2 * copyright (c) 2001 Fabrice Bellard
4 * This file is part of Libav.
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 #ifndef AVFORMAT_AVIO_H
21 #define AVFORMAT_AVIO_H
25 * unbuffered I/O operations
27 * @warning This file has to be considered an internal but installed
28 * header, so it should not be directly included in your projects.
33 #include "libavutil/common.h"
34 #include "libavutil/log.h"
36 #include "libavformat/version.h"
42 * New fields can be added to the end with minor version bumps.
43 * Removal, reordering and changes to existing fields require a major
45 * sizeof(URLContext) must not be used outside libav*.
47 typedef struct URLContext {
49 const AVClass *av_class; ///< information for av_log(). Set by url_open().
51 struct URLProtocol *prot;
53 int is_streamed; /**< true if streamed (no seek possible), default = false */
54 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
56 char *filename; /**< specified URL */
61 typedef struct URLPollEntry {
69 * @defgroup open_modes URL open modes
70 * The flags argument to url_open and cosins must be one of the following
71 * constants, optionally ORed with other flags.
74 #define URL_RDONLY 0 /**< read-only */
75 #define URL_WRONLY 1 /**< write-only */
76 #define URL_RDWR 2 /**< read-write */
82 * Use non-blocking mode.
83 * If this flag is set, operations on the context will return
84 * AVERROR(EAGAIN) if they can not be performed immediately.
85 * If this flag is not set, operations on the context will never return
87 * Note that this flag does not affect the opening/connecting of the
88 * context. Connecting a protocol will always block if necessary (e.g. on
89 * network protocols) but never hang (e.g. on busy devices).
90 * Warning: non-blocking protocols is work-in-progress; this flag may be
93 #define URL_FLAG_NONBLOCK 4
95 typedef int URLInterruptCB(void);
99 * @defgroup old_url_funcs Old url_* functions
100 * @deprecated use the buffered API based on AVIOContext instead
103 attribute_deprecated int url_open_protocol (URLContext **puc, struct URLProtocol *up,
104 const char *url, int flags);
105 attribute_deprecated int url_alloc(URLContext **h, const char *url, int flags);
106 attribute_deprecated int url_connect(URLContext *h);
107 attribute_deprecated int url_open(URLContext **h, const char *url, int flags);
108 attribute_deprecated int url_read(URLContext *h, unsigned char *buf, int size);
109 attribute_deprecated int url_read_complete(URLContext *h, unsigned char *buf, int size);
110 attribute_deprecated int url_write(URLContext *h, const unsigned char *buf, int size);
111 attribute_deprecated int64_t url_seek(URLContext *h, int64_t pos, int whence);
112 attribute_deprecated int url_close(URLContext *h);
113 attribute_deprecated int64_t url_filesize(URLContext *h);
114 attribute_deprecated int url_get_file_handle(URLContext *h);
115 attribute_deprecated int url_get_max_packet_size(URLContext *h);
116 attribute_deprecated void url_get_filename(URLContext *h, char *buf, int buf_size);
120 * Return a non-zero value if the resource indicated by url
121 * exists, 0 otherwise.
123 int url_exist(const char *url);
126 * The callback is called in blocking functions to test regulary if
127 * asynchronous interruption is needed. AVERROR_EXIT is returned
128 * in this case by the interrupted function. 'NULL' means no interrupt
131 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
134 /* not implemented */
135 attribute_deprecated int url_poll(URLPollEntry *poll_table, int n, int timeout);
139 * Pause and resume playing - only meaningful if using a network streaming
140 * protocol (e.g. MMS).
141 * @param pause 1 for pause, 0 for resume
143 int av_url_read_pause(URLContext *h, int pause);
146 * Seek to a given timestamp relative to some component stream.
147 * Only meaningful if using a network streaming protocol (e.g. MMS.).
148 * @param stream_index The stream index that the timestamp is relative to.
149 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
150 * units from the beginning of the presentation.
151 * If a stream_index >= 0 is used and the protocol does not support
152 * seeking based on component streams, the call will fail with ENOTSUP.
153 * @param timestamp timestamp in AVStream.time_base units
154 * or if there is no stream specified then in AV_TIME_BASE units.
155 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
156 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
157 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
158 * fail with ENOTSUP if used and not supported.
