Question on DVD obfuscation

[johng]

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]

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.

[johng]

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]

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.

[johng]

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.

[johng]

One last comment on the time alignment issue. I ripped an .avi version of the DVD with DVD Decrypter & AutoGK and played that version next to the .mkv version that MakeMkV made and the time stayed in sync for the entire movie. Based on that the issue must be in the actual authoring of the movie (ie. the VTS.ifo / VTS.vob files) since that is common between both rips.

With movies like that it makes doing the compare a bit trickier, and you may want to jump by chapter and then from there jump by time a few more minutes. Then repeat to the next chapter, etc. That way you should stay close to in sync video wise (even though the relative time may vary by a minute or so) with the DVD you are comparing to.

Anyways hopefully this will be useful going forward.

[Mysus456]

I have summarized below my thoughts on the Lionsgate Obfuscation protection mechanism, but posted the full detail in the Ken Burns: The Vietnam War post, if there is any confusion: https://www.makemkv.com/forum/viewtopic ... 698#p67698


I don't know the release dates between my title and Wonder, but my experience with Juliet, Dead is perhaps there are multiple valid titles with the same initial playback duration to make the process more time consuming? Either way, here is the list and the Title played by VLC for first and second runs.