Ok I need to take a 720x576 image rescale the picture so its smaller, then I want to add black letter box / pillar box or some sort of padding so that the video is smaller but still actually 720x576 if that makes sense?

I need to basically go 720x576 >>> some other size >>>>>720x576

____720____
| |
| |
| | 576
| |
|__________|

to

____300____
| |
| |
| | 300
| |
|__________|

to

____720____
| |
| |
| | 576
| |
|__________|

TIA