Having FFmpeg with h.264 support as a dependency carries licensing information along with its use / deployment. There are two primary licenses we are concerned with herein, GNU General Public License and GNU Lesser General Public License. GPL being the most restrictive of the two and requiring the implementer to meet their specific requirements (see the license and/or consult your lawyer).
In order to use the new OrientationPostProcessor method, you must have at least version 4.0 of FFMpeg. If you have an older version of FFmpeg installed, remove that first:
sudo apt-get remove ffmpeg
Then, add the
sudo add-apt-repository ppa:jonathonf/ffmpeg-4
And confirm the resulting message by pressing [enter].
sudo apt update && sudo apt upgrade
Now FFmpeg is available to be installed with apt:
sudo apt-get install ffmpeg