Documentarian Ken Burns talks with Recode's Peter Kafka about his new 18-hour documentary, "The Vietnam War." Burns says he sought to upend conventional wisdom about the war by rewinding the iconic images, stories and music of the time and telling history through the lens of all the countries involved in the fighting. He believes we are in a "golden age" of documentaries, but Burns says he has no desire to leave his career-long home, PBS, for a more digital-focused platform like HBO, Netflix or Amazon. He also talks about how war documentaries will change now that no one writes letters anymore, why critics have stopped fretting about the length of his films and why it's okay to watch that cute cat video online — so long as you come back to something more substantial later on.