I am trying to join together several audio files into one mp4/m4a file containing chapter metadata.

I am currently using QTKit to do this but unfortunately when QTKit exports to m4a format the metadata is all stripped out (this has been confirmed as a bug by Apple) see sample code. I think this rules QTKit out for this job, but would be happy to be proven wrong as it is a really neat API for it if it worked.

So, I am looking for a way to concatenate audio files (input format does not really matter as I can do conversion) into an m4a file with chapters metadata.

As an alternative to code, I am open to the idea of using an existing command line tool to accomplish this as long as it is redistributable as part of another application.

Any ideas?

+3  A: 

Audiobook Maker does something like this, and I believe it uses ffmpeg under the hood. It's open source, so maybe its worth a look?

It's using ChapterTool and unfortunately it's still a PPC binary.

Depending on where the bug is, you could try going straight to the QuickTime C APIs to write the movie file. You might also try adding the chapters track using the C APIs.

Any word on when Apple will fix the bug? I am planning to create enhanced podcasts with QTKit, and need this to work.

No word on when the bug will be fixed but please log it in Radar as that will bump it up the priority list.
Dave Verwer
Is it fixed yet?
+1  A: 

I discovered these guys: sensoryresearch who license an API for writing chapter/text/link tracks to MP4s (which is what an M4A is).