SETLOCAL ENABLEDELAYEDEXPANSION
SETLOCAL ENABLEEXTENSIONS
for /F "delims=;" %%A IN ('dir /b *.mkv') DO (
ffmpeg -i "%%A" -vcodec copy -acodec copy -y "%%~nA.mp4"
MP4Box -inter 0.5 "%%~nA.mp4"
)
pause