Correctable uncorrectable L-EC read errors?

[dbminter]

Got this at the layer change on a Verify of a burn in my LG BD burner.

 

 

W 12:17:21 Failed to Read Sectors 1914032 - 1914063 - Reason: L-EC Uncorrectable Error

 

 

However, the Verify continued on without a problem.

 

 

So, is it possible for "uncorrectable" errors to correct themselves?

 

 

It seems nothing was wrong as I ran a Verify against the image file in a different drive and there was nothing that indicated anything wrong on the Pioneer.  And I played the entire contents, without a problem at the layer change.

 

 

So, it seems everything was all right.  But, if "uncorrectable" errors can correct themselves, why are they called uncorrectable errors?    Is it because a retry was done and the retry itself didn't fail?  Because there were no repeated failures of retries to the point where ImgBurn gives up, it's not considered an "error?"

[LIGHTNING UK!]

The program usually asks the drive to return 32 sectors worth of data at a time - it's quicker. If that request fails, it asks for 1 sector at a time from the same range to try and read as much as possible and find the actual bad sector. It's possible (as is the case here) that the drive manages to read the 'problem' sector(s) when asked to read them again. So think of it as a built in 'retry' mechanism - but it's not a real 'retry' and doesn't get logged as such.

 

I'd still be a little curious as to how well that disc actually burnt though and how readable it is. PIPO scan it if you're so inclined.

[dbminter]

Should I be worried about this being more than a fluke?  I burned another MKM DVD+R DL immediately after the one in question and got no notices at all from the LG.  I did a Verify against the image, and have played the entire movie from beginning to end on a PS3.  The only thing not tested yet is the rest of the 2nd audio stream I'm playing and then the last audio stream of the disc.

 

 

IF I can remember I'll see about getting a PIPO scan for you.  You'll have to interpret it for me as I STILL can't read the damn things! 

[zurst]

If you know which file is affected you can compare hash of both files, the original one in the hard disk and the other one in the disc.That's what I checked additionally with my last burns, related to the problem I'm having with Mediarange BD-R DL. I used 'Hashtools', very nice program.

 

Kind regards

[dbminter]

I could do that, but in this case I don't think it would point out any problem with the actual disc quality.  The files Verify and play fine so it would probably pass a hash comparison as the files are not corrupted.  What might be a problem down the road with PIPO or any other type of jitter may be that the disc fails to read at all sooner than it should.

[dbminter]

I'm running a PI/PIF scan in DVDInfo now.  Now, I don't do these, well, hardly ever.  I can't remember the last time I did one.  And I don't know if it was on a DVD+R DL.  It's been running for about an hour and a half is only 54% done.  It seemed to complete 50% in the first half hour and is now still running.  How long should such a test take on a DVD+R DL?  It's only like 6 GB full, I think.  Is this an indication it's finding a lot of problems because of how long it's taking?  Or is it simply that these tests take a long time to run?

[dbminter]

I think something is wrong with this scan in the Pioneer.  The drive was making a sound while the scan was running.  It then stopped making noise.  The drive light is still solid, but there's no sound coming from the drive.  It's also been stuck at 55% for the past half hour.  Even if the scan IS still running, it will take forever for it complete at this rate.

[dbminter]

I cancelled the scan in the Pioneer and will reattempt it in the LG.  Here's the results that came through, though, from the scan I stopped.

[dbminter]

Ah, and of damn well course, the LG drive isn't supported!    Well, there's nothing else I can do but try the ASUS USB drive, which probably won't be supported, either.

[dbminter]

I can, of course, predict the future in most cases, just as I did with the ASUS drive. 

 

 

So, there's nothing I can do.  The Pioneer scan will probably never complete and will just wear out the drive in the attempt.

[dbminter]

I've decided to run a scan on the 2nd DVD+R DL disc I burned right after this first one I tried testing.  See how that goes.  If it goes at a speed where it will actually COMPLETE I'll see what the results of that are.  That 2nd disc had no returned errors in the burn and verify log.  If they seem to be good, I think, to be on the safe side, I'll try a 2nd burn of this first disc.

