I started making backups of my Blu-rays and DVDs a few weeks ago. This was partly to make it easier to view multi-disc sets (a full season of TV shows, for example), but also to see if any of the discs had suffered from rot.
So far, I've backed up over 500 discs using a combination of MakeMKV, AnyDVD, and Linux's "dvdbackup". I've been using 3 drives for this:
- Pioneer BDR-209M (cross-flashed to BDR-211UBK firmware)
LG WH16NS60
LG BU40N (inside an Archgon MD-8107S-U3-UHD)
Usually (but not always), the WH16 is much faster at ripping Blu-rays than the Pioneer, and the Pioneer is much faster at ripping DVDs. The BU40N is consistently the slowest.
Unfortunately, I found that both LG drives will occasionally (but rarely) get in that "confused" mode and start making bad rips until they're powered down. See below.
DVD rips cannot be automatically verified (we need AccurateRip for DVDs)
Unlike Blu-rays, there are no hashes stored on DVDs to use in checking that the files are being correctly ripped. I realized my LG drive was silently providing bad data when I tried to turn a "VIDEO_TS" folder into an ISO and Linux's "genisoimage" reported invalid data in one of the IFO files.
A clean rip should result in all the BUP and IFO files matching exactly. I scripted a check of all the BUP/IFO pairs in my ISOs and found several cases where they didn't match. I then re-ripped those discs on my Pioneer drive and confirmed that the new rip had matching BUP/IFO pairs. (Re-ripping using the LG drives also worked after powering-down and restarting.)
I haven't found a practical way to check the actual video files (VOB) for corruption, so I just have to hope that catching the BUP/IFO mismatches is going to find most or all cases where the drive started silently misreading.
To be sure, I can rip each disc twice using two different drives and compare the results, but that's not practical when you're doing hundreds of discs.
I now do a comparison of all BUP/IFO pairs after every rip as a form of spot-checking. It'd be nice if MakeMKV had something like this built-in.
We need an AccurateRip database for DVDs. There's a thread on DBPowerAmp suggesting the same https://forum.dbpoweramp.com/showthread ... for-DVD-BR thing, but the replies are that it's not necessary. Clearly this is not correct.
LG drives getting confused is a real thing
One of the reasons I found I was getting some bad DVD copies is that MakeMKV started reporting bad M2TS hash values on Blu-ray copies using the WH16. Once it started, it kept doing it with other discs, and this is also when I noticed that the DVD copies I'd made recently with that drive were bad.
Turning off the machine and restarting it made the hash errors go away.
My Pioneer drive hasn't done that once yet.
AnyDVD positives and negatives
I like that AnyDVD can directly create an ISO image of a Blu-ray. It's a two-step process with MakeMKV (make Blu-ray backup with MakeMKV then create an ISO image using ImgBurn). It's weird that MakeMKV creates ISO files for DVD backups but not for Blu-rays.
On the other hand, AnyDVD doesn't report much of anything while it's working, so I don't trust that it's catching errors as well as MakeMKV does. I haven't been able to confirm whether or not it checks M2TS hashes on Blu-rays, but it didn't do it as of a couple of years ago.
Check your old discs
The majority of my discs were fine, but there were a small number that were unreadable even though they looked completely fine. No scratches or dust. When a disc failed to read, I would clean it and try it on a different drive, but some were just unreadable on any drive despite looking perfectly spotless.
This was most common with DVDR's. Adult Swim had this great build-to-order service where you could pick specific episodes of shows you wanted and they'd send you a custom DVD with just those items on it. These discs full of rare shows are all unreadable now.
I hope these notes help someone else out!