[linux-audio-dev] XAP: a polemic

Steve Harris S.W.Harris at ecs.soton.ac.uk
Wed Dec 18 05:23:01 UTC 2002


On Wed, Dec 18, 2002 at 12:09:24 -0800, Tim Hockin wrote:
> > 	SET(..., value)
> > 	RAMP(..., target, duration)
> > 	SPLINE(..., target, target_slope, duration);
> 
> do we really need spline?  How many plugins are going to implement that?  If
> the host wants to approximate a spline, send multiple short linear ramp
> events.  Then you only need timestamp (start), duration, and value.  The
> plugin just has to arrive at that value by the end of the duration.  Slope
> is implied.

Agreed, I dont see the value in overspecifying control curves, many
plugins should (and will) ignore it anyway as the host doesn't know what
its asking.

This could be either because recalculating the parameter is very expensive
and the prarmeter calculation results have to be interpolated (which makes
the hosts specification of it irrelevent), or because the parameter
absolutly cannot have excursions, but needs a constant derivative in
which case the plugin will need to override the ramp method.

I dont see any point in having anythign other than ramp, and /maybe/
set, but it just seems like a ramp with a duration of 0 to me.

- Steve



More information about the Linux-audio-dev mailing list