So for 1280x720 it's obvious that resolution equals to 720p with an aspect ratio of 1,777777778 (16:9).
But given the width (560px) and height (320px) of a video, how do I calculate the resolution? Or is it just like using the height of the video? (320px = 320p?) And if not, what's the formula to calculate the resolution?
Because with 560x320 I have an aspect ratio of 1,75 which is close to 16:9 but this doesn't mean it's the same resolution.
Image resolution is the product of the vertical and horizontal pixels that make up the image.
Therefore the resolution of 1280 x 720 = 921.600 which is higher than 560 x 320 = 179.200.
Television historically only had a vertical resolution that was discrete. The horizontal signal was fully analogue.
This might be the reason why modern video formats and tv standards use the vertical resolution to refer to the image resolution.
The p means progressive. A few years back it was common that frames where not progressive but interlaced (i), meaning that one frame contained only the odd lines while the next frame only showed the even lines.
Well, progressive shows a complete frame at a time.