ToolMfccFb.m

%> see function mfcc.m from Slaneys Auditory Toolbox
function [H] = ToolMfccFb (iMagSpecLength, f_s)

    % initialization
    f_start         = 133.3333;
    
    iNumLinFilters  = 13;
    iNumLogFilters  = 27;
    iNumFilters     = iNumLinFilters + iNumLogFilters;

    linearSpacing   = 66.66666666;
    logSpacing      = 1.0711703;

    % compute band frequencies
    f = f_start + (0:iNumLinFilters-1)*linearSpacing;
    f(iNumLinFilters+1:iNumFilters+2) = ...
		      f(iNumLinFilters) * logSpacing.^(1:iNumLogFilters+2);

    % sanity check
    f = f (f<f_s/2);
    iNumFilters = length(f)-2;
    
    f_l = f(1:iNumFilters);
    f_c = f(2:iNumFilters+1);
    f_u = f(3:iNumFilters+2);

    % allocate memory for filters and set max amplitude
    H = zeros(iNumFilters,iMagSpecLength);
    afFilterMax = 2./(f_u-f_l);
    f_k = (0:iMagSpecLength-1)/(iMagSpecLength-1)*f_s/2;

    % compute the transfer functions
    for c = 1:iNumFilters
        H(c,:)      = ...
            (f_k > f_l(c) & f_k <= f_c(c)).* ...
            afFilterMax(c).*(f_k-f_l(c))/(f_c(c)-f_l(c)) + ...
            (f_k > f_c(c) & f_k < f_u(c)).* ...
            afFilterMax(c).*(f_u(c)-f_k)/(f_u(c)-f_c(c));
    end
end