Batch

C:\mpv\mpv.exe "C:\ffmpeg\Spice and Wolf -05.mkv" -o "C:\ffmpeg\Spice and Wolf -05.mp4" -ovc libx264 -ovcopts "preset=slow,level=41,crf=18" libfdk_aac  "ab=256k"


                                         Batch script :

for %%a in ("*.mkv") do ffmpeg -i "%%a" -vcodec copy -acodec copy "newfiles\%%~na.mp4"
pause