To install libde265, run the following command in macOS terminal (Applications->Utilities->Terminal)
sudo port install libde265
To see what files were installed by libde265, run:
port contents libde265
To later upgrade libde265, run:
sudo port selfupdate && sudo port upgrade libde265
Reporting an issue on MacPorts Trac
The MacPorts Project uses a system called Trac to file tickets to report bugs and enhancement requests.
Though anyone may search Trac for tickets, you must have a GitHub account in order to login to Trac to create tickets.