Hi,i am starting a little game project and y have the next problem.

I want to use motion capture animations that i have in .bvh files, and i have the next problems trying to adapt the skeleton to my mesh.

I created my human mesh with makehuman, when the mesh and the .bvh file are imported into blender the first problem are the dimensions of the skeleton but if i rescale the skeleton the animation changes.

The second problem is that the position of the bones doesn´t match exactly to the mesh and if i try to move the position of the bones then the animation has many bugs.

another thing that i don´t understand is that if click on an icon with a human skeleton that are near the armature name the position of the skeleton changes to he one in image 2

Well to start off, there should be a parent null controlling the entire skeleton. If you want to move the entire skeleton, simply grab this null and position it where you want it. You could possibly try scaling the parent null as well, to see if it scales all the bones correctly, but you may still get a wonky animation. You could always try selecting the bones and changing their bone size parameter, although I don't know if this can be done in Blender, I know it can be done in XSI.

As for the change in position, that is most likely your parent null.