Re: Problem with AUParameterSet

Subject: Re: Problem with AUParameterSet
From: William Stewart <email@hidden>
Date: Fri, 16 Feb 2007 11:49:22 -0800

On 15/02/2007, at 3:41 PM, Eric Johnson wrote:

On Feb 15, 2007, at 2:12 PM, William Stewart wrote:

Why are you doing this on the AU side? You shouldn't need to as long as your view is listening to the parameter changes messages.

Hi Bill,
We call AUParamSet from the process component to set & notify all listeners about the parameter change (this a a VU meter change).

You could use the mechanism we do for this. We flag parameters as read only, and add the following flag:

kAudioUnitParameterFlag_MeterReadOnly = (1L << 15),

Then the UI establishes a read-only meter timing task for this parameter, and just polls the parameter value at the frequency which it will draw the meter (say 30 times a sec).

Bill

This part is done on the view side (Only once, to set up the listener):
// Setting up the listener
OSStatus osResults = ::AUListenerCreate(SysListenerProc, this, NULL, NULL, 0, &mParameterListenerRef);
osResults = ::AUListenerAddParameter(mParameterListenerRef, NULL, &mCAAUParameter);

This part is done on the process component side whenever a parameter changes:
// Sending the parameter change notifications
AUParameterSet(NULL, NULL, &parameterDetails, currFloatValue, 0);

mailto:email@hidden

tel: +1 408 974 4056

__________________________________________________________________________

"Much human ingenuity has gone into finding the ultimate Before.

The current state of knowledge can be summarized thus:

In the beginning, there was nothing, which exploded" - Terry Pratchett

__________________________________________________________________________

 _______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:

This email sent to email@hidden

Follow-Ups:
- Re: Problem with AUParameterSet
  - From: Eric Johnson <email@hidden>

References:
	>Problem with AUParameterSet (From: Eric Johnson <email@hidden>)
	>Re: Problem with AUParameterSet (From: William Stewart <email@hidden>)
	>Re: Problem with AUParameterSet (From: Eric Johnson <email@hidden>)

Prev by Date: Re: AU parameter names and units
Next by Date: Re: AU parameter names and units
Previous by thread: Re: Problem with AUParameterSet
Next by thread: Re: Problem with AUParameterSet
Index(es):
- Date
- Thread