MFSampleExtension_LongTermReferenceFrameInfo attribute

Specifies Long Term Reference (LTR) frame info and is returned on the output sample.

Data type



H.264/AVC encoders:

Encoders shall return this attribute on the output sample when the application controls LTR frames, which is specified by CODECAPI_AVEncVideoLTRBufferControl.

MFSampleExtension_LongTermReferenceFrameInfo returns up to two fields.

The first field, bits[0..15], is LongTermFrameIdx associated with the output frame if it is marked as a LTR frame. The first value is 0xffff, if this output frame is a short term reference frame or a non-reference frame.

The second field, bits[16..31], is a bitmap consisting of MaxNumLTRFrames many bits that indicate which LTR frame(s) were used for encoding this output frame, starting from bit 16. The rest of bits shall be set to 0. The second value is 0 if this output frame is not encoded using any LTR frames. MaxNumLTRFrames is the maximum number of LTR frames set through CODECAPI_AVEncVideoLTRBufferControl.


Minimum supported client

Windows 8.1 [desktop apps | UWP apps]

Minimum supported server

Windows Server 2012 R2 [desktop apps | UWP apps]



See also

Alphabetical List of Media Foundation Attributes