How do you guys make it to know which encoder and version was used to create a mp3 file?

I mean how to know a file is a "LAME 3.90 320 kbps" or a "LAME 3.98.2 256 kbps"?

I would like to know how you guys look for it.

Thanks

There are a couple of things you can use. I have dBpowerAMP and it integrates itself with Windows Explorer. All I have to do is hover my mouse over any audio file and dBpowerAMP will display the bitrate, encoding setting, encoder version, format, artist, genre, etc. for that file. foobar2000 can even display file information but you have to look at the files' properties through foobar2000. iTunes can also identify the version of Lame, Nero, iTunes/QuickTime that a file was encoded with.

There are plenty of options but I believe dBpowerAMP is the only one that can integrate with Windows Explorer.

I just look at all tags information.
I have a panel for this on foobar.
Right now I'm playing a track, with a tag called "Tool",
and the value 'Lame3.97".
Off course these tags can be fake, but there's no reason for someone to change them.

Mr. Questionman http://www.burrrn.net/?page_id=5 can also show you useful information, like average bitrate, used encoder and settings, etc.

Another one to show such information is Audiodata

Just out of curiousity if you were to burn the file from the CD to say FLAC, then go from FLAC to wav then mp3, that would remove all tags right. Not that there's any reason to do that, but I was just thinking

Well, for starters CD has no tags. But assuming that your ripper adds tags to the FLAC files, the remaining steps depend on what does each conversion. dBpoweramp, for example, will preserve tags going fron FLAC to wav and wav to mp3.

As said above, there are many ways. For your question, one way is Audioshell. This program integrates itself into explorer so you just hover over the file or right click and hit properties. Small size and free too.

http://www.softpointer.com/AudioShell.htm

EncSpot

Thanks for your answers!

To answer the original question, the way these programs identify the encoder of an MP3 is by reading a metadata tag which actually has the encoder info in it. The tag is the LAME tag, and it's an extension of the Xing VBR tag. I believe it's usually near the beginning of the MP3. If the tag isn't there, then the program can only make an educated guess about the encoder.