Re: bus count and channel info confusion
Re: bus count and channel info confusion
- Subject: Re: bus count and channel info confusion
- From: William Stewart <email@hidden>
- Date: Wed, 21 Jul 2004 12:33:47 -0700
On 21/07/2004, at 11:03 AM, Stefan Gretscher wrote:
>
>
Am 21.07.2004 um 04:33 schrieb William Stewart:
>
>>> 7. Audio Effect that processes stereo only, but has a side chain
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>>> input that can be mono or stereo.
>
>>> Input Bus Count: 2, not writeable
>
>>> Output Bus Count: 1, not writeable
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>>> Channel Info: Not possible to describe
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>>
>
>> Yeah, I think that you just can't do this, though I'm not sure about
>
>> that.
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>
>
> I believe this should be described as Reaktor (and Reaktor FX)
>
> describes its channels:
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> Input Bus Count: 1, writable
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> Output Bus Count: 1, not writable
>
> Channel Info: { -4, 2 }
>
>
>
> Then the host can decide to use either 3 or 4 of the input channels as
>
> the user wants. The AU can easily deal with this situation even if the
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> host configures this as 4 mono inputs too, I believe.
>
>
>
> By formatting the first bus to be stereo input (and output), then I
>
> think the AU is providing a pretty reasonable hint to the host about
>
> its preferred configuration (and some hosts may even decide to use
>
> this
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> as the starting off point when presenting dynamically configurable
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> AU's).
>
>
How should hosts deal in this case with mono in stereo out
>
configuration?
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I would assume that if a plug-in provides a channel info of { -4, 2}
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that it
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is able to do mono in stereo out. However, there's no guarantee for it
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as far as I understood it, and it's not the case in the example.
>
This is problematic for host like Logic as they would have to try to
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initialize
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the AU to find out whether it really can do mono in stereo out, which
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is
>
increasing startup time.
Yes, this assumes that the effect can do mono in, stereo out.
No intialization is required - the channel info is telling you what it
can do. (Its easy enough for the AU to support)
>
So it would be great if it could be made sure that a channel info of {
>
-4, 2}
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means that all formats {1, 2} {2, 2} {3, 2} and {4, 2} can be used.
Yes
>
>
Another possible solution of the problem might be taking the element
>
parameter into account and going for:
No - we've been down this path. The problem for this is that you end up
not being able to express any dependencies that exist between
configurations across buses - so, its just as incomplete and complex as
the current model. Urs had a wonderfully complex and horrible chart to
express this when we went through this sometime ago.
The elegance of reporting channel capabilities is I think a pretty
reasonable solution particularly as the AU side isn't that hard to do
either, and it provides a degree of flexibility to hosts that they can
use as appropriate.
Bill
>
>
Input Bus Count: 2, not writeable
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Output Bus Count: 1, not writeable
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Channel Info for element 0 : { 2,2 }
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Channel Info for element 1 : { 1,2 } { 2,2}
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>
This ofcourse only makes sense when the bus counts of the AU are not
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writeable, otherwise the meaning of the element parameter might be
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unclear.
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>
>
Stefan Gretscher
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>
plug-in development & 3rd party plug-in support
>
Emagic Soft- & Hardware GmbH
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>
--
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