I'm using ExtAudioFileWrite to write audio data into a file. But when it is interrupted by an alarm, although the file is saved, I get this error. What kind of error is this?
To decode an error from core audio, search the header files of the framework. In this case, you can look in ExtendedAudioFile.h for -66560, which will lead you to:
kExtAudioFileError_CodecUnavailableInputNotConsumed