2 * copyright (c) 2001 Fabrice Bellard
4 * This file is part of FFmpeg.
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.
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.
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
20 #ifndef AVFORMAT_AVIO_H
21 #define AVFORMAT_AVIO_H
25 * Buffered I/O operations
30 #include "libavutil/common.h"
31 #include "libavutil/log.h"
33 #include "libavformat/version.h"
36 #define AVIO_SEEKABLE_NORMAL 0x0001 /**< Seeking works like for a local file */
39 * Bytestream IO Context.
40 * New fields can be added to the end with minor version bumps.
41 * Removal, reordering and changes to existing fields require a major
43 * sizeof(AVIOContext) must not be used outside libav*.
45 * @note None of the function pointers in AVIOContext should be called
46 * directly, they should only be set by the client application
47 * when implementing custom I/O. Normally these are set to the
48 * function pointers specified in avio_alloc_context()
51 unsigned char *buffer; /**< Start of the buffer. */
52 int buffer_size; /**< Maximum buffer size */
53 unsigned char *buf_ptr; /**< Current position in the buffer */
54 unsigned char *buf_end; /**< End of the data, may be less than
55 buffer+buffer_size if the read function returned
56 less data than requested, e.g. for streams where
57 no more data has been received yet. */
58 void *opaque; /**< A private pointer, passed to the read/write/seek/...
60 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
61 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
62 int64_t (*seek)(void *opaque, int64_t offset, int whence);
63 int64_t pos; /**< position in the file of the current buffer */
64 int must_flush; /**< true if the next seek should flush */
65 int eof_reached; /**< true if eof reached */
66 int write_flag; /**< true if open for writing */
68 attribute_deprecated int is_streamed;
71 unsigned long checksum;
72 unsigned char *checksum_ptr;
73 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
74 int error; /**< contains the error code or 0 if no error happened */
76 * Pause or resume playback for network streaming protocols - e.g. MMS.
78 int (*read_pause)(void *opaque, int pause);
80 * Seek to a given timestamp in stream with the specified stream_index.
81 * Needed for some network streaming protocols which don't support seeking
84 int64_t (*read_seek)(void *opaque, int stream_index,
85 int64_t timestamp, int flags);
87 * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
97 * New fields can be added to the end with minor version bumps.
98 * Removal, reordering and changes to existing fields require a major
100 * sizeof(URLContext) must not be used outside libav*.
101 * @deprecated This struct will be made private
103 typedef struct URLContext {
104 const AVClass *av_class; ///< information for av_log(). Set by url_open().
105 struct URLProtocol *prot;
107 int is_streamed; /**< true if streamed (no seek possible), default = false */
108 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
110 char *filename; /**< specified URL */
114 #define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */
117 * @deprecated This struct is to be made private. Use the higher-level
118 * AVIOContext-based API instead.
120 typedef struct URLProtocol {
122 int (*url_open)(URLContext *h, const char *url, int flags);
123 int (*url_read)(URLContext *h, unsigned char *buf, int size);
124 int (*url_write)(URLContext *h, const unsigned char *buf, int size);
125 int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
126 int (*url_close)(URLContext *h);
127 struct URLProtocol *next;
128 int (*url_read_pause)(URLContext *h, int pause);
129 int64_t (*url_read_seek)(URLContext *h, int stream_index,
130 int64_t timestamp, int flags);
131 int (*url_get_file_handle)(URLContext *h);
133 const AVClass *priv_data_class;
135 int (*url_check)(URLContext *h, int mask);
138 typedef struct URLPollEntry {
144 /* not implemented */
145 attribute_deprecated int url_poll(URLPollEntry *poll_table, int n, int timeout);
148 * @name URL open modes
149 * The flags argument to url_open and cosins must be one of the following
150 * constants, optionally ORed with other flags.
153 #define URL_RDONLY 1 /**< read-only */
154 #define URL_WRONLY 2 /**< write-only */
155 #define URL_RDWR (URL_RDONLY|URL_WRONLY) /**< read-write */
161 * Use non-blocking mode.
162 * If this flag is set, operations on the context will return
163 * AVERROR(EAGAIN) if they can not be performed immediately.
164 * If this flag is not set, operations on the context will never return
166 * Note that this flag does not affect the opening/connecting of the
167 * context. Connecting a protocol will always block if necessary (e.g. on
168 * network protocols) but never hang (e.g. on busy devices).
