Blender supposedly supports import of the Biovision Hierarchy Animation files (.bvh) which contains bipedal models and can further work with them and save in the default .blend 3D data format. You can get and download Blender for free for both Windows and OS X.
Convert Biovision Hierarchy Animation file to Blender 3D data file.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert bvh to blend on Windows
A very popular free program used for work with 3D graphics
Convert from bvh file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.