Re: [Linuxsampler-devel] Re: resampling benchmarks, sampler module, effect sends

[Steve H. <S.W...@ec...>]

I'm assuming you meant to apply to the list...

On Thu, Nov 14, 2002 at 02:37:54 +0000, Nathaniel Virgo wrote:
> > For reverb and chrous I think you want them to be serial, parallel:
> >
> >      .----> chorus ---.
> >
> > -----+                +------>
> >
> >      '----> reverb ---'
> >
> > will sound odd I think.
> 
> On my aging Yamaha CS1x keyboard (an XG thing with lots of "analogue-style" 
> sounds and built in fx) they are in parallel on most of the presets.  You can 
> put them in series (kind of) but it makes the reverb take up more of the mix.

OK, well that answers that then. Sure, this can be configurable, we have
to support both anyway. And the code will be build dynamically, so it wont
really hurt speed.

> Why not allow the user to set up the routing however they want it?  Perhaps 
> you could simplify things a lot by letting the user send each voice to either 
> a mono JACK output or a stereo pair, and do effects routing in something like 
> Ardour.  Or would that be inefficient/impractical/at odds with the aims of 
> this project?

One of the (eventual) aims is to build optimal optimal code paths for the
effects routing, to get the voice count as high / cpu load as low as
possible, that kind of rules out external processing, and it would be
problematic anyway and the number of active voices varies from block to
block.

PS I was vaguely worried about the overhead from having to use position
independent code in the recompiled voices, but it turns out to only be a
few percent overhead on my PIIIM (which has terrible rspeed4 benchmark
performance BTW, >100 cycles for the last test). Benno, you could add
-fPIC -DPIC to the CFLAGS if you want to account for this in your
benchmarks.

- Steve