If your source data is 480p, you can’t make more data (except possibly by a filter that guesses and extrapolates in a more rounded way, or to apply a smoothing filter).

Your best bet would be to find a higher-res version of the same thing. Otherwise, there’s no way to squeeze more real resolution.

You can’t just increase the resolution without heavy computer manipulation. FBI and CIA have such programs.

You can upconvert to higher resolution formats but you can’t add actual resolution. Upconverting does look better in HD though.

@ARE_you_kidding_me has the answer, it’s upconverting, also called upscaling. It is built into some TVs and DVD players and other AV equipment. Video editing software can do it, too.

It can’t literally increase the resolution and give more detail but it smooths out the pixelation.

Adjust the sharpness of the video playback unit. Also, adjust the contrast.