audio - How to develop an iphone app with reverb functionality?

Question

I am developing an iPhone application (like Audio Processing). I have to give some effect to the audios. If it is desktop app, many options are there. We can get good examples and full project like audacity. But I want to develop for iPhone.

I got an app with reverb option; (take a look at following link). Just I watch the "video", I did not test this application in my iPhone device.
http://www.appstorehq.com/reverb-iphone-89870/app

My question is; How can I develop the app with reverb functionality ? Is there any documentation for that ? If it is, just share with us.

NOTE: We can use AudioUnit to develop the app with reverb functionality (I am not clear with this.).

EDIT: I don't like to use any third party library.

If anybody having knowledge about this, please share with us.

Thanks.

Answer 1

if yourre targeting ios5 you can just the audio unit subtype kAudioUnitSubType_Reverb2 of the effect audio unit.

reverb unit

AudioComponentDescription auEffectUnitDescription;
    auEffectUnitDescription.componentType = kAudioUnitType_Effect;
    auEffectUnitDescription.componentSubType = kAudioUnitSubType_Reverb2;
    auEffectUnitDescription.componentManufacturer = kAudioUnitManufacturer_Apple;

AUGraphAddNode(
                              processingGraph,
                              &auEffectUnitDescription,
                              &auEffectNode), 

Failing that you could just write your own reverb code in the remoteio callback. A simple delay might be easier to do and would sound similar.