[PD] [nbuntil]: an non-blocking [until] replacement

[Jonathan Wilkes]

Why not just trigger each iteration with [bang~]?

-Jonathan




----- Original Message -----
> From: Roman Haefeli <reduzent at gmail.com>
> To: Pd List <pd-list at iem.at>
> Cc: 
> Sent: Sunday, December 16, 2012 4:51 PM
> Subject: [PD] [nbuntil]: an non-blocking [until] replacement
> 
> Hi all
> 
> Audio drop-outs happen, when Pd needs more time to do something than is
> available (i.e. the configured audio buffer size). The underlying
> reasons are manifold, often it is because something requiring lots of
> CPU power is processed in zero logical time. For such of those problems,
> that can be divided into smaller tasks or those that already are of an
> iterative nature, [nbuntil] may provide a solution to avoid audio
> drop-outs.
> 
> [nbuntil] works similar to the regular [until], but unlike the original,
> it breaks Pd's principle of "depth first". It measures how much 
> time
> each iteration requires and delays the next iteration by this time. By
> employing [nbuntil], many kinds of tasks can be performed without
> causing drop-outs, that would otherwise block Pd for a certain amount of
> time. 
> 
> Example applications include loading presets or dynamic creation of
> parts "in the background". Yet, I use it to pre-calculate a set of
> tables while audio is running. I could imagine using it to create an
> emulation of a threaded [soundfiler], though a proof of concept is yet
> lacking and needs to be created. Contrary to Miller's suggestion of
> using a [readsf~] in an upsampled subpatch, [nbuntil]'s adaptive
> approach uses the maximum available CPU power. 
> 
> I'm curios to see whether other people find it useful and even find use
> cases I haven't thought of yet. Despite its rather simple design, I
> can't remember having seen this approach discussed here on the list. I'd
> also be interested if similar or different approaches have been used,
> but not yet discussed here.
> 
> I'm currently not in the urgent need of a vanilla pseudo-threaded
> [soundfiler], but if there is enough interest, I'd be happy to dedicate
> some time to it (not totally sure, that it would work, though).
> 
> Roman
> 
> 
> 
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