I'm progressively downloading a video from a server using URLStream and FileStream classes to download and save the data to disk. While this is happening, I would also like to begin playback of the video so the user can progressively watch while this is happening. The player uses a standard FLVPlayback (version 2.5) control to load and playback videos. Unfortuantely, FileStream creates a read & write lock on the file and nobody has thus no one else can have access to it. This is a little bezarre to me because a read lock on a download is counter-intuitive, especailly for my application. I looked around the API docs but I could not find an option where I can manually set the locking mechanism on a file. Is this at all possible in Adobe AIR?