How to make a simple EQ AudioUnit (bass, mid, treble) with iOS?

André picture André · Oct 27, 2010 · Viewed 15.6k times · Source

does anyone know how to make a simple EQ audio unit (3 bands - low, mid, hi) with iOS ? I know how to add an iPod EQ Audio Unit to my AU Graph. But it only give you access to presets and I need proper control of the EQ.

I've looked around for some tutorials or explanations but no luck.

Thanks.

André

Answer

Nik Reiman picture Nik Reiman · Oct 28, 2010

The iPhone doesn't exactly support custom AudioUnits. Or, more precisely, it doesn't allow you to register an AudioUnit's identifier so you could load it in an AUGraph. You can, however, register a render callback, get raw PCM data, and process it accordingly. This is how I've implemented effect processing in the iPhone.