Sometimes cannot open titles from backups?

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Caleb87
Posts: 7
Joined: Tue Jan 30, 2024 12:57 am

Sometimes cannot open titles from backups?

Post by Caleb87 » Thu Mar 21, 2024 6:13 pm

I typically backup the entire disc, and then open the files with makemkv to pull the title out.

Some movies will open the titles direct from the optical disc drive, but when I open the titles from the backup files, it fails to open. I have done disc backups from makemkv, and I have also just used file browser to copy disc and paste onto my hard drive. It doesn't seem to matter.

When I open the files to get titles, I go to Movie>BDMV>index.bdmv which typically works. I have copied the discs twice without errors, and they won't open with this method (says "disc failed to open" and generates a report), but when I open it direct from the optical drive, it opens it.

Anyone know why some movies won't open from the backup?

dcoke22
Posts: 3106
Joined: Wed Jul 22, 2020 11:25 pm

Re: Sometimes cannot open titles from backups?

Post by dcoke22 » Fri Mar 22, 2024 2:53 am

Are you making a decrypted backup with MakeMKV? Does this happen with DVDs, blu-rays, or 4K UHDs?

Caleb87
Posts: 7
Joined: Tue Jan 30, 2024 12:57 am

Re: Sometimes cannot open titles from backups?

Post by Caleb87 » Fri Mar 22, 2024 4:31 pm

Blurays and 4k UHD. It works on some movies, and other movies it doesn't.

I am making an encrypted backup I believe.
Backup method 1: using the "Backup" button on makemkv (don't believe this decrypts anything?)
Backup method 2: using File Explorer to just copy the disc to my computer

Both methods work on both blurays and 4ks to later use "Open Files" to view titles and export the mkv. Both methods also fail to later use "Open Files".

It was 90% success rate, but lately it's been like 25% success. It is movie specific where certain movies won't work. I've copied the disc multiple times with both methods to ensure it wasn't a backup issue.

dcoke22
Posts: 3106
Joined: Wed Jul 22, 2020 11:25 pm

Re: Sometimes cannot open titles from backups?

Post by dcoke22 » Fri Mar 22, 2024 4:53 pm

In MakeMKV when you go through the backup process, there's a checkbox for making a decrypted backup.

Can you copy & paste in the complete log file of a failed attempt, perhaps both from a regular blu-ray and a 4K UHD?

4K UHDs require a decryption key to be available for MakeMKV to download in order for MakeMKV to be able to create .mkv files. It is possible some of the errors on 4K UHDs are related to a key not being available.

Regular blu-rays, however, should just work, no downloaded keys needed. When MakeMKV creates the backup I would expect it work. If you use File Explorer to make the backup, then it may or may not work. When you make a backup, are you copying to local storage?

Caleb87
Posts: 7
Joined: Tue Jan 30, 2024 12:57 am

Re: Sometimes cannot open titles from backups?

Post by Caleb87 » Mon Mar 25, 2024 4:48 pm

The decrypted backup was unchecked. Is that why? I was doing some of them with makemkvcon terminal and I didn't see a flag for decrypting it (obviously it's there, I'll re-read docs).

So if I make a backup that's still encrypted, makemkv cannot open it in the future? Do you know if there's any other way to decrypt once it's already backed up?

I prefer using the linux cp command to get the disc as makemkv throws errors and fails more often. I have about 2000 blurays I'm digitizing, so I'm trying to streamline the process. I've made a few shell scripts, and so far I've found it easiest to do a disc copy (slow from reading optical), and then extract the movie title once it's on an NVME drive as it takes 15-60 seconds. I'll probably have to go back to makemkvcon for disc backups if I can't decrypt them :(

Thanks for your help!

dcoke22
Posts: 3106
Joined: Wed Jul 22, 2020 11:25 pm

Re: Sometimes cannot open titles from backups?

Post by dcoke22 » Mon Mar 25, 2024 5:23 pm

Strictly speaking, you don't have to make a decrypted backup. When you open the backup in MakeMKV later, the decryption can happen then. However, for 4K UHDs, a hashed key downloaded from a server on the internet is required to decrypt the disc or backup.

If a key isn't available either because a key isn't available or because MakeMKV is having difficulty reaching the server hosting keys, there will be details to that effect in the log.

My usual workflow is to make a decrypted backup of a disc, then process that backup with MakeMKV. The upside of making a decrypted backup is I can get access to the .m2ts files of a blu-ray or UHD to verify a title is what I think it is before I create .mkv files.

One of the things MakeMKV does when making a backup or .mkv files of a blu-ray or UHD is verify the data against the content hash tables stored on the disc. When reading from an optical disc, this is a good way to verify that the drive is correctly reading the disc. If the drive can't get a good read of the data, MakeMKV will output an error and not write out that title.
If you use the file browser to copy the contents of an optical disc to the filesystem, this checking won't be done and the drive might incorrectly read some of the data. Then, when MakeMKV attempts to make a .mkv file from the file browser copied data it'll detect the error via content hash table checking and refuse to create your .mkv file.

