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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 /**
38  * Seeking works like for a local file.
39  */
40 #define AVIO_SEEKABLE_NORMAL (1 << 0)
41 
42 /**
43  * Seeking by timestamp with avio_seek_time() is possible.
44  */
45 #define AVIO_SEEKABLE_TIME (1 << 1)
46 
47 /**
48  * Callback for checking whether to abort blocking functions.
49  * AVERROR_EXIT is returned in this case by the interrupted
50  * function. During blocking operations, callback is called with
51  * opaque as parameter. If the callback returns 1, the
52  * blocking operation will be aborted.
53  *
54  * No members can be added to this struct without a major bump, if
55  * new elements have been added after this struct in AVFormatContext
56  * or AVIOContext.
57  */
58 typedef struct AVIOInterruptCB {
59  int (*callback)(void*);
60  void *opaque;
62 
63 /**
64  * Directory entry types.
65  */
78 };
79 
80 /**
81  * Describes single entry of the directory.
82  *
83  * Only name and type fields are guaranteed be set.
84  * Rest of fields are protocol or/and platform dependent and might be unknown.
85  */
86 typedef struct AVIODirEntry {
87  char *name; /**< Filename */
88  int type; /**< Type of the entry */
89  int utf8; /**< Set to 1 when name is encoded with UTF-8, 0 otherwise.
90  Name can be encoded with UTF-8 even though 0 is set. */
91  int64_t size; /**< File size in bytes, -1 if unknown. */
92  int64_t modification_timestamp; /**< Time of last modification in microseconds since unix
93  epoch, -1 if unknown. */
94  int64_t access_timestamp; /**< Time of last access in microseconds since unix epoch,
95  -1 if unknown. */
96  int64_t status_change_timestamp; /**< Time of last status change in microseconds since unix
97  epoch, -1 if unknown. */
98  int64_t user_id; /**< User ID of owner, -1 if unknown. */
99  int64_t group_id; /**< Group ID of owner, -1 if unknown. */
100  int64_t filemode; /**< Unix file mode, -1 if unknown. */
101 } AVIODirEntry;
102 
103 typedef struct AVIODirContext {
106 
107 /**
108  * Different data types that can be returned via the AVIO
109  * write_data_type callback.
110  */
112  /**
113  * Header data; this needs to be present for the stream to be decodeable.
114  */
116  /**
117  * A point in the output bytestream where a decoder can start decoding
118  * (i.e. a keyframe). A demuxer/decoder given the data flagged with
119  * AVIO_DATA_MARKER_HEADER, followed by any AVIO_DATA_MARKER_SYNC_POINT,
120  * should give decodeable results.
121  */
123  /**
124  * A point in the output bytestream where a demuxer can start parsing
125  * (for non self synchronizing bytestream formats). That is, any
126  * non-keyframe packet start point.
127  */
129  /**
130  * This is any, unlabelled data. It can either be a muxer not marking
131  * any positions at all, it can be an actual boundary/sync point
132  * that the muxer chooses not to mark, or a later part of a packet/fragment
133  * that is cut into multiple write callbacks due to limited IO buffer size.
134  */
136  /**
137  * Trailer data, which doesn't contain actual content, but only for
138  * finalizing the output file.
139  */
141  /**
142  * A point in the output bytestream where the underlying AVIOContext might
143  * flush the buffer depending on latency or buffering requirements. Typically
144  * means the end of a packet.
145  */
147 };
148 
149 /**
150  * Bytestream IO Context.
151  * New fields can be added to the end with minor version bumps.
152  * Removal, reordering and changes to existing fields require a major
153  * version bump.
154  * sizeof(AVIOContext) must not be used outside libav*.
155  *
156  * @note None of the function pointers in AVIOContext should be called
157  * directly, they should only be set by the client application
158  * when implementing custom I/O. Normally these are set to the
159  * function pointers specified in avio_alloc_context()
160  */
161 typedef struct AVIOContext {
162  /**
163  * A class for private options.
164  *
165  * If this AVIOContext is created by avio_open2(), av_class is set and
166  * passes the options down to protocols.
167  *
168  * If this AVIOContext is manually allocated, then av_class may be set by
169  * the caller.
170  *
171  * warning -- this field can be NULL, be sure to not pass this AVIOContext
172  * to any av_opt_* functions in that case.
