My Blu-Ray Player plays movie fine, MakeMKV = SCSI Errors

[gordonf238]

My Blu-Ray Player plays all of my Blu-Ray discs just fine. No pausing, skipping or any other playback issues.

However, when I try to rip many of my Blu-Ray discs with MakeMKV for OSX, 70% of the discs cannot be ripped due to constant SCSI Errors. NONE of the discs have scratches. If anything, some have only superficial swirl marks.

I've gone through about 5 different Blu-Ray disc players for my iMac, and none seem to alleviate the issue. I've also ensured DASPI is installed. MakeMKV sometimes reads my discs in OS access mode, other times in direct disc mode. Neither mode seems better or worse.

What I've come to realize is that MakeMKV is EXTREMELY sensitive to discs, so that anything but a brand-new Blu-Ray disc is fully readable. Anything with even a microscopic imperfection, and it's SCSI Errors left and right.

If my Blu-Ray Player can read the discs fine, why can't MakeMKV?

The experience is beyond frustrating. I've been donating to this software and always updating it, but after years of use, the experience has not improved one bit.

If anyone has had better experience with a Windows platform, please let me know. I might just consider investing into a cheap Dell laptop with a Bly-Ray player if that improves disc reading rates.

[Woodstock]

A BD player is designed to ignore imperfections. Minor flaws are ignored, because you may not notice. If one frame has a bit of a tear from lack of data, the software can usually hide it by inserting data from the frame before or after. For a single-sector flaw, you MIGHT see a portion of the screen momentarily out of place.

MakeMKV is designed to make bit-perfect copies of the titles you ask it to rip. If the operating system says the disk can't be read at sector XXXXXXX, that is a flaw that makes the copy incomplete. MakeMKV isn't going to try to fill in that flaw with early or late data, like a player might.

If you have tried 5 different drives and MacOS reports that the disk has the same error, why does point at MakeMKV as the source of the problem? Both the disks themselves and the operating system are also common elements. The SCSI error is from MacOS (or Windows, or Linux, they all do it). DASPI does not fix whether or not the disk has a read issue, it simply speeds up the interface a bit.

Do the errors appear at the same offset, regardless of the drive used?

[gordonf238]

Well I blame MakeMKV because it IS at fault here. There are numerous CD-ripping applications that go back a decade, and they employ error-correcting mechanisms to ensure that music gets transcoded even if the disc is less than perfect. CD players use the same technology, and so do Blu-Ray disc players.

You say MakeMKV is designed to read 1s and 0s. I disagree. MakeMKV is a video-ripping software. After all these years, it really ought to have some error-correcting methods to read less-than-perfect discs.

Mind you, I'm not referring to visibly scratched discs. I'm talking about discs where a miniscule swirl is barely visible, yet because MakeMKV fails to read one byte out of trillions, it throws a fit and results in a SCSI error.

It's a poor excuse for software that's been in development for so long, and my disappointment is well justified.

[Lovely Rita]

Nope...
If that's that case (70% of your rips fail due to SCSI errors on OSX, therefore MakeMKV IS the culprit) then shouldn't I also be experiencing the same issues, being on OSX, myself?

[Woodstock]

Every sector on a DVD or BD has a "check code" (usually called a Cyclic Redundancy Check or CRC) to tell you whether the read was "good" or "bad". One bit bad causes the CRC to not match. 2048 bits bad cause the CRC to not match. You cannot tell from "not match" how many bits were bad.

More information on CRCs can be found here: https://en.wikipedia.org/wiki/Cyclic_redundancy_check

"Not match" usually causes the DRIVE to say the read failed. Usually, because there are drives out there that will return data even if the CRCs don't match. That is an entirely different can of worms.

Remember - the SCSI errors COME FROM THE OPERATING SYSTEM, and MakeMKV reports them to you.

By your logic, your Mac itself is the defective part, because MacOS is claiming errors.

Edited to add: It is possible to program the firmware of a drive to ignore CRC errors. This is normally only done in consumer video players; Doing so for drives intended for data usage, like found in computers, would be disasterous.

[gordonf238]

If MakeMKV is having trouble with a lot of my Blu-Ray discs, while my Blu-Ray player isn't, is there a way I can use the HDMI output from my Blu-Ray player to encode the movie?

[Woodstock]

HDMI is a funny thing - it has protocols to identify devices that are allowed to see high definition video. If your encoding device doesn't provide that, your BD player will not give HD video out.

A search for "hdmi video capture" will give you some devices that might work... But, fixing the issue with the disks (or possibly the drive) is less expensive.

[Destry]

I agree the new 1.17 ver of makemkv sucks as it has issues with flawless blue ray disc of mine but seems to do better with DVD disc instead and that sucks so therefore will not buy a license and just find other alternatives