Build libdvdcss 1.4.0 for macOS
The latest version of libdvdcss for macOS available is 1.4.0 (released in 2015). You may need to have this installed in order to utilize Handbrake. This tutorial is actually broken up into two parts. The first part covers installing it with the Homebrew package manager. The second part will cover building the library from the soruce code. Either choice will work, it just depends on your preference.
Installing with Homebrew
Step 1 - Install Homebrew
Installing Homebrew will allow you to easily install other packages.
Step 2 - Install lildvdcss
Install libdvdcss through the package manager.
Building from Source
Step 1 - Download and Extract the libdvdcss Source
Download the source code for the latest version of libdvdcss from the VLC website.
Step 3 - Compile Source
This will compile the library and install it into /usr/local/lib directory instead of /usr/lib. If you don't have the Xcode Command Line Tools installed, it will prompt you to install them. If that's the case, you may have to rerun
./configure again after the toolset has been installed. It may give you a few warnings, but it should successfully build the library.