173  */
175 
176  /*
177  * The following shows the relationship between buffer, buf_ptr,
178  * buf_ptr_max, buf_end, buf_size, and pos, when reading and when writing
179  * (since AVIOContext is used for both):
180  *
181  **********************************************************************************
182  * READING
183  **********************************************************************************
184  *
185  * | buffer_size |
186  * |---------------------------------------|
187  * | |
188  *
189  * buffer buf_ptr buf_end
190  * +---------------+-----------------------+
191  * |/ / / / / / / /|/ / / / / / /| |
192  * read buffer: |/ / consumed / | to be read /| |
193  * |/ / / / / / / /|/ / / / / / /| |
194  * +---------------+-----------------------+
195  *
196  * pos
197  * +-------------------------------------------+-----------------+
198  * input file: | | |
199  * +-------------------------------------------+-----------------+
200  *
201  *
202  **********************************************************************************
203  * WRITING
204  **********************************************************************************
205  *
206  * | buffer_size |
207  * |--------------------------------------|
208  * | |
209  *
210  * buf_ptr_max
211  * buffer (buf_ptr) buf_end
212  * +-----------------------+--------------+
213  * |/ / / / / / / / / / / /| |
214  * write buffer: | / / to be flushed / / | |
215  * |/ / / / / / / / / / / /| |
216  * +-----------------------+--------------+
217  * buf_ptr can be in this
218  * due to a backward seek
219  *
220  * pos
221  * +-------------+----------------------------------------------+
222  * output file: | | |
223  * +-------------+----------------------------------------------+
224  *
225  */
226  unsigned char *buffer; /**< Start of the buffer. */
227  int buffer_size; /**< Maximum buffer size */
228  unsigned char *buf_ptr; /**< Current position in the buffer */
229  unsigned char *buf_end; /**< End of the data, may be less than
230  buffer+buffer_size if the read function returned
231  less data than requested, e.g. for streams where
232  no more data has been received yet. */
233  void *opaque; /**< A private pointer, passed to the read/write/seek/...
234  functions. */
235  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
236  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
237  int64_t (*seek)(void *opaque, int64_t offset, int whence);
238  int64_t pos; /**< position in the file of the current buffer */
239  int eof_reached; /**< true if eof reached */
240  int write_flag; /**< true if open for writing */
242  unsigned long checksum;
243  unsigned char *checksum_ptr;
244  unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
245  int error; /**< contains the error code or 0 if no error happened */
246  /**
247  * Pause or resume playback for network streaming protocols - e.g. MMS.
248  */
249  int (*read_pause)(void *opaque, int pause);
250  /**
251  * Seek to a given timestamp in stream with the specified stream_index.
252  * Needed for some network streaming protocols which don't support seeking
253  * to byte position.
254  */
255  int64_t (*read_seek)(void *opaque, int stream_index,
256  int64_t timestamp, int flags);
257  /**
258  * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
259  */
260  int seekable;
261 
262  /**
263  * max filesize, used to limit allocations
264  * This field is internal to libavformat and access from outside is not allowed.
265  */
266  int64_t maxsize;
267 
268  /**
269  * avio_read and avio_write should if possible be satisfied directly
270  * instead of going through a buffer, and avio_seek will always
271  * call the underlying seek function directly.
272  */
273  int direct;
274 
275  /**
276  * Bytes read statistic
277  * This field is internal to libavformat and access from outside is not allowed.
278  */
279  int64_t bytes_read;
280 
281  /**
282  * seek statistic
283  * This field is internal to libavformat and access from outside is not allowed.
284  */
286 
287  /**
288  * writeout statistic
289  * This field is internal to libavformat and access from outside is not allowed.
290  */
292 
293  /**
294  * Original buffer size
295  * used internally after probing and ensure seekback to reset the buffer size
296  * This field is internal to libavformat and access from outside is not allowed.
297  */
299 
300  /**
301  * Threshold to favor readahead over seek.
302  * This is current internal only, do not use from outside.
303  */
305 
306  /**
307  * ',' separated list of allowed protocols.
308  */
309  const char *protocol_whitelist;
310 
311  /**
312  * ',' separated list of disallowed protocols.
313  */
314  const char *protocol_blacklist;
315 
316  /**
317  * A callback that is used instead of write_packet.
