Added encoding and copyright

[RichardLitt]

Also added TLEN alias to duration (see https://en.wikipedia.org/wiki/ID3).

[RichardLitt]

Hmm: reading the README, TLEN doesn't mean duration. Any idea how to get the duration in seconds from TLEN?

The other lines should stay, but I will have to edit this. Not RFM!

[leetreveil]

I would never use TLEN to fetch the duration of an mp3 file.

Use:

mm(fs.createReadStream('sample.mp3'), { duration: true }, function (err, metadata) {});

Instead.

[RichardLitt]

Fixed.