I'm not going to pretend that I'm smart enough to know enough about Meta Data to pretend to know what I'm talking about. (That does actually make sense. Read it again.) I do know, however, that Meta Data includes things like the duration, the width and height, the framerate, and more of the like.
FLVMDI is a command line tool, meaning that in order to use it, you must pass arguments to it. Normally, I just drag the FLV onto FLVMDI, meaning it will use the default settings, and overwrite the file. There are handles, however, that can further enhance how you treat your FLV files.
/x - will create an XML file with all of the metadata of the input file, in case you want to look at itThere are several more, in which case I highly recommend reading the developer's site (link at the bottom of the post). Although FLVMDI is a command line tool, there is also a GUI released for it as well, making it much easier to use the above options.
/e - will write a string as "xtradata" into the FLV file
/v - will only create an XML file, meaning no data will be injected to the FLV
/p - will show the progress
Again, I am no expert at FLVs and Metadata and whatnot, and this post proves it. But what I do know is that when I've had "broken" FLV files in the past, FLVMDI has usually fixed them. The best part about it is that it's tiny at only 240kb (plus 450kb for the GUI), and is portable. Usually I'm afraid of injections, but this is one exception I gladly make.
Visit FLVMDI (Manitu Group) website for download