Audio Processing in recorded audio

Question

I am developing an application where i use AVAudioRecorder to record & AVAudioPlayer to play audio files.

But what i want to do is after recording the voice , do some speech processing and make it to cartoon voice & play the audio after that.

So is there any library or framework available by which i will convert my recorded audio to some cartoon voice ?

Answer 1

Dirac2 is one commercial iOS library for independent time pitch stretching, which is the effect that some apps use for the funny voices.

Added later: Apple added the NewTimePitch Audio Unit, now built into iOS, circa 2012.

Answer 2

Use the SoundTouch library as a starting point. ( http://www.surina.net/soundtouch/ ) It's what I'm using in my application, and with the right settings it runs amazing in real time. I would suggest taking a look at Audio Units for at least the playback part. They aren't as hard as people make them seem.