JS Bin// source http://jsbin.com/cohomuyeji

jsbin.cohomuyeji.js

function getOutputResolution(max_width, max_height, videoInfo) {
    var tmp_max_width = 0
    var tmp_max_height = 0
    // ShrinkToFit: don't scale up videos
    max_width = (max_width > videoInfo.width) ? videoInfo.width : max_width
    max_height = (max_height > videoInfo.height) ? videoInfo.height : max_height

    if (videoInfo.width < videoInfo.height) { // for portrait
      tmp_max_width = Math.min(max_width, max_height) // getting the smallest number for width
      tmp_max_height = Math.max(max_width, max_height) // getting the biggest number for height
    } else { // for landscape
      tmp_max_width = Math.max(max_width, max_height)
      tmp_max_height = Math.min(max_width, max_height)
    }

    var scalingFactor = Math.min(
      tmp_max_width / videoInfo.width,
      tmp_max_height / videoInfo.height
    );

    //console.log(scalingFactor, scalingFactor * videoInfo.width, scalingFactor * videoInfo.width)
    // fix for odd pixel error
    var result_width = 2 * Math.round(Math.floor(scalingFactor * videoInfo.width) / 2)
    var result_height = 2 * Math.round(Math.floor(scalingFactor * videoInfo.height) / 2)

    // calculated the desired width and height of the video
    return ({width: result_width, height: result_height})


  }


var video = {width: 568, height: 320};
console.log( getOutputResolution(376, 376, video) );