Esempio n. 1
0
        /// <summary>
        /// Calculates a normalization offset for the current window function. Every window function leads to
        /// a different FFT result peak value, and since the peak value of each windowed FFT means 0dB, this
        /// offset can be used to adjust the calculated dB values.
        /// </summary>
        private void CalculateWindowFunctionNormalizationOffset()
        {
            if (windowFunction == null)
            {
                windowFunctionNormalizationDecibelOffset = 0;
            }
            else
            {
                SineGeneratorStream sine   = new SineGeneratorStream(1024, 16, new TimeSpan(0, 0, 1));
                float[]             input  = new float[WindowSize];
                float[]             output = new float[input.Length / 2];
                WindowFunction      wf     = WindowUtil.GetFunction(windowFunction.Type, input.Length);

                sine.Read(input, 0, input.Length);
                wf.Apply(input);
                fft.Forward(input);
                int   maxIndex = FFTUtil.Results(input, output);
                float maxValue = output[maxIndex];
                windowFunctionNormalizationDecibelOffset = 1f - maxValue;
            }
        }
Esempio n. 2
0
 public void Apply(float[] values, int valuesOffset)
 {
     WindowUtil.Apply(values, valuesOffset, window);
 }