318  */
319  int (*write_data_type)(void *opaque, uint8_t *buf, int buf_size,
320  enum AVIODataMarkerType type, int64_t time);
321  /**
322  * If set, don't call write_data_type separately for AVIO_DATA_MARKER_BOUNDARY_POINT,
323  * but ignore them and treat them as AVIO_DATA_MARKER_UNKNOWN (to avoid needlessly
324  * small chunks of data returned from the callback).
325  */
327 
328  /**
329  * Internal, not meant to be used from outside of AVIOContext.
330  */
332  int64_t last_time;
333 
334  /**
335  * A callback that is used instead of short_seek_threshold.
336  * This is current internal only, do not use from outside.
337  */
339 
340  int64_t written;
341 
342  /**
343  * Maximum reached position before a backward seek in the write buffer,
344  * used keeping track of already written data for a later flush.
345  */
346  unsigned char *buf_ptr_max;
347 
348  /**
349  * Try to buffer at least this amount of data before flushing it
350  */
352 } AVIOContext;
353 
354 /**
355  * Return the name of the protocol that will handle the passed URL.
356  *
357  * NULL is returned if no protocol could be found for the given URL.
358  *
359  * @return Name of the protocol or NULL.
360  */
361 const char *avio_find_protocol_name(const char *url);
362 
363 /**
364  * Return AVIO_FLAG_* access flags corresponding to the access permissions
365  * of the resource in url, or a negative value corresponding to an
366  * AVERROR code in case of failure. The returned access flags are
367  * masked by the value in flags.
368  *
369  * @note This function is intrinsically unsafe, in the sense that the
370  * checked resource may change its existence or permission status from
371  * one call to another. Thus you should not trust the returned value,
372  * unless you are sure that no other processes are accessing the
373  * checked resource.
374  */
375 int avio_check(const char *url, int flags);
376 
377 /**
378  * Move or rename a resource.
379  *
380  * @note url_src and url_dst should share the same protocol and authority.
381  *
382  * @param url_src url to resource to be moved
383  * @param url_dst new url to resource if the operation succeeded
384  * @return >=0 on success or negative on error.
385  */
386 int avpriv_io_move(const char *url_src, const char *url_dst);
387 
388 /**
389  * Delete a resource.
390  *
391  * @param url resource to be deleted.
392  * @return >=0 on success or negative on error.
393  */
394 int avpriv_io_delete(const char *url);
395 
396 /**
397  * Open directory for reading.
398  *
399  * @param s directory read context. Pointer to a NULL pointer must be passed.
400  * @param url directory to be listed.
401  * @param options A dictionary filled with protocol-private options. On return
402  * this parameter will be destroyed and replaced with a dictionary
403  * containing options that were not found. May be NULL.
404  * @return >=0 on success or negative on error.
405  */
406 int avio_open_dir(AVIODirContext **s, const char *url, AVDictionary **options);
407 
408 /**
409  * Get next directory entry.
410  *
411  * Returned entry must be freed with avio_free_directory_entry(). In particular
412  * it may outlive AVIODirContext.
413  *
414  * @param s directory read context.
415  * @param[out] next next entry or NULL when no more entries.
416  * @return >=0 on success or negative on error. End of list is not considered an
417  * error.
418  */
420 
421 /**
422  * Close directory.
423  *
424  * @note Entries created using avio_read_dir() are not deleted and must be
425  * freeded with avio_free_directory_entry().
426  *
427  * @param s directory read context.
428  * @return >=0 on success or negative on error.
429  */
431 
432 /**
433  * Free entry allocated by avio_read_dir().
434  *
435  * @param entry entry to be freed.
436  */
438 
439 /**
440  * Allocate and initialize an AVIOContext for buffered I/O. It must be later
441  * freed with avio_context_free().
442  *
443  * @param buffer Memory block for input/output operations via AVIOContext.
444  * The buffer must be allocated with av_malloc() and friends.
445  * It may be freed and replaced with a new buffer by libavformat.
446  * AVIOContext.buffer holds the buffer currently in use,
447  * which must be later freed with av_free().
448  * @param buffer_size The buffer size is very important for performance.
449  * For protocols with fixed blocksize it should be set to this blocksize.
450  * For others a typical size is a cache page, e.g. 4kb.
451  * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.
452  * @param opaque An opaque pointer to user-specific data.
453  * @param read_packet A function for refilling the buffer, may be NULL.
454  * For stream protocols, must never return 0 but rather
455  * a proper AVERROR code.
