Cross compile for TX2

I have a large source code written in c++ and I want to execute this project on my TX2 (based on Ubuntu-18.04Lts), arm-64 bit architecture. I downloaded tool-chain src_aarch64_gcc-4.8.5.tar.gz from download center.
Now I don’t have any idea how do I proceed further and create executable for the my TX2 machine.
My host machine is also ubutnu 18.04Lts.

You can have a reference to the multimedia_api to use cmake to build it.

https://developer.nvidia.com/embedded/r32-2-3_Release_v1.0/t186ref_release_aarch64/Tegra_Multimedia_API_R32.2.3_aarch64.tbz2

Can you give more information on how I am going to use both packages?
Till this point I did following things,

With the package src_aarch64_gcc-4.8.5.tar.gz,
I got a toolchain and I have *.gz of gcc, glibc, mprf, build_binutils, build_gcc1 after running “make-aarch64-toolchain.sh” tool.

My question is basically after installing this toolchain what is the process and as you mentioned
“multimedia_api to use cmake to build it” what needs to be done for this?

I might sound naive because this is my first attempt to do cross compiling.

Thanks for your help.

Please download the multimedia API sample code to check the README to know how.