#camera {
  position: relative;
  top: 0; right: 0; bottom: 0; left: 0;
  overflow: hidden;
}
#camera > video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height:35%;
  transform: rotateY(180deg); /*ESPELHAMENTO*/
}
/* 1. No object-fit support: */
@media (min-aspect-ratio: 16/9) {
  #camera > video { height: 300%; }
}
@media (max-aspect-ratio: 16/9) {
  #camera > video { width:100%;}
}
/* 2. If supporting object-fit, overriding (1): */
@supports (object-fit:cover) {
  #camera > video {
    top: 0; left: 0;
    width: 100%; height: 70%;
    object-fit: cover;
  }
}