* libvlc.h: libvlc external API
*****************************************************************************
* Copyright (C) 1998-2009 VLC authors and VideoLAN
* $Id$
*
* Authors: Clément Stenac <zorglub@videolan.org>
* Jean-Paul Saman <jpsaman@videolan.org>
* Pierre d'Herbemont <pdherbemont@videolan.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
* \defgroup libvlc LibVLC
* LibVLC is the external programming interface of the VLC media player.
* It is used to embed VLC into other applications or frameworks.
* @{
* \file
* LibVLC core external API
*/
#ifndef VLC_LIBVLC_H
#define VLC_LIBVLC_H 1
#if defined (_WIN32) && defined (DLL_EXPORT)
# define LIBVLC_API __declspec(dllexport)
#elif defined (__GNUC__) && (__GNUC__ >= 4)
# define LIBVLC_API __attribute__((visibility("default")))
#else
# define LIBVLC_API
#endif
#ifdef __LIBVLC__
# define LIBVLC_DEPRECATED
#elif defined(__GNUC__) && \
(__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0)
# define LIBVLC_DEPRECATED __attribute__((deprecated))
#else
# define LIBVLC_DEPRECATED
#endif
#include <stdio.h>
#include <stdarg.h>
#include <stdint.h>
# ifdef __cplusplus
extern "C" {
# endif
* \ingroup libvlc
* Before it can do anything useful, LibVLC must be initialized.
* You can create one (or more) instance(s) of LibVLC in a given process,
* with libvlc_new() and destroy them with libvlc_release().
*
* \version Unless otherwise stated, these functions are available
* from LibVLC versions numbered 1.1.0 or more.
* Earlier versions (0.9.x and 1.0.x) are <b>not</b> compatible.
* @{
*/
typedef struct libvlc_instance_t libvlc_instance_t;
typedef int64_t libvlc_time_t;
* @{
*/
* A human-readable error message for the last LibVLC error in the calling
* thread. The resulting string is valid until another error occurs (at least
* until the next LibVLC call).
*
* @warning
* This will be NULL if there was no error.
*/
LIBVLC_API const char *libvlc_errmsg (void);
* Clears the LibVLC error status for the current thread. This is optional.
* By default, the error status is automatically overridden when a new error
* occurs, and destroyed when the thread exits.
*/
LIBVLC_API void libvlc_clearerr (void);
* Sets the LibVLC error status and message for the current thread.
* Any previous error is overridden.
* \param fmt the format string
* \param ap the arguments
* \return a nul terminated string in any case
*/
LIBVLC_API const char *libvlc_vprinterr (const char *fmt, va_list ap);
* Sets the LibVLC error status and message for the current thread.
* Any previous error is overridden.
* \param fmt the format string
* \param args the arguments
* \return a nul terminated string in any case
*/
LIBVLC_API const char *libvlc_printerr (const char *fmt, ...);
* Create and initialize a libvlc instance.
* This functions accept a list of "command line" arguments similar to the
* main(). These arguments affect the LibVLC instance default configuration.
*
* \note
* LibVLC may create threads. Therefore, any thread-unsafe process
* initialization must be performed before calling libvlc_new(). In particular
* and where applicable:
* - setlocale() and textdomain(),
* - setenv(), unsetenv() and putenv(),
* - with the X11 display system, XInitThreads()
* (see also libvlc_media_player_set_xwindow()) and
* - on Microsoft Windows, SetErrorMode().
* - sigprocmask() shall never be invoked; pthread_sigmask() can be used.
*
* On POSIX systems, the SIGCHLD signal <b>must not</b> be ignored, i.e. the
* signal handler must set to SIG_DFL or a function pointer, not SIG_IGN.
* Also while LibVLC is active, the wait() function shall not be called, and
* any call to waitpid() shall use a strictly positive value for the first
* parameter (i.e. the PID). Failure to follow those rules may lead to a
* deadlock or a busy loop.
* Also on POSIX systems, it is recommended that the SIGPIPE signal be blocked,
* even if it is not, in principles, necessary, e.g.:
* @code
sigset_t set;
signal(SIGCHLD, SIG_DFL);
sigemptyset(&set);
sigaddset(&set, SIGPIPE);
pthread_sigmask(SIG_BLOCK, &set, NULL);
* @endcode
*
* On Microsoft Windows Vista/2008, the process error mode
* SEM_FAILCRITICALERRORS flag <b>must</b> be set before using LibVLC.
