[linux-audio-dev] RDF for CAPS plugins

[Tim Goetze]

[Paul Winkler]

>On Thu, Apr 20, 2006 at 10:51:20PM +0200, Tim Goetze wrote:
>> The 0.3.0 CAPS release actually comes with an rdf file supposed to 
>> label the enumerated int ports (the Cabinet model switches and the 
>> SweepVF filter modes).
>
>Argh! I already had 0.3.0, but apparently the gentoo ebuild fails to
>install the rdf file.  I'll file a gentoo bug.

rdf-install is a separate make target, that makes it easy to 
overlook I guess.

>I merged yours with mine and yep, it works - now I get both
>categorization and useful dropdown widgets on those four plugins.
>Yay!

Good. The proposed 0.3.1 caps.rdf will more or less be the same merge.

>btw, the guy that wrote yours didn't apparently understand
>how the categories work. I had it mostly right by copying
>other files, but I just now stumbled on where the taxonomy is
>actually defined, it's at:
>
>/usr/share/ladspa/rdf/ladspa.rdfs
>
>...  which apparently comes with liblrdf.

Or here: http://plugin.org.uk/lrdf/examples/ladspa.rdfs

One thing I don't understand about this lrdf business is how you type 
(or generate) a line that reads

<rdfs:Class rdf:about="http://ladspa.org/ontology#TimePlugin" 
ladspa:hasLabel="Time">

when http://ladspa.org/ontology is (and has been for some time) a 404.

In any event, I'll make sure the plugin types are properly assigned.

>It should be possible to stub out the rdf for enumerated parameters by
>looking at the "ports:" output of analyseplugin. That might be handy.

There's some old code I keep around that runs ladspa plugins under 
python control (that's how the port info, cpu usage and 
impulse/frequency response figures for caps.pdf are generated). It 
comes with full python access to the port definitions, so it should be 
rather easy to generate the rdf port info along with it.

>> Steve, are the dc:creator, dc:rights, dc:title tags necessary? Paul's 
>> caps.rdf simply copies the data found in caps.so -- is it possible to 
>> simply eliminate this redundancy?
>
>dc (dublin core) metadata is generally optional.
>I just put those in without thinking because it was easy to parse out.
>I like having at least the title, it makes the rdf much more
>human-readable.

True. But this should be valid xml/rdf too:

<!-- CabinetX: genuine tweed-covered, smoke-stained, whisky-drowned 
  '60s speaker cabinet, almost -->

Alas, humanely commented code has always been a rare commodity ... :))

Cheers, Tim