From http:// TV .abang.com/od/knowledge/a/screenraito.htm
We often talk about the video sizes of P and P, but what is the resolution of this size? Generally, 1920 P is 1080x1280 (width x height), and 720 p is X. Because the naked eye is more sensitive to horizontal resolution, it has a higher horizontal resolution, that is, the number of horizontal lines, that is, the number of lines that we usually talk about plays a decisive role in the definition of HD images.
However, when we watch these videos, we often find that the actual resolution is not exactly 1920x1080 and 1280x720. For example, for many movies, the resolution of 1280 p is 544x720. In this case, there is a question: why is there 544 lines when the horizontal line is clearly lines? Is it a lie?
In fact, we should start with filming movies. The earliest films were 4: 3 films, and the images were 4: 3 images close to the square. Later, through the study of human vision, we found that people will have a wider image preference. Therefore, the concept of masking has been developed. Although the 4-3 film is used, the upper and lower parts are covered. During the screening, the image is 1.85: 1. Later, with the development of film screening, more and more movies use a wider picture. Most new movies use a 2.40: 1 format. When we go to the cinema, we will find that the screen is very wide. When we sit in the best movie watching seat, our sight will be filled with the screen of the movie, and the viewing will have a better sense of substitution.
In this way, when making a video for home playback, the original scene's intention cannot be excessively damaged. Although our TV is at, that is, the resolution of 1920x1080, you can only choose the ratio of 2.35: 1 to keep the image complete. In this way, 1280 is equal to 1280 except 2.35 at 544 points horizontally.
Similarly, in a 1920 p video, the landscape must be filled with 816, and the horizontal resolution can only reach 800 or.
During compression and production, the production staff can cut useless black borders up and down to save space and achieve better image effects within a limited capacity. Therefore, playback software such as KMP will report, the resolution of a video is only 1280x544 or 1920x816. In fact, this is also the Standard 1080 p and P.