159 * @return >= 0 on success
160 * @see AVInputFormat::read_seek
162 int64_t av_url_read_seek(URLContext *h, int stream_index,
163 int64_t timestamp, int flags);
165 #define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */
167 typedef struct URLProtocol {
169 int (*url_open)(URLContext *h, const char *url, int flags);
170 int (*url_read)(URLContext *h, unsigned char *buf, int size);
171 int (*url_write)(URLContext *h, const unsigned char *buf, int size);
172 int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
173 int (*url_close)(URLContext *h);
174 struct URLProtocol *next;
175 int (*url_read_pause)(URLContext *h, int pause);
176 int64_t (*url_read_seek)(URLContext *h, int stream_index,
177 int64_t timestamp, int flags);
178 int (*url_get_file_handle)(URLContext *h);
180 const AVClass *priv_data_class;
184 #if FF_API_REGISTER_PROTOCOL
185 extern URLProtocol *first_protocol;
188 extern URLInterruptCB *url_interrupt_cb;
191 * If protocol is NULL, returns the first registered protocol,
192 * if protocol is non-NULL, returns the next registered protocol after protocol,
193 * or NULL if protocol is the last one.
195 URLProtocol *av_protocol_next(URLProtocol *p);
197 #if FF_API_REGISTER_PROTOCOL
199 * @deprecated Use av_register_protocol() instead.
201 attribute_deprecated int register_protocol(URLProtocol *protocol);
204 * @deprecated Use av_register_protocol2() instead.
206 attribute_deprecated int av_register_protocol(URLProtocol *protocol);
210 * Register the URLProtocol protocol.
212 * @param size the size of the URLProtocol struct referenced
214 int av_register_protocol2(URLProtocol *protocol, int size);
216 #define AVIO_SEEKABLE_NORMAL 0x0001 /**< Seeking works like for a local file */
223 * Bytestream IO Context.
224 * New fields can be added to the end with minor version bumps.
225 * Removal, reordering and changes to existing fields require a major
227 * sizeof(AVIOContext) must not be used outside libav*.
230 unsigned char *buffer;
232 unsigned char *buf_ptr, *buf_end;
234 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
235 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
236 int64_t (*seek)(void *opaque, int64_t offset, int whence);
237 int64_t pos; /**< position in the file of the current buffer */
238 int must_flush; /**< true if the next seek should flush */
239 int eof_reached; /**< true if eof reached */
240 int write_flag; /**< true if open for writing */
242 attribute_deprecated int is_streamed;
245 unsigned long checksum;
246 unsigned char *checksum_ptr;
247 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
248 int error; ///< contains the error code or 0 if no error happened
249 int (*read_pause)(void *opaque, int pause);
250 int64_t (*read_seek)(void *opaque, int stream_index,
251 int64_t timestamp, int flags);
253 * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
259 typedef attribute_deprecated AVIOContext ByteIOContext;
261 attribute_deprecated int init_put_byte(AVIOContext *s,
262 unsigned char *buffer,
266 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
267 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
268 int64_t (*seek)(void *opaque, int64_t offset, int whence));
269 attribute_deprecated AVIOContext *av_alloc_put_byte(
270 unsigned char *buffer,
274 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
275 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
276 int64_t (*seek)(void *opaque, int64_t offset, int whence));
279 * @defgroup old_avio_funcs Old put_/get_*() functions
280 * @deprecated use the avio_ -prefixed functions instead.
283 attribute_deprecated int get_buffer(AVIOContext *s, unsigned char *buf, int size);
284 attribute_deprecated int get_partial_buffer(AVIOContext *s, unsigned char *buf, int size);
285 attribute_deprecated int get_byte(AVIOContext *s);
286 attribute_deprecated unsigned int get_le16(AVIOContext *s);
287 attribute_deprecated unsigned int get_le24(AVIOContext *s);
288 attribute_deprecated unsigned int get_le32(AVIOContext *s);
289 attribute_deprecated uint64_t get_le64(AVIOContext *s);
290 attribute_deprecated unsigned int get_be16(AVIOContext *s);
291 attribute_deprecated unsigned int get_be24(AVIOContext *s);
292 attribute_deprecated unsigned int get_be32(AVIOContext *s);
293 attribute_deprecated uint64_t get_be64(AVIOContext *s);
295 attribute_deprecated void put_byte(AVIOContext *s, int b);
296 attribute_deprecated void put_nbyte(AVIOContext *s, int b, int count);
297 attribute_deprecated void put_buffer(AVIOContext *s, const unsigned char *buf, int size);
298 attribute_deprecated void put_le64(AVIOContext *s, uint64_t val);
299 attribute_deprecated void put_be64(AVIOContext *s, uint64_t val);
300 attribute_deprecated void put_le32(AVIOContext *s, unsigned int val);
301 attribute_deprecated void put_be32(AVIOContext *s, unsigned int val);
302 attribute_deprecated void put_le24(AVIOContext *s, unsigned int val);
303 attribute_deprecated void put_be24(AVIOContext *s, unsigned int val);
304 attribute_deprecated void put_le16(AVIOContext *s, unsigned int val);
305 attribute_deprecated void put_be16(AVIOContext *s, unsigned int val);
306 attribute_deprecated void put_tag(AVIOContext *s, const char *tag);
311 attribute_deprecated int av_url_read_fpause(AVIOContext *h, int pause);
312 attribute_deprecated int64_t av_url_read_fseek (AVIOContext *h, int stream_index,
313 int64_t timestamp, int flags);
316 * @defgroup old_url_f_funcs Old url_f* functions
317 * @deprecated use the avio_ -prefixed functions instead.
