How to get file properties from Matroska (MKV) file

I Need some C++ code for example. I can't understand what i need for reading header from MKV.
Could someone help me.
I don't need complex processing of video it's just simple information needed such as video frame dimensions or duration time.

Please don't point me to matrska.org site I saw it.
May be someone can make a wise advise )