Video File Metadata in "Get Info"
How can I use Mac OS to query the dimensions (aka aspect ratio, or resolution) of video files that do not display that information in "Get Info > More Info" dialog, or add these dimensions to the file metadata once discovered? I notice this info is missing for some .mp4, .mkv, and .avi files. so it doesn't seem to be the container that is problematic. Is there a way to edit file metadata natively in MacOS X?
Mac mini, 10.11