[LAU] LADSPA processing time for audio zeroes

Nigel Henry cave.dnb2m97pp at aliceadsl.fr
Sat Mar 28 12:09:12 EDT 2009

On Saturday 28 March 2009 16:39, Ken Restivo wrote:
> When a LADSPA plugin is being sent zeroes-- i.e. when the volume of the
> input data is down to nothing-- is it still sucking up CPU cycles?
> I understand from the JACK API that anytime a client gets a callback with
> data, it has to drop down and deal with the data and then return, even if
> the data is zero. But that could be lightweight, if the data are zero, or
> is that very compute-intensive for the plugin?
> I'm trying to build an outboard effects chain in various LADSPA hosts (JACK
> Rack, ecasound, AMS, others... haven't settled on one yet), and when I've
> got that plugin's volume MIDI'ed down to zero, I'd like it to not be
> dominating CPU cycles at that time.
> -ken

Hi Ken.

Your not experiencing a denormals problem perhaps with the plugins? Googling 
denormals bring up some interesting hits on the first page. May be worth a 
look if that is the problem.


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