LibVLC media player time watch API

Collaboration diagram for LibVLC media player time watch API:

Data Structures
struct	libvlc_media_player_time_point_t
	Media Player timer point. More...
struct	libvlc_media_player_watch_time_cbs
	struct defining callbacks for libvlc_media_player_watch_time() More...

Typedefs
typedef struct libvlc_media_player_time_point_t	libvlc_media_player_time_point_t
	Media Player timer point.

Functions
LIBVLC_API int	libvlc_media_player_watch_time (libvlc_media_player_t *p_mi, libvlc_time_t min_period_us, const struct libvlc_media_player_watch_time_cbs *cbs, void *cbs_opaque)
	Watch for times updates.
LIBVLC_API void	libvlc_media_player_unwatch_time (libvlc_media_player_t *p_mi)
	Unwatch time updates.
LIBVLC_API int	libvlc_media_player_time_point_interpolate (const libvlc_media_player_time_point_t *point, libvlc_time_t system_now_us, libvlc_time_t *out_ts_us, double *out_pos)
	Interpolate a timer value to now.
LIBVLC_API libvlc_time_t	libvlc_media_player_time_point_get_next_date (const libvlc_media_player_time_point_t *point, libvlc_time_t system_now_us, libvlc_time_t interpolated_ts_us, libvlc_time_t next_interval_us)
	Get the date of the next interval.

Detailed Description

Typedef Documentation

libvlc_media_player_time_point_t

typedef struct libvlc_media_player_time_point_t libvlc_media_player_time_point_t

Media Player timer point.

Note

ts and system_date values should not be used directly by the user. libvlc_media_player_time_point_interpolate() will read these values and return an interpolated ts.

See also

libvlc_media_player_watch_time_on_update

Function Documentation

libvlc_media_player_time_point_get_next_date()

LIBVLC_API libvlc_time_t libvlc_media_player_time_point_get_next_date	(	const libvlc_media_player_time_point_t *	point,
		libvlc_time_t	system_now_us,
		libvlc_time_t	interpolated_ts_us,
		libvlc_time_t	next_interval_us )

Get the date of the next interval.

Can be used to setup an UI timer in order to update some widgets at specific interval. A next_interval of VLC_TICK_FROM_SEC(1) can be used to update a time widget when the media reaches a new second.

Note

The media time doesn't necessarily correspond to the system time, that is why this function is needed and uses the rate of the current point.

Parameters

point	time update obtained via the libvlc_media_player_watch_time_on_update()
system_now_us	same system date used by libvlc_media_player_time_point_interpolate()
interpolated_ts_us	ts returned by libvlc_media_player_time_point_interpolate()
next_interval_us	next interval, in us

Returns

the absolute system date, in us, of the next interval, use libvlc_delay() to get a relative delay.

Version

LibVLC 4.0.0 or later

libvlc_media_player_time_point_interpolate()

LIBVLC_API int libvlc_media_player_time_point_interpolate	(	const libvlc_media_player_time_point_t *	point,
		libvlc_time_t	system_now_us,
		libvlc_time_t *	out_ts_us,
		double *	out_pos )

Interpolate a timer value to now.

Parameters

point	time update obtained via the libvlc_media_player_watch_time_on_update() callback
system_now_us	current system date, in us, returned by libvlc_clock()
out_ts_us	pointer where to set the interpolated ts, in us
out_pos	pointer where to set the interpolated position

Returns

0 in case of success, -1 if the interpolated ts is negative (could happen during the buffering step)

Version

LibVLC 4.0.0 or later

References LIBVLC_API.

libvlc_media_player_unwatch_time()

LIBVLC_API void libvlc_media_player_unwatch_time

(

libvlc_media_player_t *

p_mi

)

Unwatch time updates.

Parameters

p_mi	the media player

Version

LibVLC 4.0.0 or later

References LIBVLC_API.

libvlc_media_player_watch_time()

LIBVLC_API int libvlc_media_player_watch_time	(	libvlc_media_player_t *	p_mi,
		libvlc_time_t	min_period_us,
		const struct libvlc_media_player_watch_time_cbs *	cbs,
		void *	cbs_opaque )

Watch for times updates.

Warning

Only one watcher can be registered at a time. Calling this function a second time (if libvlc_media_player_unwatch_time() was not called in-between) will fail.

Parameters

p_mi	the media player
min_period_us	corresponds to the minimum period, in us, between each updates, use it to avoid flood from too many source updates, set it to 0 to receive all updates.
cbs	callback to listen to events (can't be NULL). The pointed struct must be kept alive (and not modified) by the caller until libvlc_media_player_unwatch_time() is called.
cbs_opaque	opaque pointer used by the callbacks

Returns

0 on success, -1 on error (allocation error, or if already watching)

Version

LibVLC 4.0.0 or later

References LIBVLC_API.