GNOME Bugzilla – Bug 583876
bug in videorate:
Last modified: 2009-05-27 00:11:38 UTC
videorate element is not applyable on encoded video.It is only applyable on decoded videos or on jpeg images.So inorder to set the framerate of encoded video a long procedure of decode->videorate->encode procedure is needed!!!!
You are correct. However, modifying encoded video to change the frame rate is impossible to do in a general purpose element. You could theoretically create an element that understood intimate details of the encoded format that could do it, but that would be very challenging and generally produce crappy results.