git clone git@github.com:YOUR-USERNAME/YOUR-FORKED-REPO.git
cd into/cloned/fork-repo
git remote add upstream git://github.com/ORIGINAL-DEV-USERNAME/REPO-YOU-FORKED-FROM.git
git fetch upstream
ffmpeg -i input_file.mp4 -framerate 30 -c:v libvpx-vp9 -an -vf scale=512:512 -pix_fmt yuva420p output_sticker.webm |
ffmpeg -i in.mkv -f srt -i in.srt -map 0:0 -map 0:1 -map 1:0 -c:v copy -c:a copy -c:s srt out.mkv |