OS X is pretty much unix, as the user facing tools share a lot with BSD (a variant of unix). However, the command line tools that come with OS X by default are not really up to scratch, so you need to install or overwrite some of the tools. You'll also want to install extra libraries, such as TBB.
Note: while many students have Macs, this isn't something that is used extensively by the teaching staff, or widely used for high-performance research. It is a decent platform, but you may need to play around with it more than in unix, and may well need to rely on advice from other students who have Macs for things like installing software.
You have three main choices:
1 - Use the homebrew package manager to install
and manage the additional tools.
2 - Use the macports package manager
to install and manage the additional tools.
3 - Run Linux in a virtual machine. For OS X I would suggest one of the above options in preference to a VM.
Note: Student consensus seems to be that brew is easier than ports, see issue 17.
Some people like macports, some like homebrew - personally I've only used macports, and that was a few yeas ago. There are instructions for installing macports on the web-site, and the process is pretty reliable.
Once macports is installed, you have a command line package manager installed. For example, if you do:
port search tbb
Then it will look for packages containing tbb. In this case the
package is just called tbb, so the following will install it:
sudo port install tbb
The sudo command allows it to run as administrator, so that it
can change system-wide settings. You can also install other tools,
for example you probably want make and git:
sudo port install make git
The macports package provides a very similar experience to Linux, and pretty much everything will work that works in Linux.
I don't regularly use OS X, but feel free to post questions as issues - I or a fellow Mac user can probably help.
@filangel suggests how to install ffmpeg using brew:
brew install ffmpeg --with-fdk-aac --with-freetype --with-libass
It was also noted by @nar213: It can take up to 10 minutes.