| Microsoft DirectX 8.1 (C++) |
The GetGroupCompressor method retrieves the compression filter for the specified
Syntax
HRESULT GetGroupCompressor(
long Group,
IBaseFilter **pCompressor
);
Parameters
Group
Zero-based index of the group.
pCompressor
Address of a pointer to receive the IBaseFilter interface of the compression filter. It receives the value NULL if there is no compression filter.
Return Value
Returns one of the following values.
| Value | Description |
| E_INVALIDARG | Invalid argument. |
| E_POINTER | NULL pointer error. |
| S_OK | Success. |
Remarks
Use this method to set properties on the compression filter, such as the key-frame rate. Call this method after calling IRenderEngine::ConnectFrontEnd, but before rendering the project. Then query the compression filter's output pin for the IAMVideoCompression interface, which contains methods for setting compression parameters. Release the interface when you are done. If you make any subsequent changes to the timeline, call ConnectFrontEnd, and then call GetGroupCompressor again to reset the compression parameters.
On return, if the value of *pCompressor is non-NULL, the IBaseFilter interface has an outstanding reference count. Be sure to release the interface when you are done using it.
See Also