Well, unfortunately, it appears that iDVD doesn’t work quite as I had predicted in a previous entry. Apparently, even though it stores the encoded video between sessions, it still needs the entire uncompressed iMovie project to be able to do anything with the project. I learned this the hard way, after I had deleted some stuff from the iMovie, and found that I could no longer go into iDVD and burn a new disc. So apparently, the encoded data that iDVD stores is only there to speed up subsequent burns, and not for archival purposes. So, this is a bit disappointing, but that’s life (I guess they figure disk space is cheap, so why wouldn’t I want to keep 15+ gigs of uncomressed video around for every tape I shoot).
Basically, what I’m looking to do here, is just archive my DVD image somehow so that I can burn extra copies down the road. Once I’ve edited the video, created the menus etc., I don’t care about making further mods to the project itself, I just want to keep a copy of my work in case a disc goes bad down the road, or whatever. It appears that iDVD isn’t my answer here.
Fortunately, the solution turns out to be much simpler: Once I burn a project to DVD, I can just extract the image from the disc, and re-burn it to a new disc. Apple conveniently provides an article that describes how to do this.
In practice, this seems to work, but the process had a couple hiccups. I tried it out with one of my previously-burned discs. Extracting the data onto the hard drive went without a hitch. Then I went to burn the image onto a new disc. The first attempt failed. I took the disc out of the drive, and it had a physical glitch (appeared to be a speck of something, but I couldn’t wipe it off the disc) right where the burning stopped. On the second try (with a new disc of course), the disc burned successfully, but then it went to verify it (which I’m guessing just does a byte-by-byte comparison of the image on the DVD with the image on the hard disk), and that failed. However, the resulting disc played fine all the way through on the Mac.
My whole recent experience with DVD-R burning leaves me feeling not overly confident about the reliability of the media, but despite the glitches, I seem to end up with playable discs. Not quite sure what to make of it. At any rate, in the future, I think I’ll burn two copies of each iDVD project. One copy can be for archival purposes (to burn more copies down the road), and the other for playing. Alternatively, I could burn one copy and then extract the image, and save the image on my hard disk. Or I could do both (I believe iDVD can create disk images directly, but I haven’t tried it yet). When finished, I’ll delete the iMovie and iDVD projects. And, I’ll be sure to keep the source tapes around.
All in all, it’s great that this technology works as well as it does, but it’s got a bit of evolving to do before I will feel like I can completely trust it!