kVTCompressionPropertyKey_TargetQualityForAlpha
The target quality to use for encoding the alpha channel.
Declaration
let kVTCompressionPropertyKey_TargetQualityForAlpha: CFStringDiscussion
Specify this value as a number in the range of 0.0 for the lowest quality to 1.0 for nearly lossless quality. Alpha plane bit rates tend to increase with increasing values. When encoding the alpha channel, the system gives priority to quality over bitrate.
See Also
Rate Control
kVTCompressionPropertyKey_AverageBitRatekVTCompressionPropertyKey_ConstantBitRatekVTCompressionPropertyKey_DataRateLimitskVTCompressionPropertyKey_EstimatedAverageBytesPerFramekVTCompressionPropertyKey_MoreFramesAfterEndkVTCompressionPropertyKey_MoreFramesBeforeStartkVTCompressionPropertyKey_QualitykVTCompressionPropertyKey_VariableBitRatekVTCompressionPropertyKey_VBVBufferDurationkVTCompressionPropertyKey_VBVInitialDelayPercentagekVTCompressionPropertyKey_VBVMaxBitRate