Each button displays helpful information about how to perform a wide variety of tasks using FFmpeg. To use this site, click on the task you would like to perform. A new window will open up with a sample command and a description of how that command works. You can copy this command and understand how the command works with a breakdown of each of the flags.
For FFmpeg basics, check out the program’s official website.
For Bash and command line basics, try the Command Line Crash Course.
+Script Ahoy: Community Resource for Archivists and Librarians Scripting
+The Sourcecaster: an app that helps you use the command line to work through common challenges that come up when working with digital primary sources.