you can use git log
with a pathspec:
git log --all -- '*.wmv'
this will get you all commits which make changes to .wmv files. yes, this will descend into subdirectories too (but you have to surround your pathspec with single quotes, so it will be passed as is to git).
if you are only interested in commit hashes (scripting etc.) use the git rev-list
machinery directly:
git rev-list --all -- '*.wmv'
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…