With Video Enhancer on GOTD, thought this might be appropriate...
A display panel, regardless its size, & regardless where it's used, has a maximum number of separate dots [pixels] it can display. If you have a 55" TV & a 5" cell phone screen, both at 1080p [1920 x 1080 = 2073600 pixels], a single pixel on the cell phone screen is going to be MUCH smaller, illustrating how a pixel itself can be any size, somewhat like the different sized grids you can have with graph paper.
If you show a 1080p picture on a screen with a maximum resolution of 1080p, every pixel will be different. If you show a smaller picture on the same screen, say 720p, you have 2 options -- you can stick to the original 720p pixels, in which case the picture will only take up a portion of the screen, or you can show the picture full screen, meaning some of the 2073600 pixels will be the same... you're effectively combining groups of individual pixels into larger pixels. And without any added processing, a 720p picture should look the same full screen on either a 720p screen or one with a max of 1080p [or 4k]. There is a sort of catch however...
If you compare a 720p picture on both a 7" & a 55" 720p screen, the picture on the 7" screen will look better. That's because the pixels on the 7" screen are so much smaller. And that's why you don't see 55" 720p TVs. BUT, I've also been talking about a picture displayed without added processing.
It's a fact of life that today's display panels are by themselves incapable of displaying every possible color at every possible level between pure black & pure white -- they come much closer to that full gamut display because of or with the electronics that send that picture to the display. If you want, think of it as electronic trickery, because in essence that's what it is. And since you've got the electronics there already, it's not that big of a deal to add an enlarging function, which works more-or-less the same as enlarging an image in an image editing app. The big difference is that the software produces a generic result, while the electronics are tailored to the actual characteristics of the display panel to which they're attached.
Currently most every TV has the capability to enlarge a smaller picture to it's own maximum resolution. And most all software players, Windows or Android, can expand a picture the same way, often using the device's electronics. Some do better than others -- some TV electronics & some software perform more processing to give you a better picture on screen. Some TVs have a host of controls you can use to adjust different aspects of it's processing, or turn separate aspects on/off. Software players offer different amounts of similar control.
A real world example, our 4k TV has loads of internal processing, so a movie on a 1080p Blu-ray looks wonderful [MUCH better than on a 1080p TV]. I've got a miniPC attached to one of its HDMI ports, and have to have most all of the TV's internal processing turned off, because otherwise the mouse lag is truly terrible. Without it the screen looks like any other 1080p screen -- not 4k. Playing the very same Blu-ray movie using the miniPC however can look just as good [if not better] as when I'm using the TV's processing, IF I use a software player that performs much the same processing.
It's important to note that enlarging the picture, whether a still image or video, cannot create more pixels out of thin air -- it's Always best to use a higher resolution picture to start with, one that doesn't need enlarging. It's also important to note that mileage varies -- some TVs have a better picture than others, some TVs & some software players will upscale better than others, some TV & software settings will work better than others. This sort of processing however does not take lots of horsepower, e.g. using its miniHDMI port, my cheap Windows tablet with an Intel Atom SOC, does just fine playing video on the 4k TV.
Which finally leads me to today's GOTD & similar... *IF* everything is as it should be, it's useless, as is paying extra for an upscaling DVD or Blu-ray player. Using software to upsample video to a file [vs. a player sending the stream to a display], gives you a larger file, and suffers from the inevitable generational loss from re-encoding. If things are Not as they should be, e.g. you've got a very poor quality TV, and don't want to spend money, it *might* provide a workable alternative. If you've got on old PC, or buy a cheap PC or miniPC, between the free MPC-Homecinema, LAVFilters, & madVR, you'll do better, or pick up PowerDVD 16 Ultra when it's on sale for ~$30.