* On later versions, that is optional and unnecessary.
* Also on Microsoft Windows (Vista and any later version), setting the default
* DLL directories to SYSTEM32 exclusively is strongly recommended for
* security reasons:
* @code
SetErrorMode(SEM_FAILCRITICALERRORS);
SetDefaultDllDirectories(LOAD_LIBRARY_SEARCH_SYSTEM32);
* @endcode
*
* \version
* Arguments are meant to be passed from the command line to LibVLC, just like
* VLC media player does. The list of valid arguments depends on the LibVLC
* version, the operating system and platform, and set of available LibVLC
* plugins. Invalid or unsupported arguments will cause the function to fail
* (i.e. return NULL). Also, some arguments may alter the behaviour or
* otherwise interfere with other LibVLC functions.
*
* \warning
* There is absolutely no warranty or promise of forward, backward and
* cross-platform compatibility with regards to libvlc_new() arguments.
* We recommend that you do not use them, other than when debugging.
*
* \param argc the number of arguments (should be 0)
* \param argv list of arguments (should be NULL)
* \return the libvlc instance or NULL in case of error
*/
LIBVLC_API libvlc_instance_t *
libvlc_new( int argc , const char *const *argv );
* Decrement the reference count of a libvlc instance, and destroy it
* if it reaches zero.
*
* \param p_instance the instance to destroy
*/
LIBVLC_API void libvlc_release( libvlc_instance_t *p_instance );
* Increments the reference count of a libvlc instance.
* The initial reference count is 1 after libvlc_new() returns.
*
* \param p_instance the instance to reference
*/
LIBVLC_API void libvlc_retain( libvlc_instance_t *p_instance );
* Try to start a user interface for the libvlc instance.
*
* \param p_instance the instance
* \param name interface name, or NULL for default
* \return 0 on success, -1 on error.
*/
LIBVLC_API
int libvlc_add_intf( libvlc_instance_t *p_instance, const char *name );
* Registers a callback for the LibVLC exit event. This is mostly useful if
* the VLC playlist and/or at least one interface are started with
* libvlc_playlist_play() or libvlc_add_intf() respectively.
* Typically, this function will wake up your application main loop (from
* another thread).
*
* \note This function should be called before the playlist or interface are
* started. Otherwise, there is a small race condition: the exit event could
* be raised before the handler is registered.
*
* \param p_instance LibVLC instance
* \param cb callback to invoke when LibVLC wants to exit,
* or NULL to disable the exit handler (as by default)
* \param opaque data pointer for the callback
* \warning This function and libvlc_wait() cannot be used at the same time.
*/
LIBVLC_API
void libvlc_set_exit_handler( libvlc_instance_t *p_instance,
void (*cb) (void *), void *opaque );
* Sets the application name. LibVLC passes this as the user agent string
* when a protocol requires it.
*
* \param p_instance LibVLC instance
* \param name human-readable application name, e.g. "FooBar player 1.2.3"
* \param http HTTP User Agent, e.g. "FooBar/1.2.3 Python/2.6.0"
* \version LibVLC 1.1.1 or later
*/
LIBVLC_API
void libvlc_set_user_agent( libvlc_instance_t *p_instance,
const char *name, const char *http );
* Sets some meta-information about the application.
* See also libvlc_set_user_agent().
*
* \param p_instance LibVLC instance
* \param id Java-style application identifier, e.g. "com.acme.foobar"
* \param version application version numbers, e.g. "1.2.3"
* \param icon application icon name, e.g. "foobar"
* \version LibVLC 2.1.0 or later.
*/
LIBVLC_API
void libvlc_set_app_id( libvlc_instance_t *p_instance, const char *id,
const char *version, const char *icon );
* Retrieve libvlc version.
*
* Example: "1.1.0-git The Luggage"
*
* \return a string containing the libvlc version
*/
LIBVLC_API const char * libvlc_get_version(void);
* Retrieve libvlc compiler version.
*
* Example: "gcc version 4.2.3 (Ubuntu 4.2.3-2ubuntu6)"
*
* \return a string containing the libvlc compiler version
*/
LIBVLC_API const char * libvlc_get_compiler(void);
* Retrieve libvlc changeset.
