Computer vision has come a long way and motion capture is getting cheaper everyday. With that in mind our in-house solution for motion capture retargetting addon Simple Retarget Tool for Blender is now free and open source under GPL3 licence.
It can be downloaded from GitHub.
https://github.com/cgvirus/Simple-Retarget-Tool-Blender
A tutorial walk through can be found here in YouTube in our official channel CGVIRUS.