param[out] next next entry or NULL when no more entries.
380  * @return >=0 on success or negative on error. End of list is not considered an
381  * error.
382  */
384 
385 /**
386  * Close directory.
387  *
388  * @note Entries created using avio_read_dir() are not deleted and must be
389  * freeded with avio_free_directory_entry().
390  *
391  * @param s directory read context.
392  * @return >=0 on success or negative on error.
393  */
395 
396 /**
397  * Free entry allocated by avio_read_dir().
398  *
399  * @param entry entry to be freed.
400  */
402 
403 /**
404  * Allocate and initialize an AVIOContext for buffered I/O. It must be later
405  * freed with av_free().
406  *
407  * @param buffer Memory block for input/output operations via AVIOContext.
408  * The buffer must be allocated with av_malloc() and friends.
409  * It may be freed and replaced with a new buffer by libavformat.
410  * AVIOContext.buffer holds the buffer currently in use,
411  * which must be later freed with av_free().
412  * @param buffer_size The buffer size is very important for performance.
413  * For protocols with fixed blocksize it should be set to this blocksize.
414  * For others a typical size is a cache page, e.g. 4kb.
415  * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.
416  * @param opaque An opaque pointer to user-specific data.
417  * @param read_packet A function for refilling the buffer, may be NULL.
418  * @param write_packet A function for writing the buffer contents, may be NULL.
419  * The function may not change the input buffers content.
420  * @param seek A function for seeking to specified byte position, may be NULL.
421  *
422  * @return Allocated AVIOContext or NULL on failure.
423  */
425  unsigned char *buffer,
426  int buffer_size,
427  int write_flag,
428  void *opaque,
429  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
430  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
431  int64_t (*seek)(void *opaque, int64_t offset, int whence));
432 
433 void avio_w8(AVIOContext *s, int b);
434 void avio_write(AVIOContext *s, const unsigned char *buf, int size);
435 void avio_wl64(AVIOContext *s, uint64_t val);
436 void avio_wb64(AVIOContext *s, uint64_t val);
437 void avio_wl32(AVIOContext *s, unsigned int val);
438 void avio_wb32(AVIOContext *s, unsigned int val);
439 void avio_wl24(AVIOContext *s, unsigned int val);
440 void avio_wb24(AVIOContext *s, unsigned int val);
441 void avio_wl16(AVIOContext *s, unsigned int val);
442 void avio_wb16(AVIOContext *s, unsigned int val);
443 
444 /**
445  * Write a NULL-terminated string.
446  * @return number of bytes written.
447  */
448 int avio_put_str(AVIOContext *s, const char *str);
449 
450 /**
451  * Convert an UTF-8 string to UTF-16LE and write it.
452  * @param s the AVIOContext
453  * @param str NULL-terminated UTF-8 string
454  *
455  * @return number of bytes written.
456  */
457 int avio_put_str16le(AVIOContext *s, const char *str);
458 
459 /**
460  * Convert an UTF-8 string to UTF-16BE and write it.
461  * @param s the AVIOContext
462  * @param str NULL-terminated UTF-8 string
463  *
464  * @return number of bytes written.
465  */
466 int avio_put_str16be(AVIOContext *s, const char *str);
467 
468 /**
469  * Mark the written bytestream as a specific type.
470  *
471  * Zero-length ranges are omitted from the output.
472  *
473  * @param time the stream time the current bytestream pos corresponds to
474  * (in AV_TIME_BASE units), or AV_NOPTS_VALUE if unknown or not
475  * applicable
476  * @param type the kind of data written starting at the current pos
477  */
478 void avio_write_marker(AVIOContext *s, int64_t time, enum AVIODataMarkerType type);
479 
480 /**
481  * ORing this as the "whence" parameter to a seek function causes it to
482  * return the filesize without seeking anywhere. Supporting this is optional.
483  * If it is not supported then the seek function will return <0.
484  */
485 #define AVSEEK_SIZE 0x10000
486 
487 /**
488  * Passing this flag as the "whence" parameter to a seek function causes it to
489  * seek by any means (like reopening and linear reading) or other normally unreasonable
490  * means that can be extremely slow.
491  * This may be ignored by the seek code.
492  */
493 #define AVSEEK_FORCE 0x20000
494 
495 /**
496  * fseek() equivalent for AVIOContext.
497  * @return new position or AVERROR.
498  */
499 int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);
500 
501 /**
502  * Skip given number of bytes forward
503  * @return new position or AVERROR.
