My fiance' has several dozen DVD's made by her ex. These consist of compiled video clips. I can get them to play in my DVD player, but when I try to rip them I get:
MakeMKV v1.17.6 darwin(arm64-release) started
Optical drive "DVD+R-DL HL-DT-ST DVDRW GX30N RP09d" opened in OS access mode.
Downloading latest SDF to /Users/Sam/Library/MakeMKV ...
Automatic SDF downloading is disabled or failed.
Using direct disc access mode
Error 'Internal error - Input parameter is incorrect (489)' occurred while reading '/VIDEO_TS/VTS_01_1.VOB' at offset '0'
Error 'Internal error - Input parameter is incorrect (489)' occurred while reading '/VIDEO_TS/VTS_01_1.VOB' at offset '0'
Title #1 in broken titleset was skipped
Failed to open disc
If it wasn't built as a "regular" DVD, it is likely it does not contain normal encryption and other things a standard DVD has.
Have you tried simply copying the VOB files to your drive, and playing them? You may need to rename them to be "useful", as the raw names were not chosen for humans to read.
For what it's worth, this is what the contents of these disks look like when I try to open them on my MacBook Pro with Apple Superdrive:
Each disk itself is labeled "LOGICAL VOLUME IDENTIFIER".
The first tier folder on the disk is "VIDEO_TS". Within that folder, there are several VOB's that show size of about 1Gb, but only VIDEO_TS.VOB (size of a few K) will open although it has nothing to show. The others won't open at all with anything I've got. Not even makevkv will open them. I've tried Handbrake with the extra DVD libraries installed (I think) but no joy. Any help would be appreciated!!!
Can you open the DVD (not a single VIDEO_TS file) directly in VLC or MPC-HC?
If yes make a simple DiscBackup with MakeMKV. Don't open the disc but click on the Backup button in the toolbar. You can then open the created folder in VLC/MPC-HC like you would open the DVD.
If the disc backup doesn't work with MakeMKV you could try dvdbackup. It's only available for linux, but with the Windos Subsystem for Linux (WSL) it's possible to run it on Windows machines (W10 + W11).