MP3 to OGG Converter, Plugin, Command Line to be used with Unity

Good morning,

I am looking for an easy to use Converter, Plugin, Command Line or library, etc (for commercial purposes) to convert mp3 to ogg (since www class in unity supports ogg only) , so the user can choose an mp3 file to play, then the converter converts it to ogg and then unity plays it. Answers supported with examples, tutorials and detailed explanation are highly preferred.

Thanks.

If you're not limited to the WebPlayer and can use external DLL's I'd recommend using FMOD for this.