/usr/lib/x86_64-linux-gnu/libgstadaptivedemux-1.0.so is in libgstreamer-plugins-bad1.0-dev 1.14.0-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libgstadaptivedemux-1.0.so.0.1400.0