I was wondering how do you inject metadata into an f4v file with quepoints? I've been reading somewhere that it's either during encoding or a custom actionscript that embeds when the file runs.
An F4V file is merely a renamed MP4 file. By and large, any tools, tips and technologies that work on MP4 file will do so for F4V files.
Seeking into MP4 files is non-trivial, and much more difficult than FLV files, which I assume you are thinking about. (But maybe I am wrong?)
That said, the meta data you are after is probably already in the MP4 in the MOOV atom. (MP4 files are composed of atoms. The MOOV atom is the meta data atom.) There probably is no need to inject it. But, to get quick starts and have a player be able to seek through out a file, then you need to have the MOOV 'atom' at the front of the file. There are tools to do this on existing files, and it can be done when encoding the file.
I've never heard of AS doing any of this.