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MFPKEY_BDELTAQP Property

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Specifies the delta increase between the picture quantizer of the anchor frame and the picture quantizer of the B-frame.

Constant for IPropertyBag

g_wszWMVCBDeltaQP

Data Type

VT_I4

Default Value

0

Remarks

Picture quantizer (QP) is a measurement of how compressed a frame is. Higher values represent higher compression ratios. The QP can be set in half-point increments. A B-frame is typically compressed at a QP the same as or 0.5 higher than the anchor frame's QP. By specifying a B-frame QP delta higher than 0, it is possible to compress B-frames at an even higher compression ratio.

The B-frame delta QP can be set only in whole-point increments. This property must be set to an integer value from 0 to 31. The recommended value is 1.

Applies To

This write-only property is available on the encoder of the following codecs:

Requirements

Client: Requires Windows Vista or Windows XP.

Header: Include wmcodecdsp.h.

See Also