Basically, to find the file:
sudo find / -name libavdevice.so.52
For example, you've found this file in the /usr/local/lib. Next include that library into your library path. Add this to your /etc/ld.so.conf:
/usr/local/lib
And finally after modifying this file run this:
sudo ldconfig
Reference: Ffmpeg: error while loading shared libraries: libavdevice.so.52: cannot open shared object file
