To add to Terje's answer, in order for your disc to be playable in as many players as possible with as few problems as possible the disc must be finalized. Once this is done there is no more available space, no matter how little of the disc the material uses.

thanks- it just seems a shame- I've just done a dvd of interviews with school kids and one question that comes up from parents is if they could add their own material to the end of it- sort of like having an autograph page at the end of a yearbook.

I guess the solution is simply to burn a new disc with the other material added, but it would be nice to partition a dvd to have the ability to record additional stuff- I guess as you point out, that 'stuff' could mess with players if not formated.

To be honest, what they want wouldn't be practical even if a DVD didn't have to be finalized to be played or if it were possible to "un-finalize" a disc to add more data. A video DVD has a specific structure, including a file that tells the player what's on the disc, what to play first, what to do after that, etc. Anything "tacked on" after that structure has been prepared is essentially a non-entity. Your DVD structure wouldn't know that their material exists let alone would it have any instructions on how to handle it.

Bottom line is that their material would have to be incorporated into yours (meaning, someone would have to go through the authoring process again) in order for a player to take notice of it. And I doubt many of the parents you're dealing with would be up to that task unless they're all familiar with DVD authoring software.

Rob

Please bear in mind that I have no idea about the nature of your project or those involved, but that said, sounds like the makings of a great, creative, community project to me, or even a commercial venture if that's the direction you wanted to take.

Whether you used the web, or loaned out a cheap camera or 3, you could weave the results into something both interesting & rewarding.

For this sort of thing to work IMHO those involved do need your skills - both for the practical aspects as Rob pointed out, and to act as director/editor putting everything together... as the saying goes: "too many cooks..."

Thanks for the input- I can see the need for protecting whatever code the DVD needs to be played across various formats.

I still think it is an interesting concept which would fulfil a need in this and probably many other applications (e.g wedding videos, graduations, sports team videos etc.), where people have additional media that they want to add. In this particular case, the day after getting a hundred copies duplicated, a parent walks up to me and says "Have you got room to throw in some animation projects the kids did?"

I know there are mini-DV discs that I use that are recordable on both sides- one side can be finalized while the other can still be recorded on- I just haven't seen anything like that in a standard DVD.