Detect if a file is a file that it says it is

[Champak]

Is there a way to see if a file is the type of file it claims to be? Ex. when you try to play an mp3 file in wmp or some other media players, if it isn't really an mp3 file it will tell you that it isn't. Is it possible to detect if something is an mp3 file with autoit without looking at the extension?

[smashly]

Hi,

The only thing i can think of is reading the header of the file.

But to do that you'd need a library of magic numbers/headers to compare against..

Cheers

[water]

Maybe this could be a good place to start collecting information: "... Forensic applications need to identify file types by content"

[ResNullius]

Depending on how many file types you need to identify, this tool http://mark0.net/soft-trid-e.html might be useful. Command line version is suitable for scripting, and there is also a GUI version.

Edit: Spelingg

Edited September 30, 2009 by ResNullius

[Champak]

Thanks, I'll take a look at TrID as soon as I get a chance. Any idea how fast it is...split second, or it takes a bit to analyze? Need to know if it will be a waste with 1000+ files at once.

[Before]

Why don't you just read the first characters of the file?

An mp3 file usualy starts with the characters ID3, and thats the only thing (most) forensic applications check.

[Champak]

Thanks for letting me know that. If that is the case, then it wouldn't work anyway. What I was trying to do is detect "corrupted" mp3 files. I figured that for whatever reason a corrupted mp3 wouldn't show up as an mp3 file....since media players are crapping out or telling me that the files are not mp3s. The ID3 is there regardless of if the file is "corrupted" or not. So I guess I have to figure a different way to do this.