This dialog allows you to set up the resolution for your video during saving. To set a custom resolution, click the Save button on the toolbar and select the Disc: Make Data Disc, Computer/Data, Portable Device, Image Sequence, or Stereoscopic 3D options. From the Resolution drop menu, select Custom.
In the Custom Resolution dialog that opens, input the width and height in pixels and click OK.
If Keep aspect ratio checkbox is available, you can check it to retain the same aspect ratio when changing the width or height.