[dbminter]

SOMETHING is wrong SOMEWHERE, it seems. 

 

 

Either the LG is not burning quality discs or the Pioneer is not reading them right in the PIPO tests.  Everything goes rapidly until the 2nd layer, it seems, because at 50%, the test rate slows to the point where it probably can NEVER complete.  It's been at 52% for the past 10 minutes.  Since it's not even DONE a full percent in 10 minutes, it will take probably at least 480 minutes for this scan to complete!    And it probably most likely never will complete.

 

 

Attached is the results for the 2nd DVD+R DL that I stopped at somewhere between 52% and 53%, as it never made it to 53%.

 

 

[dbminter]

I think I'll try letting this 2nd DVD+R DL go overnight.  I don't know how long these scans are supposed to take, but if it's not complete after 15 to 20 hours, it probably WON'T get done.  Simple as that.

[dbminter]

Now HOW can this be?!  I started the test again on the 1st DVD+R DL and got a RADICALLY different result! 

 

 

It's not done yet, but at 53%, the PI total is now 75526, nearly 40,000 times the first test!    Quality rating of 1%, where it was 87 before! 

 

 

So, what the Hell am I supposed to believe?  Test one or test two? 

 

 

I've stopped this test and started it again.  If I get the same standard deviation of 40,000, I say screw these tests.  People put TOO much concern into them.  As long as I'm using quality media, which I am, as long as the discs play, as long as the Verify against the source image in a different drive didn't return any issues, I saw screw it!  How can I trust these tests when there's no consistency between them?  And they may never even complete on the 2nd layer! 

[dbminter]

Yeah, 46.87 percent quality this time on the 2nd disc which had a 98 before the first time.  These tests are unreliable, so screw them.

[LIGHTNING UK!]

You do need the right hardware for scanning really. A LiteOn drive is what I use as they're still readily available and I have a fair few of them.

[dbminter]

That would be the only reason for me to get a LiteOn drive.  LiteOn's have a tendency to add random pauses in DVD Video image burns on playback that are not layer breaks.

 

 

In fact, I think the last time I probably did a PIPO scan was back when I still bought LiteOns.  So, it probably was with a LiteOn.

[dbminter]

So, you're saying I can probably ignore these far distant results for these scans because the drive isn't a LiteOn?

[LIGHTNING UK!]

I haven't scanned with anything else for a long time, so I wouldn't know how accurate the results were or how they compare to what a LiteOn would report.

 

So if you don't have a LiteOn to do it with, don't worry about it - especially if they won't even get through a complete scan without getting stuck

[dbminter]

Yeah, I'd say because of the radically different range of results I was getting on the same disc with different scan attempts in the LiteOn coupled with the fact that the scan would probably never complete on the 2nd layer, it's probably safe to say to ignore the results of the Pioneer PIPO scans.

[Outlier]

On 2/9/2017 at 11:21 AM, LIGHTNING UK! said:

The program usually asks the drive to return 32 sectors worth of data at a time - it's quicker. If that request fails, it asks for 1 sector at a time from the same range to try and read as much as possible and find the actual bad sector. It's possible (as is the case here) that the drive manages to read the 'problem' sector(s) when asked to read them again. So think of it as a built in 'retry' mechanism - but it's not a real 'retry' and doesn't get logged as such.

 

I'd still be a little curious as to how well that disc actually burnt though and how readable it is. PIPO scan it if you're so inclined.

I just had a BD-R DL burn without error, but when verifying it showed an error: "Failed to Read Sector 12699456 - Reason: L-EC Uncorrectable Error"  I then clicked to "Retry" and then there were no problems and it says 0 Read Errors (1 Retry). Since it does say 0 Read Errors, can I assume that the disc is fine?

