/** Area that the subtitle covers on its corresponding video, expressed in
* proportions of the image size; e.g. rectangle.x = 0.5 would mean that
* the rectangle starts half-way across the video.
/** Area that the subtitle covers on its corresponding video, expressed in
* proportions of the image size; e.g. rectangle.x = 0.5 would mean that
* the rectangle starts half-way across the video.