[LAD] ladspa: what does LADSPA_PROPERTY_REALTIME mean?

David Robillard d at drobilla.net
Wed Sep 16 00:27:40 UTC 2015

On Sun, 2015-09-13 at 10:28 +0200, Tim Goetze wrote:
> [David Robillard]
> >I believe #1 is the intent.  The hint serves to distinguish plugins that
> >have some dependency on real time, from those that do not (only
> >processing their input).  The latter can be used in a more functional
> >way, being called to process a block whenever, where the actual time run
> >is called is irrelevant.  The hint being set essentially means "if the
> >plugin is activated, run() must be called regularly at a rate roughly
> >corresponding to the passage of real time"
> >
> >Th[e] comment says "plugin has a real-time dependency (e.g. listens to a
> >MIDI device)" which seems pretty clear.  Explanation #2, while perhaps a
> >useful thing in some circumstances, really does not follow from the
> >hint's definition.
> "This", as it is so succinctly put nowadays.
> (I seem to remember Steve Harris telling me he'd asked for the
> inclusion of this flag but would later find it ill-conceived and of no
> practical use.  Could be wrong though, mists of time and all that.  In
> any event, ignoring the flag altogether seems to be the most pragmatic
> solution.)

I can see its use in theory, though not much in practice seems to have
any need for it.

It makes me think of a "purely functional" flag, which would be more
useful (you only need one instance to run on whatever), but that's much
stronger and forbids any state whatsoever, not just time...


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