waveFile='sunday.wav';
au=myAudioRead(waveFile); y=au.signal; fs=au.fs;
index1=9000;
frameSize=512;
index2=index1+frameSize-1;
frame=y(index1:index2);
maxShift=length(frame);
method=1;
acf=frame2acf(frame, maxShift, method);
acf2=acf;
maxFreq=1000; n1=floor(fs/maxFreq+1); acf2(1:n1)=-inf;
minFreq=40; n2=ceil(fs/minFreq+1); acf2(n2:end)=-inf;
[maxValue, maxIndex]=max(acf2);
fprintf('Pitch = %f Hz = %f semitone\n', fs/(maxIndex-1), freq2pitch(fs/(maxIndex-1)));

subplot(2,1,1);
plot(frame, '.-');
title('Input frame');
subplot(2,1,2);
xVec=1:length(acf);
plot(xVec, acf, '.-', xVec, acf2, 'm.-', maxIndex, maxValue, 'ksquare');
axisLimit=axis;
line(n1*[1 1]+0.5, axisLimit(3:4), 'color', 'r');
line(n2*[1 1]-0.5, axisLimit(3:4), 'color', 'r');
title(sprintf('ACF vector (method = %d)', method));
legend('Original ACF', 'Truncated ACF', 'ACF pitch point');