Videos Copied to External HDD not playing - truly WTF issue

[IronSkull]

Alright guys, it's time for you to show me how tech-savvy you lot are - this problem has pretty much dumbfounded me.

So here's the deal. A friend's MacBook had a few MKV files on it that I copied onto a hard drive and plugged the hard drive into my TV and played them on the TV. Worked fine. Everything was great. I sourced more MKV files onto the Mac, copied to the HDD and played on the TV. Woo.

NOW.

I used my MacBook the other day. There's an MKV file on my MacBook that I copied into the same hard drive - but when I played the hard drive on the TV, it said that the file cannot be played.

WTF?

So. I played the file on my MacBook from the internal HDD - it worked. I copied the file to the external drive and tried to play it on my MacBook - it didn't work. This is really strange. The same file plays fine when it's stored on my internal hard drive, but as soon as I copy it onto an external drive to play it (on MacBook or on TV) - it doesn't play.

For all of you wondering - I have Paragon NTFS installed on my MacBook as well which lets me read and write files, same as my friend's Mac. What do you think the problem could be GT? What's happening to the file when it's transferred to the hard drive that it's not playing?

[Nashy]

Is it possible that it's a USB bandwidth issue?

[dfuk]

compare hashes for the files, its not unheard of for files to be corrupted when transferring them to external drives, verification is often turned off to make the copy faster.

[IronSkull]

Nashy - how so?

dfuk - Interesting idea. I've seen hashes before, how does one go about checking them out? Also - how would I turn verification on when copying files? Would I need a separate utility? Could you suggest a good free one? :)

EDIT: Figured out how to check hashes. Terminal > MD5. I'll try this out when I have access to my external HDD again. Until then, any good tools that will assist in copy and verify?

BTW - in the event that the hashes are mismatched, what then? Copy the file again? I tried to copy the same file about 2-3 times last night. :(

[IronSkull]

Update: The hashes didn't match. :(

[Torolol]

sign of defective hardware either the USB drive itself or the USB controllers.

[+BudMan MVC]

^ exactly if the hashes are not matching.. Then the file either did not copy correctly, or your having an issue reading the file back. Either way you can not expect the file to play if hashes are not same from the source file.

What is difficult to say is are you having issues reading the file in the first place, or doing the copy to your external.

If you copy the file to another location on your local disk, does this files hash match? What is the size of the file? Your not using a native driver for reading and writing to ntfs - possible its issue with the software and size of file?

Can you not just try a different external drive? that should rule out issue with the current external

[IronSkull]

Budman, I tried using a different external drive - same result.

BUT, problem solved. :) I got a free tool called arRsync, used it to "backup" the file to the external drive - which essentially just meant that the file was copied and verified in the external drive.

It worked like a charm - the file played just fine on the TV and on my MacBook from the externalHDD.

[+BudMan MVC]

That's just a front end gui to rsync ;)

I would still look to see why your normal copy process did not work.

[GameOverRob]

I'm having the exact same issue myself unfortunately for me I didn't notice until the original files had been removed from the mac.

 

Although it could have something to do with the NTFS for Mac OS X program that i'm using; its fully licensed and paid for so not a dodgy copy.

[+BudMan MVC]

Well if you removed the originals your kind of SOL..

[GameOverRob]

Lol, you misunderstand me. I am perfectly aware that unfortunately I am rather unlucky on that part, partly careless by me but I've never once had this issue before now and I move lots of data around on a regular basis. What I was really asking for was how can I ensure that I don't have the issue of the files not working again, as in how can I located the problem component; probably most likely the usb controller or something?

[+BudMan MVC]

It could of been something of a fluke.. It could of been lots of things.. Maybe it was just a bad usb connection?

For starters I would prob use a file system that your OS natively understands vs 3rd party. Mac OS extended or something like that I believe.

I would think your normal file copy process should verify file copy.. If not use rsync to do your copies, or run an md5 check after, etc.