Duplicate songs detector via audio fingerprinting

// Sound Fingerprinting framework
// https://code.google.com/p/soundfingerprinting/
// Code license: GNU General Public License v2
// ciumac.sergiu@gmail.com
using System;

namespace SoundfingerprintingLib.NeuralHashing.MMI
{
    /// <summary>
    ///   Class that allows one to calculate minimal mutual information between 2 samples
    /// </summary>
    public static class MutualInformation
    {
        /// <summary>
        ///   Compute minimal mutual information between 2 samples
        /// </summary>
        /// <param name = "samples1">Sample 1</param>
        /// <param name = "samples2">Sample 2</param>
        /// <returns>Value of minimal mutual information</returns>
        public static double Compute(float[] samples1, float[] samples2)
        {
            if (samples1.Length != samples2.Length)
            {
                throw new ArgumentException("The length of arrays should be equal");
            }
            int length = samples1.Length;

            float f00 = 0;
            float f01 = 0;
            float f10 = 0;
            float f11 = 0;
            for (int k = 0; k < length; k++)
            {
                if (samples1[k] < 0.1 && samples2[k] < 0.1)
                    f00++;
                else if (samples1[k] > 0.9 && samples2[k] > 0.9)
                    f11++;
                else if (samples1[k] < 0.1 && samples2[k] > 0.9)
                    f01++;
                else
                    f10++;
            }

            if (f00 == 0.0)
                f00++;
            if (f10 == 0.0)
                f10++;
            if (f01 == 0.0)
                f01++;
            if (f11 == 0.0)
                f11++;

            float pX0Y0 = f00/length;
            float pX0Y1 = f01/length;
            float pX1Y0 = f10/length;
            float pX1Y1 = f11/length;
            float pX0 = pX0Y0 + pX0Y1;
            float pX1 = pX1Y0 + pX1Y1;
            float pY0 = pX0Y0 + pX1Y0;
            float pY1 = pX0Y1 + pX1Y1;

            double mutualInformation = (float) (pX0Y0*Math.Log(pX0Y0/(pX0*pY0)) +
                                                pX0Y1*Math.Log(pX0Y1/(pX0*pY1)) +
                                                pX1Y0*Math.Log(pX1Y0/(pX1*pY0)) +
                                                pX1Y1*Math.Log(pX1Y1/(pX1*pY1)));
            return mutualInformation;
        }
    }
}