How to find/detect the real video resolution? Imagine you have recorded/captured the screen at 1080p, but it was displaying a 480p video maximized to fullscreen.
The result file is technically 1080p, but it really is showing a 480p video, that is what I mean by &quot;real resolution&quot;.
Now imagine I have a lot of these 1080p videos, having different and unknown &quot;real resolutions&quot;, how can I find/detect these resolutions?
The goal is resize the videos to the real resolutions and not waste disk space.
(same question for FPS)

The tool that I prefer to use is ffmpeg, but i'm open to other tools/apps if they are free for personal use.
If you satisfy with your video outputting on a 1080p device, the original video aspect ratio has to be 16:9; therefore, the original video has no choice to be 480p, 720p, or 1080p. The next step is the transformation, there are plenty of filters you can choose to determine it is 480p; on the other hand, choosing transforming to 720p or no transformation, stay in 1080p, depends on contours detection on white background.
As you mentioned ffmpeg and opencv, you should find such APIs easily.