IQualityControl interface (strmif.h)

[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The IQualityControl interface provides support for quality control. An object exposes this interface if it can generate or receive quality-control messages. This includes renderer filters (which typically generate quality control messages), pins (which receive them), and external quality managers (which also receive them).

A renderer filter generates a quality-control message by calling the IQualityControl::Notify method on the output pin of the upstream filter. The upstream filter either handles the message or passes it upstream.

An application can implement its own quality-control manager. Call IQualityControl::SetSink on the renderer to designate the quality-control manager as the recipient for quality-control messages. Calling this method overrides the default handling of quality-control messages.

However, most applications will not implement their own quality-control managers; and aside from this special case, applications typically do not use this interface. For more information, see Quality-Control Management


The IQualityControl interface inherits from the IUnknown interface. IQualityControl also has these types of members:


The IQualityControl interface has these methods.


The Notify method notifies the filter that a quality change is requested.

The SetSink method sets the IQualityControl object that will receive quality messages.


Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header strmif.h (include Dshow.h)