HD DVD Discussions Forum? Bitrot & ddrescue?

[clarkjohnken]

Apologies if this should go in... BD forum? Where is the best place for HD DVD questions?

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As many are aware Warner's HD DVDs are notorious for having bitrot. I've just been opening sealed WB discs tonight and finding fingerprints on the unopened discs. I doubt their QC/QA was good anywhere.

So here's my question... I'm on a Mac. Can I use ddrescue to grab two different disc images of the same title and merge them... and then use makemkv on the final merged .iso? Or is the disc itself also protected and this won't work?

Basically I'm following this guide for using ddrescue on the Mac. The question is about how the encryption works and how I might go about merge two partially damaged copies of the same disc where the damage is not on the same spots.

[thetoad]

yes, I use ddrescue all the time for blurays and dvds on linux. For dvds I need to auth the disc on rpc2 drives (lsdvd /dev/dvd does the trick). For blurays don't have to do anything (assuming one has the vuk elsewhere) if not a bus encryption drive or disc. If a bus encryption drive, for blurays I would use makemkv to libredrive it before I read, disabling bus encryption (or using an old non bus encryption drive I have). I'd assume hd-dvd would be relatively simple unless it has some form of bus encryption. If you'd need to auth the disc to the drive, makemkv would probably do that.

also, you don't use ddrescue to grab to disc images. you use it to make a disc image with a map (log) file, and then you use the second disc to fill in the missing pieces into the first image you made.