169 * Warning: non-blocking protocols is work-in-progress; this flag may be
172 #define URL_FLAG_NONBLOCK 4
174 typedef int URLInterruptCB(void);
175 extern URLInterruptCB *url_interrupt_cb;
178 * @defgroup old_url_funcs Old url_* functions
179 * The following functions are deprecated. Use the buffered API based on #AVIOContext instead.
182 attribute_deprecated int url_open_protocol (URLContext **puc, struct URLProtocol *up,
183 const char *url, int flags);
184 attribute_deprecated int url_alloc(URLContext **h, const char *url, int flags);
185 attribute_deprecated int url_connect(URLContext *h);
186 attribute_deprecated int url_open(URLContext **h, const char *url, int flags);
187 attribute_deprecated int url_read(URLContext *h, unsigned char *buf, int size);
188 attribute_deprecated int url_read_complete(URLContext *h, unsigned char *buf, int size);
189 attribute_deprecated int url_write(URLContext *h, const unsigned char *buf, int size);
190 attribute_deprecated int64_t url_seek(URLContext *h, int64_t pos, int whence);
191 attribute_deprecated int url_close(URLContext *h);
192 attribute_deprecated int64_t url_filesize(URLContext *h);
193 attribute_deprecated int url_get_file_handle(URLContext *h);
194 attribute_deprecated int url_get_max_packet_size(URLContext *h);
195 attribute_deprecated void url_get_filename(URLContext *h, char *buf, int buf_size);
196 attribute_deprecated int av_url_read_pause(URLContext *h, int pause);
197 attribute_deprecated int64_t av_url_read_seek(URLContext *h, int stream_index,
198 int64_t timestamp, int flags);
199 attribute_deprecated void url_set_interrupt_cb(int (*interrupt_cb)(void));
202 * returns the next registered protocol after the given protocol (the first if
203 * NULL is given), or NULL if protocol is the last one.
205 URLProtocol *av_protocol_next(URLProtocol *p);
208 * Register the URLProtocol protocol.
210 * @param size the size of the URLProtocol struct referenced
212 attribute_deprecated int av_register_protocol2(URLProtocol *protocol, int size);
218 typedef attribute_deprecated AVIOContext ByteIOContext;
220 attribute_deprecated int init_put_byte(AVIOContext *s,
221 unsigned char *buffer,
225 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
226 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
227 int64_t (*seek)(void *opaque, int64_t offset, int whence));
228 attribute_deprecated AVIOContext *av_alloc_put_byte(
229 unsigned char *buffer,
233 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
234 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
235 int64_t (*seek)(void *opaque, int64_t offset, int whence));
238 * @defgroup old_avio_funcs Old put_/get_*() functions
239 * The following functions are deprecated. Use the "avio_"-prefixed functions instead.
242 attribute_deprecated int get_buffer(AVIOContext *s, unsigned char *buf, int size);
243 attribute_deprecated int get_partial_buffer(AVIOContext *s, unsigned char *buf, int size);
244 attribute_deprecated int get_byte(AVIOContext *s);
245 attribute_deprecated unsigned int get_le16(AVIOContext *s);
246 attribute_deprecated unsigned int get_le24(AVIOContext *s);
247 attribute_deprecated unsigned int get_le32(AVIOContext *s);
248 attribute_deprecated uint64_t get_le64(AVIOContext *s);
249 attribute_deprecated unsigned int get_be16(AVIOContext *s);
250 attribute_deprecated unsigned int get_be24(AVIOContext *s);
251 attribute_deprecated unsigned int get_be32(AVIOContext *s);
252 attribute_deprecated uint64_t get_be64(AVIOContext *s);
254 attribute_deprecated void put_byte(AVIOContext *s, int b);
255 attribute_deprecated void put_nbyte(AVIOContext *s, int b, int count);
256 attribute_deprecated void put_buffer(AVIOContext *s, const unsigned char *buf, int size);
257 attribute_deprecated void put_le64(AVIOContext *s, uint64_t val);
258 attribute_deprecated void put_be64(AVIOContext *s, uint64_t val);
259 attribute_deprecated void put_le32(AVIOContext *s, unsigned int val);
260 attribute_deprecated void put_be32(AVIOContext *s, unsigned int val);
261 attribute_deprecated void put_le24(AVIOContext *s, unsigned int val);
262 attribute_deprecated void put_be24(AVIOContext *s, unsigned int val);
263 attribute_deprecated void put_le16(AVIOContext *s, unsigned int val);
264 attribute_deprecated void put_be16(AVIOContext *s, unsigned int val);
265 attribute_deprecated void put_tag(AVIOContext *s, const char *tag);
270 attribute_deprecated int av_url_read_fpause(AVIOContext *h, int pause);
271 attribute_deprecated int64_t av_url_read_fseek (AVIOContext *h, int stream_index,
272 int64_t timestamp, int flags);
275 * @defgroup old_url_f_funcs Old url_f* functions
276 * The following functions are deprecated, use the "avio_"-prefixed functions instead.
