Letterboxing?

[rdeman]

hi all,

I am encoding to a 4:3 (640x480) format from a unknown uploaded source material.
This means I have no control on whatever people upload: widescreen, etc. etc. anything but standard 4:3 format video.

How would I add automatigally letterboxing to retain aspect ration? Any help?

[jschaf01]

Have you tried the rescale filter? I use the IVideoOptions interface to get the input aspect ratio, and then compare that to my required output aspect ratio, and resize accordingly.