Automatically detect keyframes in the timeline from runtime AS3

I want to detect when the playhead hits a keyframe without having to put a function call on the keyframe. If it hits multiple keyframes at the same time (ie keyframes on different layers) I’d want to know that too. I’d happily parse some timeline data and find the keyframes myself, but I haven’t been able to find out where this info can be found. Is there a Timeline Class I don’t know of?

I looked into xfl uncompressed format, and I could read the xml format to find the keyframes and where they’re at, but thats a pre or post process, and obviously won’t work with our runtime code. I want to know this inside runtime code from within flash player.

Thanks in advance for any help.