[PD] Re: [PD-ot] how low (latency) can you go?

[Hans-Christoph Steiner]

On Dec 16, 2006, at 8:38 PM, Mathieu Bouchard wrote:

> On Sun, 17 Dec 2006, Patco wrote:
>> aws a écrit :
>>> A general method for latency measurement of any system is  
>>> described in this paper: Matthew Wright, Ryan Cassidy, Michael  
>>> Zbyszynski, Audio and Gesture Latency Measurements on Linux and  
>>> OSX, Proceedings of ICMC 2004, Miami
>>
>> or just connect ãudio input to audio output of the soundcard and  
>> take a measure with some patch magics.
>
> Exactly. That's what I said a few mails ago. Try doc/7.stuff/tools/ 
> latency.pd ... however it doesn't seem to be super precise. Do you  
> have any ideas on how to make it more precise?
>
> And then how is one supposed to be able to get the above paper? It  
> doesn't seem to be online.
>
> Apart from measuring the echo time of a click like what Miller's  
> patch already does, the only other way I've thought of, is playing  
> a linear chirp, and then mix it with an offset copy of itself using  
> adc/dac as the delay line. This will cause a beat phenomenon, whose  
> frequency can be quite precisely measured (yes?).

Such a technique would allow for the measurement of jitter as well,  
which  really should be considered at least as much as latency.

.hc


------------------------------------------------------------------------

News is what people want to keep hidden and everything else is  
publicity.          - Bill Moyers