[LAU] using jdelay

[Pieter Palmers]

hollunder at gmx.at wrote:
> 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.

Aside from that, make sure that you don't have any hardware monitoring 
enabled on the channel the jdelay signal is generated on.

Greets,

Pieter