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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 must_flush; /**< unused */
240  int eof_reached; /**< true if eof reached */
241  int write_flag; /**< true if open for writing */
243  unsigned long checksum;
244  unsigned char *checksum_ptr;
245  unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
246  int error; /**< contains the error code or 0 if no error happened */
247  /**
248  * Pause or resume playback for network streaming protocols - e.g. MMS.
249  */
250  int (*read_pause)(void *opaque, int pause);
251  /**
252  * Seek to a given timestamp in stream with the specified stream_index.
253  * Needed for some network streaming protocols which don't support seeking
254  * to byte position.
255  */
256  int64_t (*read_seek)(void *opaque, int stream_index,
257  int64_t timestamp, int flags);
258  /**
259  * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
260  */
261  int seekable;
262 
263  /**
264  * max filesize, used to limit allocations
265  * This field is internal to libavformat and access from outside is not allowed.
266  */
267  int64_t maxsize;
268 
269  /**
270  * avio_read and avio_write should if possible be satisfied directly
271  * instead of going through a buffer, and avio_seek will always
272  * call the underlying seek function directly.
273  */
274  int direct;
275 
276  /**
277  * Bytes read statistic
278  * This field is internal to libavformat and access from outside is not allowed.
279  */
280  int64_t bytes_read;
281 
282  /**
283  * seek statistic
284  * This field is internal to libavformat and access from outside is not allowed.
285  */
287 
288  /**
289  * writeout statistic
290  * This field is internal to libavformat and access from outside is not allowed.
291  */
293 
294  /**
295  * Original buffer size
296  * used internally after probing and ensure seekback to reset the buffer size
297  * This field is internal to libavformat and access from outside is not allowed.
298  */
300 
301  /**
302  * Threshold to favor readahead over seek.
303  * This is current internal only, do not use from outside.
304  */
306 
307  /**
308  * ',' separated list of allowed protocols.
309  */
310  const char *protocol_whitelist;
311 
312  /**
313  * ',' separated list of disallowed protocols.
314  */
315  const char *protocol_blacklist;
316 
317  /**
318  * A callback that is used instead of write_packet.
319  */
320  int (*write_data_type)(void *opaque, uint8_t *buf, int buf_size,
321  enum AVIODataMarkerType type, int64_t time);
322  /**
323  * If set, don't call write_data_type separately for AVIO_DATA_MARKER_BOUNDARY_POINT,
324  * but ignore them and treat them as AVIO_DATA_MARKER_UNKNOWN (to avoid needlessly
325  * small chunks of data returned from the callback).
326  */
328 
329  /**
330  * Internal, not meant to be used from outside of AVIOContext.
331  */
333  int64_t last_time;
334 
335  /**
336  * A callback that is used instead of short_seek_threshold.
337  * This is current internal only, do not use from outside.
338  */
340 
341  int64_t written;
342 
343  /**
344  * Maximum reached position before a backward seek in the write buffer,
345  * used keeping track of already written data for a later flush.
346  */
347  unsigned char *buf_ptr_max;
348 
349  /**
350  * Try to buffer at least this amount of data before flushing it
351  */
353 } AVIOContext;
354 
355 /**
356  * Return the name of the protocol that will handle the passed URL.
357  *
358  * NULL is returned if no protocol could be found for the given URL.
359  *
360  * @return Name of the protocol or NULL.
361  */
362 const char *avio_find_protocol_name(const char *url);
363 
364 /**
365  * Return AVIO_FLAG_* access flags corresponding to the access permissions
366  * of the resource in url, or a negative value corresponding to an
367  * AVERROR code in case of failure. The returned access flags are
368  * masked by the value in flags.
369  *
370  * @note This function is intrinsically unsafe, in the sense that the
371  * checked resource may change its existence or permission status from
372  * one call to another. Thus you should not trust the returned value,
373  * unless you are sure that no other processes are accessing the
374  * checked resource.
