Audio/video file formats that support embedded markers and comments/annotations?

I am looking at creating an app for OS X and/or iOS that allows the user to arbitrarily embed markers into the audio at various intervals during the audio recording process. It would be nice to have a single file that could contain this information, but may or may not be efficient or feasible. I suppose it is similar to what YouTube annotations allows.

Requirements:

• Ability to insert markers at certain time points of an audio recording
• Ability to save a name for the marker as well as a brief description

This is for audio created by the app I'm working on, so is not for importing audio from other sources for markup.

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EDIT: Maybe MP4 + XMP?

EDIT2: Has anyone tried using custom XMP fields with Audio or Video on the iOS platform? On the Mac platform? I have downloaded the XMP Toolkit from Adobe (which has an Xcode project) - but it is a touch out of my comfort zone. From a high level it appears pretty straightforward, but anyone with experience with the XMP Toolkit have any thoughts?

As is suggested in an answer below, does anyone have experience with alternative solutions such as QuickTime with chapter markers? Pros and Cons to various approaches?

After thinking about it, it would be nice to do something that supports both audio and video formats, even if initially the current requirement is audio only.

EDIT3 (cleanup): So, just to close the loop here. I ended up digging into the iOS 4.开发者_StackOverflow0 APIs for AVAsset, AVMetadataItem, et al in the AV Foundation Framework. Still have not completed the project, but it appears these APIs will satisfy the requirement without the need for an external library.

have you read up on the CAF format?

basically, it functions as a wrapper for many audio formats, and allows you to embed all sorts of data (as well as user defined data). it may be an option since interchange is not an issue (in your case).

The CAF File Specification

You might consider MPEG-4 or QuickTime formats with a chapter track.