[linux-audio-dev] LADSPA proposal for named values

[Steve Harris]

On Sat, Jan 04, 2003 at 09:51:20 +0100, Pascal Haakmat wrote:
> Hi all,
> 
> It appears as though LADSPA at the moment lacks a means to provide
> names for control values (this topic has probably crossed the list
> before so I'll try to keep it short).
> 
> The common solution for this problem (e.g. as used in Steve Harris'
> plugin collection) is to use an integer control port to encode for the
> different options that the port can have, then add some text to the
> PortName to describe those options (e.g. "1=sin, 2=saw, ...").

My RDF plugin schema can represent this, eg. from sample.rdf

    <ladspa:InputControlPort rdf:about="&ladspa;1416.1">
      <ladspa:hasLabel>wave</ladspa:hasLabel>
      <ladspa:hasScale>
        <ladspa:Scale>
          <ladspa:hasPoint>
            <ladspa:Point rdf:value="1" ladspa:hasLabel="Sine" />
          </ladspa:hasPoint>
          <ladspa:hasPoint>
            <ladspa:Point rdf:value="2" ladspa:hasLabel="Triangle" />
          </ladspa:hasPoint>
          <ladspa:hasPoint>
            <ladspa:Point rdf:value="3" ladspa:hasLabel="Square" />
          </ladspa:hasPoint>
          <ladspa:hasPoint>
            <ladspa:Point rdf:value="4" ladspa:hasLabel="Saw" />
          </ladspa:hasPoint>
        </ladspa:Scale>
      </ladspa:hasScale>
    </ladspa:InputControlPort>

It could be less verbose, but this is the long form of it, which I think
is clearest.

However no hosts can read RDF yet. http://plugin.org.uk/lrdf/ for code.
It can also do a number of other metadata tasks incuding categorisation.
I think its better to solve all these problems at once.

- Steve