How to determine display format

Question

By display format, I mean names like 360p, 720p, 1080, 2K, 4K, 8K.

If I have a bunch of videos, how do I determine which format is each? Their resolutions vary, some are 1280x720, which is 720p, but others are 1270x528, which should still be 720p? Same with 960x720.

Answer 1

I made a small array with some common resolutions. The algorithm looks first for the lines and then for the dots.

var resolution = [
        { name: '480p', dots: 852, lines: 480 },
        { name: '576p', dots: 768, lines: 576 },
        { name: '720p', dots: 1280, lines: 720 },
        { name: '1080p', dots: 1920, lines: 1080 },
        { name: '2160p', dots: 3840, lines: 2160 },
        { name: '4320p', dots: 7680, lines: 4320 },
    ];

function findResolution(dots, lines) {
    var i = 0;
    while (lines > resolution[i].lines) {
        i++;
    }
    while (dots > resolution[i].dots) {
        i++;
    }
    return resolution[i].name;
}
document.write(findResolution(600, 600) + '<br>');
document.write(findResolution(1920, 600) + '<br>');        
document.write(findResolution(1270, 528) + '<br>');
document.write(findResolution(960, 720) + '<br>');