On my system the necessary Command Line Tools take up some 303.6MB (I am using macOS Sierra 10.12.3 on a 2012 AirBook). Also, for what it is worth /Applications/XCode.app is only ~6+GB on this same computer.
I don't know that this is a comprehensive storage requirement assessment, but...
~ 500MB Total Storage
To install Command Line Tools without the full Xcode install:
$ xcode-select --install
See also this step-by-step guide.
To uninstall simply delete the folder
To install Homebrew:
$ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
When using Homebrew, it's good to run brew commands such as
brew update &
...prior to installations. See here for some brewing tips.
To uninstall Homebrew:
$ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/uninstall)"
Download the uninstall script and run
./uninstall --help to view more uninstall options.
To install the most basic ffmpeg with Homebrew:
$ brew install ffmpeg
After installing ffmpeg confirm that ffplay, ffprobe and ffserver have successfully installed and are available in your command line by using, for example:
$ ffplay -version
If they are not all available, you may need to use the following brew command:
$ brew unlink ffmpeg && brew link ffmpeg
Some ffmpeg resources:
FFmpeg documentation: http://ffmpeg.org/documentation.html
An FFmpeg support forum - http://ffmpeg.gusari.org/
"FFmpeg Basics" by Frantisek Korbel
To uninstall ffmpeg with Homebrew:
$ brew uninstall ffmpeg