There are a total of 26 frames of video, and in the original (posted) sequence it lasts a total of about 12.4 seconds, meaning that the time between frames is about 0.477 seconds.
It is interesting to note that there is no bridge movement between the first and second frames, meaning that the video has captured the entire collapse from the start (which begins between frames 2 and 3, and is already underway at frame 3. It is also interesting to note that there is a very slight upward shift of the camera between frames 2 and 3 (coincident with the beginning of the collapse).
It is also noteworthy that the bridge segments closest to the camera (at least from initial observation) appear to be falling straight down. It is difficult from this perspective to tell if the east (far) side of the bridge was falling ahead of the west (near) side.
Even though the bridge appears to have broken somewhere on the south end, out of camera view, these pictures can perhaps still provide some additional information and insight into the collapse.
Bridge00.gif
Bridge01.gif
Bridge02.gif
Bridge03.gif
Bridge04.gif
Bridge05.gif
Bridge06.gif
Bridge07.gif
Bridge08.gif
Bridge09.gif
Bridge10.gif
Bridge11.gif
Bridge12.gif
Bridge13.gif
Bridge14.gif
Bridge15.gif
Bridge16.gif
Bridge17.gif
Bridge18.gif
Bridge19.gif
Bridge20.gif
Bridge21.gif
Bridge22.gif
Bridge23.gif
Bridge24.gif
Bridge25.gif