375  */
376 int avio_check(const char *url, int flags);
377 
378 /**
379  * Move or rename a resource.
380  *
381  * @note url_src and url_dst should share the same protocol and authority.
382  *
383  * @param url_src url to resource to be moved
384  * @param url_dst new url to resource if the operation succeeded
385  * @return >=0 on success or negative on error.
386  */
387 int avpriv_io_move(const char *url_src, const char *url_dst);
388 
389 /**
390  * Delete a resource.
391  *
392  * @param url resource to be deleted.
393  * @return >=0 on success or negative on error.
394  */
395 int avpriv_io_delete(const char *url);
396 
397 /**
398  * Open directory for reading.
399  *
400  * @param s directory read context. Pointer to a NULL pointer must be passed.
401  * @param url directory to be listed.
402  * @param options A dictionary filled with protocol-private options. On return
403  * this parameter will be destroyed and replaced with a dictionary
404  * containing options that were not found. May be NULL.
405  * @return >=0 on success or negative on error.
406  */
407 int avio_open_dir(AVIODirContext **s, const char *url, AVDictionary **options);
408 
409 /**
410  * Get next directory entry.
411  *
412  * Returned entry must be freed with avio_free_directory_entry(). In particular
413  * it may outlive AVIODirContext.
414  *
415  * @param s directory read context.
416  * @param[out] next next entry or NULL when no more entries.
417  * @return >=0 on success or negative on error. End of list is not considered an
418  * error.
419  */
421 
422 /**
423  * Close directory.
424  *
425  * @note Entries created using avio_read_dir() are not deleted and must be
426  * freeded with avio_free_directory_entry().
427  *
428  * @param s directory read context.
429  * @return >=0 on success or negative on error.
430  */
432 
433 /**
434  * Free entry allocated by avio_read_dir().
435  *
436  * @param entry entry to be freed.
437  */
439 
440 /**
441  * Allocate and initialize an AVIOContext for buffered I/O. It must be later
442  * freed with av_free().
443  *
444  * @param buffer Memory block for input/output operations via AVIOContext.
445  * The buffer must be allocated with av_malloc() and friends.
446  * It may be freed and replaced with a new buffer by libavformat.
447  * AVIOContext.buffer holds the buffer currently in use,
448  * which must be later freed with av_free().
449  * @param buffer_size The buffer size is very important for performance.
450  * For protocols with fixed blocksize it should be set to this blocksize.
451  * For others a typical size is a cache page, e.g. 4kb.
452  * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.
453  * @param opaque An opaque pointer to user-specific data.
454  * @param read_packet A function for refilling the buffer, may be NULL.
455  * @param write_packet A function for writing the buffer contents, may be NULL.
456  * The function may not change the input buffers content.
457  * @param seek A function for seeking to specified byte position, may be NULL.
458  *
459  * @return Allocated AVIOContext or NULL on failure.
460  */
462  unsigned char *buffer,
463  int buffer_size,
464  int write_flag,
465  void *opaque,
466  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
467  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
468  int64_t (*seek)(void *opaque, int64_t offset, int whence));
469 
470 void avio_w8(AVIOContext *s, int b);
471 void avio_write(AVIOContext *s, const unsigned char *buf, int size);
472 void avio_wl64(AVIOContext *s, uint64_t val);
473 void avio_wb64(AVIOContext *s, uint64_t val);
474 void avio_wl32(AVIOContext *s, unsigned int val);
475 void avio_wb32(AVIOContext *s, unsigned int val);
476 void avio_wl24(AVIOContext *s, unsigned int val);
477 void avio_wb24(AVIOContext *s, unsigned int val);
478 void avio_wl16(AVIOContext *s, unsigned int val);
479 void avio_wb16(AVIOContext *s, unsigned int val);
480 
481 /**
482  * Write a NULL-terminated string.
483  * @return number of bytes written.
484  */
485 int avio_put_str(AVIOContext *s, const char *str);
486 
487 /**
488  * Convert an UTF-8 string to UTF-16LE and write it.
