A while ago, I tried running DVD Rebuilder on my Mac (in a Windows XP partition using VM Ware Fusion) but gave up in frustration. The main problem seemed to be that Rebuilder couldn't recognize my ripped files or ISO images as UDF format. As I thought about it, I realized that a problem like that could trace to the fact that I was running Win XP in a partition on my main Mac hard drive. Further, this partition had been set up back in '09 as only 32 gb in FAT32, meaning that I had to use a shared folder in one of my Mac partitions just to find the room for BluRay-size files.

I decided that to give Rebuilder a fair chance, I had to run it under conditions as close as possible to a reasonably modern actual Windows PC.

Luckily I have a Quad-core Xeon Mac Pro with 4 hard drive bays, so I rearranged things to dedicate one 500 gb drive entirely to my Win XP installation under Boot Camp. This allowed me to format this drive in NTFS. That meant that this drive would be read-only from the Mac OS, but I think that NTFS (and having tons of free space) was the answer.

I did a clean Boot Camp and Win XP installation on this disk, then installed BD Rebuilder, VERY carefully following the instructions in milOtis how-to guide on installing all the other necessary supporting apps.

I then ripped several of my BluRays to the new hard drive using AnyDVD HD and, sure enough, Rebuilder worked like a charm, making both full-disk backups compressed for a BD 25 and creating a feature-only backup. This also worked whether I was running Windows in Boot Camp mode (where you actually shut down the mac and re-boot the whole computer in Windows) or under VM Ware Fusion (where you run Windows in a Virtual PC under the Mac OS.)

Interestingly, I also was able to make everything work without the extra fuss of creating and mounting a lot of disk images, which some Rebuilder users have found necessary. My workflow was simply: a) Rip the original BluRay to the hard drive as files using AnyDVD b) Run BD Rebuilder on the BDMV folder just created and save the output as files. (Be sure to use a different folder for Rebuilder's work and output files, or you risk a crash when it tries to save its new output to the folder containing the original rip. c) check the main stream file with VLC to make sure you've got good sound, the subtitle files you want, etc. d) When you're sure that file is good, burn the backup using ImgBurn. I do all my backups as BDR 25s (why compress all the way down to 9 gb just to save 75 cents?.) However, I can't imagine why this wouldn't work just as well for compressing to DVD sizes.