gistfile1.txt

audio session init
audio session active
set audio category
set audio route change notification
prefer_buffer 005

get sample hardware rate 
setup rio for input
setup rio for ouput

render callback kAudioUnitProperty_SetRenderCallback

        outFormat.SetAUCanonical(2, false);
        
        		XThrowIfError(AudioUnitSetProperty(inRemoteIOUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, 0, &outFormat, sizeof(outFormat)), "couldn't set the remote I/O unit's output client format");
		XThrowIfError(AudioUnitSetProperty(inRemoteIOUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, 1, &outFormat, sizeof(outFormat)), "couldn't set the remote I/O unit's input client format");