Detect video aspect ratio based on
Select how the aspect ratio of video playback is determined:
- Video source -- The resolution of source video determines the aspect ratio. For example, a video with a resolution of 320 x 240 has an aspect ratio of 4:3.
- Video window -- The size of the video window determines the aspect ratio. (Some video player programs may preserve the aspect ratio of the video even when the video window is stretched. In this case, the black borders displayed in the video window won't appear on your secondary display.)