[LAU] using jdelay

[hollunder at gmx.at]

On Thu, 02 Apr 2009 11:16:39 +0200
Atte André Jensen <atte.jensen at gmail.com> wrote:

> Hi
> 
> I tried measuring my latency with jdelay. Started in on the
> commandline, first it said
> 
> Signal below threshold...
> 
> Then I connected it's input to the output of system:capture_1 with my 
> microphone connected and it output to the input of
> system:playback_1+2. Now I get a squareish tone and when "singing"
> into the microphone I get reading like these:
>   22442.483 Inv
>   58010.411 ??
>   43602.390 ?? Inv
>   43474.474
>   43474.474 ?? Inv
> Signal below threshold...
> Signal below threshold...
> Signal below threshold...
>   25549.731 ??
>   25549.731 ?? Inv
>   37749.225 ??
>   37749.225 ?? Inv
>   37749.225 ??
>   24653.357 ??
>   24653.228 ?? Inv
>   25677.165 ??
>   11013.134 ?? Inv
>   25677.153 ??
>    2821.046 ?? Inv
>    2821.046 ??
> 
> The man page says the values are in samples, so for instance a value
> of 37749.225 should be 0.77 seconds at 48000, right? This seems bogus 
> (qjackctl reports 10 ms).
> 
> What am I doing wrong?
> 

Hi Atte.
I made the same mistake at first.
Simply don't use a microphone, just a patch cable.
Latencies are calculated by frames/samplerate, the resulting numbers
are milliseconds.

What interface are you using? Maybe some comparison would be possible
(I have a usb interface).

Best regards,
Philipp