Binary package “gem-plugin-v4l2” in ubuntu cosmic

Graphics Environment for Multimedia - V4L2 output support

 Gem is a loadable library for Pure Data (Pd), which adds OpenGL graphics
 rendering and animation to Pd. Pd is a graphical programming language and
 computer music system.
 .
 This package provides video input and output using V4L2.
 .
 For video output, you might want to use a loopback device, for which you will
 have to install the v4l2loopback kernel module as well.