[PD] setting plugin~ control inputs

derek holzer derek at x-i.net
Sun Apr 17 23:01:04 CEST 2005

I'm curious how to set the values of a LADSPA plugin uing the [plugin~] 
object. Seems like it's a bit of a pain in the ass to use. For example 
this one:

Loaded from library "/usr/lib/ladspa/mvclpf24.so".
Control input(s):
  #1 "Input gain (dB)"
  #2 "Frequency"
  #3 "Exp FM gain"
  #4 "Resonance"
  #5 "Resonance gain"
  #6 "Filter poles"
  #7 "Output gain (dB)"
Control output(s):
Audio input(s):
  #1 "Input"
  #2 "Frequency"
  #3 "Exp FM"
  #4 "Resonance"
Audio output(s):
  #1 "Output"

The object itself has 5 inlets, of which I assume that the first is for 
control messages and the other four are for the "Audio inputs".

My question is how to format the messages to the control input when the 
expected format is something like "Input gain (dB)". If I use the message:

control "Input gain (dB)" $1

or something similar using the format given by the "print"
message, it does not accept it:

error: Bad arguments for message 'control' to object 'plugin~'

I could try the first word, such as "input" or "filter", but this is 
ambiguous in the case of arguments like "Resonance"/"Resonance gain". 
Sometimes the use of an underscore works, as in "Resonance_gain":

plugin~: warning: parameter limited to within [0.000000, 1.000000]

However "Filter_poles" results in:

error: plugin~: plugin doesn't have a control input port named 

Is there a systematic way of dealing with this besides pure dumb hacking 
away? Any help from the LADSPA masters.... (Yo Frankie B, you in da house?)


derek holzer ::: http://www.umatic.nl
---Oblique Strategy # 173:
"Voice your suspicions"

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