279 attribute_deprecated int url_fopen( AVIOContext **s, const char *url, int flags);
280 attribute_deprecated int url_fclose(AVIOContext *s);
281 attribute_deprecated int64_t url_fseek(AVIOContext *s, int64_t offset, int whence);
282 attribute_deprecated int url_fskip(AVIOContext *s, int64_t offset);
283 attribute_deprecated int64_t url_ftell(AVIOContext *s);
284 attribute_deprecated int64_t url_fsize(AVIOContext *s);
286 attribute_deprecated int url_fgetc(AVIOContext *s);
287 attribute_deprecated int url_setbufsize(AVIOContext *s, int buf_size);
288 attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...) av_printf_format(2, 3);
289 attribute_deprecated void put_flush_packet(AVIOContext *s);
290 attribute_deprecated int url_open_dyn_buf(AVIOContext **s);
291 attribute_deprecated int url_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
292 attribute_deprecated int url_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
293 attribute_deprecated int url_fdopen(AVIOContext **s, URLContext *h);
298 attribute_deprecated int url_ferror(AVIOContext *s);
300 attribute_deprecated int udp_set_remote_url(URLContext *h, const char *uri);
301 attribute_deprecated int udp_get_local_port(URLContext *h);
303 attribute_deprecated void init_checksum(AVIOContext *s,
304 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
305 unsigned long checksum);
306 attribute_deprecated unsigned long get_checksum(AVIOContext *s);
307 attribute_deprecated void put_strz(AVIOContext *s, const char *buf);
308 /** @note unlike fgets, the EOL character is not returned and a whole
309 line is parsed. return NULL if first char read was EOF */
310 attribute_deprecated char *url_fgets(AVIOContext *s, char *buf, int buf_size);
312 * @deprecated use avio_get_str instead
314 attribute_deprecated char *get_strz(AVIOContext *s, char *buf, int maxlen);
316 * @deprecated Use AVIOContext.seekable field directly.
318 attribute_deprecated static inline int url_is_streamed(AVIOContext *s)
322 attribute_deprecated URLContext *url_fileno(AVIOContext *s);
325 * @deprecated use AVIOContext.max_packet_size directly.
327 attribute_deprecated int url_fget_max_packet_size(AVIOContext *s);
329 attribute_deprecated int url_open_buf(AVIOContext **s, uint8_t *buf, int buf_size, int flags);
331 /** return the written or read size */
332 attribute_deprecated int url_close_buf(AVIOContext *s);
335 * Return a non-zero value if the resource indicated by url
336 * exists, 0 otherwise.
337 * @deprecated Use avio_check instead.
339 attribute_deprecated int url_exist(const char *url);
340 #endif // FF_API_OLD_AVIO
343 * Return AVIO_FLAG_* access flags corresponding to the access permissions
344 * of the resource in url, or a negative value corresponding to an
345 * AVERROR code in case of failure. The returned access flags are
346 * masked by the value in flags.
348 * @note This function is intrinsically unsafe, in the sense that the
349 * checked resource may change its existence or permission status from
350 * one call to another. Thus you should not trust the returned value,
351 * unless you are sure that no other processes are accessing the
354 int avio_check(const char *url, int flags);
357 * The callback is called in blocking functions to test regulary if
358 * asynchronous interruption is needed. AVERROR_EXIT is returned
359 * in this case by the interrupted function. 'NULL' means no interrupt
362 void avio_set_interrupt_cb(int (*interrupt_cb)(void));
365 * Allocate and initialize an AVIOContext for buffered I/O. It must be later
366 * freed with av_free().
