code: func MinMaxFloat(buf *audio.PCMBuffer) (min, max float64) {
  	if buf == nil || buf.Len() == 0 {
  		return 0, 0
  	}
  	buf.SwitchPrimaryType(audio.Float)
  	min = buf.Floats[0]
  
  	for _, v := range buf.Floats {
  		if v > max {
  			max = v
  		} else if v < min {
  			min = v
  		}
  	}
  
  	return min, max
  }
docs: // MinMaxFloat returns the smallest and biggest samples in the buffer