Most of the videos that one will find for Nigersaurus online at this moment come from National Geographic and the research of Sereno et al. along with some of the models of the Witmer Lab at Ohio University. In 2007 Nat. Geo. did a spread on bizarre dinosaurs, of which Nigersaurus was one. They produced a few short videos about the animals in the spread talking to the scientists where available such as this one with Paul Sereno.
Tyler Keillor uploaded a clip from another Nat Geo video which featured the model he helped to create in Sereno's fossil lab. This clip also has Sereno and Larry Witmer discussing the CT scans done at Ohio in his lab.
There are so many other clips that I could spend all day posting them up here. The only other one I will post for now other than the search results from yourtube is from National Geographic Live which is just a short interview with Paul Sereno about the animal and some other things. There is a much longer interview with him on there as well, but I've chosen the short one for you.