How to extract all subtitles from video with cli?

[Shaorin]

I want to automate this so I need a command line method to auto extract all subtitles from a video file like mkv. Not all video contain multiple subtitles so how can I do this?

[Subtitles]

Check out ffmpeg

[pcspeak]

I've modified an older batch file I wrote.
All my mkv videos have .srt subs, so no testing .ass, etc.

demux-all-subtitle-streams-v01.cmd

@echo off
 if not exist Subs\ md Subs
for %%a in (*.mkv) do call :process1 "%%a"
goto :end

:process1
rem Get a list of streams - pare down to subtitle streams.
ffmpeg.exe -i "%~1" -y nul 2>&1 | find /i "stream" | find /i "subtitle" >"%~n1.txt"

rem Using the temp file, "%~n1.txt", to set mapping and the output file name.
for /f "usebackq tokens=1-7 delims=^(^)^:^#^ " %%a in ("%~n1.txt") do (
    setlocal enabledelayedexpansion
    set stream=%%b:%%c
    ffmpeg.exe -i "%~1" -map !stream! -y "Subs\%~n1-%%d.%%g"
)
goto :eof

:end
rem uncomment the next line to delete all temp txt files.
rem del "*.txt"
echo. &echo Output is in the Subs\ folder &pause

Cheers.