Open Radar

 
02-Nov-2009 03:30 PM Thomas Blench:
Summary:

Creating an AudioUnitwith a read-only parameter with the kAudioUnitParameterFlag_MeterReadOnly flag also set results in a meter in the generic view, but it does not respond to having values set.  The meter is always at its minimum value.

Additionally, Apple Audio Units such as AUDynamicsProcessor do not show their meter values either, ie for gain reduction.  These values appear in the custom view but not in the generic view.

This has been confirmed in Logic Express 8 and in AU Lab on Mac OS X 10.6.1 (I have filed this against QuickTime and given the version of OS X as the version number as these seemed to be the closest approximations).

Steps to Reproduce:

1: Create a new AudioUnit using the "Audio Unit Effect" template in XCode
2: Create a read-only parameter which also has the kAudioUnitParameterFlag_MeterReadOnly flag set
3: In the Kernel::Process method, or elsewhere, set the parameter to a value between its minimum and maximum
4: Build and deploy to plug-ins folder.  Observe in AU Lab or Logic Express that the meter in the generic view is not reading the correct value.

OR

1: Observe the meter values of the generic view of an Apple Audio Unit such as AUDynamicsProcessor whilst processing material which should cause the meters to read non-zero values.

Expected Results:

Meters should show expected values.

Actual Results:

Meters do not show expected values (always stuck at 0/minimum value such that meter is not "filled")

Regression:

I believe I saw these meters working fine on 10.5.x but do not have any such machines to verify this.

Notes:

None