MP4Box is included when you install GPAC. Go over and download one of the builds for GPAC.
Once you have downloaded the application drag and drop the installer into your Applications folder. Once the application is in your Applications directory your PATH variable will need to know where to find the MP4Box executable run the two commands to copy over MP4Box to the bin and lib directories.
sudo cp /Applications/Osmo4.app/Contents/MacOS/MP4Box /usr/local/bin/ sudo cp -R /Applications/Osmo4.app/Contents/MacOS/lib/* /usr/local/lib
Now you have installed MP4Box in your OSX box.
For Windows and linux users you will have to find out how to execute the binary in your specific operating system.
Till Next Time,