This book has BVH info. You can sign up for a free 10 day trial with no credit card required.

https://learning.oreilly.com/library/view/real-time-3d-character/9780240516646/

"We will look at creating a BVH viewer and applying some sample BVH files to a single mesh character."

@Genesis111 Here are more details about the File format and it includes an example bvh file. Hope this helps. https://research.cs.wisc.edu/graphics/Courses/cs-838-1999/Jeff/BVH.html