Renaming files according to the folder they're in

Save this as a batch file in the root of your tree:

@echo off
for /r /d %%x in (*) do (
 pushd "%%x"
 echo %%x
 for /F "delims=" %%i in ("%%x") do (
  ren *.mkv "%%~ni.mkv" 2> NUL
  ren *.avi "%%~ni.avi" 2> NUL
  ren *.mp4 "%%~ni.mp4" 2> NUL
 )
 popd
)

Disclaimer: I bear no responsibility for any damage caused.

Though I've tested it on the list you gave, I highly recommend that you back up the files before running the batch file.