Re: Multi-input bus (sidechain) configuration
Re: Multi-input bus (sidechain) configuration
- Subject: Re: Multi-input bus (sidechain) configuration
- From: Steve Baker <email@hidden>
- Date: Mon, 03 Nov 2008 14:15:02 +0000
Thanks Brian. AUBase turned out to be good advice for this.
Steve.
Brian Willoughby wrote:
Steve,
The standing advice from this list, if I recall, is that you must
derive from AUBase to do what you want.
That said, AUEffectBase implements some very useful things which
nearly everyone needs, and it's quite a pain to implement them every
time you use AUBase. It would be great if Apple split AUEffectBase
into two, perhaps with AUEffectNxNBase and AUEffectMxNBase as
appropriate. Most of AUEffectBase is very specific to effects which
have the same number of busses on input and output, with
correspondingly-matching channel counts.
I suggest you look closely at AUBase, and start by deriving from
that. If you're successful, you might try learning how to achieve the
same results with AUEffectBase, but you might have to hack things too
much.
Brian Willoughby
Sound Consulting
On Oct 21, 2008, at 12:33, steve wrote:
I'm trying to create a AU plug-in with a fixed configuration of 2x
stereo bus inputs, and 1x stereo bus output by modifying the
FilterDemo example plugin from the SDK (derived from AUEffectBase),
with the following modifications:
1. I've added creation of an additional input bus in the constructor
thus:
AUBase::CreateElements();
SetBusCount(kAudioUnitScope_Input, 2);
2. I've overridden SupportedNumChannels to return a single { 4, 2 }
pair.
3. I've overridden Initialize() so it doesn't simply try to match the
above pair to the Input(0) and Output(0) channel counts.
I'm clearly missing something fundamental though - though the buses
seem to be correctly reported with sensible audio stream formats,
auval fails with the following output:
VERIFYING DEFAULT SCOPE FORMATS:
Input Scope Bus Configuration:
Default Bus Count:2
Format Bus 0: AudioStreamBasicDescription: 2 ch, 44100 Hz, 'lpcm'
(0x00000029) 32-bit little-endian float, deinterleaved
Format Bus 1: AudioStreamBasicDescription: 2 ch, 44100 Hz, 'lpcm'
(0x00000029) 32-bit little-endian float, deinterleaved
Output Scope Bus Configuration:
Default Bus Count:1
Default Format: AudioStreamBasicDescription: 2 ch, 44100 Hz,
'lpcm' (0x00000029) 32-bit little-endian float, deinterleaved
ERROR: Default Format of unit does not match reported Channel
handling capabilities
* * FAIL
Can anyone give me any pointers in the direction of my (I suspect)
obvious error?
Thanks,
Steve.
--
=============================================================
Steve Baker
FXpansion Audio UK Ltd
http://www.fxpansion.com
Registered address: 5 Underwood Street, London N1 7LY, UK
Registered in England: 4455834
=============================================================
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