DVD -What are they 480i ? 480p ?

[kramden66]

What exactly are dvds ? some look nice when upconverted to 1080 but some don't , the ones that don't are usualy the ones that if you play them on a regular dvd player and zoom 2x the image doesn't look that good , its pixelated where others you can zoom 2x and they look nice , those look well upconverted , an example would be hawaii five-o season one looks bad when zoomed up but seasons 2 , 3 , 4 , 5 etc all look nice , you can even notice on an analog set a slight difference in the video quality on those that fall apart when zoomed and those that don't and your not zooming , so why is this ?
my brother says its probably because the ones that look bad on 2x zoom are interlaced and the ones that aren't are progressive scan , i say its because its not taken from a high def master , thats my guess , so what is the real story here ? you guys would know.

mike