I use this for add subtitle for Tvshows or Movies on Windows.
Just create "subbed" folder and bat file in the video and sub directory.Put code in bat file and run.
for /R %%f in (*.mov,*.mxf,*.mkv,*.webm) do (
ffmpeg.exe -i "%%~f" -i "%%~nf.srt" -map 0:v -map 0:a -map 1:s -metadata:s:a language=eng -metadata:s:s:1 language=tur -c copy ./subbed/"%%~nf.mkv"
)