320 attribute_deprecated int url_fopen( AVIOContext **s, const char *url, int flags);
321 attribute_deprecated int url_fclose(AVIOContext *s);
322 attribute_deprecated int64_t url_fseek(AVIOContext *s, int64_t offset, int whence);
323 attribute_deprecated int url_fskip(AVIOContext *s, int64_t offset);
324 attribute_deprecated int64_t url_ftell(AVIOContext *s);
325 attribute_deprecated int64_t url_fsize(AVIOContext *s);
327 attribute_deprecated int url_fgetc(AVIOContext *s);
328 attribute_deprecated int url_setbufsize(AVIOContext *s, int buf_size);
330 attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
332 attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...);
334 attribute_deprecated void put_flush_packet(AVIOContext *s);
335 attribute_deprecated int url_open_dyn_buf(AVIOContext **s);
336 attribute_deprecated int url_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
337 attribute_deprecated int url_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
338 attribute_deprecated int url_fdopen(AVIOContext **s, URLContext *h);
344 * @deprecated use AVIOContext.eof_reached
346 attribute_deprecated int url_feof(AVIOContext *s);
347 attribute_deprecated int url_ferror(AVIOContext *s);
349 attribute_deprecated int udp_set_remote_url(URLContext *h, const char *uri);
350 attribute_deprecated int udp_get_local_port(URLContext *h);
352 attribute_deprecated void init_checksum(AVIOContext *s,
353 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
354 unsigned long checksum);
355 attribute_deprecated unsigned long get_checksum(AVIOContext *s);
359 * Allocate and initialize an AVIOContext for buffered I/O. It must be later
360 * freed with av_free().
362 * @param buffer Memory block for input/output operations via AVIOContext.
363 * @param buffer_size The buffer size is very important for performance.
364 * For protocols with fixed blocksize it should be set to this blocksize.
365 * For others a typical size is a cache page, e.g. 4kb.
366 * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.
367 * @param opaque An opaque pointer to user-specific data.
368 * @param read_packet A function for refilling the buffer, may be NULL.
369 * @param write_packet A function for writing the buffer contents, may be NULL.
370 * @param seek A function for seeking to specified byte position, may be NULL.
372 * @return Allocated AVIOContext or NULL on failure.
374 AVIOContext *avio_alloc_context(
375 unsigned char *buffer,
379 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
380 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
381 int64_t (*seek)(void *opaque, int64_t offset, int whence));
383 void avio_w8(AVIOContext *s, int b);
384 void avio_write(AVIOContext *s, const unsigned char *buf, int size);
385 void avio_wl64(AVIOContext *s, uint64_t val);
386 void avio_wb64(AVIOContext *s, uint64_t val);
387 void avio_wl32(AVIOContext *s, unsigned int val);
388 void avio_wb32(AVIOContext *s, unsigned int val);
389 void avio_wl24(AVIOContext *s, unsigned int val);
390 void avio_wb24(AVIOContext *s, unsigned int val);
391 void avio_wl16(AVIOContext *s, unsigned int val);
392 void avio_wb16(AVIOContext *s, unsigned int val);
395 attribute_deprecated void put_strz(AVIOContext *s, const char *buf);
399 * Write a NULL-terminated string.
400 * @return number of bytes written.
402 int avio_put_str(AVIOContext *s, const char *str);
405 * Convert an UTF-8 string to UTF-16LE and write it.
406 * @return number of bytes written.
408 int avio_put_str16le(AVIOContext *s, const char *str);
411 * Passing this as the "whence" parameter to a seek function causes it to
412 * return the filesize without seeking anywhere. Supporting this is optional.
413 * If it is not supported then the seek function will return <0.
415 #define AVSEEK_SIZE 0x10000
418 * Oring this flag as into the "whence" parameter to a seek function causes it to
419 * seek by any means (like reopening and linear reading) or other normally unreasonble
420 * means that can be extreemly slow.
