Subject: Re: [linux-audio-dev] Plugin APIs (again)
From: David Olofson (david_AT_olofson.net)
Date: Sun Dec 08 2002 - 02:14:10 EET
On Sunday 08 December 2002 01.01, Steve Harris wrote:
> On Sun, Dec 08, 2002 at 12:29:24 +0100, David Olofson wrote:
> > > SILENT (plugin to host - sent when reverb tails or whatnot have
> > > died..)
> >
> > Great idea. Sample accurate end-of-tail notification. :-) (In
> > Audiality, I do that by fiddling with the plugin state, which is
> > rather ugly and not sample accurate.)
>
> As long as its not required, you can't allways tell (eg. gong
> again).
Of course. There are three cases, I think:
1) Plugins that can't/won't tell when the tail has ended.
2) Plugins that don't have any tail at all.
3) Plugins that will give you SILENT events.
I think you'd have to tell the host where you belong, so the host
knows why it's not getting any SILENT events... (There's no point in
sending them for case 2), IMHO - but it's still ok to shut the plugin
off, or whatever, without analyzing the output or anything.)
Plain delay effects are one example of plugins that definitely
*should* be in 3) - since you can't be sure by just looking at the
output. It may be dead silent for a good while, and still have data
in the internal buffers.
Now, what's the definition of "silent"? :-)
IMHO, even when the plugin does the work, the *host* should decide
what the maximum signal level for "silent" is, since this differs
depending on the target data format. With 24 bits, you'll have to
wait quite a bit longer than with 16 bits, before you can "safely"
cut the tail...
//David Olofson - Programmer, Composer, Open Source Advocate
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