Question on DVD obfuscation

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johng
Posts: 74
Joined: Tue Sep 23, 2014 11:49 pm

Re: Question on DVD obfuscation

Post by johng » Fri Oct 12, 2018 3:59 am

OK, so ripping Chappaquiddick was a snap. Loaded disk, started VLC and it always plays Title 55. Start MakeMKV and Open the disc and the edited log is below. Title 55 shows a length of 1:46:29, and only 6 valid titles show in the main window after the disc open is complete. Out of those only 1 has a length of 1:46:29 when I select through them. Ripped that title and did a quick compare using "Jump to Specific Time" and again it's the correct movie.

One question though - In the Title Information screen when I select the correct title what does "Source title ID: 48" mean? Is this a different title than the info VLC shows as Title 55? The log has Title 48 and it has the same 1:46:29 length so it's confusing ...


This is the Title Information when I select the only title with duration 1:46:48 which is what matches the above Title #55 which is what VLC plays.
--------------------------------------------

Title information
Source title ID: 48
Duration: 1:46:29
Chapters count: 17
Size: 5.3 GB
Segment count: 1
Segment map: 2-19
File name: title02.mkv


---------------Start Output From File Open Disc
......skipped beginning stuff as not relevant ...
......
Title #47 was added (19 cell(s), 1:46:48)
CellWalk algorithm failed (structure protection is too tough?), trying CellTrim algorithm
Cells 1-1 were removed from title start
Title #48 was added (18 cell(s), 1:46:29)
CellWalk algorithm failed (structure protection is too tough?), trying CellTrim algorithm
Cells 1-1 were removed from title start
Title #49 was added (18 cell(s), 1:46:29)
CellWalk algorithm failed (structure protection is too tough?), trying CellTrim algorithm
Cells 1-1 were removed from title start
Title #50 was added (18 cell(s), 1:46:29)
Cells 2-4 were skipped due to cell commands (structure protection?)
Title #51 was added (19 cell(s), 1:44:39)
Cells 2-4 were skipped due to cell commands (structure protection?)
Title #52 was added (19 cell(s), 1:44:12)
Cells 2-4 were skipped due to cell commands (structure protection?)
Title #53 was added (19 cell(s), 1:44:09)
CellWalk algorithm failed (structure protection is too tough?), trying CellTrim algorithm
Cells 1-1 were removed from title start
Title #55 was added (18 cell(s), 1:46:29)
CellWalk algorithm failed (structure protection is too tough?), trying CellTrim algorithm
Cells 1-1 were removed from title start
Title #56 was added (18 cell(s), 1:46:29)
Title #57 was added (20 cell(s), 1:49:07)
Title #58 was added (20 cell(s), 1:49:07)
Title 1 in VTS 34 is equal to title 1 and was skipped
Title 1 in VTS 34 is equal to title 1 and was skipped
Title 1 in VTS 34 is equal to title 1 and was skipped
Title 1 in VTS 26 is equal to title 1 and was skipped
Title 1 in VTS 26 is equal to title 1 and was skipped
Title 1 in VTS 26 is equal to title 1 and was skipped
Title 1 in VTS 26 is equal to title 1 and was skipped
Operation successfully completed
-----------------------------End Output from File/OpenDisc----------------------------

johng
Posts: 74
Joined: Tue Sep 23, 2014 11:49 pm

Re: Question on DVD obfuscation

Post by johng » Sat Oct 13, 2018 1:27 am

OK last movie is Wonder which was commented on earlier that it would play different titles when ejected/reinserted. I noticed it jumped between chapters prior to getting to the actual DVD menu where you had to hit play to start the real movie (vs all the previews, warning, logo), but once you did that VLC always picked title 65 for me. Then when I loaded it into MakeMKV it only came up with 2 valid titles, but when I picked the one that matched the length of title 65 and did the "jump to specific time" compare with playing the actual dvd it didn't match (see future post as this was the correct title). Then I went back and ripped the other valid title, and it didn't finish because of scsi errors.
Last edited by johng on Sun Oct 14, 2018 8:04 pm, edited 1 time in total.

johng
Posts: 74
Joined: Tue Sep 23, 2014 11:49 pm

Re: Question on DVD obfuscation

Post by johng » Sat Oct 13, 2018 1:39 am

These are the actual errors from trying to rip title00.mkv from Wonder, so if anyone knows what these mean please let me know.