*
* Example: "aa9bce0bc4"
*
* \return a string containing the libvlc changeset
*/
LIBVLC_API const char * libvlc_get_changeset(void);
* Frees an heap allocation returned by a LibVLC function.
* If you know you're using the same underlying C run-time as the LibVLC
* implementation, then you can call ANSI C free() directly instead.
*
* \param ptr the pointer
*/
LIBVLC_API void libvlc_free( void *ptr );
* LibVLC emits asynchronous events.
*
* Several LibVLC objects (such @ref libvlc_instance_t as
* @ref libvlc_media_player_t) generate events asynchronously. Each of them
* provides @ref libvlc_event_manager_t event manager. You can subscribe to
* events with libvlc_event_attach() and unsubscribe with
* libvlc_event_detach().
* @{
*/
* Event manager that belongs to a libvlc object, and from whom events can
* be received.
*/
typedef struct libvlc_event_manager_t libvlc_event_manager_t;
struct libvlc_event_t;
* Type of a LibVLC event.
*/
typedef int libvlc_event_type_t;
* Callback function notification
* \param p_event the event triggering the callback
*/
typedef void ( *libvlc_callback_t )( const struct libvlc_event_t *p_event, void *p_data );
* Register for an event notification.
*
* \param p_event_manager the event manager to which you want to attach to.
* Generally it is obtained by vlc_my_object_event_manager() where
* my_object is the object you want to listen to.
* \param i_event_type the desired event to which we want to listen
* \param f_callback the function to call when i_event_type occurs
* \param user_data user provided data to carry with the event
* \return 0 on success, ENOMEM on error
*/
LIBVLC_API int libvlc_event_attach( libvlc_event_manager_t *p_event_manager,
libvlc_event_type_t i_event_type,
libvlc_callback_t f_callback,
void *user_data );
* Unregister an event notification.
*
* \param p_event_manager the event manager
* \param i_event_type the desired event to which we want to unregister
* \param f_callback the function to call when i_event_type occurs
* \param p_user_data user provided data to carry with the event
*/
LIBVLC_API void libvlc_event_detach( libvlc_event_manager_t *p_event_manager,
libvlc_event_type_t i_event_type,
libvlc_callback_t f_callback,
void *p_user_data );
* Get an event's type name.
*
* \param event_type the desired event
*/
LIBVLC_API const char * libvlc_event_type_name( libvlc_event_type_t event_type );
* libvlc_log_* functions provide access to the LibVLC messages log.
* This is used for logging and debugging.
* @{
*/
* Logging messages level.
* \note Future LibVLC versions may define new levels.
*/
enum libvlc_log_level
{
LIBVLC_DEBUG=0,
LIBVLC_NOTICE=2,
LIBVLC_WARNING=3,
LIBVLC_ERROR=4
};
typedef struct vlc_log_t libvlc_log_t;
* Gets log message debug infos.
*
* This function retrieves self-debug information about a log message:
* - the name of the VLC module emitting the message,
* - the name of the source code module (i.e. file) and
* - the line number within the source code module.
*
* The returned module name and file name will be NULL if unknown.
* The returned line number will similarly be zero if unknown.
*
* \param ctx message context (as passed to the @ref libvlc_log_cb callback)
* \param module module name storage (or NULL) [OUT]
* \param file source code file name storage (or NULL) [OUT]
* \param line source code file line number storage (or NULL) [OUT]
* \warning The returned module name and source code file name, if non-NULL,
* are only valid until the logging callback returns.
*
* \version LibVLC 2.1.0 or later
*/
LIBVLC_API void libvlc_log_get_context(const libvlc_log_t *ctx,
const char **module, const char **file, unsigned *line);
* Gets log message info.
*
* This function retrieves meta-information about a log message:
* - the type name of the VLC object emitting the message,
* - the object header if any, and
* - a temporaly-unique object identifier.
*
* This information is mainly meant for <b>manual</b> troubleshooting.
*
* The returned type name may be "generic" if unknown, but it cannot be NULL.
* The returned header will be NULL if unset; in current versions, the header
* is used to distinguish for VLM inputs.
* The returned object ID will be zero if the message is not associated with
* any VLC object.
*
* \param ctx message context (as passed to the @ref libvlc_log_cb callback)
* \param name object name storage (or NULL) [OUT]
* \param header object header (or NULL) [OUT]
* \param line source code file line number storage (or NULL) [OUT]
* \warning The returned module name and source code file name, if non-NULL,
* are only valid until the logging callback returns.
