How can I add black bars to convert SD to HD aspect ratio?

Hi,

I have some 720x480 standard-definition video that I’d like to edit with iMovie. I use Brorsoft Video Converter to convert it to Apple Intermediate Codec format which is good for iMovie to edit. (I used to use MPEG Streamclip for this purpose, but it stopped working for some reason.) I import the AIC clip into iMovie and add this clip to a project. In iMovie, it appears it always wants to create HD (i.e., 16:9 aspect-ratio) output. To achieve this, it crops the top and bottom of my video clip. I don’t want it to crop.

(Here’s the math I assume it’s doing: My clip is 720x480. It seems to keep the 720 width. To get to 16:9, the height needs to be 405, so it lops off 37 video lines from the top and from the bottom.)

What I want is to add black bars on the right and left sides of the video to arrive at 16:9. A resolution of 853x480 would do that. So I need to add about 66 pixels to the right and left sides.

I know iMovie cannot do this (at least I haven’t heard of or found a way). It seems that Brorsoft Video Converter has some aspect-ratio-changing functions, but they seem to always involve cropping and never adding black bars.

Handbrake has a some video-cropping features as well, but I can’t seem to find a way to add the black bars I’m interested in.

Any ideas?

Best, Eric