456  * @param write_packet A function for writing the buffer contents, may be NULL.
457  * The function may not change the input buffers content.
458  * @param seek A function for seeking to specified byte position, may be NULL.
459  *
460  * @return Allocated AVIOContext or NULL on failure.
461  */
463  unsigned char *buffer,
464  int buffer_size,
465  int write_flag,
466  void *opaque,
467  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
468  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
469  int64_t (*seek)(void *opaque, int64_t offset, int whence));
470 
471 /**
472  * Free the supplied IO context and everything associated with it.
473  *
474  * @param s Double pointer to the IO context. This function will write NULL
475  * into s.
476  */
478 
479 void avio_w8(AVIOContext *s, int b);
480 void avio_write(AVIOContext *s, const unsigned char *buf, int size);
481 void avio_wl64(AVIOContext *s, uint64_t val);
482 void avio_wb64(AVIOContext *s, uint64_t val);
483 void avio_wl32(AVIOContext *s, unsigned int val);
484 void avio_wb32(AVIOContext *s, unsigned int val);
485 void avio_wl24(AVIOContext *s, unsigned int val);
486 void avio_wb24(AVIOContext *s, unsigned int val);
487 void avio_wl16(AVIOContext *s, unsigned int val);
488 void avio_wb16(AVIOContext *s, unsigned int val);
489 
490 /**
491  * Write a NULL-terminated string.
492  * @return number of bytes written.
493  */
494 int avio_put_str(AVIOContext *s, const char *str);
495 
496 /**
497  * Convert an UTF-8 string to UTF-16LE and write it.
498  * @param s the AVIOContext
499  * @param str NULL-terminated UTF-8 string
500  *
501  * @return number of bytes written.
502  */
503 int avio_put_str16le(AVIOContext *s, const char *str);
504 
505 /**
506  * Convert an UTF-8 string to UTF-16BE and write it.
507  * @param s the AVIOContext
508  * @param str NULL-terminated UTF-8 string
509  *
510  * @return number of bytes written.
511  */
512 int avio_put_str16be(AVIOContext *s, const char *str);
513 
514 /**
515  * Mark the written bytestream as a specific type.
516  *
517  * Zero-length ranges are omitted from the output.
518  *
519  * @param time the stream time the current bytestream pos corresponds to
520  * (in AV_TIME_BASE units), or AV_NOPTS_VALUE if unknown or not
521  * applicable
522  * @param type the kind of data written starting at the current pos
523  */
524 void avio_write_marker(AVIOContext *s, int64_t time, enum AVIODataMarkerType type);
525 
526 /**
527  * ORing this as the "whence" parameter to a seek function causes it to
528  * return the filesize without seeking anywhere. Supporting this is optional.
529  * If it is not supported then the seek function will return <0.
530  */
531 #define AVSEEK_SIZE 0x10000
532 
533 /**
534  * Passing this flag as the "whence" parameter to a seek function causes it to
535  * seek by any means (like reopening and linear reading) or other normally unreasonable
536  * means that can be extremely slow.
537  * This may be ignored by the seek code.
538  */
539 #define AVSEEK_FORCE 0x20000
540 
541 /**
542  * fseek() equivalent for AVIOContext.
543  * @return new position or AVERROR.
544  */
545 int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);
546 
547 /**
548  * Skip given number of bytes forward
549  * @return new position or AVERROR.
550  */
551 int64_t avio_skip(AVIOContext *s, int64_t offset);
552 
553 /**
554  * ftell() equivalent for AVIOContext.
555  * @return position or AVERROR.
556  */
558 {
559  return avio_seek(s, 0, SEEK_CUR);
560 }
561 
562 /**
563  * Get the filesize.
564  * @return filesize or AVERROR
565  */
566 int64_t avio_size(AVIOContext *s);
567 
568 /**
569  * feof() equivalent for AVIOContext.
570  * @return non zero if and only if end of file
571  */
572 int avio_feof(AVIOContext *s);
573 
574 /** @warning Writes up to 4 KiB per call */
575 int avio_printf(AVIOContext *s, const char *fmt, ...) av_printf_format(2, 3);
576 
577 /**
578  * Force flushing of buffered data.
579  *
580  * For write streams, force the buffered data to be immediately written to the output,
581  * without to wait to fill the internal buffer.
582  *
583  * For read streams, discard all currently buffered data, and advance the
584  * reported file position to that of the underlying stream. This does not
585  * read new data, and does not perform any seeks.
