What is the code rate? Part 3
Video imaging methods are mainly divided into two types: interlaced scan and progressive scan.
In plain and simple terms, an image (a frame) is made up of lines made up of hundreds of rows of pixels.
Interlacing means that only half of the lines are displayed on one screen at a time, and is made up of odd or even lines, displayed alternately with each other. It is commonly said “i”.
Originally, the image the TV would transmit per second was set to 50 frames per second. Think that the image does not flash in our eyes. However, according to the technology at the time, it was difficult to achieve 50 frames per second of TV transmission. Scientists used the persistence of human vision to invent interlaced transmission.
Interleaving is a technology developed to transmit television signals using limited bandwidth. In an interlaced system, only half the number of horizontal lines per video frame is transmitted at a time. The viewer can perceive each frame at full resolution due to transfer speed, display persistence, and persistence of vision. All analog TV standards use interlace technology. Digital television standards include interlaced and non-interlaced technologies.
(The above is official Adobe content)
We all use no field (line by line) now
video ratio
Video ratio refers to the ratio of the length to width of the video screen played by the video player. The ratio between the length and width of the CRT television used in ordinary homes is 4:3, that is, the video ratio is 4:3. The high-definition screen video ratio (TV and mobile) that is currently being developed is 16:9. The current full screen mobile phone is 17: 9
Due to the development and application of various screens, video production is also relatively informal, and will be adjusted according to the requirements of Part A, such as large conference screens and advertising screens.
