[MPlayer-users] resizing

[Tomoki Taniguchi]

I am working to get a thumbnail made from a given video.
I am currently playing around with outputting an animated gif (-vo gif89a) and 
a single thumbnail image (-vo jpeg -frame 1).

Now that part works for the most part, though I do notice a bit of color 
distortions in the gif89a animation (it looks like everything gets a blue 
tint), but I can live with that.  

ok, now I've been trying to shrink the output image to a desired size, but 
have been having some trouble.

(-vop scale=w:h)  I'm trying to set all thumbnails to a particular width.  
this option seems to only work when the size change is a clean one...  
meaning 3x,2x, ...1/2 x,1/3 x....  But when the change is not a clean one it 
distorts the image.  The each row in the image is shifted over some....   

(-x, -y, -xy)  tried using these three options.  According to the screen 
output, the images are being scaled properly, but the final output file is 
still the same size as the images created without those options.

any help on cleanly resizing an image output would be appreciated.
I can always run the output image through imagemagick, but would like to avoid 
a step if I can.

-tomoki