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Comment by PakG1 | Hacker News Reader

I manage the IT for a school. As we've gone more and more away from DVDs (thanks, Apple), teachers have been asking me to rip their old DVDs. Tried doing that, but a lot of the DVDs did not rip perfectly, so that the ripped video ended up having a lot of corruption. I'm not entirely clear why software could not play the ripped DVDs and just deal with the jitter and corrupted data, but playing from a DVD drive could deal with it. It was weird. Googled a bit, couldn't find much information other than the fact that CDs and DVDs can deteriorate over time.

My question is not necessarily related to OP. But can anyone tell me why my ripped DVDs could not play in DVD software properly when there was jitter or corrupted data, but it could play properly when in the DVD drive? When I got lucky, the ripped DVDs would play fine. Otherwise, it was play fine for a few minutes until it ran into the first bit of corruption. Confused the heck out of me.

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That's generally caused by a combination of a cheap/bad high speed DVD-ROM drive and/or bad ripping software/options settings. What seems to happen is the ripping software is running a marginal drive/dvd at full speed and disabling the drive retry on error. Combined with all the soft ways these drives fail it results in a bad rip.

This used to happen to me a few years ago, and it was overwhelmingly just a sign of a marginal drive. For about 10 years, I was replacing drives about once a year. It doesn't happen as frequently since I started using bluray drives (usually LG) to rip DVDs and a piece of software designed for "piracy".

Anyway, two software things to try, are lower the ripping speed to 1x-2x, and make sure to leave the drive retry on bad sectors enabled. Most decent ripping software will have options to control the error correction/retry logic. The problem is some copy protection schemes leave bad sectors on the disks, and this will hang a lot of the "honest" ripping software that doesn't know how to deal with it.

If the OP has been using a low-quality DVD drive, I recommend using an Apple SuperDrive, since he mentioned Apple.

They may not have all the latest whiz-bang features, but they are rock solid, and are USB powered. I have two at home, and use them to rip DVDs, and have never had a failure in I don't know how many years.

New they run $79 from Apple. Or you can get a used one off shopgoodwill.com usually for around $15.

Problem happened with SuperDrives too though. :(

As I understand it, software playing a ripped DVD doesn't "know" when a data source is a ripped DVD and does not expect any corruption -- it will not seek over or ignore issues like a DVD player connected to a TV will. I've run into this issue a lot, but fortunately MakeMKV, my software of choice, will fail to rip DVDs when it is unable to make a perfect rip. Then, I know there is a problem before I begin ffmpeg compression.

The solution: a wet polisher for DVDs. Luckily, my local used-game shop polishes disks for $3 each. They use an [Elm Eco AutoSmart][1] and it makes the discs like-new. I have never seen a disc it could not fix. You'd have to ask/search around locally to find one near you... I think some libraries have these machines, too, to maintain their DVD collections.

[1]: https://www.elm-usa.com/products/eco-autosmart

If they're not copy-protected, try gddrescue; it logs what it's read, and it can resume. Try another drive if you can. And, I know it sounds odd, you can rub your finger against the side of your nose and then across any scratches on the shiny side.

When I was a kid I used screen capture software to do what handbrake does today. Considering how much lower quality DVD quality is, it should be fine. This is incredibly time consuming though.

That sounds horrible. I'd rather tell everyone that I can't rip their DVDs! :(

Assuming you were ripping to video files, you might have better luck creating a disk image for the DVD, mounting it with something like Daemon Tools, and playing from there.

Tried this, same result.

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