Changing FPS with mencoder

[Cabhan]

Howdy all. I downloaded a video from YouTube and the video ended up being too fast. However, when I play the video with:

mplayer Terry\ Tate\ -\ Original.flv -fps 18.167

(that is, manually setting the FPS to 18.167), it plays perfectly. The default fps for this video is 29.970.

So I attempted to use this command to change the FPS:

mencoder Terry\ Tate\ -\ Original.flv -o Terry\ Tate\ -\ Original.new.flv -oac copy -ovc copy -fps 18.167

However, the output for mencoder says:

VIDEO:  [FLV1]  320x240  0bpp  29.970 fps    0.0 kbps ( 0.0 kbyte/s)
...
Input fps will be interpreted as 18.17 instead.

Now, this is incorrect. The input FPS is 29.970. And sure enough, the video is still off after being encoded (and the FPS is reported as 18.167 instead).

My next attempt was:

mencoder Terry\ Tate\ -\ Original.flv -fps 29.970 -o Terry\ Tate\ -\ Original.new.flv -oac copy -ovc copy -fps 18.167

but this gives the same result.

Does anyone know how I can do this properly?