The video explains how integers can be coded in a compact way.
Since the standard binary code of n always starts with 1 (except for n =0), let’s code n as the standard binary code of n+2 stripped of its heading 1. In python: bin(n+2)[3:]
To distinguish round numbers (in base 10), we reintroduce a bit at the front: 1 for "normal" integers, 0 for round numbers.
A round number n is coded as 0 followed by the compact code of n stripped of its trailing zeros, followed by the compact code of the number of zeros.
Space separators are used to make the code unambiguous.