In my view, the best strategy is to use MakeMKV to make decrypted backups of discs, then process those backups. If the backup fails because the optical drive can't correctly read the disc, you can deal with that failure by cleaning the disc, trying the disc in a different optical drive (which works more often than you might think), or replacing the disc. If the backup of a UHD fails because there isn't yet a hashed key for that title, you can submit the generated dump file, set the disc aside, and try again in a week or two; or make an encrypted backup (which does the content hash table checking), let the backup sit on your storage and try to open that backup occasionally to see if a hashed key has been made available.

MakeMKV can work with more than one optical drive at the same time. In the GUI, in preferences you can set the preference 'ask for single drive mode' which 'locks' an instance of MakeMKV to a single optical drive when you start an instance of MakeMKV. With this, you can use more than one optical drive and multiple instances of MakeMKV to create more than one backup at the same time. This way you can do the slow part in parallel.

Caleb87
Posts: 7
Joined: Tue Jan 30, 2024 12:57 am

Re: Sometimes cannot open titles from backups?

Post by Caleb87 » Mon Mar 25, 2024 8:04 pm

Thanks for all your help. I was researching more as well and came to the same conclusion. I have a machine with 6 drives, but upgrading to 12 drives so I really like the CLI with automation. I'll go back to using makemkvcon. I also found the --decrypt flag in the docs here: https://www.makemkv.com/developers/usage.txt

I included my basic shell script to backup bulk movies if anyone stumbles upon this and wants it. I have to manually match the drive to the makemkv disc, because I couldn't figure out how to efficiently pull the movie title using makemkvcon. I'll try to remember to update this when I enhance it. I'm going to have it check if anything failed and warn me. I create a movieName.finished so I can more easily see it's done rather than checking a log.txt file or something.


Code: Select all

#!/bin/bash
echo "Processing"
#makemkvcon -r --cache=1 info disc:9999
echo "
do drives match?
0=sr3
1=sr2
2=sr5
3=sr1
4=sr4
5=sr0"

# SR3 is disc:0
title=$(blkid -o value -s LABEL /dev/sr3)
if [[ -z "$title" ]]; then
        echo "COULD NOT FETCH TITLE"
else 
        nohup makemkvcon --robot --noscan --decrypt --cache=1024 backup disc:0 ~/Videos/backup/${title} > "${title}.log" && touch "${title}.finished" &
        echo 'continue'
fi

# SR2 is disc:1
title=$(blkid -o value -s LABEL /dev/sr1)
if [[ -z "$title" ]]; then
        echo "COULD NOT FETCH TITLE"
else 
        nohup makemkvcon --robot --noscan --decrypt --cache=1024 backup disc:1 ~/Videos/backup/${title} > "${title}.log" && touch "${title}.finished" &
        echo 'continue'
fi

# SR5 is disc:2
title=$(blkid -o value -s LABEL /dev/sr2)
if [[ -z "$title" ]]; then
        echo "COULD NOT FETCH TITLE"
else 
        nohup makemkvcon --robot --noscan --decrypt --cache=1024 backup disc:2 ~/Videos/backup/${title} > "${title}.log" && touch "${title}.finished" &
        echo 'continue'
fi

# SR1 is disc:3
title=$(blkid -o value -s LABEL /dev/sr3)
if [[ -z "$title" ]]; then
        echo "COULD NOT FETCH TITLE"
else 
        nohup makemkvcon --robot --noscan --decrypt --cache=1024 backup disc:3 ~/Videos/backup/${title} > "${title}.log" && touch "${title}.finished" &
        echo 'continue'
fi

# SR4 is disc:4
title=$(blkid -o value -s LABEL /dev/sr4)
if [[ -z "$title" ]]; then
        echo "COULD NOT FETCH TITLE"
else 
        nohup makemkvcon --robot --noscan --decrypt --cache=1024 backup disc:4 ~/Videos/backup/${title} > "${title}.log" && touch "${title}.finished" &
        echo 'continue'
fi

# SR0 is disc:5
title=$(blkid -o value -s LABEL /dev/sr5)
if [[ -z "$title" ]]; then
        echo "COULD NOT FETCH TITLE"
else 
        nohup makemkvcon --robot --noscan --decrypt --cache=1024 backup disc:5 ~/Videos/backup/${title} > "${title}.log" && touch "${title}.finished" &
        echo 'continue'
fi





Faber
Posts: 24
Joined: Thu Oct 04, 2018 3:57 pm

Re: Sometimes cannot open titles from backups?

Post by Faber » Mon Apr 15, 2024 6:43 pm

Caleb87 wrote:
Mon Mar 25, 2024 8:04 pm
Thanks for all your help. I was researching more as well and came to the same conclusion. I have a machine with 6 drives, but upgrading to 12 drives so I really like the CLI with automation.
Just out of curiosity, how many of those 12 drives will be external?

Caleb87
Posts: 7
Joined: Tue Jan 30, 2024 12:57 am

Re: Sometimes cannot open titles from backups?

Post by Caleb87 » Mon Apr 15, 2024 6:58 pm

All 12 are internal, but I have another machine I had 4 externals working on too. I've bought a lot of movies, so well worth it to get project done in timely manner.

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