In such video we can clearly see squares (blocks) but these squares are not all solid, they have some details within. A real pixellation is different. In case of real pixellation, the image (or its part) consists of solid squares, where all pixels within one square have the same colour. Here's an example of pixellated video:
Same effect is also called mosaic. If you have this type of video, read how to remove mosaic.
And if your case looks like the first example above, then what you really need is deblocking. This process will smooth edges between blocks while keeping details within blocks. There's nothing to do for super-resolution, it doesn't really work on strongly compressed video (see when super resolution doesn't work). There are two filters for getting rid of blocking artefacts that you can use in Video Enhancer: MSU Deblocking and MSU Smart Deblocking. The latter is included in VirtualDub Filter Pack. Just open your video in Video Enhancer, switch to Advanced mode, select one of these filters, select output compression and press Start. After deblocking you'll have something like this:
