Program to analyse MKV-files

Is there anyone familiair with good software where you can analyse MKV-files? Cause I’ve got a question:
how is it possible that one mkv-file (res 1280x720) is 232mb and another mkv file with the same resolution almost 600mb?
I’ve got wondershare uniconverter but I can’t compress that much.

The achievable compression is dependent on a number of factors:

  1. the used video codec (the older, the less efficient)
  2. the chosen upper limit of bandwidth/quality for the encode
  3. the content of the video picture itself, its amount and speed of movement
  4. the quality of the source material (lots of film grain need a lot of bandwidth)
  5. the speed at which the video was encoded (no joke. lower speed = better quality or lower file size)

I recommend you to have these items in your toolbox:

Look at Why Snow and Confetti Ruin YouTube Video Quality - YouTube for a pretty good illustration of points 3 and 4.