[PlanetCCRMA] delay test

"Alexander Carôt" alexander_carot@gmx.net
Wed Apr 14 15:48:02 2004

The problem is that I need an external soundsource as a reference signal. 
What I did was this :

mono source to stereo source

left channel directly to left channel of recording device

right channel sent to ALSA-PC LineIn

line out of PC sent to right channel of recording device

The gap between the left and the right channel indicates the delay BUT the
ALSA PC sends the input directly bypassing the soundcard which is why I
measure a delay of 0 ms (same signal of course). 
When I´m muting the capture channel the signal might get captured but I
doesn´t appear on the master anymore.                                     

Help !!!


-- A l e x

> On Wed, Apr 14, 2004 at 02:57:40 +0200, "Alexander Carôt" wrote:
> > > You have to set which input you want to be recorded from.
> > 
> > I attached a screenshot the mixer for my USB device is on.
> > 
> > I want to have the input source signal on the left and the soundcard
> output
> > signal on the right   or    
> > both of them on one channel if I still canfigure out the delay.
> I've done it by running a loopback cable from the line out to the line in.
> Then record one channle of the soundcard input and one channel of an
> jack client.
> eg:
> alsa_pcm:capture_1 ------------------>
>                                        jack recorder
>         ----------------------------->
>     AMS
>         ----------------------------------------> alsa_pcm:playback_1
> Hope that makes sense
> - Steve