Two features in WebAudio gets values out of range

[Oortone]

Describe the bug
SpectralSlope and spectralKurtosis gets values out of range (as stated in documentation) when used in WebAudio in Chrome.

To Reproduce
I initialize Meyda at 48 kHz like this (a bit simplified but in general):

audioCtx = new AudioContext({sampleRate: 48000})
stream = await navigator.mediaDevices.getUserMedia({ audio : {echoCancellation: false, noiseReduction: false, autoGainControl: false}, video: false })
 inputStream = audioCtx.createMediaStreamSource(stream)

  volumeOut = audioCtx.createGain()  
  volumeOut.connect(audioCtx.destination)
  inputStream.connect(volumeOut)
  volumeOut.gain.value = 0.1
  analysisGain = audioCtx.createGain() 
  inputStream.connect(analysisGain)
  analysisGain.gain.value = 2

  analyzer = Meyda.createMeydaAnalyzer({
    'audioContext': audioCtx,
    'source': analysisGain,
    'sampleRate': 48000,
    'bufferSize': 2048,
    'hopSize': 2048,
    'numberOfMFCCCoefficients': 0,
    'windowingFunction': 'hanning', 
    'featureExtractors': ["spectralSlope"],
    'callback': onNewFeatures     //this prints values and calculates max and min
  })

These are examples of erraneous ranges (presented as [min, max]) I got when playing some audio to the browser input:

spectralSlope: I got - [-1.1e-9, 7.8e-8] - documentation range: 0.0 - 1.0
spectralKurtosis: I got - [-354, 299] - documentation range: 0.0 - 1.0

Also tried 44100 sampling frequency but same thing.

Expected behavior
The two features being in the documented range. spectralSlope in general have extremely small values so even when they are all positive the are never anyway near 1.0, seldom above 10e-7.

Environment configuration
Meyda in Chrome Version 98.0.4758.102 on macOS 10.14.6
Audio in via USB-Class compliant Mackie Onyx @ 48kHz (and @ 44.1)

[hughrawlinson]

Hmm, that does sound like either a bug or a documentation issue - I'll look into this when I can, thanks for reporting.