[PD] name of latency measurement algorithm

[Peter P.]

* Roman Haefeli <reduzent at gmail.com> [2018-12-13 13:52]:
> On Thu, 2018-12-13 at 13:21 +0100, Peter P. wrote:
> > * Roman Haefeli <reduzent at gmail.com> [2018-12-13 11:58]:
> > > Hey all
> > > 
> > > I once read about a simple and robust way to perform latency
> > > measurements with an audio signal. 
> > > 
> > > Explained in a few words, the test signal consists of a sweeping
> > > sine
> > > tone. The return signal ring-modulates the source signal and the
> > > resulting signal consists of two frequencies, the sum ( f_src+f_ret
> > > ) 
> > > and difference ( f_src - f_ret), while the lower frequency is
> > > proportional to the latency and can be detected quite easily
> > > with  with
> > > e.g. [sigmund~].
> > > 
> > > I have troubles finding the name of this algorithm and don't
> > > remember
> > > the original source. I would like to read more about it and
> > > correctly
> > > attribute the original author / inventor.
> > 
> > See jack_delay on https://kokkinizita.linuxaudio.org/linuxaudio/
> 
> That's a different algorithm and probably much more precise. The one
> I'm looking for is simpler (and I'd probably know how to implement it
> in Pd).

What about 7.stuff/tools/latency.pd?