12 May
2009
12 May
'09
4:45 a.m.
I have been messing around with the XML of JACK-RACK's patch files (to play with
smudge/clean filters in git to store them in my source control system), and noticed
something weird:
<channels>2</channels>
<samplerate>48000</samplerate>
Huh? Jack-rack saves the sample rate of a patch? Why?
I wonder what that's for? If I open a patch that I saved when using my internal
HDA-Intel card at 48000Hz, then open it when using my FastTrack Pro (only does 44.1Khz),
will Jack-Rack waste cycles doing all kinds of crazy sample-rate conversions in order to
match what its saved file told it to do?
Perhaps more insanely, do I need to keep separate, parallel versions of all my Jack-Rack
patches-- the only difference being the sample rate-- for each of the audio interfaces I
use?
-ken
18 Jun
18 Jun
12:11 p.m.
(Sorry for the delayed response -- it's been a while since I've caught
up on l-a-u!)
Ken Restivo <ken(a)restivo.org> writes:
Huh? Jack-rack saves the sample rate of a patch? Why?
One of the possible hints for LADSPA controls is to indicate that the
control's value should be scaled when the sample rate changes. This
means that if you save a rack at one sample rate and reload it at
another, JACK Rack has to know about it in order to adjust the control
values correctly. If it didn't do this, then you would need to maintain
a different rack file for each sample rate as you suggest, which'd be a
bit annoying.
I don't think I've actually seen it used in practice -- none of the
plugins I use have a parameter that's related to the sample rate...
--
Adam Sampson <ats(a)offog.org> <http://offog.org/>
5638
days inactive
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Ken Restivo