IQualProp Interface
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4/8/2010
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 |
|---|---|
Retrieves the average frame rate achieved. |
|
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). |
|
Retrieves the average time difference between when a frame was due for rendering and when rendering began (this is returned as a standard deviation). |
|
Retrieves the number of frames drawn since streaming started. |
|
Retrieves the number of frames dropped by the renderer. |
|
Expresses the average time between successive frames delivered to the video renderer. |
Requirements
| Windows Embedded CE | Windows CE 2.12 and later |
| Windows Mobile | Pocket PC for Windows Mobile Version 5.0 and later, Smartphone for Windows Mobile Version 5.0 and later |
| Note | Microsoft DirectShow applications and DirectShow filters have different include file and Library requirements For more information, see Setting Up the Build Environment |