|GdkFrameTimings *||gdk_frame_timings_ref ()|
Types and Values
A GdkFrameTimings object holds timing information for a single frame
of the application’s displays. To retrieve GdkFrameTimings objects,
The information in GdkFrameTimings is useful for precise synchronization
of video with the event or audio streams, and for measuring
quality metrics for the application’s display, such as latency and jitter.
GdkFrameTimings * gdk_frame_timings_ref (
Increases the reference count of
void gdk_frame_timings_unref (
Decreases the reference count of
is no longer referenced, it will be freed.
gint64 gdk_frame_timings_get_frame_counter (
Gets the frame counter value of the GdkFrameClock when this this frame was drawn.
gboolean gdk_frame_timings_get_complete (
The timing information in a GdkFrameTimings is filled in
incrementally as the frame as drawn and passed off to the
window system for processing and display to the user. The
accessor functions for GdkFrameTimings can return 0 to
indicate an unavailable value for two reasons: either because
the information is not yet available, or because it isn't
available at all. Once
TRUE for a frame, you can be certain that no further values
will become available and be stored in the GdkFrameTimings.
gint64 gdk_frame_timings_get_frame_time (
Returns the frame time for the frame. This is the time value
that is typically used to time animations for the frame. See
gint64 gdk_frame_timings_get_presentation_time (
Reurns the presentation time. This is the time at which the frame became visible to the user.
the time the frame was displayed to the user, in the
g_get_monotonic_time(), or 0 if no presentation
time is available. See
gint64 gdk_frame_timings_get_refresh_interval (
Gets the natural interval between presentation times for the display that this frame was displayed on. Frame presentation usually happens during the “vertical blanking interval”.
the refresh interval of the display, in microseconds,
or 0 if the refresh interval is not available.
gint64 gdk_frame_timings_get_predicted_presentation_time (
Gets the predicted time at which this frame will be displayed. Although
no predicted time may be available, if one is available, it will
be available while the frame is being generated, in contrast to
gdk_frame_timings_get_presentation_time(), which is only available
after the frame has been presented. In general, if you are simply
animating, you should use
than this function, but this function is useful for applications
that want exact control over latency. For example, a movie player
may want this information for Audio/Video synchronization.
The predicted time at which the frame will be presented,
in the timescale of
g_get_monotonic_time(), or 0 if no predicted
presentation time is available.