504  */
505 int64_t avio_skip(AVIOContext *s, int64_t offset);
506 
507 /**
508  * ftell() equivalent for AVIOContext.
509  * @return position or AVERROR.
510  */
512 {
513  return avio_seek(s, 0, SEEK_CUR);
514 }
515 
516 /**
517  * Get the filesize.
518  * @return filesize or AVERROR
519  */
520 int64_t avio_size(AVIOContext *s);
521 
522 /**
523  * feof() equivalent for AVIOContext.
524  * @return non zero if and only if end of file
525  */
526 int avio_feof(AVIOContext *s);
527 #if FF_API_URL_FEOF
528 /**
529  * @deprecated use avio_feof()
530  */
532 int url_feof(AVIOContext *s);
533 #endif
534 
535 /** @warning Writes up to 4 KiB per call */
536 int avio_printf(AVIOContext *s, const char *fmt, ...) av_printf_format(2, 3);
537 
538 /**
539  * Force flushing of buffered data.
540  *
541  * For write streams, force the buffered data to be immediately written to the output,
542  * without to wait to fill the internal buffer.
543  *
544  * For read streams, discard all currently buffered data, and advance the
545  * reported file position to that of the underlying stream. This does not
546  * read new data, and does not perform any seeks.
547  */
548 void avio_flush(AVIOContext *s);
549 
550 /**
551  * Read size bytes from AVIOContext into buf.
552  * @return number of bytes read or AVERROR
553  */
554 int avio_read(AVIOContext *s, unsigned char *buf, int size);
555 
556 /**
557  * @name Functions for reading from AVIOContext
558  * @{
559  *
560  * @note return 0 if EOF, so you cannot use it if EOF handling is
561  * necessary
562  */
563 int avio_r8 (AVIOContext *s);
564 unsigned int avio_rl16(AVIOContext *s);
565 unsigned int avio_rl24(AVIOContext *s);
566 unsigned int avio_rl32(AVIOContext *s);
567 uint64_t avio_rl64(AVIOContext *s);
568 unsigned int avio_rb16(AVIOContext *s);
569 unsigned int avio_rb24(AVIOContext *s);
570 unsigned int avio_rb32(AVIOContext *s);
571 uint64_t avio_rb64(AVIOContext *s);
572 /**
573  * @}
574  */
575 
576 /**
577  * Read a string from pb into buf. The reading will terminate when either
578  * a NULL character was encountered, maxlen bytes have been read, or nothing
579  * more can be read from pb. The result is guaranteed to be NULL-terminated, it
580  * will be truncated if buf is too small.
581  * Note that the string is not interpreted or validated in any way, it
582  * might get truncated in the middle of a sequence for multi-byte encodings.
583  *
584  * @return number of bytes read (is always <= maxlen).
585  * If reading ends on EOF or error, the return value will be one more than
586  * bytes actually read.
587  */
588 int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);
589 
590 /**
591  * Read a UTF-16 string from pb and convert it to UTF-8.
592  * The reading will terminate when either a null or invalid character was
593  * encountered or maxlen bytes have been read.
594  * @return number of bytes read (is always <= maxlen)
595  */
596 int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);
597 int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);
598 
599 
600 /**
601  * @name URL open modes
602  * The flags argument to avio_open must be one of the following
603  * constants, optionally ORed with other flags.
604  * @{
605  */
606 #define AVIO_FLAG_READ 1 /**< read-only */
607 #define AVIO_FLAG_WRITE 2 /**< write-only */
608 #define AVIO_FLAG_READ_WRITE (AVIO_FLAG_READ|AVIO_FLAG_WRITE) /**< read-write pseudo flag */
609 /**
610  * @}
611  */
612 
613 /**
614  * Use non-blocking mode.
615  * If this flag is set, operations on the context will return
616  * AVERROR(EAGAIN) if they can not be performed immediately.
617  * If this flag is not set, operations on the context will never return
618  * AVERROR(EAGAIN).
619  * Note that this flag does not affect the opening/connecting of the
620  * context. Connecting a protocol will always block if necessary (e.g. on
621  * network protocols) but never hang (e.g. on busy devices).
622  * Warning: non-blocking protocols is work-in-progress; this flag may be
623  * silently ignored.
624  */
625 #define AVIO_FLAG_NONBLOCK 8
626 
627 /**
628  * Use direct mode.
