Interpolation? Probably depends on software.
Avisynth = no
Pixels are simply truncated, if frame size not set to resize. (Noting in VirtualDub
, you resize to a 720x480 palette -- not the palette contents, which just re-centers on the colored/black background palette.)
708 = 12 pixels chopped off sides.
12 are added back to mask for 720. Basic math. 708+12=720
IMPORTANT: ALWAYS CROP BY 2 WHEN INTERLACED! Never odd numbers!