489  * @param s the AVIOContext
490  * @param str NULL-terminated UTF-8 string
491  *
492  * @return number of bytes written.
493  */
494 int avio_put_str16le(AVIOContext *s, const char *str);
495 
496 /**
497  * Convert an UTF-8 string to UTF-16BE 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_str16be(AVIOContext *s, const char *str);
504 
505 /**
506  * Mark the written bytestream as a specific type.
507  *
508  * Zero-length ranges are omitted from the output.
509  *
510  * @param time the stream time the current bytestream pos corresponds to
511  * (in AV_TIME_BASE units), or AV_NOPTS_VALUE if unknown or not
512  * applicable
513  * @param type the kind of data written starting at the current pos
514  */
515 void avio_write_marker(AVIOContext *s, int64_t time, enum AVIODataMarkerType type);
516 
517 /**
518  * ORing this as the "whence" parameter to a seek function causes it to
519  * return the filesize without seeking anywhere. Supporting this is optional.
520  * If it is not supported then the seek function will return <0.
521  */
522 #define AVSEEK_SIZE 0x10000
523 
524 /**
525  * Passing this flag as the "whence" parameter to a seek function causes it to
526  * seek by any means (like reopening and linear reading) or other normally unreasonable
527  * means that can be extremely slow.
528  * This may be ignored by the seek code.
529  */
530 #define AVSEEK_FORCE 0x20000
531 
532 /**
533  * fseek() equivalent for AVIOContext.
534  * @return new position or AVERROR.
535  */
536 int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);
537 
538 /**
539  * Skip given number of bytes forward
540  * @return new position or AVERROR.
541  */
542 int64_t avio_skip(AVIOContext *s, int64_t offset);
543 
544 /**
545  * ftell() equivalent for AVIOContext.
546  * @return position or AVERROR.
547  */
549 {
550  return avio_seek(s, 0, SEEK_CUR);
551 }
552 
553 /**
554  * Get the filesize.
555  * @return filesize or AVERROR
556  */
557 int64_t avio_size(AVIOContext *s);
558 
559 /**
560  * feof() equivalent for AVIOContext.
561  * @return non zero if and only if end of file
562  */
563 int avio_feof(AVIOContext *s);
564 #if FF_API_URL_FEOF
565 /**
566  * @deprecated use avio_feof()
567  */
569 int url_feof(AVIOContext *s);
570 #endif
571 
572 /** @warning Writes up to 4 KiB per call */
573 int avio_printf(AVIOContext *s, const char *fmt, ...) av_printf_format(2, 3);
574 
575 /**
576  * Force flushing of buffered data.
577  *
578  * For write streams, force the buffered data to be immediately written to the output,
579  * without to wait to fill the internal buffer.
580  *
581  * For read streams, discard all currently buffered data, and advance the
582  * reported file position to that of the underlying stream. This does not
583  * read new data, and does not perform any seeks.
584  */
585 void avio_flush(AVIOContext *s);
586 
587 /**
588  * Read size bytes from AVIOContext into buf.
589  * @return number of bytes read or AVERROR
590  */
591 int avio_read(AVIOContext *s, unsigned char *buf, int size);
592 
593 /**
594  * @name Functions for reading from AVIOContext
595  * @{
596  *
597  * @note return 0 if EOF, so you cannot use it if EOF handling is
598  * necessary
599  */
600 int avio_r8 (AVIOContext *s);
601 unsigned int avio_rl16(AVIOContext *s);
602 unsigned int avio_rl24(AVIOContext *s);
603 unsigned int avio_rl32(AVIOContext *s);
604 uint64_t avio_rl64(AVIOContext *s);
605 unsigned int avio_rb16(AVIOContext *s);
606 unsigned int avio_rb24(AVIOContext *s);
607 unsigned int avio_rb32(AVIOContext *s);
608 uint64_t avio_rb64(AVIOContext *s);
609 /**
610  * @}
611  */
612 
613 /**
614  * Read a string from pb into buf. The reading will terminate when either
615  * a NULL character was encountered, maxlen bytes have been read, or nothing
616  * more can be read from pb. The result is guaranteed to be NULL-terminated, it
617  * will be truncated if buf is too small.
