Background Music & SFX on iPhone

I'm so glad that many people are sharing their findings and how they are getting things done in iPhone:

First of all, there is a super-convenient set of classes in the cocos2d package that can be used for playing background music and sound FX. The only thing I have to figure out is how I can tweak these guys to stop iPod music in case the user explicitly wants to enable in-game sound. But that's probably a piece of cake, too!

The next help comes from Tinker Blog which lists suitable file formats and conversion commands. Essentially, iPhone allows you to play one compressed file (like MP3) and several uncompressed files in parallel. Since there's only a single hardware decoder for compressed files available, not more than a single compressed file can play at the same time, though. The idea is to take your most expoensive sound and use it as an MP3 within your application (eg background music) and convert the smaller sounds (typically sound effects) to a format like "IMA4" packed inside of a "CAF" file.