Useless Feature Request: Disc Test

[ndjamena]

I'd almost finished ripping my complete Blu Ray box set of Star Trek TOS but the 5th disc of the third set refused to read and upon closer inspection I noticed a rather prominent scratch on the surface. I had to take the entire box set back to the store to be replaced. Now I'm stuck with a completely new box set, since I only need to rip that one disc it leaves the question of whether all the other discs in the set are OK. What I'm going to do is activate the *TESTDUMP* feature and try ripping each and every disc using a basic profile, but I figure it might be an idea to add a disc integrity check option to MakeMKV so we can tell if our discs are OK or not without making a file on the hard drive. It would be useful in my current situation, but it would also be useful in checking the contents of all the sections on our discs that we don't plan on ripping for the moment (like the special features on all my Doctor Who DVDs). I'd settle for *TESTDISC* if that's all the program could manage.

(Woh, in searching through all the options checking to see if this capability exists already I've discovered I can stream a Blu Ray directly to my WDTV Live SMP! I wish I could find a good use for that.)

[mike admin]

It is already there. Blu-ray discs do contain verification hashes for 99.9% of M2TS files - this is part of AACS protection. MakeMKV checks these hashes during full disc backup and will tell you if any M2TS file is corrupted or not. Currently MakeMKV is not checking the hashes during regular conversion to MKV, but this functionality is long on the to-do list. So, making a backup would validate hashes for all M2TS files.

If you do want to run just a full disc integrity check without saving the backup, you can use the "NULL folder" hack. Make a backup as usual, but when selecting destination folder, name it "C:/tmp/NULL/anything" on windows or "/tmp/NULL/anything" on linux/osx. The portion before "anything" is vital, and must be entered exactly - including the case and forward slashes.
MakeMKV will pretend that it writes to that folder, but in reality it will discard the output data.

[ndjamena]

http://www.makemkv.com/forum2/viewtopic ... ULL#p27193

I guess I can be excused for not finding the only mention of this feature.

Thank you.

[ndjamena]

Um, the feature seems to be broken.

I copy/pasted C:/tmp/NULL/anything into the backup directory field and began a backup but it created a folder on my SSD called "C:/tmp/NULL/anything" and began filling it with files before I cancelled it. I also copy/pasted the directory C:/tmp/NULL/ from the other thread and it did the same thing.

-Edit- Oh, never mind, it works in MKV mode.

-Edit 2- Oh, I guess I need it working in backup mode to test the disc fully.

[mike admin]

It surely works in backup mode. Can you double-check?

[ndjamena]

Nope, I've set my default destination to C:/tmp/NULL/ in preferences, it works fine for MKV mode but not for backup mode.


I'm not sure which is better, backup mode will read through the entire disc without doubling up on re-edits/angles, but MKVMode actually de-muxes the files which would detect any actual data errors.