System: ubuntu 20.04
$ sudo apt install librockchip-mpp1
Reading package lists… Done
Building dependency tree
Reading state information… Done
Package librockchip-mpp1 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package ‘librockchip-mpp1’ has no installation candidate