586  */
587 void avio_flush(AVIOContext *s);
588 
589 /**
590  * Read size bytes from AVIOContext into buf.
591  * @return number of bytes read or AVERROR
592  */
593 int avio_read(AVIOContext *s, unsigned char *buf, int size);
594 
595 /**
596  * Read size bytes from AVIOContext into buf. Unlike avio_read(), this is allowed
597  * to read fewer bytes than requested. The missing bytes can be read in the next
598  * call. This always tries to read at least 1 byte.
599  * Useful to reduce latency in certain cases.
600  * @return number of bytes read or AVERROR
601  */
602 int avio_read_partial(AVIOContext *s, unsigned char *buf, int size);
603 
604 /**
605  * @name Functions for reading from AVIOContext
606  * @{
607  *
608  * @note return 0 if EOF, so you cannot use it if EOF handling is
609  * necessary
610  */
611 int avio_r8 (AVIOContext *s);
612 unsigned int avio_rl16(AVIOContext *s);
613 unsigned int avio_rl24(AVIOContext *s);
614 unsigned int avio_rl32(AVIOContext *s);
615 uint64_t avio_rl64(AVIOContext *s);
616 unsigned int avio_rb16(AVIOContext *s);
617 unsigned int avio_rb24(AVIOContext *s);
618 unsigned int avio_rb32(AVIOContext *s);
619 uint64_t avio_rb64(AVIOContext *s);
620 /**
621  * @}
622  */
623 
624 /**
625  * Read a string from pb into buf. The reading will terminate when either
626  * a NULL character was encountered, maxlen bytes have been read, or nothing
627  * more can be read from pb. The result is guaranteed to be NULL-terminated, it
628  * will be truncated if buf is too small.
629  * Note that the string is not interpreted or validated in any way, it
630  * might get truncated in the middle of a sequence for multi-byte encodings.
631  *
632  * @return number of bytes read (is always <= maxlen).
633  * If reading ends on EOF or error, the return value will be one more than
634  * bytes actually read.
635  */
636 int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);
637 
638 /**
639  * Read a UTF-16 string from pb and convert it to UTF-8.
640  * The reading will terminate when either a null or invalid character was
641  * encountered or maxlen bytes have been read.
642  * @return number of bytes read (is always <= maxlen)
643  */
644 int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);
645 int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);
646 
647 
648 /**
649  * @name URL open modes
650  * The flags argument to avio_open must be one of the following
651  * constants, optionally ORed with other flags.
652  * @{
653  */
654 #define AVIO_FLAG_READ 1 /**< read-only */
655 #define AVIO_FLAG_WRITE 2 /**< write-only */
656 #define AVIO_FLAG_READ_WRITE (AVIO_FLAG_READ|AVIO_FLAG_WRITE) /**< read-write pseudo flag */
657 /**
658  * @}
659  */
660 
661 /**
662  * Use non-blocking mode.
663  * If this flag is set, operations on the context will return
664  * AVERROR(EAGAIN) if they can not be performed immediately.
665  * If this flag is not set, operations on the context will never return
666  * AVERROR(EAGAIN).
667  * Note that this flag does not affect the opening/connecting of the
668  * context. Connecting a protocol will always block if necessary (e.g. on
669  * network protocols) but never hang (e.g. on busy devices).
670  * Warning: non-blocking protocols is work-in-progress; this flag may be
671  * silently ignored.
672  */
673 #define AVIO_FLAG_NONBLOCK 8
674 
675 /**
676  * Use direct mode.
677  * avio_read and avio_write should if possible be satisfied directly
678  * instead of going through a buffer, and avio_seek will always
679  * call the underlying seek function directly.
680  */
681 #define AVIO_FLAG_DIRECT 0x8000
682 
683 /**
684  * Create and initialize a AVIOContext for accessing the
685  * resource indicated by url.
686  * @note When the resource indicated by url has been opened in
687  * read+write mode, the AVIOContext can be used only for writing.
688  *
689  * @param s Used to return the pointer to the created AVIOContext.
690  * In case of failure the pointed to value is set to NULL.
691  * @param url resource to access
692  * @param flags flags which control how the resource indicated by url
693  * is to be opened
694  * @return >= 0 in case of success, a negative value corresponding to an
695  * AVERROR code in case of failure
696  */
697 int avio_open(AVIOContext **s, const char *url, int flags);
698 
699 /**
700  * Create and initialize a AVIOContext for accessing the
701  * resource indicated by url.
