iOS direct sound recording to .m4a file (audio/mpeg-4) using TPAACAudioConverter

Question

I work on iOS app with recording feature. I have big problem with straight AAC mpeg4-audio recording in .m4a file.

My working solution is recording in .caf and then converting this file in required .m4a format, but is it slow and not acceptable.

I found the Michael Tyson's wrapper TPAACAudioConverter, which is maybe the right solution, but my problem is, that i don't know how to correct initialize and use this wrapper for direct AAC recording in .m4a file (without the supplementary post-conversion after recording).

If anyone have the working example on Github or can me help with it, please let me know.

Many thanks.

Answer 1

TPAACAudioConverter's not well suited for live recording, just because of the way it's structured, pulling audio from a delegate instead of offering the ability to send audio to it directly.

I recommend using the ExtAudioFile services directly, as it already does the work for you.

If you really have to use TPAACAudioConverter, you'll need to use a ring buffer (like TPCircularBuffer) to store audio until TPAACAudioConverter retrieves it via the delegate method. It's messy though; use ExtAudioFile.

For the record, The Amazing Audio Engine contains a very simple mechanism for recording straight to AAC, or any other supported format. It'll be out soon.