Corrupt IFO File Help?

[AleranChampion]

I recently converted a number of folders I'd copied from dvds into mkvs, and while I didn't have problems with most, one of them gave me a message like this:

MakeMKV v1.9.10 win(x64-release) started
Opening files on harddrive at C:/Users/Nathan Allen/Desktop/VSL15/VIDEO_TS
Calculated BUP offset for VTS #1 does not match one in IFO header.
IFO file for VTS #1 is corrupt, VOB file must be scanned. This may take very long time, please be patient.
Title #1 has length of 21 seconds which is less than minimum title length of 120 seconds and was therefore skipped
Title #3 was added (1 cell(s), 0:14:02)
Title #4 was added (1 cell(s), 0:03:25)
Title #5 was added (1 cell(s), 0:17:05)
Title #6 was added (1 cell(s), 0:05:49)
Title #7 was added (1 cell(s), 0:02:47)
Operation successfully completed

Needless to say, none of the files were what I was looking for. I remember the dvd playing fine, so could the problem possibly be the aforementioned IFO file? How can I fix this?

[Woodstock]

It is possible that the IFO is an issue, but... I get errors like that on several known-good disks, because they were authored in weird ways. It forces MakeMKV to scan the disk, which can take a while if you're not working from an ISO on a hard drive.

It is possible that your disk requires opening in "manual" mode.

I'd follow the FAQ linked in my signature and send the requested information to support@makemkv.com, so that Mike can take a look at it.

[AleranChampion]

It is possible that the IFO is an issue, but... I get errors like that on several known-good disks, because they were authored in weird ways. It forces MakeMKV to scan the disk, which can take a while if you're not working from an ISO on a hard drive.

It is possible that your disk requires opening in "manual" mode.

I'd follow the FAQ linked in my signature and send the requested information to support@makemkv.com, so that Mike can take a look at it.

Thank you for the advice. Quick question for the less-knowledgeable: How might I go about opening it in "manual mode" to extract the movie?

[Woodstock]

/manualdvd/ describes the "how", but really doesn't describe how to chose what to put in the command box.

Starting from version 1.9.0 MakeMKV can open a DVD disc in a so-called manual mode. The bad part about this mode is that its usage requires advanced knowledge about DVD authoring. The good part is that in this mode user has precise control over DVD layout interpretation. Any part of the disc can be assigned to any title in any order. Any title can be forced to be non-fake, titles can be split by cell (or chapter) boundaries, in any order.

The first step would be to make sure debug logging is turned on, so that you can get as detailed information as you can about the disk structure. The log will say what titles it is skipping and for what reasons.

From there, the "secret" is to try different things.

[AleranChampion]

Managed to open it in manual mode, but there's a new problem: I tried opening the skipped portion, only to get this in my log:

MakeMKV v1.9.10 win(x64-release) started
Debug logging enabled, log will be saved as C:\Users\Nathan Allen/MakeMKV_log.txt
Using direct disc access mode
IFO file for VTS #1 is corrupt, VOB file must be scanned. This may take very long time, please be patient.
Open DVD manually : "2"
DEBUG: Code 257420 at ']&-u`AZ2oOZ%`5bF@:213135895
DEBUG: Code 0 at ']&-u`AZ2oOZ%`5bF@:29405292
DEBUG: Code 0 at ']&-u`AZ2oOZ%`5bF@:29406833
Title #2 (0:43:32) was skipped due to navigation error
Failed to open disc

So it (apparently) can find the file, but it won't open it, for whatever reason.
Is there a way to get past this, or should I wait for an update to hopefully fix this?

[Woodstock]

Navigation errors, to my knowledge, are where the data returned from the disk points to places where the next portion of the data is not found, so things get lost.

One possible cause Mike has mentioned for this is drives that do not give error messages if they can "almost" read the disk; instead, they will return a "mostly correct" data packet. MakeMKV reports this as corrupted data (it doesn't make sense), and tries to work around it if it can. If it can work around them, it continues on - otherwise it tries different work-arounds until it runs out of things to try.

If cleaning the disk did not help, this one will have to wait until Mike can review the information. It's beyond what I can help with.