I’ll try to avoid spoilers — but honestly, if you haven’t seen the movie, this thread won’t interest you very much.
Anyway.
Javert sings his last song on a bridge over the Seine. What is that weird, oval, terraced thingie in the water?
The real Seine doesn’t have one, and I don’t believe it had one in the 1830s, either. I know they filmed the movie in London, but I’m not aware of the Thames having anything like that. Therefore, I assume its CGI.
But what the heck is it supposed to be? Just some unidentified thing that looks cool and give the water a loud rushing sound?
Yeah, but at least it gave the sound editors the chance to have some fun. There were a few chuckles in my theater when Javert hit the weir, and we heard that giant CRACK.
I think part of the reason they used this is that otherwise, a guy jumping into a river just kind of looks like he’s going for a swim. On stage, it’s all in your head that the guy just disappears and therefore is dead. In a movie, you have to see him die so when he jumps in he either has to almost comically pretend to drown or maybe disappear under a torrent of water (and even then, it’s not clear that he’s dead). Or, as in this case, hit something on the way down so that it’s clear he won’t be getting up.
According to that link, they filmed this scene in late October - only about a month before the first screenings of the movie and months after principal photography had been completed. If I had to hazard a guess, they probably did it via CGI or some other means and it wasn’t working so they ran out and shot this instead.
Thanks for pointing out that it was a weir. I thought it was very noticeable, too, but I thought it had something to do with the book: if I’m remembering correctly, Hugo specifically mentioned a set of rapids along the Seine, such that no one could survive jumping from the point that Javert did-- very much as **interface2x **points out. Seems more likely that it was an artifact of the location filming, though.