629  * avio_read and avio_write should if possible be satisfied directly
630  * instead of going through a buffer, and avio_seek will always
631  * call the underlying seek function directly.
632  */
633 #define AVIO_FLAG_DIRECT 0x8000
634 
635 /**
636  * Create and initialize a AVIOContext for accessing the
637  * resource indicated by url.
638  * @note When the resource indicated by url has been opened in
639  * read+write mode, the AVIOContext can be used only for writing.
640  *
641  * @param s Used to return the pointer to the created AVIOContext.
642  * In case of failure the pointed to value is set to NULL.
643  * @param url resource to access
644  * @param flags flags which control how the resource indicated by url
645  * is to be opened
646  * @return >= 0 in case of success, a negative value corresponding to an
647  * AVERROR code in case of failure
648  */
649 int avio_open(AVIOContext **s, const char *url, int flags);
650 
651 /**
652  * Create and initialize a AVIOContext for accessing the
653  * resource indicated by url.
654  * @note When the resource indicated by url has been opened in
655  * read+write mode, the AVIOContext can be used only for writing.
656  *
657  * @param s Used to return the pointer to the created AVIOContext.
658  * In case of failure the pointed to value is set to NULL.
659  * @param url resource to access
660  * @param flags flags which control how the resource indicated by url
661  * is to be opened
662  * @param int_cb an interrupt callback to be used at the protocols level
663  * @param options A dictionary filled with protocol-private options. On return
664  * this parameter will be destroyed and replaced with a dict containing options
665  * that were not found. May be NULL.
666  * @return >= 0 in case of success, a negative value corresponding to an
667  * AVERROR code in case of failure
668  */
669 int avio_open2(AVIOContext **s, const char *url, int flags,
671 
672 /**
673  * Close the resource accessed by the AVIOContext s and free it.
674  * This function can only be used if s was opened by avio_open().
675  *
676  * The internal buffer is automatically flushed before closing the
677  * resource.
678  *
679  * @return 0 on success, an AVERROR < 0 on error.
680  * @see avio_closep
681  */
682 int avio_close(AVIOContext *s);
683 
684 /**
685  * Close the resource accessed by the AVIOContext *s, free it
686  * and set the pointer pointing to it to NULL.
687  * This function can only be used if s was opened by avio_open().
688  *
689  * The internal buffer is automatically flushed before closing the
690  * resource.
691  *
692  * @return 0 on success, an AVERROR < 0 on error.
693  * @see avio_close
694  */
695 int avio_closep(AVIOContext **s);
696 
697 
698 /**
699  * Open a write only memory stream.
700  *
701  * @param s new IO context
702  * @return zero if no error.
703  */
705 
706 /**
707  * Return the written size and a pointer to the buffer. The buffer
708  * must be freed with av_free().
709  * Padding of AV_INPUT_BUFFER_PADDING_SIZE is added to the buffer.
710  *
711  * @param s IO context
712  * @param pbuffer pointer to a byte buffer
713  * @return the length of the byte buffer
714  */
715 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
716 
717 /**
718  * Iterate through names of available protocols.
719  *
720  * @param opaque A private pointer representing current protocol.
721  * It must be a pointer to NULL on first iteration and will
722  * be updated by successive calls to avio_enum_protocols.
723  * @param output If set to 1, iterate over output protocols,
724  * otherwise over input protocols.
725  *
726  * @return A static string containing the name of current protocol or NULL
727  */
728 const char *avio_enum_protocols(void **opaque, int output);
729 
730 /**
731  * Pause and resume playing - only meaningful if using a network streaming
732  * protocol (e.g. MMS).
733  *
734  * @param h IO context from which to call the read_pause function pointer
735  * @param pause 1 for pause, 0 for resume
736  */
737 int avio_pause(AVIOContext *h, int pause);
738 
739 /**
740  * Seek to a given timestamp relative to some component stream.
741  * Only meaningful if using a network streaming protocol (e.g. MMS.).
742  *
743  * @param h IO context from which to call the seek function pointers
744  * @param stream_index The stream index that the timestamp is relative to.
745  * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
746  * units from the beginning of the presentation.
747  * If a stream_index >= 0 is used and the protocol does not support
748  * seeking based on component streams, the call will fail.
749  * @param timestamp timestamp in AVStream.time_base units
750  * or if there is no stream specified then in AV_TIME_BASE units.
751  * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
752  * and AVSEEK_FLAG_ANY. The protocol may silently ignore
753  * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
754  * fail if used and not supported.
