| Microsoft DirectX 8.1 (C++) |
The IBaseFilter interface provides methods for controlling a filter. All DirectShow filters expose this interface. The Filter Graph Manager uses this interface to control filters. Applications can use this interface to enumerate pins and query for filter information, but should not use it to change the state of a filter. Instead, use the IMediaControl interface on the Filter Graph Manager.
Filter developers: Implement this interface on every DirectShow filter. The CBaseFilter base class implements this interface.
In addition to the methods inherited from IUnknown and the IMediaFilter interface, the IBaseFilter interface exposes the following methods.
| Method | Description |
| EnumPins | Enumerates the pins on this filter. |
| FindPin | Retrieves the pin with the specified identifier. |
| JoinFilterGraph | Notifies the filter that it has joined or left the filter graph. |
| QueryFilterInfo | Retrieves information about the filter. |
| QueryVendorInfo | Retrieves a string containing vendor information. |