Re: [Linuxsampler-devel] Supporting various sample library formats

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

On Mon, Nov 04, 2002 at 10:15:56 +0100, Matthias Weiss wrote:
> > Regarding JACK we will probably need to use the in-process model (which
> > is actually not used much AFAIK)
> >  in order to achieve latencies at par with direct output so this needs
> > further research.
> 
> Well this means we have to provide GUI implementations for every graphic
> toolkit that is used by the available sequencers.
> If it's right that processes and threads are handled very similar in the
> Linux kernel there should be not alot of a performance difference
> between in-process and out-of-process model, anyone knows more about
> that?

One idea was that linuxsampler UI's would communicate with the main engine
over a (non X) socket of some kind.

The problem with out-of-context is the the cache has to be cleared and
refilled (well the part touched, and I imagine a big sample set would use
a lot of cache) and the context switch time is small, but non-zero. As you
pointied out we dont have very long to write out 64 samples for every
active sample of every active note.

> > regarding the AKAI samples: Steve says akai samplers were quite limited
> > in terms or RAM availabilty (32-64MB)
> >  and since akai samplers allow some funny stuff like modulating the loop
> > points I was wondering what you thing about not
> > using disk streaming for this format.
> 
> Or caching enough audio data that covers the modulation range which
> might impact RAM usage.

The 3000 series were limited to 32meg, generaly the samples were small,
but in either case the point is that the optimal implementation isn't disk
streamed. Its just an example though, dont get hung up on AKAIs.

- Steve