/usr/lib/x86_64-linux-gnu/libtheoraenc.so is in libtheora-dev 1.1.1+dfsg.1-14+b1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libtheoraenc.so.1.1.2
/usr/lib/x86_64-linux-gnu/libtheoraenc.so.1.1.2