Phạm Hà Thanh phamhathanh

phamhathanh / calculate_sound_level.swift

Created September 4, 2018 02:15

Sound level calculation in Swift

	func calculateSoundLevel(oldSoundLevel: Float, frameLength: UInt, samples: UnsafeMutablePointer<Float>) {
	let lowPassAlpha : Float = 0.1

	var amplitude : Float = 0
	vDSP_meamgv(samples, 1, &amplitude, vDSP_Length(frameLength))

	let level = amplitude == 0 ? -100 : 20.0*log10f(amplitude)

	return lowPassAlphalevel + (1 - lowPassAlpha)oldSoundLevel
	}