Re: [linux-audio-dev] latest news: the editor taketh shape

New Message Reply About this list Date view Thread view Subject view Author view Other groups

Subject: Re: [linux-audio-dev] latest news: the editor taketh shape
From: Paul Barton-Davis (pbd_AT_Op.Net)
Date: Tue Oct 24 2000 - 04:32:36 EEST


>I personally think the causality issue is a massively underestimated
>problem. Solving it (as MN does) leads to a synth engine that handles
>feedback loops, network delays, non-real-time audio in a real-time context
>etc in a (mostly) transparent fashion.

There is NO causality issue here. At some time in the future, there
might be, given a sufficiently complex send/return/insert/bus/strip
architecture. But at this point in time, ardour doesn't have to face
this problem in any way.

>writing a "snippet" processing engine for MN to allow MN to take snippets
>(generally a few seconds, under strict criteria) of audio from a live audio
>stream and pass them through the signal chain as events. Horribly high CPU
>costs, but semantically useful and sounds good ;-). Snippets are then
>processed further down the event chain before being reconstructed as audio.
>The processors have some reasonably thorough rules to constrain their live
>use of CPU time (this is all single-threaded to make it quantifiable).

yeah, and now try this on 24 live streams of 32 bit samples coming
from the disk, and then see how practical this model is for an HDR
system :)

>I think the statement that "LADSPA is fundamentally designed around a
>different premise than the one most suitable for editing" is misleading.
>Though precise, it misses the point. 90% of real-world effects are handled
>through LADSPA.

agreed, except that we don't have the luxury of a DSP farm to run them
on during real-time playback, and so figuring out how to execute them
in "batch mode" is a necessary exercise, and a futile one for an
application: its going to be done over and over again by different
editing applications. thats why i'd this to be part of LADSPA, not
part of any particular app.

>plugins will also run live. The only issue that LADSPA does not handle is
>manipulation of the time dimension.

which happens to be one of the main things one wants to do while
editing, precisely because it can't be done in real-time.

>Incidentally, I've forgotten how VST supports reverse and timestretch
>algorithms. Could someone remind me/us?

it has a "batch-driven mode", where the plugins are executed in a
different way. its been a while since i read the SDK, but it was
definitely part of their design space, IIRC.

--p


New Message Reply About this list Date view Thread view Subject view Author view Other groups

This archive was generated by hypermail 2b28 : Tue Oct 24 2000 - 05:03:50 EEST