slackbuilds_ponce/multimedia/dssi

DSSI (pronounced "dizzy") is an API for audio processing plugins, particularly
useful for software synthesis plugins with user interfaces.

DSSI is an open and well-documented specification developed for use in Linux
audio applications, although portable to other platforms. It may be thought of
as LADSPA-for-instruments, or something comparable to VSTi.

This requires qt3 from extra/kde3-compat, ladspa_sdk, libsamplerate, liblo, 
and jack.