IQualProp Interface (Compact 2013)

3/26/2014

This interface is exposed by renderers, typically a video renderer, to return information about the performance achieved; for example, the number of frames per second (fps).

The values returned through the interface are reset each time the filter is run.

The base classes of the DirectShow SDK have a standard property page that displays the information available from this interface.

When to Implement

The IQualProp interface is implemented by the DirectShow video renderer.

Other video renderers might want to implement this interface as well, although it is optional.

When to Use

Applications use this interface to retrieve video renderer performance information.

Methods in Vtable Order

The following table shows the methods that appear in the Vtable beneath the standard COM methods inherited from IUnknown.

Method	Description
get_AvgFrameRate	Retrieves the average frame rate achieved.
get_AvgSyncOffset	Retrieves the average time difference between when a frame was due for rendering and when rendering began (this is returned as a value in milliseconds).
get_DevSyncOffset	Retrieves the average time difference between when a frame was due for rendering and when rendering began (this is returned as a standard deviation).
get_FramesDrawn	Retrieves the number of frames drawn since streaming started.
get_FramesDroppedInRenderer	Retrieves the number of frames dropped by the renderer.
get_Jitter	Expresses the average time between successive frames delivered to the video renderer.

Requirements

Header	dshow.h
Library	Strmiids.lib

See Also

Reference

DirectShow Interfaces