I am trying to do what I naively thought was the simple task of trimming off the front and back of some audio my app records from the mic. Right now I have a PCM audio in a .caf file that I need to trim from some timeindex to some timeindex.
I have discovered ExtAudioFile... methods that seem to do what I want, albeit criptically. There does not seem to be any Obj-C way to do this.
What I intend to do is read the file with ExtAudioFileOpenURL, skip over the first part with ExtAudioFileSeek, and write it with ExtAudioFileWrite which allows writing up to a number of frames.
Will this work? I still haven't solved the problem of converting seconds to frames.