[PD] name of latency measurement algorithm

[Peter P.]

* 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/