Head-Fi.org › Forums › Equipment Forums › Computer Audio › Windows Media changes my music when it plays it
New Posts  All Forums:Forum Nav:

Windows Media changes my music when it plays it

post #1 of 9
11/13/09 at 1:48pm
Thread Starter 
I have a large archive of lossless music on my computer which I very much want to keep in original condition. Therefore I have taken several precautions,

1.) I back up my all my files locally and to an offsite drive
2.) I keep SFV (Simple File Verification) files for my archives to determine if they have changed (e.g. dropped bits) and on which backup they have changed.

The funny thing is, whenever I play an mp3 or wma lossless in Windows Media player, the file changes. The date of last modification changes and the actual bit contents change so that it fails its checksum. I am curious as to why this might be occurring. I imagine there must be some tag in the file, maybe saying something about the last time it was played. This is annoying because if I am constantly listening to my files then I basically can't use SFV to differentiate between a change due to the file being played or a legitimate corruption.

Any ideas?
Reply
post #2 of 9
11/13/09 at 2:25pm
In the options menu, look under the Library tab. There are some settings for downloading missing info from the internet and renaming files. Make sure those are disabled, and see if that helps.
Reply
post #3 of 9
11/13/09 at 2:45pm
Or change your player.
Reply
post #4 of 9
11/13/09 at 2:50pm
I am not familiar with the workings of that media player but it may be updating tags for each play. If it stores playcount, last play date, etc in the metadata that would cause that issue.
Reply
post #5 of 9
11/13/09 at 2:53pm
Did this ever work? Because as you said in your post the last accessed date will be changed by NTFS and there's nothing you can do about it. I don't know anything about SFV but maybe there are options to change what it looks at, or some other programs that are more configurable?
Reply
post #6 of 9
11/13/09 at 3:19pm
Thread Starter 
Quote:
Did this ever work? Because as you said in your post the last accessed date will be changed by NTFS and there's nothing you can do about it. I don't know anything about SFV but maybe there are options to change what it looks at, or some other programs that are more configurable?
I'm sorry, I meant last modification date, not last access date. You can effectively think of SFV as verifying that every bit in the file is the same as it used to be. It doesn't interpret sections of the file as tags versus actual data.
Reply
post #7 of 9
11/13/09 at 4:14pm
I ask because it's something that interests me, I'd thought about the idea before but never bothered looking for programs. I do understand the basic concept of checksums but I don't know whether they typically look at file system info or not versus just file content.

Anyhow that's why I asked whether it ever worked, whether accessing the file by WMP or any other way, even just Windows Explorer. I read more carefully that you're saying the file itself changes in addition to the last modification? Does it happen every time you play a file, over and over, or only the first time?
Reply
post #8 of 9
11/13/09 at 4:23pm
If it is changing information that is not related to the audio content then no big deal.
If for some strange reason it is modifying the actual audio data then that is very bad.
There may be part of the file that is being changed, tag info...etc.
Reply
post #9 of 9
11/13/09 at 10:23pm
Thread Starter 
Quote:
I ask because it's something that interests me, I'd thought about the idea before but never bothered looking for programs.
Yeah, checksums (I use QuickSFV) take all of the bits of information in the file and run it through a calculation to get a representative number such that it would be very unlikely to get that number if some of the bits of information are randomly changed. This becomes very useful for situations where you have a backup of your files and a year later you compare your backup (bit-by-bit) to your originals and they are different. You can run the SFV files on the backup and on the original and see which one corresponds to the original. On my computer, I have separate hard drives for my OS and for my data. My OS drive died recently and for some reason caused collateral damage (data corruption) on my data drive. Using the SFV files were very useful for finding out which files were corrupted and should be restored from the backup.

Everyone who cares about long term archiving of their data (Family photos, music, work) should really do a reality check on their backup system. Many people are oblivious to the concept of bit-rot, the random localized corruption
of data on an otherwise functioning drive. It happens.

Quote:
If it is changing information that is not related to the audio content then no big deal. If for some strange reason it is modifying the actual audio data then that is very bad. There may be part of the file that is being changed, tag info...etc.
For me it is still a big deal because it prevents me from periodically running my SFV files to determine if the audio files became corrupted or if their tags were just changed.
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Computer Audio
Head-Fi.org › Forums › Equipment Forums › Computer Audio › Windows Media changes my music when it plays it