755  * @return >= 0 on success
756  * @see AVInputFormat::read_seek
757  */
758 int64_t avio_seek_time(AVIOContext *h, int stream_index,
759  int64_t timestamp, int flags);
760 
761 /* Avoid a warning. The header can not be included because it breaks c++. */
762 struct AVBPrint;
763 
764 /**
765  * Read contents of h into print buffer, up to max_size bytes, or up to EOF.
766  *
767  * @return 0 for success (max_size bytes read or EOF reached), negative error
768  * code otherwise
769  */
770 int avio_read_to_bprint(AVIOContext *h, struct AVBPrint *pb, size_t max_size);
771 
772 /**
773  * Accept and allocate a client context on a server context.
774  * @param s the server context
775  * @param c the client context, must be unallocated
776  * @return >= 0 on success or a negative value corresponding
777  * to an AVERROR on failure
778  */
780 
781 /**
782  * Perform one step of the protocol handshake to accept a new client.
783  * This function must be called on a client returned by avio_accept() before
784  * using it as a read/write context.
785  * It is separate from avio_accept() because it may block.
786  * A step of the handshake is defined by places where the application may
787  * decide to change the proceedings.
788  * For example, on a protocol with a request header and a reply header, each
789  * one can constitute a step because the application may use the parameters
790  * from the request to change parameters in the reply; or each individual
791  * chunk of the request can constitute a step.
792  * If the handshake is already finished, avio_handshake() does nothing and
793  * returns 0 immediately.
794  *
795  * @param c the client context to perform the handshake on
796  * @return 0 on a complete and successful handshake
797  * > 0 if the handshake progressed, but is not complete
798  * < 0 for an AVERROR code
799  */
801 #endif /* AVFORMAT_AVIO_H */
int avio_open(AVIOContext **s, const char *url, int flags)
Create and initialize a AVIOContext for accessing the resource indicated by url.
Definition: aviobuf.c:1027
void avio_wb64(AVIOContext *s, uint64_t val)
Definition: aviobuf.c:440
const char const char void * val
Definition: avisynth_c.h:634
void avio_wl16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:446
const char * s
Definition: avisynth_c.h:631
Bytestream IO Context.
Definition: avio.h:147
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:309
int64_t(* read_seek)(void *opaque, int stream_index, int64_t timestamp, int flags)
Seek to a given timestamp in stream with the specified stream_index.
Definition: avio.h:238
int avpriv_io_delete(const char *url)
Delete a resource.
Definition: avio.c:521
int avio_put_str16be(AVIOContext *s, const char *str)
Convert an UTF-8 string to UTF-16BE and write it.
int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
Return the written size and a pointer to the buffer.
Definition: aviobuf.c:1272
int64_t filemode
Unix file mode, -1 if unknown.
Definition: avio.h:92
const char * fmt
Definition: avisynth_c.h:632
int64_t last_time
Definition: avio.h:315
unsigned char * buf_ptr
Current position in the buffer.
Definition: avio.h:210
int writeout_count
writeout statistic This field is internal to libavformat and access from outside is not allowed...
Definition: avio.h:274
unsigned char * buf_end
End of the data, may be less than buffer+buffer_size if the read function returned less data than req...
Definition: avio.h:211
int write_flag
true if open for writing
Definition: avio.h:223
int avio_read_to_bprint(AVIOContext *h, struct AVBPrint *pb, size_t max_size)
Read contents of h into print buffer, up to max_size bytes, or up to EOF.
Definition: aviobuf.c:1132
Describes single entry of the directory.
Definition: avio.h:78
const char * b
Definition: vf_curves.c:113
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:230
unsigned char * buffer
Start of the buffer.
Definition: avio.h:208
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:304
int64_t(* seek)(void *opaque, int64_t offset, int whence)
Definition: avio.h:219
void * opaque
A private pointer, passed to the read/write/seek/...
Definition: avio.h:215
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:736
int64_t maxsize
max filesize, used to limit allocations This field is internal to libavformat and access from outside...
Definition: avio.h:249
int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen)
Read a UTF-16 string from pb and convert it to UTF-8.
int avio_open_dyn_buf(AVIOContext **s)
Open a write only memory stream.
Definition: aviobuf.c:1260
void * opaque
Definition: avio.h:52
Trailer data, which doesn't contain actual content, but only for finalizing the output file...
