问题
I know that a subset of Core Audio is available in the iPhone OS, but I don't know how much of all the effects / filters is available. If it is available, I would like to get some directions on how to apply some simple effects over an audio unit (delay, echo etc...).
回答1:
There are a couple of things you can do on the iPhone WRT to audio.
The first is OpenAL, a cross-platform audio manipulation library that is supported on the iPhone. You can find a FAQ for it here: https://web.archive.org/web/20100725234354/https://developer.apple.com/iphone/library/technotes/tn2008/tn2199.html
Next you can use one of the services available to you on the iPhone as part of the Core Audio subset. You can get a list of the services available to both iPhone and Mac OS X Core Audio developers here: Core Audio Services
From what I can tell, it doesn't look like there are any canned audio effects. So where you have pre-defined transitions available for you in Core Animation, I don't think you have higher level effects available to you out of the box in iPhone's CA. That said, OpenAL is cross-platform and you should be able to find plenty of sample effects that are part of the OpenAL 1.1 SDK or as part of other public contributions.
回答2:
the effects aren't included, you will have to write your own. you can use the iPod eq but that is about it. some of the converters are available, although the float to int ones arent.
来源：https://stackoverflow.com/questions/742706/can-i-use-core-audio-effects-on-the-iphone