702  * @note When the resource indicated by url has been opened in
703  * read+write mode, the AVIOContext can be used only for writing.
704  *
705  * @param s Used to return the pointer to the created AVIOContext.
706  * In case of failure the pointed to value is set to NULL.
707  * @param url resource to access
708  * @param flags flags which control how the resource indicated by url
709  * is to be opened
710  * @param int_cb an interrupt callback to be used at the protocols level
711  * @param options A dictionary filled with protocol-private options. On return
712  * this parameter will be destroyed and replaced with a dict containing options
713  * that were not found. May be NULL.
714  * @return >= 0 in case of success, a negative value corresponding to an
715  * AVERROR code in case of failure
716  */
717 int avio_open2(AVIOContext **s, const char *url, int flags,
719 
720 /**
721  * Close the resource accessed by the AVIOContext s and free it.
722  * This function can only be used if s was opened by avio_open().
723  *
724  * The internal buffer is automatically flushed before closing the
725  * resource.
726  *
727  * @return 0 on success, an AVERROR < 0 on error.
728  * @see avio_closep
729  */
730 int avio_close(AVIOContext *s);
731 
732 /**
733  * Close the resource accessed by the AVIOContext *s, free it
734  * and set the pointer pointing to it to NULL.
735  * This function can only be used if s was opened by avio_open().
736  *
737  * The internal buffer is automatically flushed before closing the
738  * resource.
739  *
740  * @return 0 on success, an AVERROR < 0 on error.
741  * @see avio_close
742  */
743 int avio_closep(AVIOContext **s);
744 
745 
746 /**
747  * Open a write only memory stream.
748  *
749  * @param s new IO context
750  * @return zero if no error.
751  */
753 
754 /**
755  * Return the written size and a pointer to the buffer.
756  * The AVIOContext stream is left intact.
757  * The buffer must NOT be freed.
758  * No padding is added to the buffer.
759  *
760  * @param s IO context
761  * @param pbuffer pointer to a byte buffer
762  * @return the length of the byte buffer
763  */
764 int avio_get_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
765 
766 /**
767  * Return the written size and a pointer to the buffer. The buffer
768  * must be freed with av_free().
769  * Padding of AV_INPUT_BUFFER_PADDING_SIZE is added to the buffer.
770  *
771  * @param s IO context
772  * @param pbuffer pointer to a byte buffer
773  * @return the length of the byte buffer
774  */
775 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
776 
777 /**
778  * Iterate through names of available protocols.
779  *
780  * @param opaque A private pointer representing current protocol.
781  * It must be a pointer to NULL on first iteration and will
782  * be updated by successive calls to avio_enum_protocols.
783  * @param output If set to 1, iterate over output protocols,
784  * otherwise over input protocols.
785  *
786  * @return A static string containing the name of current protocol or NULL
787  */
788 const char *avio_enum_protocols(void **opaque, int output);
789 
790 /**
791  * Pause and resume playing - only meaningful if using a network streaming
792  * protocol (e.g. MMS).
793  *
794  * @param h IO context from which to call the read_pause function pointer
795  * @param pause 1 for pause, 0 for resume
796  */
797 int avio_pause(AVIOContext *h, int pause);
798 
799 /**
800  * Seek to a given timestamp relative to some component stream.
801  * Only meaningful if using a network streaming protocol (e.g. MMS.).
802  *
803  * @param h IO context from which to call the seek function pointers
804  * @param stream_index The stream index that the timestamp is relative to.
805  * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
806  * units from the beginning of the presentation.
807  * If a stream_index >= 0 is used and the protocol does not support
808  * seeking based on component streams, the call will fail.
809  * @param timestamp timestamp in AVStream.time_base units
810  * or if there is no stream specified then in AV_TIME_BASE units.
811  * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
812  * and AVSEEK_FLAG_ANY. The protocol may silently ignore
813  * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
814  * fail if used and not supported.
815  * @return >= 0 on success
816  * @see AVInputFormat::read_seek
817  */
818 int64_t avio_seek_time(AVIOContext *h, int stream_index,
819  int64_t timestamp, int flags);
820 
821 /* Avoid a warning. The header can not be included because it breaks c++. */
822 struct AVBPrint;
823 
824 /**
825  * Read contents of h into print buffer, up to max_size bytes, or up to EOF.
