$ sudo apt-get update
$ sudo apt-get install libavfilter2 

libavfilter2 is installed in your system.

Make ensure the libavfilter2 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libavfilter2 *

You will get with libavfilter2 package name, version, architecture and description in a table

libavfilter2 package basic information: