function [ASBP] = AudioSpectralBandPower(raw, fs, noOfFrames, frameLength)
% this file normalises the frequency spectrum and calculates the spectral
% power in frequency band 100 - 1000 Hz and in the top 
x = buffer( raw, frameLength );
myColor = 'rx';

hiEdgeSamples = getMaxFreq; % the highest fundamental
loEdgeSamples = getMinFreq; % the lowest fundamental

hiFreqBin = ceil(((frameLength/2)/(fs/2))*hiEdgeSamples);
loFreqBin = floor(((frameLength/2)/(fs/2))*loEdgeSamples);

bandWidth = hiFreqBin - loFreqBin;

for n = 1:noOfFrames
    spectrum = abs( fft( x(:,n) ));
    spectrum = spectrum( 1 : frameLength/2 );
    % normalise
%     spectrum = spectrum/max(spectrum);
    % fundamental frequency band
    lBand = ( loFreqBin : hiFreqBin );
    hBand = ( frameLength/2 - ( bandWidth ) : frameLength/2 );
    lBandPower = sum( spectrum( lBand ));
    hBandPower = sum( spectrum( hBand ));
%     gm(n) = nthroot( prod( spectrum ), frameLength );
%     am(n) = sum( spectrum )/frameLength;
    ASBP(n) = lBandPower/hBandPower;
%     subplot(421); plot( x(:,n) );
%     subplot(422); plot( spectrum ); hold on; 
%     plot( loFreqBin : hiFreqBin, spectrum( lBand ), 'r' );
%     plot( hBand, spectrum( hBand ), 'r' ); hold off
%     
% %     look at the frame with reference to the surrounding 10 frames
%     if( n>5 )
%         startPlot = (n-5)*frameLength+1;
%         endPlot = (n+5)*frameLength;
%     else
%         startPlot = 1;
%         endPlot = 10*frameLength;
%     end
%     subplot(412); plot( raw( startPlot : endPlot ) ); hold on; 
%     plot( ((n-1)*frameLength+1) - startPlot : (n*frameLength) - startPlot, x(:,n), 'r' ); hold off;
%     
%     subplot(425); plot( n, lBandPower, myColor ); hold on;%plot( n, gm(n), myColor ); hold on;
%     subplot(426); plot( n, hBandPower, myColor ); hold on;%plot( n, am(n), myColor ); hold on;
%     subplot(414); plot( n, lBandPower / hBandPower, myColor ); hold on;%plot( n, ASF(n), myColor ); hold on;
% end
end





