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CODECAPI_AVEncVideoLTRBufferControl property

Specifies the maximum number of Long Term Reference (LTR) frames controlled by application.

Data type

ULONG (VT_UI4)

Property GUID

CODECAPI_AVEncVideoLTRBufferControl

Property value

The value of this control includes two fields, where each field has 16 bits.

Value Meaning
The first field
Bits[0..15]
 The number of LTR frames controlled by the application.
H.264/AVC encoders:
Assuming the value is N and N is non-zero value, at each IDR frame the encoder must automatically mark the frames following the IDR frame (and including the IDR frame) as LTR frames as long as all 3 of the following apply:
  • The frame is not already set to be marked as a long term reference frame.
  • The frame is a base layer frame. For example, syntax element temporal_id equal to 0.
  • The number of frames currently marked as LTR is less than N.
The second field
Bits[16..31]
 The trust mode of LTR control.
H.264/AVC encoders:
1 (Trust Until) means the encoder may use an LTR frame unless the app explicitly invalidates it through the CODECAPI_AVEncVideoUseLTRFrame control.
Other values are invalid and reserved for future use.

Remarks

This is a static API.

Default value shall be 0

Requirements

Requirement Value
Minimum supported client
 Windows 8.1 [desktop apps | UWP apps]
Minimum supported server
 Windows Server 2012 R2 [desktop apps | UWP apps]
Header
Codecapi.h

See also

Media Foundation Properties