There is SimpleFlvWriter (for AIR). You may modify it to get a non-AIR version. But memory management will be an issue since BitmapData will take up a lot of memory... It may be possible for a few seconds flv but definite not for several minutes.
Usually we stream things to a Flash server (eg. Flash Media Server, Red5) and let the server create the flv. But you need to find a way to convert the screen captures to NetStream
. Or you may find other server side technology that can create flv from sequence of BitmapData
. But in anyway it will consume a lot of bandwidth.
An alternative I can think of, is to save all the game commands(in XML, or other text format) and send it to the server. And you write a program in server-side to generate the flv from only the game commands. But it will be the most difficult solution to be implemented.