[01100011]

Encoding can work however you like. The important thing is that the output complies with the standard.

It's nice to have a reference implementation, but it's not like that's the only way it can be done.

[userbinator]

The important thing is that the output complies with the standard.

That's a good point --- you can write an H.264 encoder that doesn't compress at all, and as expected, the amount of code to do so is quite small:

https://cardinalpeak.com/blog/worlds-smallest-h-264-encoder/

However, minih264 may currently be the smallest encoder that does compress.