Has anyone had any problems with WMA and WMV files. Some of my files are acting very strange lately. One minute they work fine but the next time I start up the computer some of them don’t work and I get a “file is corrupt” message. The same exact file (a backup copy) in a different directory on the same hard drive may work perfectly even though it’s “newer” so to speak i.e. it’s a copy of the file that is now corrupted.

Also some video files open but they just show a scrambled video of some other file. For instance a few files (all different clips) in the same folder all showed the exact same clip of some concert for a few minutes. This concert is from a completly different file on my computer. It’s like the files have somehow mixed together.

Something similar has actually happened before with some mp3 files. When I opened one file I didn’t get the song I expected but a completely different song and it just starts in the middle of that song. The next files in the directory alphabetically were also screwed up and all played the same wrong song. This goes for a few files in either direction (alphabetically) and then the rest of the files are ok.

Any ideas? This just started recently and it’s drving me insane. Maybe my computer is posessed?

Well they could be possessed by virii or trojan.
Do you have a good anti-virus, anti-spyware and firewall solution in place?

Are you running with multiple processors?

What is your OS, including service pack level, etc?

Are you completely updated with fixes to your OS?

Problems similar to yours on multiple processor machines are not unheard of.

Are the supposedly identical original and copy files in fact identical? This can be verified by tools to test if they have the same checksum value, one way to verify that they are substantially identical.

If you want to get fancy, I have seen programs that to "byte for byte" file comparisons to establish that files are identical. One of these is at http://noclone.net/ and is called "NoClone" from Reasonable Software.

Establishing identity may be important - and I am seeking information from experts here - because I recall reading sometime ago that some media players (and possibly other programs - are capable of modifying files and making them unuseable if the player detects copyright license issues with the file. What I read may have been false, but it also suggested that to prevent this you not only had to change the files to "read only" but you had to make sure the applications accessing the files did not have authority to override the read only permission settings. HUH? Is this possible?

Hi and thanks for the reply.

Yes I have a good solution in place. I'm using Trend Micro which is updated every day.

Hi there.

Thank you guys for all your help. I really appreciate it.

Are you running with multiple processors?

No, not to my knowledge. The computer is fairly simple. Just your standard PC. I’m no expert though, but I don’t think so.

What is your OS, including service pack level, etc?Are you completely updated with fixes to your OS?

I’m using Win2000. I believe all updates are installed. Automatic updates is turned on so I think I have everything I need.

Problems similar to yours on multiple processor machines are not unheard of. Are the supposedly identical original and copy files in fact identical? This can be verified by tools to test if they have the same checksum value, one way to verify that they are substantially identical.

I’m 100% positive. For instance I was watching one file. After watching it I copied it to a back-up location. I opened the back-up and it worked. The next day when I turned the computer back on it didn’t work.

Establishing identity may be important - and I am seeking information from experts here - because I recall reading sometime ago that some media players (and possibly other programs - are capable of modifying files and making them unuseable if the player detects copyright license issues with the file. What I read may have been false, but it also suggested that to prevent this you not only had to change the files to "read only" but you had to make sure the applications accessing the files did not have authority to override the read only permission settings. HUH? Is this possible?

This could be correct. I have to check it out when I get home. Is this something I would simply change in the players settings? When I think about it the WMV files in question are all from protected sources downloaded using the program NetTransport, so this might be the reason. The strange thing is that they work first, then they don’t. Yesterday I took the back-up files (that worked) and copied them back into the original directory over the original files (the ones that DON’T work). I have restarted since then and they work!!?!?!? I’m going to check them out again today when I come home. See what happens when I turn on the computer.

This however does not reffer to the mp3 files I mentioned in my first post i.e. the ones that got screwed up and mixed together. Those weren’t from any protected sources. They were either my own rips or from Kaaza/Lime Wire etc.

Could all of this perhaps be a question of using Win2000. I’ve had some WMV files on my laptop (WinXP) that worked perfectly. When I copied them onto my PC at home the sound worked but the video didn’t. I believe I have all the necessary codecs on both computers.

Thanks again.

Well nice you provided more details. I misinterpreted your original post. (I had a friend whose files were altered due to a virus)

Anyway sounds like DRM (digital rights management) or Apple's fairplay policy at work whether you like it or not. Your experience seems to suggest that this is the case with WMA/WMV files with DRM protection. I.e. not allowed to make copies or copy from one computer to another. (Didn't you read the license agreement?)

DRM can behave erratically on one machine and not the other. Unless you buy them outright, you can only use them for a short time unless you find a way to circumvent the technology (We can't discuss that here!)

As far as the MP3 file sharing (whether it is legal or not), it is possible the files are corrupted or altered by RIAA (antipiracy group). When you use Kazaa or other P2P software, you take that risk not to mention fear of lawsuit and copyright infringement.

Hope that helps.

What Mishcabob says, plus, YES, it could be Windows 2000.

Windows 2000 has done wierd things with media files in the past. In one case, it involved multiprocessor machines running Win2k. There may have been others. My search for more specifics was interrupted by Rita and bill collectors.

Maybe I'll be able to get back to it Thursday, or not, and maybe you will beat me to it.

Thank all you guys so much for your help. I'm going to look into this. Maybe I'll try updating to WinXP

Don't be too surprised if I'm back with a few more questions though

Thanks!

Hello again.

I just noticed something. When the files get corrupted they grow in size. Is this possible. I'm sure I'm not mistaken (let's say 99,9% sure:))

Anyone seen heard of this before?

Thanks

Yes, after a fashion. Its been more years than I want to think that I measured or inspected bad files in any detail. Corrupted would imply that the file has changed in some way, so I reckon it is apt to be either smaller or larger.

If "corruption" were a random, and not a systemic, process then you might expect what the stats refer to as a "normal distribution" or bell curve around the original size. But a systemic process, such as DRM, or maybe even RIAA/MPA bait files, could well increase file size by a variable or constant amount.

Or, the problems - I have still not found a direct reference - where some versions of Win2000 have caused media files to act up, could do the same. (I'll try to get on that today.)

Someone posted a very well described problem in which they were attempting to convert "MJPEG" files to a format that could be played on his camera. They described (I think WinHEX) software that let them read the HEX code of the files, so they could compare the ones that worked with the ones that did not. If you want to get into detail on this, you might check it out. There is a free download, about 1200Kb.

Try Duplicate Finder this is also very good tool to find and eliminate true duplicate files.
Duplicate Finder search duplicates using byte by byte or crc32 to give you most accurate and faster results.

Good interface with lots of features.

http://www.ashisoft.com