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

[Dave Griffiths]

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.

> > see current implementation...
> [...]
> > one advantage is with silent sub nets....
> 
> I'm not sure it's that easy. What about plugins with tails and/or 
> internal state? (Delay, reverbs, most filters, ...) You can't just 
> stopp running these when they get no input, or when you don't need 
> their output.

I must admit I haven't followed this discussion too closely, so you've probably covered all this before, but I think all this work to figure out if you are processing silent data is not really as much a win to be worth the hassle - as it won't ever make the worst case faster. 

Time would probably be better spent finding actual bottlenecks and optimising them.

dave