Re: Device Sync (was Re: Multiple HALAOUs don't get along?)
Re: Device Sync (was Re: Multiple HALAOUs don't get along?)
- Subject: Re: Device Sync (was Re: Multiple HALAOUs don't get along?)
- From: William Stewart <email@hidden>
- Date: Fri, 18 Jun 2004 14:27:29 -0700
On 18/06/2004, at 9:19 AM, Dave Addey wrote:
>
Hi Bill,
>
>
Thanks for clearing that up - and I think I understand the reasons
>
why, too.
>
I'm assuming this would be the same if you used a DefaultOutputUnit for
>
output rather than one of the AUHALs, too.
>
>
Just to be sure I'm getting this right, in my case the source audio
>
data
>
coming into the MatrixMixer would be coming from a file, not from an
>
input
>
AUHAL... it's just that I want *2* output buses on the output of the
>
MatrixMixer, each going to an AUHAL for a different output device. So
>
the
>
two AUHALs aren't connected to each other, just both to the
>
MatrixMixer's
>
two output buses. I think this is still the same limitation?
Yes - as the two different devices (one for each AUHAL) is going to
call out on a separate thread... This could get really knarly if you do
this way as you will at some point have two threads in the MatrixMixer
at the same time. I wouldn't recommend doing that... :-)
Rather I think you'd need to separate the thread that calls your matrix
mixer's outputs - then you'd have to buffer that output for each
device...
Its rather knarly - did I mention WWDC :-)
>
Just a thought, but will the sample code you mentioned be an extension
>
of
>
the MatrixMixerTest project, with (for example) two output buses
>
rather than
>
one? Would be great for me if it is :-)
The Matrix Mixer is fine to have as many output buses as you like - but
all bets are off if you call any of those outputs from a different
thread than another one... (especially if you end up having those two
threads in the matrix at the same time!)
Bill
>
>
Best wishes,
>
>
Dave.
>
>
> From: William Stewart <email@hidden>
>
> Date: Thu, 17 Jun 2004 17:59:00 -0700
>
> To: Dave Addey <email@hidden>
>
> Cc: email@hidden
>
> Subject: Re: Device Sync (was Re: Multiple HALAOUs don't get along?)
>
>
>
> On 17/06/2004, at 12:50 AM, Dave Addey wrote:
>
>
>
>> Hi Bill,
>
>>
>
>> Not sure I'm understanding this correctly, but this has worried me
>
>> slightly
>
>> due to a piece of work I'm about to start...
>
>>
>
>> I'm planning to have a MatrixMixer, with four inputs, and two outputs
>
>> (each
>
>> of which is an AUHAL). Ideally, these two outputs will be separate
>
>> AUHALs
>
>> and will point to different physical devices. The whole thing will
>
>> be
>
>> tied
>
>> together with an AUGraph to manage the connections.
>
>>
>
>> Am I only allowed one AUHAL in my entire graph in this situation? Or
>
>> is it
>
>> only a problem if I'm connecting the AUHAL units to each other
>
>> (which I
>
>> wouldn't be)?
>
>
>
> one per graph... the comments below should also make it clear why you
>
> can't directly connect one AUHAL (on one device) with another AUHAL on
>
> another device.
>
>
>
> What you'd end up having to do is have an AUGraph with all of your
>
> AU's
>
> for output - then at the top, have a callback from your input to the
>
> input matrix mixer that reads from the data you get from the other
>
> AUHAL which is your input...
>
>
>
> We're looking at doing some sample code now that will have this
>
> basically working - don't know how long it will take us to make this
>
> available, but we're prioritising it
>
>
>
> Bill
>
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