Even with the introduction and acceptance of digital TV and HDTV broadcasting and source devices (such as Blu-ray Disc players and media streaming), the old barriers to a universal video standard have not been removed. This article explains why the NTSC and PAL standards are still important.
The difference between NTSC and PAL
Although video is now largely digital, the frame rate used in analog video systems has been incorporated into digital TV and HDTV standards. In video (analog, HD, and 4K Ultra HD), the images viewed on a screen appear as complete frames, just as in film. However, there are differences in the way frames are transmitted by broadcasters, transferred via streaming or physical media devices, and displayed on a screen.
Live or recorded video images consist of scan lines or rows of pixels. In film, the entire image is displayed at once. In contrast, the lines or rows of pixels in a video image are displayed across the screen, starting at the top of the screen and continuing down. These rows are displayed in an interlaced or progressive format.
Interlacing or interlaced scan splits the lines into two fields. Odd lines or pixel rows are displayed first, and even lines or pixel rows are displayed second, resulting in a complete frame.