Here are the relevant lines of the log file:

20:03:48 Image File File System(s): ISO9660, Joliet, UDF (2.60)
20:03:48 Read Speed (Data/Audio): MAX / MAX
20:03:49 Read Speed - Effective: 3.3x - 8x
20:03:49 Verifying Session 1 of 1... (1 Track, LBA: 0 - 23331583)
20:03:49 Verifying Track 1 of 1... (MODE1/2048, LBA: 0 - 23331583)
20:03:49 Verifying Layer 0... (LBA: 0 - 12219391)
20:21:49 Verifying Layer 1... (LBA: 12219392 - 23331583)
20:24:00 Failed to Read Sectors 12699456 - 12699487 - Reason: L-EC Uncorrectable Error
20:24:07 Failed to Read Sector 12699456 - Reason: L-EC Uncorrectable Error
20:24:07 Sector 12699456 maps to File: \MyFolder\Subfolder\file.mp4
20:24:25 Retrying (1)...
20:24:27 Verifying Sectors...
21:04:54 Exporting Graph Data...
21:04:54 Graph Data File: C:\Users\Username\AppData\Roaming\ImgBurn\Graph Data Files\PIONEER_BD-RW_BDR-209M_1.54_TUESDAY-OCTOBER-19-2021_7-37_PM_VERBAT-IMf-000_MAX.ibg
21:04:54 Export Successfully Completed!
21:04:54 Operation Successfully Completed! - Duration: 01:01:04
21:04:54 Average Verify Rate: 12,739 KiB/s (2.9x) - Maximum Verify Rate: 34,437 KiB/s (7.8x)

The write speed was set at 8x. Should I re-burn it at 4x just to be certain? Or does that not make a difference since the error occurred during Verification? Is there a way to set the Verify Rate?

[Outlier]

Actually I just tried testing the file in question corresponding to the error.  It's a video file.  When I play it on the disc, the video gets stuck at a certain time point.  Even after ejecting and re-inserting the disc, the video still gets stuck at the same time point.  So even though ImgBurn said there were 0 Read Errors (with 1 retry), there was apparently still an error.  So I'm guessing that the safest way to burn discs is to make sure there are absolutely no hitches during the Verification (no retries, etc.) even if it says that the Verification eventually completed successfully.

I will re-burn the files.  Lightning UK, I have seen you suggest burning DL discs at a write speed of 4x.  Do you suggest this when I try again?  The disc is an M-Disc BD-R DL (50 GB), the label says it's capable of 6x, but ImgBurn apparently believes it to be capable of 8x.

Edited October 20, 2021 by Outlier

[LIGHTNING UK!]

If your drive reports a read error at any point during the verification phase, I'd consider that disc to be a little suspect, even if it eventually managed to read the problem sectors after x retries.

Different drives are more/less capable at reading problem sectors than others, so it may totally fail in another drive or it may not show an error at all. Verification is good for that drive at that moment in time.

I guess it wouldn't hurt to retry the burn at 4x, the drive might do a better job of burning it. Please note that it's not ImgBurn claiming it can be burnt at 8x, it's the firmware in your drive. ImgBurn can't do anything your drive isn't programmed for - that's the purpose of the drive's firmware... to control all of the burn parameters for every different media.

[Outlier]

14 hours ago, LIGHTNING UK! said:

If your drive reports a read error at any point during the verification phase, I'd consider that disc to be a little suspect, even if it eventually managed to read the problem sectors after x retries.

Different drives are more/less capable at reading problem sectors than others, so it may totally fail in another drive or it may not show an error at all. Verification is good for that drive at that moment in time.

I guess it wouldn't hurt to retry the burn at 4x, the drive might do a better job of burning it. Please note that it's not ImgBurn claiming it can be burnt at 8x, it's the firmware in your drive. ImgBurn can't do anything your drive isn't programmed for - that's the purpose of the drive's firmware... to control all of the burn parameters for every different media.

Lightning UK, what is your recommendation for the write speed to burn an M-Disc BD-R TL (100 GB) disc?  4x?  or less than that?  I care more about accuracy than speed, please let me know what you would suggest...

[LIGHTNING UK!]

Did the last paragraph of my reply not cover it?

I don’t know which speeds are available for your drive/media/firmware combo and I don’t know which one will produce the best quality burn. That’s something you’d have to find out for yourself by trial and error.