Help with the implementation of this beat detection algorithm?

Question

I recently tried to implement the beat detection code found here, namely the derivation and unwinding algorithm # 1 :: http://archive.gamedev.net/reference/programming/features/beatdetection/page2.asp

I'm not too sure that I have successfully implemented it, as I am not getting good results. I was wondering if anyone had done this successfully or only to good people who want to help in general. Here is my implementation:

//Cycle through Tempo (60 to 200) incrementing each time by 10
for (int i = (int)mintempo; i <= maxtempo; i += 10)
{
    //Clear variables to be used
    curtempo = i;
    fftPulse.Clear();
    offset = 0;
    energy = 0;
    short[] prevBuffer = null;

    //Calculate ti
    ti = (60 / curtempo) * 44100;
    ti = Math.Round(ti, 0);

    //Generate pulse train
    for (int j = 0; j < pulseTrain.Length; j++)
    {
        if ((j % ti) == 0)
            pulseTrain[j] = short.MaxValue;
        else
            pulseTrain[j] = 0;
    }

    //Compute FFT of the pulseTrain array
    while (offset < pulseTrain.Length)
    {
        //Generate block samples (1024 is my blocksize)
        short[] fftPulseBuffer = new short[po.blocksize / 2];

        //Store samples from pulseTrain in a 1024 block buffer for passing to the FFT algorithm
        index = 0;
        for (int j = offset; j < (offset + (po.blocksize / 2)) && j < pulseTrain.Length; j++)
        {
            fftPulseBuffer[index] = pulseTrain[j];
            index++;
        }

        //Initialize prevBuffer, which contains samples from the previous block, used in conjunction with the current block for the FFT
        if (prevBuffer == null)
            prevBuffer = new short[po.blocksize / 2];

        //Calculate the FFT using the current and previous blocks
        fftPulse.Add(CalculateFFT(fftPulseBuffer,prevBuffer));

        //Set prevBuffer and increment to next block start position
        prevBuffer = fftPulseBuffer;
        offset += (po.blocksize / 2);
    }

//Calculate energy
    for (int j = 0; j < intendomainarr.Count; j++)
    {
        double[] signalarr = intendomainarr[j];
        double[] pulsearr = fftPulse[j];
        for (int x = 0; x < signalarr.Length; x++)
        {
            energy += Math.Abs(signalarr[x] * pulsearr[x]);
        }
    }

    //Get current best tempo match
    if (energy > maxenergy)
    {
        chosentempo = curtempo;
        maxenergy = energy;
    }
}

The results that I get are always very high, usually around 190 and 200 BPM, which should NOT be, since my .wav files have rates only between 60-120BPM.

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Answer 1

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Answer 2

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    //Generate block samples (1024 is my blocksize)
    short[] fftPulseBuffer = new short[po.blocksize / 2];

    //Store samples from pulseTrain in a 1024 block buffer for passing to the FFT algorithm
    index = 0;
    for (int j = offset; j < (offset + (po.blocksize / 2)) && j < pulseTrain.Length; j++)
    {
        fftPulseBuffer[index] = pulseTrain[j];
        index++;
    }

fftPulseBuffer - 512, 1024.