MP3 File Recovery?

[patrickd]

Is there any software that will successfully recover deleted (i.e., trash can emptied)MP3's? The downloaded shareware utilities I've tried "recover" files, but the recovered files are all intermingled - a few seconds of one song, a few seconds of another, etc.
Pat Dennis
patrickd@prime-vision.com

[jelloman]

Patrickd, I don't know that there is a good way to do this. To understand what i'm about to say you need to have a basic understanding of how hard drives work...(simplified greatly of course)

a harddrive is basically a set of rotating disks (stacked pancake style) and a head that reads the disk. When you save a file to your harddrive, The file is placed at some arbitrary physical location on the drive, and then the system keeps a record of exactly where that file and other files are located so you can retrieve them in the future. This record is called the File Allocation Table (or FAT). To explain further, imagine a string of characters "ABCDEF" and a separate record that says "file 1 is characters 1-3 and file 2 is characters 4-6"... so file 1 would be "ABC" and file two would be "DEF"

when you delete a file (by emptying your recycle bin), your computer doesn't actually erase that file off your drive, it just deletes the record for that file. Instead of saying "this location on the drive is reserved for whatever.mp3" it now just says that it is free space. This means the data for your mp3 is still there, but nothing is pointing to it. The problem is that now any program can write over that space, or a part of it anyway, since it has been marked as free space. once that happens, nothing can be done to retrieve that whole file.

So the point is that any file recovery utility will only work if no other program has written over the actual place the file was saved. your best bet is to try to download or create the mp3 (or mp3s) again

More of an explanation than you bargained for huh? well i was bored so i thought i would go haywire on ya http://forums.winamp.com/ubb/smile.gif

[patrickd]

Hi Jelloman -
Thanks for the response. The problem is this: I deleted (recycle -> empty recycle bin) an entire folder of MP3's. I immediately realized what I had done, then turned off the computer and rebooted with that drive disabled to insure that no data was overwritten. I have since downloaded a variety of recovery utilities (Recover98, Recover-4-All, Lost & Found), and all share the same characteristic: they easily identify the deleted files, but on attempted restoration, the "restored" files turn out to be intermingled. Each restored song consists of 1-10 second fragments of many songs, seemingly strung together at random. One of the tech support people said that the commonly used file reconstruction algorithms fail on MP3's & suggested manually piecing them together block-by-block on a hex-editor. It would a whole lot quicker to download again (except Metallica, of course!)
Pat Dennis
patrickd@prime-vision.com


<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by jelloman:
Patrickd, I don't know that there is a good way to do this. To understand what i'm about to say you need to have a basic understanding of how hard drives work...(simplified greatly of course)

a harddrive is basically a set of rotating disks (stacked pancake style) and a head that reads the disk. When you save a file to your harddrive, The file is placed at some arbitrary physical location on the drive, and then the system keeps a record of exactly where that file and other files are located so you can retrieve them in the future. This record is called the File Allocation Table (or FAT). To explain further, imagine a string of characters "ABCDEF" and a separate record that says "file 1 is characters 1-3 and file 2 is characters 4-6"... so file 1 would be "ABC" and file two would be "DEF"

when you delete a file (by emptying your recycle bin), your computer doesn't actually erase that file off your drive, it just deletes the record for that file. Instead of saying "this location on the drive is reserved for whatever.mp3" it now just says that it is free space. This means the data for your mp3 is still there, but nothing is pointing to it. The problem is that now any program can write over that space, or a part of it anyway, since it has been marked as free space. once that happens, nothing can be done to retrieve that whole file.

So the point is that any file recovery utility will only work if no other program has written over the actual place the file was saved. your best bet is to try to download or create the mp3 (or mp3s) again

More of an explanation than you bargained for huh? well i was bored so i thought i would go haywire on ya http://forums.winamp.com/ubb/smile.gif<HR></BLOCKQUOTE>

[jelloman]

sorry i gave that description at a thrid grade reading level, seems you know what you are doing so probably knew all of what i told you. http://forums.winamp.com/ubb/smile.gif (of course many don't) well, i'm no expert with file recovery utilities so don't know what to tell ya beyond that.

one detail i left out in the previous description (to keep things simple) is that files are most often not saved in one continuous piece so a file's data might be cut up in several sections and spread out over the surface of the HD, and that could cause the problem with reconstructing the mp3s (you probably knew that too though http://forums.winamp.com/ubb/smile.gif)

[just a guy]

okay I have your answare right here but it's way to late for it since you have to do it before you actually delete the file. First I'd like to thank jelloman for that description I'm new to the home computer game and I need all the info I can get. okay on to the answare theres a program called goback by wildfire that won't let your computer forget where the info is untill maybe a couple of days later all you have to do is go into goback and go to "recover a deleted file" and it's been a life saver for me. It will also revert your harddrive to a previous time/date incase you say catch a virus you just "go back" to when you didn't have it and it's all gone. The only way I know about this is because it was already on my new gateway (lucky me) but heres the good news...if you can scurry out and find the may issue of "maximum PC" they have it on there demo disk I don't know whats all included in this version but it's the same size as the one on my computer so your guess is as good as mine. I didn't try it out because I'd have to uninstall the version I have now and I wasn't about to do that. If you can't find that mag I believe office max has it for like $40. well I thought I'd just throw my two cents in later...

[dad]

Me too! I very much enjoyed and appreciated the Hard Drive description provided by the jelloman. Well done. By the way, could you try explaining how these "plug-ins" work next? Thanks! http://forums.winamp.com/ubb/smile.gif

[jelloman]

well that's a much more technical issue. check the winamp developers page (http://www.winamp.com/nsdn/index.jhtml) for an in depth explanation.

In basic terms, a plugin is just a module that can be added to a program to give it new functionality. An analogy would be a vacuum cleaner. In most cases a vacuum has a long hose with no termination at the end. Well it would be crazy to try to vacuum your whole floor with just that hose. So this hose has a way to attach a "module" onto the end of it. Vacuums usually come with a set of these attachments so you can use the vacuum cleaner in hard to reach places, hard floors, carpet, etc., thus adding new functionality to the vacuum. Modularity is the name of the game.

well whoever writes the program (in this case Nullsoft) develops a way to attach different modules to the main program. this can be compared to the attachment at the end of the vacuum hose. The program itself could be compared to the actual vacuum body, and plugins can be compared to all the different vacuum heads you can attach.

That's pretty much it and all seems pretty straightforward to me.