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: Fri, 23 Jul 2004 14:17:41 -0700
An alternate way is that the AU could know which version of logic is
running (by getting the main bundle of the process and checking the
version). Then it could tell if it was the "new Logic" and publish
formats only using the correct way. In the older versions of Logic, it
would publish the old way. If not Logic, then it only publishes the
correct way.
Bill
On 23/07/2004, at 1:19 PM, Pavol Markovic wrote:
>
On 23.7.2004, at 21:25, William Stewart wrote:
>
>
>
> On 21/07/2004, at 11:54 AM, Pavol Markovic wrote:
>
>
>
>> On 21.7.2004, at 19:34, Stefan Gretscher wrote:
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>>
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>>> Am 20.07.2004 um 20:44 schrieb Pavol Markovic:
>
>>>> Example:
>
>>>> AU has 1 stereo and 6 mono outs.
>
>>>> It creates 7 buses.
>
>>>> On first bus it allows to set 2-8 channels via StreamFormat
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>>>> property (this is for logic workaround, but NOT the right way)
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>>>> On others it allows to set only 1 channel per element/bus
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>>>>
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>>>> (Currently only the first bus with 8 channels are used in Logic;
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>>>> all 7 buses with mono/stereo channels are used in Live 4 and maybe
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>>>> later in others.)
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>>> Thanks for the clarification, I agree with your suggestion.
>
>>>
>
>>>> Additionally the AU checks the AudioChannelsLayout property, as it
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>>>> expects the newer hosts with multibus/multichannel ability will
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>>>> also check this. This is not needed for hosts that don't support
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>>>> more channels then two per bus, as these will never try set more
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>>>> then two channels per bus.
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>>> So you mean that if the host sets bus 1 to 8 outputs and does not
>
>>> specify an AudioChannelsLayout, the AU will know that it's bad old
>
>>> Logic-style. This sounds very reasonable to me as setting 8 outputs
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>>> without setting AudioChannelsLayout is something that "nice" hosts
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>>> shouldn't do from how I understand it.
>
>>
>
>> Yes, exactly.
>
>
>
> Well, except that this is making an assumption that is not always
>
> true.
>
>
>
> For example. Lets say that I have an effect that can be set to any
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> num channels in to out as long as they are the same (this is the
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> default for most effects).
>
>
>
> Now, I have a 6 channel stream.. Somewhere above my effect that
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> stream has some kind of surround/spatial characteristic. But the
>
> effect doesn't know about this - it just takes 6 channels in and
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> outputs 6 channels.
>
>
>
> It does NOT support the AudioChannelLayout property. It doesn't need
>
> to because it is just processing channels with no implications to if
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> of where those channels are spatially.
>
>
>
> Therefore, we've specified that support of the ACL is optional and
>
> should only be supported by those AU's that are doing something based
>
> on spatial locations. So, our MatrixReverb supports this, as when it
>
> generates a 4 or 5 channel output it does so based on the presumed
>
> spatial location of those channels (as described by its ACL).
>
>
>
> I guess you could argue that an AU Instrument is generating audio and
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> typically not processing it, so if it is outputting more than 2
>
> channels it is likely to be doing so with some spatiality assumed.
>
> But I'm loathe to make this a rule...
>
>
It was not meant as the rule, but a "silent agreement" between host
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and plugin devs on solving present multiout instruments problem. I'd
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be happy to drop this way anytime, but it's not possible, unless we
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provide two separate binaries - one for Logic and one for the others -
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which is the worse scenario.
>
>
PM
>
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