618  * Note that the string is not interpreted or validated in any way, it
619  * might get truncated in the middle of a sequence for multi-byte encodings.
620  *
621  * @return number of bytes read (is always <= maxlen).
622  * If reading ends on EOF or error, the return value will be one more than
623  * bytes actually read.
624  */
625 int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);
626 
627 /**
628  * Read a UTF-16 string from pb and convert it to UTF-8.
629  * The reading will terminate when either a null or invalid character was
630  * encountered or maxlen bytes have been read.
631  * @return number of bytes read (is always <= maxlen)
632  */
633 int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);
634 int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);
635 
636 
637 /**
638  * @name URL open modes
639  * The flags argument to avio_open must be one of the following
640  * constants, optionally ORed with other flags.
641  * @{
642  */
643 #define AVIO_FLAG_READ 1 /**< read-only */
644 #define AVIO_FLAG_WRITE 2 /**< write-only */
645 #define AVIO_FLAG_READ_WRITE (AVIO_FLAG_READ|AVIO_FLAG_WRITE) /**< read-write pseudo flag */
646 /**
647  * @}
648  */
649 
650 /**
651  * Use non-blocking mode.
652  * If this flag is set, operations on the context will return
653  * AVERROR(EAGAIN) if they can not be performed immediately.
654  * If this flag is not set, operations on the context will never return
655  * AVERROR(EAGAIN).
656  * Note that this flag does not affect the opening/connecting of the
657  * context. Connecting a protocol will always block if necessary (e.g. on
658  * network protocols) but never hang (e.g. on busy devices).
659  * Warning: non-blocking protocols is work-in-progress; this flag may be
660  * silently ignored.
661  */
662 #define AVIO_FLAG_NONBLOCK 8
663 
664 /**
665  * Use direct mode.
666  * avio_read and avio_write should if possible be satisfied directly
667  * instead of going through a buffer, and avio_seek will always
668  * call the underlying seek function directly.
669  */
670 #define AVIO_FLAG_DIRECT 0x8000
671 
672 /**
673  * Create and initialize a AVIOContext for accessing the
674  * resource indicated by url.
675  * @note When the resource indicated by url has been opened in
676  * read+write mode, the AVIOContext can be used only for writing.
677  *
678  * @param s Used to return the pointer to the created AVIOContext.
679  * In case of failure the pointed to value is set to NULL.
680  * @param url resource to access
681  * @param flags flags which control how the resource indicated by url
682  * is to be opened
683  * @return >= 0 in case of success, a negative value corresponding to an
684  * AVERROR code in case of failure
685  */
686 int avio_open(AVIOContext **s, const char *url, int flags);
687 
688 /**
689  * Create and initialize a AVIOContext for accessing the
690  * resource indicated by url.
691  * @note When the resource indicated by url has been opened in
692  * read+write mode, the AVIOContext can be used only for writing.
693  *
694  * @param s Used to return the pointer to the created AVIOContext.
695  * In case of failure the pointed to value is set to NULL.
696  * @param url resource to access
697  * @param flags flags which control how the resource indicated by url
698  * is to be opened
699  * @param int_cb an interrupt callback to be used at the protocols level
700  * @param options A dictionary filled with protocol-private options. On return
701  * this parameter will be destroyed and replaced with a dict containing options
702  * that were not found. May be NULL.
703  * @return >= 0 in case of success, a negative value corresponding to an
704  * AVERROR code in case of failure
705  */
706 int avio_open2(AVIOContext **s, const char *url, int flags,
708 
709 /**
710  * Close the resource accessed by the AVIOContext s and free it.
711  * This function can only be used if s was opened by avio_open().
