Gdk.FrameTimings

Fields

None

Methods

get_complete ()

get_frame_counter ()

get_frame_time ()

get_predicted_presentation_time ()

get_presentation_time ()

get_refresh_interval ()

ref ()

unref ()

Details

class Gdk.FrameTimings

A GdkFrameTimings object holds timing information for a single frame of the application’s displays.

To retrieve GdkFrameTimings objects, use [method`Gdk`.FrameClock.get_timings] or [method`Gdk`.FrameClock.get_current_timings]. 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.

get_complete()[source]
Returns:

True if all information that will be available for the frame has been filled in.

Return type:

bool

Returns whether self are 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 this function returns True for a frame, you can be certain that no further values will become available and be stored in the GdkFrameTimings.

get_frame_counter()[source]
Returns:

the frame counter value for this frame

Return type:

int

Gets the frame counter value of the GdkFrameClock when this frame was drawn.

get_frame_time()[source]
Returns:

the frame time for the frame, in the timescale of GLib.get_monotonic_time()

Return type:

int

Returns the frame time for the frame.

This is the time value that is typically used to time animations for the frame. See [method`Gdk`.FrameClock.get_frame_time].

get_predicted_presentation_time()[source]
Returns:

The predicted time at which the frame will be presented, in the timescale of GLib.get_monotonic_time(), or 0 if no predicted presentation time is available.

Return type:

int

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 [method`Gdk`.FrameTimings.get_presentation_time], which is only available after the frame has been presented.

In general, if you are simply animating, you should use [method`Gdk`.FrameClock.get_frame_time] rather 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.

get_presentation_time()[source]
Returns:

the time the frame was displayed to the user, in the timescale of GLib.get_monotonic_time(), or 0 if no presentation time is available. See [method`Gdk`.FrameTimings.get_complete]

Return type:

int

Reurns the presentation time.

This is the time at which the frame became visible to the user.

get_refresh_interval()[source]
Returns:

the refresh interval of the display, in microseconds, or 0 if the refresh interval is not available. See [method`Gdk`.FrameTimings.get_complete].

Return type:

int

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”.

ref()[source]
Returns:

self

Return type:

Gdk.FrameTimings

Increases the reference count of self.

unref()[source]

Decreases the reference count of self.

If self is no longer referenced, it will be freed.