fft pitch amp detection for guitar
Posted 12 May 2012 - 11:39 AM
I heard from a forum post that you look for the harmonic with the highest amplitude and thats a fundamental harmonic, so you detect this and that forms the amplitude and pitch for the string, could i do all the strings at once like this? (even bending?)
thanks for any replies.
Posted 12 May 2012 - 02:46 PM
My two cents:
use logarithmic frequency scale instead of linear (FFT),
for each frequency F with power A add scores C1*A, C2*A, C3*A... to frequencies F, F/2, F/3... then choose frequency with highest score as fundamental.
Posted 12 May 2012 - 03:49 PM
Posted 12 May 2012 - 04:48 PM
Posted 12 May 2012 - 05:42 PM
Posted 19 July 2012 - 09:08 PM
In the resulting "FFT" you have you will find the largest peak is the pitch.
This method works, is increidbly quick, but you get really rubbish resolution (its not bad for most things though).
The method I'm currently using for speech pitch tracking is based on an auto correlation. Basically you take an auto correlation of the window (as in window functioned window of audio) you wish to analyse and then you measure the distance to the next highest peak (This is complicated as suually the peak will lie between 2 samples so you need to break out the interpolation). This distance is the sample offset to your fundamental frequency (pitch) in samples. It is very fiddly getting this right but gives by FAR the best resolution I've come across. Its a very intensive calculation though! The bonus of this method is that by applying a levinson-durbin recursion to the resulting auto correlation data you can easily convert to an LPC representation. Find the roots and you have F1 through Fn as well.
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