368 * @param buffer Memory block for input/output operations via AVIOContext.
369 * The buffer must be allocated with av_malloc() and friends.
370 * @param buffer_size The buffer size is very important for performance.
371 * For protocols with fixed blocksize it should be set to this blocksize.
372 * For others a typical size is a cache page, e.g. 4kb.
373 * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.
374 * @param opaque An opaque pointer to user-specific data.
375 * @param read_packet A function for refilling the buffer, may be NULL.
376 * @param write_packet A function for writing the buffer contents, may be NULL.
377 * @param seek A function for seeking to specified byte position, may be NULL.
379 * @return Allocated AVIOContext or NULL on failure.
381 AVIOContext *avio_alloc_context(
382 unsigned char *buffer,
386 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
387 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
388 int64_t (*seek)(void *opaque, int64_t offset, int whence));
390 void avio_w8(AVIOContext *s, int b);
391 void avio_write(AVIOContext *s, const unsigned char *buf, int size);
392 void avio_wl64(AVIOContext *s, uint64_t val);
393 void avio_wb64(AVIOContext *s, uint64_t val);
394 void avio_wl32(AVIOContext *s, unsigned int val);
395 void avio_wb32(AVIOContext *s, unsigned int val);
396 void avio_wl24(AVIOContext *s, unsigned int val);
397 void avio_wb24(AVIOContext *s, unsigned int val);
398 void avio_wl16(AVIOContext *s, unsigned int val);
399 void avio_wb16(AVIOContext *s, unsigned int val);
402 * Write a NULL-terminated string.
403 * @return number of bytes written.
405 int avio_put_str(AVIOContext *s, const char *str);
408 * Convert an UTF-8 string to UTF-16LE and write it.
409 * @return number of bytes written.
411 int avio_put_str16le(AVIOContext *s, const char *str);
414 * Passing this as the "whence" parameter to a seek function causes it to
415 * return the filesize without seeking anywhere. Supporting this is optional.
416 * If it is not supported then the seek function will return <0.
418 #define AVSEEK_SIZE 0x10000
421 * Oring this flag as into the "whence" parameter to a seek function causes it to
422 * seek by any means (like reopening and linear reading) or other normally unreasonble
423 * means that can be extreemly slow.
424 * This may be ignored by the seek code.
426 #define AVSEEK_FORCE 0x20000
429 * fseek() equivalent for AVIOContext.
430 * @return new position or AVERROR.
432 int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);
435 * Skip given number of bytes forward
436 * @return new position or AVERROR.
438 int64_t avio_skip(AVIOContext *s, int64_t offset);
441 * ftell() equivalent for AVIOContext.
442 * @return position or AVERROR.
444 static av_always_inline int64_t avio_tell(AVIOContext *s)
446 return avio_seek(s, 0, SEEK_CUR);
451 * @return filesize or AVERROR
453 int64_t avio_size(AVIOContext *s);
456 * feof() equivalent for AVIOContext.
457 * @return non zero if and only if end of file
459 int url_feof(AVIOContext *s);
461 /** @warning currently size is limited */
462 int avio_printf(AVIOContext *s, const char *fmt, ...) av_printf_format(2, 3);
464 void avio_flush(AVIOContext *s);
468 * Read size bytes from AVIOContext into buf.
469 * @return number of bytes read or AVERROR
471 int avio_read(AVIOContext *s, unsigned char *buf, int size);
474 * @name Functions for reading from AVIOContext
477 * @note return 0 if EOF, so you cannot use it if EOF handling is
480 int avio_r8 (AVIOContext *s);
481 unsigned int avio_rl16(AVIOContext *s);
482 unsigned int avio_rl24(AVIOContext *s);
483 unsigned int avio_rl32(AVIOContext *s);
484 uint64_t avio_rl64(AVIOContext *s);
485 unsigned int avio_rb16(AVIOContext *s);
486 unsigned int avio_rb24(AVIOContext *s);
487 unsigned int avio_rb32(AVIOContext *s);
488 uint64_t avio_rb64(AVIOContext *s);
494 * Read a string from pb into buf. The reading will terminate when either
495 * a NULL character was encountered, maxlen bytes have been read, or nothing
496 * more can be read from pb. The result is guaranteed to be NULL-terminated, it
497 * will be truncated if buf is too small.