-------------------------------------------
Saving 1 titles into directory E:/Video/_WONDER_C36B
Error 'Scsi error - MEDIUM ERROR:UNRECOVERED READ ERROR' occurred while reading '/VIDEO_TS/VTS_21_1.VOB' at offset '30431232'
Error 'OS error - STATUS_DEVICE_DATA_ERROR' occurred while reading '\Device\CdRom0' at offset '30431232'
Error 'OS error - STATUS_DEVICE_DATA_ERROR' occurred while reading '\Device\CdRom0' at offset '30431232'
Error 'OS error - STATUS_DEVICE_DATA_ERROR' occurred while reading '\Device\CdRom0' at offset '30431232'
Error 'OS error - STATUS_DEVICE_DATA_ERROR' occurred while reading '\Device\CdRom0' at offset '30431232'
Error 'OS error - STATUS_DEVICE_DATA_ERROR' occurred while reading '\Device\CdRom0' at offset '30431232'
Error 'Scsi error - MEDIUM ERROR:UNRECOVERED READ ERROR' occurred while reading '/VIDEO_TS/VTS_21_1.VOB' at offset '30431232'
Error 'Scsi error - MEDIUM ERROR:UNRECOVERED READ ERROR' occurred while reading '/VIDEO_TS/VTS_21_1.VOB' at offset '30431232'
Error 'Scsi error - MEDIUM ERROR:UNRECOVERED READ ERROR' occurred while reading '/VIDEO_TS/VTS_21_1.VOB' at offset '30431232'
Error 'Scsi error - MEDIUM ERROR:UNRECOVERED READ ERROR' occurred while reading '/VIDEO_TS/VTS_21_1.VOB' at offset '30431232'
Error 'Scsi error - MEDIUM ERROR:UNRECOVERED READ ERROR' occurred while reading '/VIDEO_TS/VTS_21_1.VOB' at offset '30431232'
Error 'Scsi error - MEDIUM ERROR:UNRECOVERED READ ERROR' occurred while reading '/VIDEO_TS/VTS_21_1.VOB' at offset '30431232'
Failed to save title 0 to file E:/Video/_WONDER_C36B/title00.mkv
Encountered 11 errors of type 'Read Error' - see http://www.makemkv.com/errors/dvdread/
0 titles saved, 1 failed

Woodstock
Posts: 5440
Joined: Sun Jul 24, 2011 11:21 pm

Re: Question on DVD obfuscation

Post by Woodstock » Sat Oct 13, 2018 5:15 am

At offset 30431232 in one of the VOB files, the drive found an error. While it was trying to read the bad sector, the operating system timed out, and thought the drive was off-line. When it finally finished trying to read the bad spot, the drive reported more errors for the same spot, until MakeMKV ran out of retries (settable in the Preferences->IO menu).

Usual causes are either a dirty/damaged disk (usually dirty), or a drive that is running out of power (USB-powered drives get this a lot, when they start spinning at full speed).

DVDs rarely get the second kind of failure; dirty disks and a persistent drive BIOS ("I will read this disk!") are more likely.
How to aid in finding the answer to your problem: https://www.makemkv.com/faq/item/8

johng
Posts: 74
Joined: Tue Sep 23, 2014 11:49 pm

Re: Question on DVD obfuscation

Post by johng » Sun Oct 14, 2018 9:21 pm

FYI I edit and made a note in my prior post regarding Wonder. The title I ripped that matched the length of title 65 was the correct one. It turns out that the "jump to specific time" can be an issue when doing the compare. The total length of the movie when I play the disk, and when I play the ripped title is within a few seconds, but the time that shows as the movie progresses is not the same.

I played both the dvd and the ripped title in 2 separate VLC windows and the video is aligned during the whole the movie, but time on the ripped movie gets out of sync within 1 minute. Around the middle of the movie the DVD showed 01:02:48 and the ripped title showed 1:04:14. Then as the movie gets closer to the end the times gradually sync back up. Anyone have any idea why this is happening?

Regardless of that the technique has worked and picked the correct title for all 3 of the obfuscated test disks.

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