function r = sfftwav(wavfile)

%% settings
spectrumwidth = 196;
spectrumkeep = 64;
normcutoff = 5;


% get ready
[numsamples numchannels] = wavread(wavfile,'size');

samplespersecond = 44100;
chunkspersecond = 30;
samplesperchunk = samplespersecond / chunkspersecond;

numchunks = numsamples / samplesperchunk;

lumplen = 30 * chunkspersecond;

pos = 1;

% walk thru wav

all = [];
lump = [];
lumpcount = 0;
for i = 1:numchunks
  last = pos + samplesperchunk - 1;
  if last > numsamples
    last = numsamples;
  end

%  [pos last]
  bit = wavread(wavfile,[pos,last]);

  % fft
  y = fft(bit,spectrumwidth*2);
  pyy = y.* conj(y) / spectrumwidth / 2;
  rpyy = pyy(1:spectrumkeep,:)';
  lump = [ lump ; rpyy ];

%    rpyy

  lumpcount = lumpcount + 1;
  if  lumpcount == lumplen 
    % normalize lump
    [h w] = size(lump);
    for col = 1:normcutoff
      lump(:,col) = lump(:,col) / (normcutoff + 1 - col);
    end

    % add
    all = [all {lump'}];
    lump = [];
    lumpcount = 0;
  end

  pos = pos + samplesperchunk;
end


r = all;