/usr/lib/ladspa/ladspa-rubberband.cat is in rubberband-ladspa 1.8.1-7ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | ladspa:ladspa-rubberband:rubberband-pitchshifter-mono::Frequency > Pitch shifters
ladspa:ladspa-rubberband:rubberband-pitchshifter-stereo::Frequency > Pitch shifters
|