[Ardour-Dev] Non-freewheeling export mode in Ardour 3?

[Paul Davis]

On Tue, Nov 1, 2011 at 9:09 AM, Fons Adriaensen <fons at linuxaudio.org> wrote:
> On Tue, Nov 01, 2011 at 07:23:35AM -0400, Paul Davis wrote:
>
>> the problem (as i realized overnight) is that the computational cost
>> of export is essentially unbounded and so its impossible to do this
>> with JACK in normal mode. sure, one could say something like "well, it
>> works on most machines if you use only a single uncompressed export
>> format". that's not very satisfactory, and isn't likely to ever be
>> reliably true enough to justify the claim in the first place.
>
> Two things are being mixed up here:
>
> 1. Non-RT processing to allow arbitrary complexity.
> 2. The results becomes an external file.
>
> AFAICS, these are orthogonal, and make sense separately.

they are somewhat orthogonal, except that to separate them requires,
as you noted, a distinct write-to-disk as a first step. Sakari wrote
all the export code in a3, and it has quite a sophisticated graph
model that allows a lot of fairly clever things. he's the only one at
present who can comment on whether its capable of "write first,
process and re-write later". i believe it may be able to do that,
since it would be an obvious way to implement simultaneous export of
multiple formats, but there are other obvious ways of doing that which
come from using freewheeling mode. i'm not sure which approach he
took, so lets hope he will comment.