712  *
713  * The internal buffer is automatically flushed before closing the
714  * resource.
715  *
716  * @return 0 on success, an AVERROR < 0 on error.
717  * @see avio_closep
718  */
719 int avio_close(AVIOContext *s);
720 
721 /**
722  * Close the resource accessed by the AVIOContext *s, free it
723  * and set the pointer pointing to it to NULL.
724  * This function can only be used if s was opened by avio_open().
725  *
726  * The internal buffer is automatically flushed before closing the
727  * resource.
728  *
729  * @return 0 on success, an AVERROR < 0 on error.
730  * @see avio_close
731  */
732 int avio_closep(AVIOContext **s);
733 
734 
735 /**
736  * Open a write only memory stream.
737  *
738  * @param s new IO context
739  * @return zero if no error.
740  */
742 
743 /**
744  * Return the written size and a pointer to the buffer.
745  * The AVIOContext stream is left intact.
746  * The buffer must NOT be freed.
747  * No padding is added to the buffer.
748  *
749  * @param s IO context
750  * @param pbuffer pointer to a byte buffer
751  * @return the length of the byte buffer
752  */
753 int avio_get_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
754 
755 /**
756  * Return the written size and a pointer to the buffer. The buffer
757  * must be freed with av_free().
758  * Padding of AV_INPUT_BUFFER_PADDING_SIZE 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_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
765 
766 /**
767  * Iterate through names of available protocols.
768  *
769  * @param opaque A private pointer representing current protocol.
770  * It must be a pointer to NULL on first iteration and will
771  * be updated by successive calls to avio_enum_protocols.
772  * @param output If set to 1, iterate over output protocols,
773  * otherwise over input protocols.
774  *
775  * @return A static string containing the name of current protocol or NULL
776  */
777 const char *avio_enum_protocols(void **opaque, int output);
778 
779 /**
780  * Pause and resume playing - only meaningful if using a network streaming
781  * protocol (e.g. MMS).
782  *
783  * @param h IO context from which to call the read_pause function pointer
784  * @param pause 1 for pause, 0 for resume
785  */
786 int avio_pause(AVIOContext *h, int pause);
787 
788 /**
789  * Seek to a given timestamp relative to some component stream.
790  * Only meaningful if using a network streaming protocol (e.g. MMS.).
791  *
792  * @param h IO context from which to call the seek function pointers
793  * @param stream_index The stream index that the timestamp is relative to.
794  * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
795  * units from the beginning of the presentation.
796  * If a stream_index >= 0 is used and the protocol does not support
797  * seeking based on component streams, the call will fail.
798  * @param timestamp timestamp in AVStream.time_base units
799  * or if there is no stream specified then in AV_TIME_BASE units.
800  * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
801  * and AVSEEK_FLAG_ANY. The protocol may silently ignore
802  * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
803  * fail if used and not supported.
804  * @return >= 0 on success
805  * @see AVInputFormat::read_seek
806  */
807 int64_t avio_seek_time(AVIOContext *h, int stream_index,
808  int64_t timestamp, int flags);
809 
810 /* Avoid a warning. The header can not be included because it breaks c++. */
811 struct AVBPrint;
812 
813 /**
814  * Read contents of h into print buffer, up to max_size bytes, or up to EOF.
815  *
816  * @return 0 for success (max_size bytes read or EOF reached), negative error
817  * code otherwise
818  */
819 int avio_read_to_bprint(AVIOContext *h, struct AVBPrint *pb, size_t max_size);
820 
821 /**
822  * Accept and allocate a client context on a server context.
823  * @param s the server context
824  * @param c the client context, must be unallocated
825  * @return >= 0 on success or a negative value corresponding
826  * to an AVERROR on failure
827  */
829 
830 /**
831  * Perform one step of the protocol handshake to accept a new client.
832  * This function must be called on a client returned by avio_accept() before
833  * using it as a read/write context.
834  * It is separate from avio_accept() because it may block.
