It works. Thanks.
But I decided to install the VideoCore - EGL/GLES/OpenVG version.
So, final solution after installing Omxplayer on fresh install:
cd /usr/lib/arm-linux-gnueabihf
ln -s libmmal_core.so.0 libmmal_core.so
ln -s libmmal_util.so.0 libmmal_util.so
ln -s libmmal_vc_client.so.0 libmmal_vc_client.so
ln -s libbcm_host.so.0 libbcm_host.so
ln -s libvcsm.so.0 libvcsm.so
ln -s libvchiq_arm.so.0 libvchiq_arm.so
ln -s libvcos.so.0 libvcos.so
curl -sSfLO 'https://raw.githubusercontent.com/raspberrypi/firmware/master/opt/vc/lib/libbrcmEGL.so'
curl -sSfLO 'https://raw.githubusercontent.com/raspberrypi/firmware/master/opt/vc/lib/libbrcmGLESv2.so'
curl -sSfLO 'https://raw.githubusercontent.com/raspberrypi/firmware/master/opt/vc/lib/libopenmaxil.so'
Could be interesting to add this entry on Dietpi-Software. What do you think if I create a new Software Request on your GitHub?