why makemkv cannot ignore read errors, like BluFab?

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kefir
Posts: 4
Joined: Mon Jan 06, 2014 5:46 am

why makemkv cannot ignore read errors, like BluFab?

Post by kefir »

For the most part makemkv works very well for me for me. Once in a while though, I will have a scratched disk and makemkv just stops.
BluFab HD/DVD/Blu-Ray Dectrypter products deal with such disks just fine. They give you a choice to ignore read error and rip as much of the disk as possible. Isn't a partially faulty rip is much better than no rip at all?
Woodstock
Posts: 9912
Joined: Sun Jul 24, 2011 11:21 pm

Re: why makemkv cannot ignore read errors, like BluFab?

Post by Woodstock »

MakeMKV is trying to obtain a bit-for-bit copy of the data on the disk.

If you are not using the Backup function (that is, you've Opened, the disk, and selected tracks to extract into individual MKV files), MakeMKV will save all the tracks that don't have errors.

It will, however, try very hard to read the sections that do have errors, because SOMETIMES, "one more read" gets you past that section. Today I had 3 disks out of 40 that had unreadable sections. Extending MakeMKV's attempts to read to 10 got 2 of the 3 to read, although they took a LONG time to extract the tracks with problems. These were brand new disks, too.
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kefir
Posts: 4
Joined: Mon Jan 06, 2014 5:46 am

Re: why makemkv cannot ignore read errors, like BluFab?

Post by kefir »

Thanks, I will try 10.
I still think though that adding an option just to ignore errors and move on would be great. It seems that makemkv just stops ripping if it encounters an error that it cannot overcome.
Woodstock
Posts: 9912
Joined: Sun Jul 24, 2011 11:21 pm

Re: why makemkv cannot ignore read errors, like BluFab?

Post by Woodstock »

MakeMKV itself doesn't stop trying to rip, it gets stopped by the retries the operating system is doing. If the OS doesn't send data, there's nothing for it to do. Retry count sets how many times MakeMKV will ask the OS to try again, so a bad sector or seek could seem like stoppage. If you watch the read rate, you can see it fall as it's waiting.

I remember when optical media was touted as being SO much better than magnetic... Read errors were going to be a thing of the past... Yeah, right! Optical media was designed for tasks that can tolerate failures, simply by skipping over the bad spot, much like a dusty record player.
MakeMKV Frequently Asked Questions
How to aid in finding the answer to your problem: Activating Debug Logging
kefir
Posts: 4
Joined: Mon Jan 06, 2014 5:46 am

Re: why makemkv cannot ignore read errors, like BluFab?

Post by kefir »

My point was, makemkv does stop when it fails to read, even if there are good sectors on disk later.
Compare it with a BluFab Decrypter, you can tell it up front to ignore all read errors and it will rip as much of the disk as it can, i.e. it will not stop like makemkv does. I am not sure how they do it, but the result is superior. That is a single reason that prevents me from using makemkv in all scenarios.

Optical disks being susceptible to scratching is true. Makes me miss floppies :-)
hosedagainx3
Posts: 4
Joined: Thu Apr 04, 2013 11:26 pm

Re: why makemkv cannot ignore read errors, like BluFab?

Post by hosedagainx3 »

Blu ray disc reads OK till part way through than stops reading, I get the following,
"ERROR OS error this devise does not exist occurred while reading BDMV/STREAM/0080.m2ts at offset 21852585984.....never seen this before...computer freezes, have to reboot
tried 4 times and stops ruffly at the same spot, don't even get a "trying to work around" just the above error.
Disc appears to have no scratches etc, I cleaned it, not new out of the box, used disc
Any help would be appreciated...
alfeberlin
Posts: 2
Joined: Mon Aug 29, 2022 12:39 pm

Re: why makemkv cannot ignore read errors, like BluFab?

Post by alfeberlin »

When I have a scratchy BluRay and try to rip it, I start an encrypted disc backup with makemkv. As soon as the discatt.dat appears, I keep that and abort this backup. Then I create a complete (encrypted) image of the disc. The emerging .iso can be mounted under Linux and the files from there, combined with the discatt.dat can be opened using makemkv. A little complicated workflow but it works.

Since ddrescue will do a lot of retries and can be used across several devices (sometimes one drive can read something another cannot), I often manage to read extremely much of a broken disc, e.g. 99.9%. It takes its time, but that’s okay for rescuing damaged mediums.

But the result is useless unless I really read 100% because makemkv won’t decrypt and convert the 99.9% which are there. One single block which cannot be read will spoil the whole endeavor.

This is not only a bad design choice of makemkv, this is just terrible. I would gladly skip some seconds of a movie or so in order to being able to see the rest.

Please allow skipping of damaged parts of a disk or track.
pipo233
Posts: 39
Joined: Sat Oct 17, 2020 6:14 pm

Re: why makemkv cannot ignore read errors, like BluFab?

Post by pipo233 »

Please allow skipping of damaged parts of a disk or track.
I couldn't agree more, this is a very annoying "feature" of makemkv..

This is asked multiple times on the forum and no solution.
Best would be an option in settings: skip read errors and fill with blank sample.
Another option would be: stop output mkv if read errors are X times, so after x times a read error occurs break.

This way the user has control over the output, at least get a output, albeit with some errors is still better than no output at all. And if the read errors are getting worse the user has the option to break off.

In the current state makemkv decides to break at any read error to ensure a flawless copy, witch is great but can often lead to no output despite only for example 1 read error
nstefanisko
Posts: 1
Joined: Wed May 24, 2023 8:55 pm

Re: why makemkv cannot ignore read errors, like BluFab?

Post by nstefanisko »

If you are not fixated on MKV files and are OK with MP4s, then you can link the MakeMKV libraries into HandBreak. HandBreak does a fairly good job of skipping errors.
Woodstock
Posts: 9912
Joined: Sun Jul 24, 2011 11:21 pm

Re: why makemkv cannot ignore read errors, like BluFab?

Post by Woodstock »

Handbrake will stop when the reading program stops. If MakeMKV is the reading program, it will stop when it hits an error, causing handbrake to stop, too. How is that supposed to help?
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How to aid in finding the answer to your problem: Activating Debug Logging
wilomit
Posts: 1
Joined: Sun Jun 25, 2023 6:16 am

Re: why makemkv cannot ignore read errors, like BluFab?

Post by wilomit »

+1 for having an option to ignore non-critical errors. 99.99% complete but failed due to some last 1 tiny bug seems unreasonable in many cases.
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