1 /*****************************************************************************
2 * libvlc.h: libvlc external API
3 *****************************************************************************
4 * Copyright (C) 1998-2009 VLC authors and VideoLAN
7 * Authors: Clément Stenac <zorglub@videolan.org>
8 * Jean-Paul Saman <jpsaman@videolan.org>
9 * Pierre d'Herbemont <pdherbemont@videolan.org>
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU Lesser General Public License as published by
13 * the Free Software Foundation; either version 2.1 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU Lesser General Public License for more details.
21 * You should have received a copy of the GNU Lesser General Public License
22 * along with this program; if not, write to the Free Software Foundation,
23 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
24 *****************************************************************************/
28 * This file defines libvlc external API
32 * \defgroup libvlc LibVLC
33 * LibVLC is the external programming interface of the VLC media player.
34 * It is used to embed VLC into other applications or frameworks.
39 #define VLC_LIBVLC_H 1
41 #if defined (WIN32) && defined (DLL_EXPORT)
42 # define LIBVLC_API __declspec(dllexport)
43 #elif defined (__GNUC__) && (__GNUC__ >= 4)
44 # define LIBVLC_API __attribute__((visibility("default")))
50 /* Avoid unhelpful warnings from libvlc with our deprecated APIs */
51 # define LIBVLC_DEPRECATED
52 #elif defined(__GNUC__) && \
53 (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0)
54 # define LIBVLC_DEPRECATED __attribute__((deprecated))
56 # define LIBVLC_DEPRECATED
66 #include <vlc/libvlc_structures.h>
68 /** \defgroup libvlc_core LibVLC core
70 * Before it can do anything useful, LibVLC must be initialized.
71 * You can create one (or more) instance(s) of LibVLC in a given process,
72 * with libvlc_new() and destroy them with libvlc_release().
74 * \version Unless otherwise stated, these functions are available
75 * from LibVLC versions numbered 1.1.0 or more.
76 * Earlier versions (0.9.x and 1.0.x) are <b>not</b> compatible.
80 /** \defgroup libvlc_error LibVLC error handling
85 * A human-readable error message for the last LibVLC error in the calling
86 * thread. The resulting string is valid until another error occurs (at least
87 * until the next LibVLC call).
90 * This will be NULL if there was no error.
92 LIBVLC_API const char *libvlc_errmsg (void);
95 * Clears the LibVLC error status for the current thread. This is optional.
96 * By default, the error status is automatically overridden when a new error
97 * occurs, and destroyed when the thread exits.
99 LIBVLC_API void libvlc_clearerr (void);
102 * Sets the LibVLC error status and message for the current thread.
103 * Any previous error is overridden.
104 * \param fmt the format string
105 * \param ap the arguments
106 * \return a nul terminated string in any case
108 LIBVLC_API const char *libvlc_vprinterr (const char *fmt, va_list ap);
111 * Sets the LibVLC error status and message for the current thread.
112 * Any previous error is overridden.
113 * \param fmt the format string
114 * \param args the arguments
115 * \return a nul terminated string in any case
117 LIBVLC_API const char *libvlc_printerr (const char *fmt, ...);
122 * Create and initialize a libvlc instance.
123 * This functions accept a list of "command line" arguments similar to the
124 * main(). These arguments affect the LibVLC instance default configuration.
127 * Arguments are meant to be passed from the command line to LibVLC, just like
128 * VLC media player does. The list of valid arguments depends on the LibVLC
129 * version, the operating system and platform, and set of available LibVLC
130 * plugins. Invalid or unsupported arguments will cause the function to fail
131 * (i.e. return NULL). Also, some arguments may alter the behaviour or
132 * otherwise interfere with other LibVLC functions.
135 * There is absolutely no warranty or promise of forward, backward and
136 * cross-platform compatibility with regards to libvlc_new() arguments.
137 * We recommend that you do not use them, other than when debugging.
139 * \param argc the number of arguments (should be 0)
140 * \param argv list of arguments (should be NULL)
141 * \return the libvlc instance or NULL in case of error
143 LIBVLC_API libvlc_instance_t *
144 libvlc_new( int argc , const char *const *argv );
147 * Decrement the reference count of a libvlc instance, and destroy it
148 * if it reaches zero.
150 * \param p_instance the instance to destroy
152 LIBVLC_API void libvlc_release( libvlc_instance_t *p_instance );
155 * Increments the reference count of a libvlc instance.
