问题
I'd like to record the audio coming from my iPhone app. So after the background music and sound effects are mixed I'd like to sample the audio before it's played from the device's speakers (or headphones).
I've been experimenting with RemoteIO Audio Units. These seem promising. However they're pretty low level. Can AVAudioRecorder (or other "high-level" object) be used to capture audio coming from an iOS device?
回答1:
As far as I can tell, there's no way to do this with AVAudioRecorder. You must use Audio Units.
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来源：https://stackoverflow.com/questions/8101873/can-avaudiorecorder-be-used-to-record-audio-coming-from-your-ios-app