421 * This may be ignored by the seek code.
423 #define AVSEEK_FORCE 0x20000
426 * fseek() equivalent for AVIOContext.
427 * @return new position or AVERROR.
429 int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);
432 * Skip given number of bytes forward
433 * @return new position or AVERROR.
435 static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
437 return avio_seek(s, offset, SEEK_CUR);
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);
455 /** @warning currently size is limited */
457 int avio_printf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
459 int avio_printf(AVIOContext *s, const char *fmt, ...);
463 /** @note unlike fgets, the EOL character is not returned and a whole
464 line is parsed. return NULL if first char read was EOF */
465 attribute_deprecated char *url_fgets(AVIOContext *s, char *buf, int buf_size);
468 void avio_flush(AVIOContext *s);
472 * Read size bytes from AVIOContext into buf.
473 * @return number of bytes read or AVERROR
475 int avio_read(AVIOContext *s, unsigned char *buf, int size);
477 /** @note return 0 if EOF, so you cannot use it if EOF handling is
479 int avio_r8 (AVIOContext *s);
480 unsigned int avio_rl16(AVIOContext *s);
481 unsigned int avio_rl24(AVIOContext *s);
482 unsigned int avio_rl32(AVIOContext *s);
483 uint64_t avio_rl64(AVIOContext *s);
486 * Read a string from pb into buf. The reading will terminate when either
487 * a NULL character was encountered, maxlen bytes have been read, or nothing
488 * more can be read from pb. The result is guaranteed to be NULL-terminated, it
489 * will be truncated if buf is too small.
490 * Note that the string is not interpreted or validated in any way, it
491 * might get truncated in the middle of a sequence for multi-byte encodings.
493 * @return number of bytes read (is always <= maxlen).
494 * If reading ends on EOF or error, the return value will be one more than
495 * bytes actually read.
497 int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);
500 * Read a UTF-16 string from pb and convert it to UTF-8.
501 * The reading will terminate when either a null or invalid character was
502 * encountered or maxlen bytes have been read.
503 * @return number of bytes read (is always <= maxlen)
505 int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);
506 int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);
510 * @deprecated use avio_get_str instead
512 attribute_deprecated char *get_strz(AVIOContext *s, char *buf, int maxlen);
514 unsigned int avio_rb16(AVIOContext *s);
515 unsigned int avio_rb24(AVIOContext *s);
516 unsigned int avio_rb32(AVIOContext *s);
517 uint64_t avio_rb64(AVIOContext *s);
521 * @deprecated Use AVIOContext.seekable field directly.
523 attribute_deprecated static inline int url_is_streamed(AVIOContext *s)
529 #if FF_API_URL_RESETBUF
530 /** Reset the buffer for reading or writing.
531 * @note Will drop any data currently in the buffer without transmitting it.
532 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
533 * to set up the buffer for writing. */
534 int url_resetbuf(AVIOContext *s, int flags);
538 * Create and initialize a AVIOContext for accessing the
539 * resource indicated by url.
540 * @note When the resource indicated by url has been opened in
541 * read+write mode, the AVIOContext can be used only for writing.
543 * @param s Used to return the pointer to the created AVIOContext.
544 * In case of failure the pointed to value is set to NULL.
545 * @param flags flags which control how the resource indicated by url
547 * @return 0 in case of success, a negative value corresponding to an
548 * AVERROR code in case of failure
550 int avio_open(AVIOContext **s, const char *url, int flags);
552 int avio_close(AVIOContext *s);
555 attribute_deprecated URLContext *url_fileno(AVIOContext *s);
558 * @deprecated use AVIOContext.max_packet_size directly.
560 attribute_deprecated int url_fget_max_packet_size(AVIOContext *s);
562 attribute_deprecated int url_open_buf(AVIOContext **s, uint8_t *buf, int buf_size, int flags);
564 /** return the written or read size */
565 attribute_deprecated int url_close_buf(AVIOContext *s);
569 * Open a write only memory stream.
571 * @param s new IO context
572 * @return zero if no error.
574 int avio_open_dyn_buf(AVIOContext **s);
577 * Return the written size and a pointer to the buffer. The buffer
578 * must be freed with av_free().
579 * Padding of FF_INPUT_BUFFER_PADDING_SIZE is added to the buffer.
581 * @param s IO context
582 * @param pbuffer pointer to a byte buffer
583 * @return the length of the byte buffer
585 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
587 #if FF_API_UDP_GET_FILE
588 int udp_get_file_handle(URLContext *h);
591 #endif /* AVFORMAT_AVIO_H */