git config
git config --global alias.co checkout
git config --global alias.br branch
git config --global alias.ci commit
git config --global alias.st status
ssh key
ssh-keygen -t rsa -C "yhtangcoder@gmail.com"
ffmpeg
mp3 to mp4
https://unix.stackexchange.com/questions/657519/how-to-convert-output-mp3-to-mp4-with-ffmpeg
ffmpeg -f lavfi -i color=c=blue:s=1280x720 -i input.mp3 -shortest -fflags +shortest output.mp4
