[linux-audio-dev] XAP spec - early scribbles

[Dave Griffiths]

On Sat, 1 Mar 2003 12:13:21 +0100
torbenh at gmx.de wrote:

> On Fri, Feb 28, 2003 at 09:01:21PM +0000, Dave Griffiths wrote:
> > On Fri, 28 Feb 2003 19:05:19 +0100
> > David Olofson <david at olofson.net> wrote:
> > 
> > > On Friday 28 February 2003 09.20, torbenh at gmx.de wrote:
> > > [...]
> > > > random latency ? how do you mean that ?
> > > 
> > > Latency depends on how you happen to construct the net (order of 
> > > instantiation, connections etc) and/or the actual layout of the
> > > net, in "non-obvious" ways.
> > 
> > In ssm I sort the network each time a connection is made/destroyed,
> > and generate a ordered list of modules to process from the root up
> > to the leaves. It has to cope with circular sections, which
> > unavoidably introduce latency, but it works. It also automatically
> > means unconnected modules don't get processed, which is nice.
> 
> how does ssm find out the latency it should impose ?
> 
> and at which position does it impose latency ?

It doesn't impose latency, if there are no circular paths there is no
internal latency (er, well there shouldn't be anyway ;)) as the data
from a buffer of input audio will hit the output in the same tick. If
there are circular sections, they will fall behind by one buffer. In
practise this is not really a problem, as you only tend to loop back
connections with things like delay effects.

dave