IAMStats interface (control.h)

The IAMStats interface retrieves performance data from the Filter Graph Manager. Filters can use this interface to record performance data.

Filter developers: As with all Filter Graph Manager interfaces, a filter must not hold a reference count on this interface, or it will cause a circular reference count. For more information, see IBaseFilter::JoinFilterGraph.


The IAMStats interface inherits from the IDispatch interface. IAMStats also has these types of members:


The IAMStats interface has these methods.


The AddValue method records a new value.

The get_Count method retrieves the number of statistics.

The GetIndex method retrieves the index for a named statistic, or creates a new statistic.

The GetValueByIndex method retrieves a statistic, by index.

The GetValueByName method retrieves a statistic, by name.

The Reset method resets all statistics to zero.


Each statistic is defined by a name and an index. Use the GetIndex method to find the index from the name. Values are always double types. The following statistics are predefined.

Name Description
RenderFile Measures the time taken by each call to IGraphBuilder::RenderFile.
ConnectDirectInternal Measures the time taken to connect two filters.
Build Mapper Cache Measures the time taken to cache information about registered filters (used by the Filter Mapper object).
Process Category CategoryName Measures the time taken to cache information about filters in a particular category, where CategoryName is the friendly name of the filter category. (See Filter Categories.)

For each of these statistics, the values represent time in milliseconds.


Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Target Platform Windows
Header control.h (include Dshow.h)

See also