826  *
827  * @return 0 for success (max_size bytes read or EOF reached), negative error
828  * code otherwise
829  */
830 int avio_read_to_bprint(AVIOContext *h, struct AVBPrint *pb, size_t max_size);
831 
832 /**
833  * Accept and allocate a client context on a server context.
834  * @param s the server context
835  * @param c the client context, must be unallocated
836  * @return >= 0 on success or a negative value corresponding
837  * to an AVERROR on failure
838  */
840 
841 /**
842  * Perform one step of the protocol handshake to accept a new client.
843  * This function must be called on a client returned by avio_accept() before
844  * using it as a read/write context.
845  * It is separate from avio_accept() because it may block.
846  * A step of the handshake is defined by places where the application may
847  * decide to change the proceedings.
848  * For example, on a protocol with a request header and a reply header, each
849  * one can constitute a step because the application may use the parameters
850  * from the request to change parameters in the reply; or each individual
851  * chunk of the request can constitute a step.
852  * If the handshake is already finished, avio_handshake() does nothing and
853  * returns 0 immediately.
854  *
855  * @param c the client context to perform the handshake on
856  * @return 0 on a complete and successful handshake
857  * > 0 if the handshake progressed, but is not complete
858  * < 0 for an AVERROR code
859  */
861 #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:1098
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:681
void avio_wb64(AVIOContext *s, uint64_t val)
Definition: aviobuf.c:461
const char const char void * val
Definition: avisynth_c.h:771
void avio_wl16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:467
const char * s
Definition: avisynth_c.h:768
Bytestream IO Context.
Definition: avio.h:161
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:334
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:255
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:1364
int64_t filemode
Unix file mode, -1 if unknown.
Definition: avio.h:100
int(* short_seek_get)(void *opaque)
A callback that is used instead of short_seek_threshold.
Definition: avio.h:338
const char * fmt
Definition: avisynth_c.h:769
int64_t last_time
Definition: avio.h:332
unsigned char * buf_ptr
Current position in the buffer.
Definition: avio.h:228
int writeout_count
writeout statistic This field is internal to libavformat and access from outside is not allowed...
Definition: avio.h:291
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:229
int write_flag
true if open for writing
Definition: avio.h:240
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:1205
Describes single entry of the directory.
Definition: avio.h:86
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:244
int min_packet_size
Try to buffer at least this amount of data before flushing it.
Definition: avio.h:351
unsigned char * buffer
Start of the buffer.
Definition: avio.h:226
int avio_read_partial(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:715
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:329
int64_t(* seek)(void *opaque, int64_t offset, int whence)
Definition: avio.h:237
void * opaque
A private pointer, passed to the read/write/seek/...
Definition: avio.h:233
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:784
int64_t maxsize
max filesize, used to limit allocations This field is internal to libavformat and access from outside...
Definition: avio.h:266
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:1335
void * opaque
Definition: avio.h:60
Trailer data, which doesn't contain actual content, but only for finalizing the output file...
Definition: avio.h:140
int64_t modification_timestamp
Time of last modification in microseconds since unix epoch, -1 if unknown.
Definition: avio.h:92
Public dictionary API.
int avio_accept(AVIOContext *s, AVIOContext **c)
Accept and allocate a client context on a server context.
Definition: aviobuf.c:1223
void avio_wl32(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:367
uint8_t
A point in the output bytestream where the underlying AVIOContext might flush the buffer depending on...
Definition: avio.h:146
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:799
void avio_write_marker(AVIOContext *s, int64_t time, enum AVIODataMarkerType type)
Mark the written bytestream as a specific type.
Definition: aviobuf.c:491
const AVClass * av_class
A class for private options.
Definition: avio.h:174
A point in the output bytestream where a demuxer can start parsing (for non self synchronizing bytest...
Definition: avio.h:128
int64_t bytes_read
Bytes read statistic This field is internal to libavformat and access from outside is not allowed...
Definition: avio.h:279
static int flags
Definition: log.c:57
ptrdiff_t size
Definition: opengl_enc.c:101
uint64_t avio_rb64(AVIOContext *s)
Definition: aviobuf.c:866
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:216
const OptionDef options[]
Definition: ffserver.c:3948
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:646
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:455
int max_packet_size
Definition: avio.h:241
Callback for checking whether to abort blocking functions.
