METransformDrainComplete event

Sent by an asynchronous Media Foundation transform (MFT) when a drain operation is complete.

Event values

Possible values retrieved from IMFMediaEvent::GetValue include the following.

VARTYPE Description
No event data.


The following attributes are defined for this event.

Attribute Description
The identifier of the stream that was drained.


Asynchronous MFTs send this event through the IMFMediaEventGenerator interface. Synchronous MFTs never send this event.

To drain an MFT, call IMFTransform::ProcessMessage with the MFT_MESSAGE_COMMAND_DRAIN message. Specify the input stream to drain in the ulParam parameter. When the drain operation is completed, an asynchronous MFT sends the METransformDrainComplete event. The MF_EVENT_MFT_INPUT_STREAM_ID attribute of the event contains the stream identifier given in the ulParam parameter.


Requirement Value
Minimum supported client
Windows 7 [desktop apps only]
Minimum supported server
Windows Server 2008 R2 [desktop apps only]
Mfobjects.h (include Mfidl.h)

See also

Media Foundation Events

Asynchronous MFTs