How exactly is ENCODER in itunes figured out?

I have some music for encoder it says UNKNOWN while all my LAME rips it list the Lame Version, is it in the Encoder setting?

Also In winamp, foobar, media monkey you can edit the field unlike itunes, so you could technically change the encoder used? since thats within the IDvtags?

iTunes uses Quicktime AAC encoder..Right-click a file within iTunes and 'Get Info', it'll show the encoder used..You can't " change the encoder used within the IDvtags"...For that you need to access the app/tool used and configure the encoder's settings..

There are encoder tags within ID3v2 that can be changed like every other tag (maybe not in iTunes). Lame writes it's version into the Xing/Lame header. Of course that could also be altered but not with common players/masstaggers.
If there's no encoder specified it's a guessing game. Tools like Encspot or Audio Identifier can do that.

what about foobar, foobar lets you change the encoders used

So when ITUNES shows encoder used thats not an ID3 tag?

Yes and no.
foobar lets you edit ID3 tags ...[ Properties > Metadata tab ],
but not encoder info found in the Xing/Lame header ...[ Properties > Properties tab ]

ok so there are two seperate things ENCODER METAdata (which will in availabilty differ based on program used)


and an actual ENCODER USE, which is something else?