Static kVTCompressionPropertyKey_BaseLayerFrameRateFraction 

pub unsafe static kVTCompressionPropertyKey_BaseLayerFrameRateFraction: &'static CFString

Available on crate feature VTCompressionProperties only.

This property indicates the desired frame rate fraction of the base layer.

This property indicates the fraction of total frames submitted that should be encoded in the base layer. For example, a value of 0.5 means that half of the frames are in the base layer, and half are in the enhancement layer.

See also Apple’s documentation