DESCRIPTIONThis manual page documents briefly the gtkguitune program. This manual page was written for the Debian GNU/Linux distribution because the original program does not have a manual page.
Guitune is a linux program for tuning guitars and other instruments by using the method of Schmitt-triggering, i.e. counting the number of triggerings between two trigger levels in a certain amount of time.
With FFT you need many samples to archieve the accuracy needed for tuning instruments. You often get times of around 1 second between two measurements and the computer is quite busy in this second calculating the FFT. Using Schmitt-triggering you get a measurement every 10th of a second or even less (depending on the sample frequency you use). Most of the time the computer only waits for the samples.
The Trigger levels are adjustable. For a pure sine-wave the trigger levels could be zero. But for a wave wth overtones like the one in the figure above you need a non-zero triggerlevel. It is preadjusted to a level of 60% of the current maximum which should be able to deal with most instruments.
AUTHORThis manual page was written by Antonín Král <[email protected]>, for the Debian GNU/Linux system (but may be used by others).