156 * The initial reference count is 1 after libvlc_new() returns.
158 * \param p_instance the instance to reference
160 LIBVLC_API void libvlc_retain( libvlc_instance_t *p_instance );
163 * Try to start a user interface for the libvlc instance.
165 * \param p_instance the instance
166 * \param name interface name, or NULL for default
167 * \return 0 on success, -1 on error.
170 int libvlc_add_intf( libvlc_instance_t *p_instance, const char *name );
173 * Registers a callback for the LibVLC exit event. This is mostly useful if
174 * the VLC playlist and/or at least one interface are started with
175 * libvlc_playlist_play() or libvlc_add_intf() respectively.
176 * Typically, this function will wake up your application main loop (from
179 * \note This function should be called before the playlist or interface are
180 * started. Otherwise, there is a small race condition: the exit event could
181 * be raised before the handler is registered.
183 * \param p_instance LibVLC instance
184 * \param cb callback to invoke when LibVLC wants to exit,
185 * or NULL to disable the exit handler (as by default)
186 * \param opaque data pointer for the callback
187 * \warning This function and libvlc_wait() cannot be used at the same time.
190 void libvlc_set_exit_handler( libvlc_instance_t *p_instance,
191 void (*cb) (void *), void *opaque );
194 * Waits until an interface causes the instance to exit.
195 * You should start at least one interface first, using libvlc_add_intf().
197 * \param p_instance the instance
198 * \warning This function wastes one thread doing basically nothing.
199 * libvlc_set_exit_handler() should be used instead.
201 LIBVLC_DEPRECATED LIBVLC_API
202 void libvlc_wait( libvlc_instance_t *p_instance );
205 * Sets the application name. LibVLC passes this as the user agent string
206 * when a protocol requires it.
208 * \param p_instance LibVLC instance
209 * \param name human-readable application name, e.g. "FooBar player 1.2.3"
210 * \param http HTTP User Agent, e.g. "FooBar/1.2.3 Python/2.6.0"
211 * \version LibVLC 1.1.1 or later
214 void libvlc_set_user_agent( libvlc_instance_t *p_instance,
215 const char *name, const char *http );
218 * Retrieve libvlc version.
220 * Example: "1.1.0-git The Luggage"
222 * \return a string containing the libvlc version
224 LIBVLC_API const char * libvlc_get_version(void);
227 * Retrieve libvlc compiler version.
229 * Example: "gcc version 4.2.3 (Ubuntu 4.2.3-2ubuntu6)"
231 * \return a string containing the libvlc compiler version
233 LIBVLC_API const char * libvlc_get_compiler(void);
236 * Retrieve libvlc changeset.
238 * Example: "aa9bce0bc4"
240 * \return a string containing the libvlc changeset
242 LIBVLC_API const char * libvlc_get_changeset(void);
245 * Frees an heap allocation returned by a LibVLC function.
246 * If you know you're using the same underlying C run-time as the LibVLC
247 * implementation, then you can call ANSI C free() directly instead.
249 * \param ptr the pointer
251 LIBVLC_API void libvlc_free( void *ptr );
253 /** \defgroup libvlc_event LibVLC asynchronous events
254 * LibVLC emits asynchronous events.
256 * Several LibVLC objects (such @ref libvlc_instance_t as
257 * @ref libvlc_media_player_t) generate events asynchronously. Each of them
258 * provides @ref libvlc_event_manager_t event manager. You can subscribe to
259 * events with libvlc_event_attach() and unsubscribe with
260 * libvlc_event_detach().
265 * Event manager that belongs to a libvlc object, and from whom events can
268 typedef struct libvlc_event_manager_t libvlc_event_manager_t;
270 struct libvlc_event_t;
273 * Type of a LibVLC event.
275 typedef int libvlc_event_type_t;
278 * Callback function notification
279 * \param p_event the event triggering the callback
281 typedef void ( *libvlc_callback_t )( const struct libvlc_event_t *, void * );
284 * Register for an event notification.
286 * \param p_event_manager the event manager to which you want to attach to.
287 * Generally it is obtained by vlc_my_object_event_manager() where
288 * my_object is the object you want to listen to.
289 * \param i_event_type the desired event to which we want to listen
290 * \param f_callback the function to call when i_event_type occurs
291 * \param user_data user provided data to carry with the event
292 * \return 0 on success, ENOMEM on error
294 LIBVLC_API int libvlc_event_attach( libvlc_event_manager_t *p_event_manager,
295 libvlc_event_type_t i_event_type,
296 libvlc_callback_t f_callback,
300 * Unregister an event notification.
