Using 'ddrescue' with MakeMKV to process defective DVDs

[seamus]

I'm finding more DVDs in my collection that are un-readable... un-readable not only by MakeMKV, but also un-readable even in my "TV-connected DVD player". Searching for a solution has turned up a GNU package called 'ddrescue'. I've used 'ddrescue' to create an ISO file of a DVD, and it seems the "defects" are minimal.

Q: Can I use MakeMKV to create an mkv file I can play/stream using (for example) VLC?

[BDR_UD03]

https://www.reddit.com/r/HDDVD/comments ... _a_visual/

That post has some info. In short, it might be able to let you stream the ISO to VLC. If you find another source, it might let you repair the damaged areas by merging the 2 together.

Your other option, very unlikely though, is to use Par2 files if you know someone that has the same disc and is willing to generate one for you.

More info here:

https://www.reddit.com/r/DataHoarder/co ... _use_par2/

https://en.wikipedia.org/wiki/Parchive

[seamus]

It seems it can! Use the 'File' menu to open the ISO file (created via GNU's 'ddrescue' utility), and process it "as usual" using MakeMKV.

A few notes to summarize my experience using 'ddrescue' with MakeMKV:

1. It's not clear to me exactly what causes a DVD to malfunction such that MakeMKV will not read it.

2. HOWEVER: If the errors on the DVD are "minimal", 'ddrescue' can create an ISO file that MakeMKV will read, process and yield output that can be played just fine using VLC, Jellyfin, etc.

3. For some DVDs with substantial errors/flaws in the media, 'ddrescue' may be incapable of producing a useful ISO file. For example, one of my failed DVDs (a fairly recent new purchase!) apparently had many errors that led to 'ddrescue' "re-tries" that went on for over 24 hours with insubstantial progress.

4. In brief summary, 'ddrescue' can be quite useful toward the objective of salvaging DVDs that MakeMKV is incapable of processing on its own. GNU maintains a summary web page on 'ddrescue'. There are numerous options available in the 'ddrescue' documentation, but the documentation is not always as clear as it could be.

A closing comment:
In a perfect world, we wouldn't need software that does what MakeMKV does! But it seems the content producers are not satisfied at virtually unlimited wealth. To create still more wealth, they "bribe" elected officials to extend copyright protection to (effectively) infinity, and they additionally proselytize governments to turn over taxpayer-provided funds to "recover"/"restore" old movies with no loss of extended copyright protection. Perhaps the content-producers' most egregious offense was making it a "Federal Crime" to remove copy protection from their work. As far as our entertainment is concerned, we live in a world that is quite a long way from "perfect".

I would encourage anyone who reads this "voice in the wilderness" to communicate their feelings to their elected government representatives; let them know that we are sick and tired of being harassed by laws which were created to serve a very rich and powerful minority.

[kaysee]

You should use multiple optical drives at the various ddrescue phases, certainly before the time-consuming scrape and retry phases.

[seamus]

You should use multiple optical drives at the various ddrescue phases, certainly before the time-consuming scrape and retry phases.

Sorry, but I'm not following your suggestion... I've got 2 drives, but it completely escapes me as to how I'd use them both to recover an ISO file from a "failing DVD". Perhaps you would care to elaborate?

[kaysee]

Do the various ddrescue phases, one at a time, alternating between drives. Whatever is skipped by the first drive can be attempted by the second drive, which may be able to read problematic areas better. That is better than just using a single drive and having it get bogged down on difficult areas that the other drive might be able to handle better.

[seamus]

Do the various ddrescue phases, one at a time, alternating between drives. Whatever is skipped by the first drive can be attempted by the second drive, which may be able to read problematic areas better. That is better than just using a single drive and having it get bogged down on difficult areas that the other drive might be able to handle better.

AH! OK - that makes sense as (I assume) the database built by 'ddrescue' can "follow" from one drive to the other.

[kaysee]

The ddrescue map file allows you to interrupt the operation and resume it some other time -- with a different disc (same pressing, different copy), different computer, different optical drive, etc. Also, you can resume and tweak the operation if you decide to reverse direction, or change which phase you want the utility to run in from then on.

[seamus]

The ddrescue map file allows you to interrupt the operation and resume it some other time -- with a different disc (same pressing, different copy), different computer, different optical drive, etc. Also, you can resume and tweak the operation if you decide to reverse direction, or change which phase you want the utility to run in from then on.

That's all very helpful - thanks... You should write this up as a detailed "HOW-TO"! I know I'd find it useful, and I'm sure others would also.

[kaysee]

This is in the manual for ddrescue, although the manual does have problems with vagueness in the early sections describing what exactly happens in the various phases. Check the sections about optical disc recovery, and some of the examples involving multiple discs and multiple drives.

I do recommend backing up your rescue image and map file after lengthy operations before starting a new phase, since a mistake may mean you end up with bad data introduced to your image and you lose track of what is good and what is bad. Also, beware of LG's jamless playback. For LG drives, only desktop-sized units with ASUS firmware should be used with error-prone discs.

[seamus]

This is in the manual for ddrescue, although the manual does have problems with vagueness in the early sections describing what exactly happens in the various phases. Check the sections about optical disc recovery, and some of the examples involving multiple discs and multiple drives.

I do recommend backing up your rescue image and map file after lengthy operations before starting a new phase, since a mistake may mean you end up with bad data introduced to your image and you lose track of what is good and what is bad. Also, beware of LG's jamless playback. For LG drives, only desktop-sized units with ASUS firmware should be used with error-prone discs.

I didn't find the man page particularly helpful. Most helpful would be (IMHO) a full example - I'll leave that for you to consider.

And thanks for the tip on LG drives... mine are ASUS and BUFFALO. I can't think of a thing to say about either of them that's negative. I did try one of the Pioneer drives before they disappeared, but was not happy & returned it.