I guess this is a preview of the mini-series which is coming to PBS in September. This is part of the AHA! Festival. From their website:

In an immersive narrative, Ken Burns and Lynn Novick tell the epic story of the Vietnam War as it has never-before been told on film. The Vietnam War features testimony from nearly 100 witnesses, including many Americans who fought in the war and others who opposed it, as well as Vietnamese combatants and civilians from both the winning and losing sides. Lynn Novick and producer Sarah Botstein will introduce the series as part of the AHA! Fest.

Free, but registration is required.

ahacsu.com