Re: [Jack-Devel] extra latency compensation

On Mon, April 18, 2011 4:35 am, Fons Adriaensen wrote:
> You are missing the correct way to calculate the extra latency.
>
>    measured_latency - n * p           for jack1 or
>    measured_latency - (n + 1) * p     for jack2 in its default mode.

Fons, thank you, that seems to have corrected the problems I was having.
At least with my PCI interface, the USB seems to have other problems not
related to this calculation.

The man page for jack_iodelay that comes with jack is currently incorrect.
 There is also no documentation that I could find which explains the
process of latency compensation, so I think I will try to write up a
correction for the man page to submit a patch, and perhaps a tutorial on
latency correction later in the week.

> These results make me think that you are indeed using jack2 in its
> default mode wich adds 1 extra period of latency.

Yes, I had forgotten about the 1 extra period with jack2.  I am using
qjackctl for convenience in displaying and setting jack parameter, and
that tool does not make visible the synchronous or asynchronous option
since the option is not common between jack1 and jack2.

-- 
Chris Caudle

1303185014.20833_0.ltw:2,a <de448f24d025d47a35ddd9f577efd4ef.squirrel at email dot powweb dot com>