TV's Upscaling vs. DVD Upconversion?

Question

My 720p HDTV upscale (zoom) picture from my DVD to fill the screen. Is this any different from DVD players when they up-convert the picture to 720p? If it's no difference (my guess), then why dose up-conversion function exists? Why would any one pay extra for a DVD with up-conversion function? If it is different, please explain. Thanks.

Answer 1

Theoretically, DVD upconversion should be better. However, to take advantage of DVD upconversion you need a TV with HDMI inputs. Upconverting DVDs output these signal on their HDMI outputs. If you have that, then the signal stays in digital form all the way from the disc to your set. If you use your set to upconvert to its native resolution, you are using analog (component) signals. Another advantage in having the DVD doing the conversion is that it can do perfect "reverse telecine 3:2 pulldown", for progressive scan outputs, which adjusts the 24fps movie frame rate to the 60fps television field rate. DVD signals are internally encoded to indicate which field comes from which movie frame so that they can be combined (two interlaced fields to one progressive one) properly. This is not always done correctly on component outputs (even though there is no reason it shouldn't be, but errors have been observed). A good upconverting DVD should use the progessive image as recorded on the disc, rather than the interlaced image generated by standard DVD players.