Hi, we have built player and gstreamer player packages. To use them, try:
$ apt-get install -y mpv
$ apt-get install -y librockchip-mpp1
$ apt-get install -y gstreamer1.0-tools gstreamer1.0-plugins-bad
$ apt-get install -y gstreamer1.0-plugins-ugly gstreamer1.0-plugins-good gstreamer1.0-plugins-base
$ apt-get install -y gstreamer1.0-plugins-base-apps glib-2.0 libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev
$ apt-get install -y gstreamer1.0-rockchip1
Bty, I use rockpi4b-ubuntu-bionic-minimal-20190104_2101-gpt.img and mate desktop. Before installing the above packages, I do this:
$ sudo apt install -y ubuntu-mate-core
$ sudo apt install -y ubuntu-mate-desktop