#video-compare-container {
      display: inline-block;
      line-height: 0;
      position: relative;
      width: 100%;
      padding-top: 42.3%;
    }

    #video-compare-container > video {
      width: 100%;
      position: absolute;
      top: 0;
      height: 100%;
    }

    #video-clipper {
      width: 50%;
      position: absolute;
      top: 0;
      bottom: 0;
      overflow: hidden;
    }

    #video-clipper video {
      width: 200%;
      postion: absolute;
      height: 100%;
    }