my goal is to rip the hard coded subtitles from https://youtu.be/w-L61QPlYOo

i am doing some experimenting now. i downloaded latest version of subrip from https://www.videohelp.com/software/Subrip and i will follow this guide http://zuggy.wz.cz/guides/video.htm

i downloaded this clip https://www.youtube.com/watch?v=bTuxsQP-Pq8. it is random clip from youtube and it has hard coded subs. i used http://en.savefrom.net/1-how-to-download-youtube-video/ to download clip from youtube. i downloaded clip and saved it as mp4

when i opened the mp4 file in subrip i got the error message "subrip is unable to open the video file in avisynth". avisynth wasnt installed. i installed it

after that i got a different error message when i opened the video file and the message is http://i65.tinypic.com/29pt62o.png. when i clicked ok i saw http://i66.tinypic.com/13zwvo5.png

what am i doing wrong?