302 * \param p_event_manager the event manager
303 * \param i_event_type the desired event to which we want to unregister
304 * \param f_callback the function to call when i_event_type occurs
305 * \param p_user_data user provided data to carry with the event
307 LIBVLC_API void libvlc_event_detach( libvlc_event_manager_t *p_event_manager,
308 libvlc_event_type_t i_event_type,
309 libvlc_callback_t f_callback,
313 * Get an event's type name.
315 * \param event_type the desired event
317 LIBVLC_API const char * libvlc_event_type_name( libvlc_event_type_t event_type );
321 /** \defgroup libvlc_log LibVLC logging
322 * libvlc_log_* functions provide access to the LibVLC messages log.
323 * This is used for logging and debugging.
328 * Logging messages level.
329 * \note Future LibVLC versions may define new levels.
331 enum libvlc_log_level
333 LIBVLC_DEBUG=0, /**< Debug message */
334 LIBVLC_NOTICE=2, /**< Important informational message */
335 LIBVLC_WARNING=3, /**< Warning (potential error) message */
336 LIBVLC_ERROR=4 /**< Error message */
340 * Callback prototype for LibVLC log message handler.
341 * \param data data pointer as given to libvlc_log_subscribe()
342 * \param level message level (@ref enum libvlc_log_level)
343 * \param fmt printf() format string (as defined by ISO C11)
344 * \param args variable argument list for the format
345 * \note Log message handlers <b>must</b> be thread-safe.
347 typedef void (*libvlc_log_cb)(void *data, int level, const char *fmt,
351 * Data structure for a LibVLC logging callbacks.
352 * \note This structure contains exactly 4 pointers and will never change.
353 * Nevertheless, it should not be accessed directly outside of LibVLC.
354 * (In fact, doing so would fail the thread memory model.)
356 typedef struct libvlc_log_subscriber
358 struct libvlc_log_subscriber *prev, *next;
361 } libvlc_log_subscriber_t;
364 * Registers a logging callback to LibVLC.
365 * This function is thread-safe.
367 * \param sub uninitialized subscriber structure
368 * \param cb callback function pointer
369 * \param data opaque data pointer for the callback function
371 * \note Some log messages (especially debug) are emitted by LibVLC while
372 * initializing, before any LibVLC instance even exists.
373 * Thus this function does not require a LibVLC instance parameter.
375 * \warning As a consequence of not depending on a LibVLC instance,
376 * all logging callbacks are shared by all LibVLC instances within the
377 * process / address space. This also enables log messages to be emitted
378 * by LibVLC components that are not specific to any given LibVLC instance.
380 * \warning Do not call this function from within a logging callback.
381 * It would trigger a dead lock.
382 * \version LibVLC 2.1.0 or later
384 LIBVLC_API void libvlc_log_subscribe( libvlc_log_subscriber_t *sub,
385 libvlc_log_cb cb, void *data );
389 * Registers a logging callback to a file.
390 * \param stream FILE pointer opened for writing
391 * (the FILE pointer must remain valid until libvlc_log_unsubscribe())
392 * \version LibVLC 2.1.0 or later
394 LIBVLC_API void libvlc_log_subscribe_file( libvlc_log_subscriber_t *sub,
398 * Deregisters a logging callback from LibVLC.
399 * This function is thread-safe.
401 * \note After (and only after) libvlc_log_unsubscribe() has returned,
402 * LibVLC warrants that there are no more pending calls of the subscription
405 * \warning Do not call this function from within a logging callback.
406 * It would trigger a dead lock.
408 * \param sub initialized subscriber structure
409 * \version LibVLC 2.1.0 or later
411 LIBVLC_API void libvlc_log_unsubscribe( libvlc_log_subscriber_t *sub );
414 * Always returns minus one.
415 * This function is only provided for backward compatibility.
417 * \param p_instance ignored
420 LIBVLC_DEPRECATED LIBVLC_API
421 unsigned libvlc_get_log_verbosity( const libvlc_instance_t *p_instance );
424 * This function does nothing.
425 * It is only provided for backward compatibility.
