iPhone Playing a sound clip while recording a video using UIImagePickerController ... possible?

I'm using openAL to pla开发者_JAVA技巧y sounds. I have a view controller that lets users upload a video. I want to give them a 1 minute warning sound so that they know to wrap things up. I tried using a call to SoundEngine_StartEffect(warningSound); but it just doesn't play anything. Is there a work around to this?

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Did you try to set mix with others?

    UInt32 doSetProperty = 1; 
    AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryMixWithOthers, sizeof(UInt32), &doSetProperty);

It is in most cases a "must have", when trying to record and play at the same time.