iOS Audio Processing Graph Demonstration

"An audio processing graph is a Core Foundation opaque type, AUGraph, that you use to construct and manage an audio unit processing chain. A graph can leverage the capabilities of multiple audio units and multiple render callback functions, allowing you to create nearly any audio processing solution you can imagine." - From Apple's "Audio Unit Hosting Guide For iOS"

AudioGraph is a superset of Apple's MixerHost application.

Features include:

* Mono and stereo mic/line input
* Audio effects including:
o Ring modulator
o FFT passthrough using Accelerate vDSP framework
o Real-time pitch shifting and detection using STFT
o Simple variable speed delay with using a ring buffer
o Recursive moving average filter with variable number of points
o Convolution example with variable filter cutoff frequency
* Stereo level meter
* Synthesizer example - sine wave with an envelope generator
* iOS 5 features (from Chris Adamson) including:
o MIDI sampler audio unit
o file player audio unit
o audio unit effects
* Runs on iPad, iPhone, and iPod-Touch
* Open source
* Music by Van Lawton
* Everything from MixerHost

Requirements:

* A device that runs iOS 6.x
* Headphones.

Instructions:

Launch the app and press Play.

Source code, documentation, support:

http://zerokidz.com/audiograph

Credits:

This project is derived from work by:

* Chris Adamson
* Stephan M. Bernsee
* Michael Tyson
* Stephen Smith
* Contributors to the Core-Audio mailing list
* Contributors to stack overflow.com
* Apple's iOS developer program,

Thank you.

Tom Zicarelli