| Microsoft DirectX 8.1 (C++) |
The IAMStats interface enables an application to retrieve performance data from the Filter Graph Manager. Filters can use this interface to record performance data. Each statistic is defined by a name and an index. 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.
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.
In addition to the methods inherited from IDispatch, the IAMStats interface exposes the following methods.
| Method | Description |
| AddValue | Records a new value. |
| get_Count | Retrieves the number of values that were collected for a given statistic. |
| GetIndex | Retrieves the index for a named statistic, or creates a new statistic. |
| GetValueByIndex | Retrieves a statistic by index. |
| GetValueByName | Retrieves a statistic by name. |
| Reset | Resets all statistics to zero. |