Handling aspect ratios, e.g. anamorphic and DV rectangular pixels

Many types of footage we’re using are old. Some are NTSC DV which has rectangular pixels, i.e. the image is 720x480 to display at 640x480. When upscaling, it would be great to be able to switch to square pixels. And for early Sony HD 16:9 recorded at 1440x1080, to be able to scale to 16:9 without having to preprocess or post-process. Thanks!