The Vektor CR-21 was a bullpup carbine made in South Africa. It was based upon their R4 rifle which was a derivative of the Israeli Galil. The internals of the CR-21 were similar and it used the same magazines as the video shows.
The CR-21 never made it out of the prototype stage but it would have been interesting to see how with a little more development it would have stacked up against the Tavor and other bullpups. It really is futuristic looking