4.4.0-92.115) is not available, but a newer one is (4.4.0-142.168). We redirected you there.
/usr/lib/x86_64-linux-gnu/libavcodec.so.53 is in libavcodec53 4:0.8.17-0ubuntu0.12.04.2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libavcodec.so.53.35.0