427 * \param p_instance ignored
428 * \param level ignored
430 LIBVLC_DEPRECATED LIBVLC_API
431 void libvlc_set_log_verbosity( libvlc_instance_t *p_instance, unsigned level );
434 * This function does nothing useful.
435 * It is only provided for backward compatibility.
437 * \param p_instance libvlc instance
438 * \return an unique pointer or NULL on error
440 LIBVLC_DEPRECATED LIBVLC_API
441 libvlc_log_t *libvlc_log_open( libvlc_instance_t *p_instance );
444 * Frees memory allocated by libvlc_log_open().
446 * \param p_log libvlc log instance or NULL
448 LIBVLC_DEPRECATED LIBVLC_API
449 void libvlc_log_close( libvlc_log_t *p_log );
452 * Always returns zero.
453 * This function is only provided for backward compatibility.
455 * \param p_log ignored
456 * \return always zero
458 LIBVLC_DEPRECATED LIBVLC_API
459 unsigned libvlc_log_count( const libvlc_log_t *p_log );
462 * This function does nothing.
463 * It is only provided for backward compatibility.
465 * \param p_log ignored
467 LIBVLC_DEPRECATED LIBVLC_API
468 void libvlc_log_clear( libvlc_log_t *p_log );
471 * This function does nothing useful.
472 * It is only provided for backward compatibility.
474 * \param p_log ignored
475 * \return an unique pointer or NULL on error or if the parameter was NULL
477 LIBVLC_DEPRECATED LIBVLC_API
478 libvlc_log_iterator_t *libvlc_log_get_iterator( const libvlc_log_t *p_log );
481 * Frees memory allocated by libvlc_log_get_iterator().
483 * \param p_iter libvlc log iterator or NULL
485 LIBVLC_DEPRECATED LIBVLC_API
486 void libvlc_log_iterator_free( libvlc_log_iterator_t *p_iter );
489 * Always returns zero.
490 * This function is only provided for backward compatibility.
492 * \param p_iter ignored
493 * \return always zero
495 LIBVLC_DEPRECATED LIBVLC_API
496 int libvlc_log_iterator_has_next( const libvlc_log_iterator_t *p_iter );
499 * Always returns NULL.
500 * This function is only provided for backward compatibility.
502 * \param p_iter libvlc log iterator or NULL
503 * \param p_buf ignored
504 * \return always NULL
506 LIBVLC_DEPRECATED LIBVLC_API
507 libvlc_log_message_t *libvlc_log_iterator_next( libvlc_log_iterator_t *p_iter,
508 libvlc_log_message_t *p_buf );
513 * Description of a module.
515 typedef struct libvlc_module_description_t
521 struct libvlc_module_description_t *p_next;
522 } libvlc_module_description_t;
525 * Release a list of module descriptions.
527 * \param p_list the list to be released
530 void libvlc_module_description_list_release( libvlc_module_description_t *p_list );
533 * Returns a list of audio filters that are available.
535 * \param p_instance libvlc instance
537 * \return a list of module descriptions. It should be freed with libvlc_module_description_list_release().
538 * In case of an error, NULL is returned.
540 * \see libvlc_module_description_t
541 * \see libvlc_module_description_list_release
544 libvlc_module_description_t *libvlc_audio_filter_list_get( libvlc_instance_t *p_instance );
547 * Returns a list of video filters that are available.
549 * \param p_instance libvlc instance
551 * \return a list of module descriptions. It should be freed with libvlc_module_description_list_release().
552 * In case of an error, NULL is returned.
554 * \see libvlc_module_description_t
555 * \see libvlc_module_description_list_release
558 libvlc_module_description_t *libvlc_video_filter_list_get( libvlc_instance_t *p_instance );
562 /** \defgroup libvlc_clock LibVLC time
563 * These functions provide access to the LibVLC time/clock.
568 * Return the current time as defined by LibVLC. The unit is the microsecond.
569 * Time increases monotonically (regardless of time zone changes and RTC
571 * The origin is arbitrary but consistent across the whole system
572 * (e.g. the system uptim, the time since the system was booted).
573 * \note On systems that support it, the POSIX monotonic clock is used.
576 int64_t libvlc_clock(void);
579 * Return the delay (in microseconds) until a certain timestamp.
580 * \param pts timestamp
581 * \return negative if timestamp is in the past,
582 * positive if it is in the future
584 static inline int64_t libvlc_delay(int64_t pts)
586 return pts - libvlc_clock();
595 #endif /* <vlc/libvlc.h> */