Definition: avio.h:132
int64_t modification_timestamp
Time of last modification in microseconds since unix epoch, -1 if unknown.
Definition: avio.h:84
Public dictionary API.
int avio_accept(AVIOContext *s, AVIOContext **c)
Accept and allocate a client context on a server context.
Definition: aviobuf.c:1150
void avio_wl32(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:346
uint8_t
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:751
void avio_write_marker(AVIOContext *s, int64_t time, enum AVIODataMarkerType type)
Mark the written bytestream as a specific type.
Definition: aviobuf.c:470
const AVClass * av_class
A class for private options.
Definition: avio.h:160
A point in the output bytestream where a demuxer can start parsing (for non self synchronizing bytest...
Definition: avio.h:120
int64_t bytes_read
Bytes read statistic This field is internal to libavformat and access from outside is not allowed...
Definition: avio.h:262
ptrdiff_t size
Definition: opengl_enc.c:101
uint64_t avio_rb64(AVIOContext *s)
Definition: aviobuf.c:818
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:511
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:204
const OptionDef options[]
Definition: ffserver.c:3969
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:598
int avio_check(const char *url, int flags)
Return AVIO_FLAG_* access flags corresponding to the access permissions of the resource in url...
Definition: avio.c:480
void avio_wl64(AVIOContext *s, uint64_t val)
Definition: aviobuf.c:434
int max_packet_size
Definition: avio.h:224
Callback for checking whether to abort blocking functions.
Definition: avio.h:50
AVIOContext * avio_alloc_context(unsigned char *buffer, int buffer_size, int write_flag, void *opaque, int(*read_packet)(void *opaque, uint8_t *buf, int buf_size), int(*write_packet)(void *opaque, uint8_t *buf, int buf_size), int64_t(*seek)(void *opaque, int64_t offset, int whence))
Allocate and initialize an AVIOContext for buffered I/O.
Definition: aviobuf.c:126
char * name
Filename.
Definition: avio.h:79
int(* write_packet)(void *opaque, uint8_t *buf, int buf_size)
Definition: avio.h:218
int(* callback)(void *)
Definition: avio.h:51
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:457
int(* read_packet)(void *opaque, uint8_t *buf, int buf_size)
Definition: avio.h:217
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:720
const char * avio_enum_protocols(void **opaque, int output)
Iterate through names of available protocols.
Definition: protocols.c:95
int avio_close(AVIOContext *s)
Close the resource accessed by the AVIOContext s and free it.
Definition: aviobuf.c:1063
int utf8
Set to 1 when name is encoded with UTF-8, 0 otherwise.
Definition: avio.h:81
const char * protocol_whitelist
',' separated list of allowed protocols.
Definition: avio.h:292
unsigned long checksum
Definition: avio.h:225
static const uint8_t offset[127][2]
Definition: vf_spp.c:92
int direct
avio_read and avio_write should if possible be satisfied directly instead of going through a buffer...
Definition: avio.h:256
const char * protocol_blacklist
',' separated list of disallowed protocols.
Definition: avio.h:297
#define av_printf_format(fmtpos, attrpos)
Definition: attributes.h:156
int seek_count
seek statistic This field is internal to libavformat and access from outside is not allowed...
Definition: avio.h:268
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:589
int(* write_data_type)(void *opaque, uint8_t *buf, int buf_size, enum AVIODataMarkerType type, int64_t time)
A callback that is used instead of write_packet.
Definition: avio.h:302
This is any, unlabelled data.
Definition: avio.h:127
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:243
int void avio_flush(AVIOContext *s)
Force flushing of buffered data.
Definition: aviobuf.c:224
unsigned int avio_rb24(AVIOContext *s)
Definition: aviobuf.c:744
void avio_free_directory_entry(AVIODirEntry **entry)
Free entry allocated by avio_read_dir().
Definition: avio.c:603
int64_t access_timestamp
Time of last access in microseconds since unix epoch, -1 if unknown.
Definition: avio.h:86
unsigned char * checksum_ptr
Definition: avio.h:226
AVIODataMarkerType
Different data types that can be returned via the AVIO write_data_type callback.
Definition: avio.h:103
void avio_wb24(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:464
int must_flush
true if the next seek should flush
Definition: avio.h:221
Libavformat version macros.
unsigned long(* update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size)
Definition: avio.h:227
int64_t size
File size in bytes, -1 if unknown.
Definition: avio.h:83
int buffer_size
Maximum buffer size.