*
* \version LibVLC 2.1.0 or later
*/
LIBVLC_API void libvlc_log_get_object(const libvlc_log_t *ctx,
const char **name, const char **header, uintptr_t *id);
* Callback prototype for LibVLC log message handler.
*
* \param data data pointer as given to libvlc_log_set()
* \param level message level (@ref libvlc_log_level)
* \param ctx message context (meta-information about the message)
* \param fmt printf() format string (as defined by ISO C11)
* \param args variable argument list for the format
* \note Log message handlers <b>must</b> be thread-safe.
* \warning The message context pointer, the format string parameters and the
* variable arguments are only valid until the callback returns.
*/
typedef void (*libvlc_log_cb)(void *data, int level, const libvlc_log_t *ctx,
const char *fmt, va_list args);
* Unsets the logging callback.
*
* This function deregisters the logging callback for a LibVLC instance.
* This is rarely needed as the callback is implicitly unset when the instance
* is destroyed.
*
* \note This function will wait for any pending callbacks invocation to
* complete (causing a deadlock if called from within the callback).
*
* \param p_instance libvlc instance
* \version LibVLC 2.1.0 or later
*/
LIBVLC_API void libvlc_log_unset( libvlc_instance_t *p_instance );
* Sets the logging callback for a LibVLC instance.
*
* This function is thread-safe: it will wait for any pending callbacks
* invocation to complete.
*
* \param cb callback function pointer
* \param data opaque data pointer for the callback function
*
* \note Some log messages (especially debug) are emitted by LibVLC while
* is being initialized. These messages cannot be captured with this interface.
*
* \warning A deadlock may occur if this function is called from the callback.
*
* \param p_instance libvlc instance
* \version LibVLC 2.1.0 or later
*/
LIBVLC_API void libvlc_log_set( libvlc_instance_t *p_instance,
libvlc_log_cb cb, void *data );
* Sets up logging to a file.
* \param p_instance libvlc instance
* \param stream FILE pointer opened for writing
* (the FILE pointer must remain valid until libvlc_log_unset())
* \version LibVLC 2.1.0 or later
*/
LIBVLC_API void libvlc_log_set_file( libvlc_instance_t *p_instance, FILE *stream );
* Description of a module.
*/
typedef struct libvlc_module_description_t
{
char *psz_name;
char *psz_shortname;
char *psz_longname;
char *psz_help;
struct libvlc_module_description_t *p_next;
} libvlc_module_description_t;
* Release a list of module descriptions.
*
* \param p_list the list to be released
*/
LIBVLC_API
void libvlc_module_description_list_release( libvlc_module_description_t *p_list );
* Returns a list of audio filters that are available.
*
* \param p_instance libvlc instance
*
* \return a list of module descriptions. It should be freed with libvlc_module_description_list_release().
* In case of an error, NULL is returned.
*
* \see libvlc_module_description_t
* \see libvlc_module_description_list_release
*/
LIBVLC_API
libvlc_module_description_t *libvlc_audio_filter_list_get( libvlc_instance_t *p_instance );
* Returns a list of video filters that are available.
*
* \param p_instance libvlc instance
*
* \return a list of module descriptions. It should be freed with libvlc_module_description_list_release().
* In case of an error, NULL is returned.
*
* \see libvlc_module_description_t
* \see libvlc_module_description_list_release
*/
LIBVLC_API
libvlc_module_description_t *libvlc_video_filter_list_get( libvlc_instance_t *p_instance );
* These functions provide access to the LibVLC time/clock.
* @{
*/
* Return the current time as defined by LibVLC. The unit is the microsecond.
* Time increases monotonically (regardless of time zone changes and RTC
* adjustements).
* The origin is arbitrary but consistent across the whole system
* (e.g. the system uptim, the time since the system was booted).
* \note On systems that support it, the POSIX monotonic clock is used.
*/
LIBVLC_API
int64_t libvlc_clock(void);
* Return the delay (in microseconds) until a certain timestamp.
* \param pts timestamp
* \return negative if timestamp is in the past,
* positive if it is in the future
*/
static inline int64_t libvlc_delay(int64_t pts)
{
return pts - libvlc_clock();
}
# ifdef __cplusplus
}
# endif
#endif