498 * Note that the string is not interpreted or validated in any way, it
499 * might get truncated in the middle of a sequence for multi-byte encodings.
501 * @return number of bytes read (is always <= maxlen).
502 * If reading ends on EOF or error, the return value will be one more than
503 * bytes actually read.
505 int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);
508 * Read a UTF-16 string from pb and convert it to UTF-8.
509 * The reading will terminate when either a null or invalid character was
510 * encountered or maxlen bytes have been read.
511 * @return number of bytes read (is always <= maxlen)
513 int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);
514 int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);
518 * @name URL open modes
519 * The flags argument to avio_open must be one of the following
520 * constants, optionally ORed with other flags.
523 #define AVIO_FLAG_READ 1 /**< read-only */
524 #define AVIO_FLAG_WRITE 2 /**< write-only */
525 #define AVIO_FLAG_READ_WRITE (AVIO_FLAG_READ|AVIO_FLAG_WRITE) /**< read-write pseudo flag */
531 * Use non-blocking mode.
532 * If this flag is set, operations on the context will return
533 * AVERROR(EAGAIN) if they can not be performed immediately.
534 * If this flag is not set, operations on the context will never return
536 * Note that this flag does not affect the opening/connecting of the
537 * context. Connecting a protocol will always block if necessary (e.g. on
538 * network protocols) but never hang (e.g. on busy devices).
539 * Warning: non-blocking protocols is work-in-progress; this flag may be
542 #define AVIO_FLAG_NONBLOCK 8
545 * Create and initialize a AVIOContext for accessing the
546 * resource indicated by url.
547 * @note When the resource indicated by url has been opened in
548 * read+write mode, the AVIOContext can be used only for writing.
550 * @param s Used to return the pointer to the created AVIOContext.
551 * In case of failure the pointed to value is set to NULL.
552 * @param flags flags which control how the resource indicated by url
554 * @return 0 in case of success, a negative value corresponding to an
555 * AVERROR code in case of failure
557 int avio_open(AVIOContext **s, const char *url, int flags);
560 * Close the resource accessed by the AVIOContext s and free it.
561 * This function can only be used if s was opened by avio_open().
563 * @return 0 on success, an AVERROR < 0 on error.
565 int avio_close(AVIOContext *s);
568 * Open a write only memory stream.
570 * @param s new IO context
571 * @return zero if no error.
573 int avio_open_dyn_buf(AVIOContext **s);
576 * Return the written size and a pointer to the buffer. The buffer
577 * must be freed with av_free().
578 * Padding of FF_INPUT_BUFFER_PADDING_SIZE is added to the buffer.
580 * @param s IO context
581 * @param pbuffer pointer to a byte buffer
582 * @return the length of the byte buffer
584 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
587 * Iterate through names of available protocols.
588 * @note it is recommanded to use av_protocol_next() instead of this
590 * @param opaque A private pointer representing current protocol.
591 * It must be a pointer to NULL on first iteration and will
592 * be updated by successive calls to avio_enum_protocols.
593 * @param output If set to 1, iterate over output protocols,
594 * otherwise over input protocols.
596 * @return A static string containing the name of current protocol or NULL
598 const char *avio_enum_protocols(void **opaque, int output);
601 * Pause and resume playing - only meaningful if using a network streaming
602 * protocol (e.g. MMS).
603 * @param pause 1 for pause, 0 for resume
605 int avio_pause(AVIOContext *h, int pause);
608 * Seek to a given timestamp relative to some component stream.
609 * Only meaningful if using a network streaming protocol (e.g. MMS.).
610 * @param stream_index The stream index that the timestamp is relative to.
611 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
612 * units from the beginning of the presentation.
613 * If a stream_index >= 0 is used and the protocol does not support
614 * seeking based on component streams, the call will fail with ENOTSUP.
615 * @param timestamp timestamp in AVStream.time_base units
616 * or if there is no stream specified then in AV_TIME_BASE units.
617 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
618 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
619 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
620 * fail with ENOTSUP if used and not supported.
621 * @return >= 0 on success
622 * @see AVInputFormat::read_seek
624 int64_t avio_seek_time(AVIOContext *h, int stream_index,
625 int64_t timestamp, int flags);
627 #endif /* AVFORMAT_AVIO_H */