METransformNeedInput event

Sent by an asynchronous Media Foundation transform (MFT) to request a new input sample.

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 needs input data.


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

When the client of the MFT receives this event, it should call IMFTransform::ProcessInput to deliver the next sample. The MF_EVENT_MFT_INPUT_STREAM_ID attribute of the event object specifies which input stream requires data.


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