835  * A step of the handshake is defined by places where the application may
836  * decide to change the proceedings.
837  * For example, on a protocol with a request header and a reply header, each
838  * one can constitute a step because the application may use the parameters
839  * from the request to change parameters in the reply; or each individual
840  * chunk of the request can constitute a step.
841  * If the handshake is already finished, avio_handshake() does nothing and
842  * returns 0 immediately.
843  *
844  * @param c the client context to perform the handshake on
845  * @return 0 on a complete and successful handshake
846  * > 0 if the handshake progressed, but is not complete
847  * < 0 for an AVERROR code
848  */
850 #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:1069
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:671
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:327
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:256
int avpriv_io_delete(const char *url)
Delete a resource.
Definition: avio.c:519
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:1333
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:339
const char * fmt
Definition: avisynth_c.h:769
int64_t last_time
Definition: avio.h:333
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:292
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:241
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:1174
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:239
int min_packet_size
Try to buffer at least this amount of data before flushing it.
Definition: avio.h:352
unsigned char * buffer
Start of the buffer.
Definition: avio.h:226
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:322
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:768
int64_t maxsize
max filesize, used to limit allocations This field is internal to libavformat and access from outside...
Definition: avio.h:267
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:1304
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:1192
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:783
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:280
static int flags
Definition: log.c:57
ptrdiff_t size
Definition: opengl_enc.c:101
uint64_t avio_rb64(AVIOContext *s)
Definition: aviobuf.c:850
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:548
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:211
const OptionDef options[]
Definition: ffserver.c:3952
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:630
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:478
void avio_wl64(AVIOContext *s, uint64_t val)
Definition: aviobuf.c:455
int max_packet_size
Definition: avio.h:242
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:341
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:464
int(* read_packet)(void *opaque, uint8_t *buf, int buf_size)
Definition: avio.h:235
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:752
const char * avio_enum_protocols(void **opaque, int output)
Iterate through names of available protocols.
Definition: protocols.c:96
int avio_close(AVIOContext *s)
Close the resource accessed by the AVIOContext s and free it.
Definition: aviobuf.c:1105
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:310
unsigned long checksum
Definition: avio.h:243
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:274
const char * protocol_blacklist
',' separated list of disallowed protocols.
Definition: avio.h:315
#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:286
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:621
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:320
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:261
int void avio_flush(AVIOContext *s)
Force flushing of buffered data.
Definition: aviobuf.c:231
unsigned int avio_rb24(AVIOContext *s)
Definition: aviobuf.c:776
void avio_free_directory_entry(AVIODirEntry **entry)
Free entry allocated by avio_read_dir().
Definition: avio.c:601
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:244
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
int must_flush
unused
Definition: avio.h:239
Libavformat version macros.
unsigned long(* update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size)
Definition: avio.h:245
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:497
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:189
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:471
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:1093
int short_seek_threshold
Threshold to favor readahead over seek.
Definition: avio.h:305
int avio_handshake(AVIOContext *c)
Perform one step of the protocol handshake to accept a new client.
Definition: aviobuf.c:1204
int avio_close_dir(AVIODirContext **s)
Close directory.
Definition: avio.c:586
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:327
int error
contains the error code or 0 if no error happened
Definition: avio.h:246
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:1148
int(* read_pause)(void *opaque, int pause)
Pause or resume playback for network streaming protocols - e.g.
Definition: avio.h:250
void avio_wb16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:473
#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:299
enum AVIODataMarkerType current_type
Internal, not meant to be used from outside of AVIOContext.
Definition: avio.h:332
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:736
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]
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:1155
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:347
int avio_read_dir(AVIODirContext *s, AVIODirEntry **next)
Get next directory entry.
Definition: avio.c:573
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:240
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:535
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:808
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:349
unsigned int avio_rl24(AVIOContext *s)
Definition: aviobuf.c:744
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:1128
uint64_t avio_rl64(AVIOContext *s)
Definition: aviobuf.c:760
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:1316