iOS AudioUnit Control - kAudioUnitSubType_Delay

Question

I can setup real time playback and have the delay unit putting in between Remote IO Unit to set up a delay effect.

 AudioComponentDescription delayDesc;
 delayDesc.componentType = kAudioUnitType_Effect;
 delayDesc.componentSubType = kAudioUnitSubType_Delay;
 delayDesc.componentManufacturer = kAudioUnitManufacturer_Apple;

However, I could not find any parameters to set and control the effect of the Delay Unit. Audio Unit Parameters Reference

I want to have the delay effect tuneable. For example, I want to delay time and fraction to be changed to see the difference. Any Hints?

Answer 1

check AudioUnitParameters.h

// Parameters for the AUDelay unit
enum {
        // Global, EqPow Crossfade, 0->100, 50
    kDelayParam_WetDryMix               = 0,

        // Global, Secs, 0->2, 1
    kDelayParam_DelayTime               = 1,

        // Global, Percent, -100->100, 50
    kDelayParam_Feedback                = 2,

        // Global, Hz, 10->(SampleRate/2), 15000
    kDelayParam_LopassCutoff            = 3
};

working example: http://idev.by/ios/23137/

Answer 2

Hold cmd button and click on kAudioUnitSubType_Delay . You will see the following:

@constant       kAudioUnitSubType_Delay                 
                    - desktop only
                A delay audio unit

It seems it is of mac os only, not iOS