@SoulSmasher
I am not 100% clear ... but here goes.
1st. You seem to say that you do not want to re-encode. Converting from mpeg4 to mpeg2 is certainlly a re-encode. Not sure what you want here.
On aspect ratios ....
1) Change the source by padding to get the AR you want
2) Resize this to your TV active picture frame size
3) Pad some more so you meet the dvd standard
1) Start with 640/256. You want 16/9 ratio. 640/16*9 = 360 .. 640/360
Code:
DirectShowSource("c:\myVid.avi")
AddBorders(0,52,0,52)
2) PAL is 702x576. Presumably you have progressive source, so a resize will not mess up the scan lines. You want to fill the PAL TV frame.
Code:
DirectShowSource("c:\myVid.avi")
AddBorders(0,52,0,52)
LanczosResize(702, 576)
3) For a DVD 720x576 would be most standard. The xtra 18 are not overscan and don't even come out of a dvd player analog out.
Code:
DirectShowSource("c:\myVid.avi")
AddBorders(0,52,0,52)
LanczosResize(702, 576)
AddBorders(0,9,0,9)
-----------------------------
Some notes ....
- TV 16/9 will not look correct on a PC unless the pc resizes it
- I assume your encoder just sets the 16/9 flags and is not doing it's own resize
- You could probably get there with less steps ... but i wanted to be clear