Definition: avio.h:58
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:129
char * name
Filename.
Definition: avio.h:87
int64_t written
Definition: avio.h:340
int(* write_packet)(void *opaque, uint8_t *buf, int buf_size)
Definition: avio.h:236
int(* callback)(void *)
Definition: avio.h:59
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:474
int(* read_packet)(void *opaque, uint8_t *buf, int buf_size)
Definition: avio.h:235
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:768
const char * avio_enum_protocols(void **opaque, int output)
Iterate through names of available protocols.
Definition: protocols.c:93
int avio_close(AVIOContext *s)
Close the resource accessed by the AVIOContext s and free it.
Definition: aviobuf.c:1134
int utf8
Set to 1 when name is encoded with UTF-8, 0 otherwise.
Definition: avio.h:89
const char * protocol_whitelist
',' separated list of allowed protocols.
Definition: avio.h:309
unsigned long checksum
Definition: avio.h:242
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:273
const char * protocol_blacklist
',' separated list of disallowed protocols.
Definition: avio.h:314
#define av_printf_format(fmtpos, attrpos)
Definition: attributes.h:155
int seek_count
seek statistic This field is internal to libavformat and access from outside is not allowed...
Definition: avio.h:285
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:637
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:319
This is any, unlabelled data.
Definition: avio.h:135
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:260
int void avio_flush(AVIOContext *s)
Force flushing of buffered data.
Definition: aviobuf.c:236
unsigned int avio_rb24(AVIOContext *s)
Definition: aviobuf.c:792
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:94
unsigned char * checksum_ptr
Definition: avio.h:243
AVIODataMarkerType
Different data types that can be returned via the AVIO write_data_type callback.
Definition: avio.h:111
void avio_wb24(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:485
Libavformat version macros.
unsigned long(* update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size)
Definition: avio.h:244
int64_t size
File size in bytes, -1 if unknown.
Definition: avio.h:91
int buffer_size
Maximum buffer size.
Definition: avio.h:227
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:383
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:88
void avio_w8(AVIOContext *s, int b)
Definition: aviobuf.c:194
void * buf
Definition: avisynth_c.h:690
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:99
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:1122
int short_seek_threshold
Threshold to favor readahead over seek.
Definition: avio.h:304
int avio_handshake(AVIOContext *c)
Perform one step of the protocol handshake to accept a new client.
Definition: aviobuf.c:1235
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:326
int error
contains the error code or 0 if no error happened
Definition: avio.h:245
void avio_wl24(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:479
int avio_pause(AVIOContext *h, int pause)
Pause and resume playing - only meaningful if using a network streaming protocol (e.g.
Definition: aviobuf.c:1179
int(* read_pause)(void *opaque, int pause)
Pause or resume playback for network streaming protocols - e.g.
Definition: avio.h:249
void avio_wb16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:473
int orig_buffer_size
Original buffer size used internally after probing and ensure seekback to reset the buffer size This ...
Definition: avio.h:298
enum AVIODataMarkerType current_type
Internal, not meant to be used from outside of AVIOContext.
Definition: avio.h:331
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:752
int
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:96
AVIODirEntryType
Directory entry types.
Definition: avio.h:66
static double c[64]
void avio_context_free(AVIOContext **s)
Free the supplied IO context and everything associated with it.
Definition: aviobuf.c:146
int64_t pos
position in the file of the current buffer
Definition: avio.h:238
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:1186
unsigned char * buf_ptr_max
Maximum reached position before a backward seek in the write buffer, used keeping track of already wr...
Definition: avio.h:346
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:122
int eof_reached
true if eof reached
Definition: avio.h:239
int64_t user_id
User ID of owner, -1 if unknown.
Definition: avio.h:98
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:375
#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:824
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:356
unsigned int avio_rl24(AVIOContext *s)
Definition: aviobuf.c:760
struct URLContext * url_context
Definition: avio.h:104
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:1159
uint64_t avio_rl64(AVIOContext *s)
Definition: aviobuf.c:776
Header data; this needs to be present for the stream to be decodeable.
Definition: avio.h:115
GLuint buffer
Definition: opengl_enc.c:102
int avio_printf(AVIOContext *s, const char *fmt,...) av_printf_format(2
int avio_get_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
Return the written size and a pointer to the buffer.
Definition: aviobuf.c:1347