Re: [Audacity-devel] Real-time effects stacks

[Jorge R. <jro...@ma...>]

Oh sorry, I guess I didn't get the on-demand part. I think I understand
better now, however I'm not sure we're talking about the same thing so I'm a
bit confused.

I think we are trying to solve different problems, and so we're talking on
different wavelengths here. What I think you're talking about is, in the
current version of Audacity, when the user selects an effect it is applied
immediately and destructively, but you want it to be only remembered and
applied "on-demand" the next time the user clicks play, only for the section
of the song that the user is playing, in order to save up-front processing
time. That's okay, but even if it does it in the context of an effects stack
it's still not what I really want to implement, which is *non*-destructive
effects. The on-demand behavior is not really all that desirable to me, I
don't mind that the program takes a moment to render the effect that I just
selected, so long as I can go and change it to listen to it again without
having to worry about the fact that all my data was just overwritten.
On-demand processing does sound like it would be a good idea, and it would
reduce the amount of processing required (or at least spread it out more)
but I'd like to focus on non-destructive effects stacks implemented in the
way I outlined in my previous email. Here's how I imagine it might work,
from a work-flow perspective:

1) The user adds an effect or two to his stack.
2) Audacity renders these effects to a separate .au audio file, keeping the
original pristine.
3) The user hits play, and Audacity plays the version of the audio with the
effects applied.
4) The user changes a parameter on the first effect and adds a third effect.
5) Audacity re-renders the track from the original pristine audio track.
6) The user hits play and hears his tweaks.

>From a UI perspective, the rendering can happen at any time, be it
on-demand, or at the push of a button in the track's control panel, or when
the effects window screen is closed, or whenever. I'm trying to meet a
design requirement that I gleaned from your first email, that the goal of
this design is not to increase the processor requirements when adding these
effects. What I'm looking for is input on whether or not this is a good
design for how to implement this feature.

-- 
Jorge Rodriguez
Matrieya Studios, LLC
Email: jro...@ma...
Phone: (919) 757-3066