MF_TRANSFORM_ASYNC attribute

Specifies whether a Media Foundation transform (MFT) performs asynchronous processing.

Data type

UINT32

Syntax

DECLSPEC_SELECTANY GUID MF_TRANSFORM_ASYNC = {0xf81a699a,0x649a,0x497d,{0x8c,0x73,0x29,0xf8,0xfe,0xd6,0xad,0x7a} }  

Get/set

To get this attribute, call IMFAttributes::GetUINT32

To set this attribute, call IMFAttributes::SetUINT32

Remarks

The attribute is a Boolean value:

• If the attribute is nonzero, the MFT performs asynchronous processing.
• If the attribute is 0 or not set, the MFT is synchronous.

To get this attribute, first call IMFTransform::GetAttributes to get the MFT’s attribute store. If that method succeeds, call IMFAttributes::GetUINT32 to get the attribute value. If either of the two methods fails, the MFT is synchronous.

For asynchronous MFTs, this attribute must be set to a nonzero value. For synchronous MFTs, this attribute is optional, but must be set to 0 if present.

Asynchronous MFTs are not compatible with earlier versions of Media Foundation. To use an asynchronous MFT, the client must set the MF_TRANSFORM_ASYNC_UNLOCK attribute on the MFT. (The Microsoft Media Foundation pipeline performs this step automatically.)

Requirements

Header: Declared in mftransform.h.