Definition: avio.h:209
int avpriv_io_move(const char *url_src, const char *url_dst)
Move or rename a resource.
Definition: avio.c:499
int avio_put_str(AVIOContext *s, const char *str)
Write a NULL-terminated string.
Definition: aviobuf.c:362
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
int type
Type of the entry.
Definition: avio.h:80
void avio_w8(AVIOContext *s, int b)
Definition: aviobuf.c:182
void * buf
Definition: avisynth_c.h:553
Definition: url.h:38
GLint GLenum type
Definition: opengl_enc.c:105
Describe the class of an AVClass context structure.
Definition: log.h:67
int64_t group_id
Group ID of owner, -1 if unknown.
Definition: avio.h:91
const char * avio_find_protocol_name(const char *url)
Return the name of the protocol that will handle the passed URL.
Definition: avio.c:473
int avio_put_str16le(AVIOContext *s, const char *str)
Convert an UTF-8 string to UTF-16LE and write it.
int avio_open2(AVIOContext **s, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Create and initialize a AVIOContext for accessing the resource indicated by url.
Definition: aviobuf.c:1051
int short_seek_threshold
Threshold to favor readahead over seek.
Definition: avio.h:287
int avio_handshake(AVIOContext *c)
Perform one step of the protocol handshake to accept a new client.
Definition: aviobuf.c:1161
int avio_close_dir(AVIODirContext **s)
Close directory.
Definition: avio.c:588
int ignore_boundary_point
If set, don't call write_data_type separately for AVIO_DATA_MARKER_BOUNDARY_POINT, but ignore them and treat them as AVIO_DATA_MARKER_UNKNOWN (to avoid needlessly small chunks of data returned from the callback).
Definition: avio.h:309
int error
contains the error code or 0 if no error happened
Definition: avio.h:228
void avio_wl24(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:458
int avio_pause(AVIOContext *h, int pause)
Pause and resume playing - only meaningful if using a network streaming protocol (e.g.
Definition: aviobuf.c:1106
int(* read_pause)(void *opaque, int pause)
Pause or resume playback for network streaming protocols - e.g.
Definition: avio.h:232
void avio_wb16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:452
static int flags
Definition: cpu.c:47
#define attribute_deprecated
Definition: attributes.h:94
int orig_buffer_size
Original buffer size used internally after probing and ensure seekback to reset the buffer size This ...
Definition: avio.h:281
enum AVIODataMarkerType current_type
Internal, not meant to be used from outside of AVIOContext.
Definition: avio.h:314
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:704
common internal and external API header
int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen)
int64_t status_change_timestamp
Time of last status change in microseconds since unix epoch, -1 if unknown.
Definition: avio.h:88
AVIODirEntryType
Directory entry types.
Definition: avio.h:58
static double c[64]
int64_t pos
position in the file of the current buffer
Definition: avio.h:220
int64_t avio_seek_time(AVIOContext *h, int stream_index, int64_t timestamp, int flags)
Seek to a given timestamp relative to some component stream.
Definition: aviobuf.c:1113
int avio_read_dir(AVIODirContext *s, AVIODirEntry **next)
Get next directory entry.
Definition: avio.c:575
A point in the output bytestream where a decoder can start decoding (i.e.
Definition: avio.h:114
int eof_reached
true if eof reached
Definition: avio.h:222
int64_t user_id
User ID of owner, -1 if unknown.
Definition: avio.h:90
int avio_open_dir(AVIODirContext **s, const char *url, AVDictionary **options)
Open directory for reading.
Definition: avio.c:537
void avio_wb32(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:354
#define av_always_inline
Definition: attributes.h:39
int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen)
Read a string from pb into buf.
Definition: aviobuf.c:776
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:328
unsigned int avio_rl24(AVIOContext *s)
Definition: aviobuf.c:712
struct URLContext * url_context
Definition: avio.h:96
int avio_closep(AVIOContext **s)
Close the resource accessed by the AVIOContext *s, free it and set the pointer pointing to it to NULL...
Definition: aviobuf.c:1086
uint64_t avio_rl64(AVIOContext *s)
Definition: aviobuf.c:728
static int write_packet(AVFormatContext *s1, AVPacket *pkt)
Definition: v4l2enc.c:86
Header data; this needs to be present for the stream to be decodeable.
Definition: avio.h:107
GLuint buffer
Definition: opengl_enc.c:102
int avio_printf(AVIOContext *s, const char *fmt,...) av_printf_format(2