Emmy Huang announced the release of SWF version 9 specs, which includes FLV specs, yesterday.
Changes in the SWF specifications from version 8 are relatively minor compared to contents of the new AS3 actionscripts tag: DoABC. ABC (Actionscript ByteCode) format was made available earlier.
As with SWF 8 specs, you need to agree to the license terms, which mainly prohibits you make use of the information to write your own Flash/SWF player. Also the specs does not include information about AMF3 for FLV files.
Just read through the spec and realized that everything you need really is in the AVM informational document that was released earlier. It’s not very complete is it? I mean, you can’t assemble a Flash 9 SWF from bytecode by hand just by reading that spec.
Even with the “SWF Uncovered: A Simple SWF File Dissected” section?!