Digital video is a video recorded in digital form, as opposed to analog video. Digital video has different ways of making, storing and playing. For example, digital video signals are directly generated by digital cameras and stored on digital tapes, P2 cards, Blu-ray discs or magnetic disks, so that digital videos of different formats can be obtained. Then play it out through a PC, a specific player, etc.

In order to store visual information, the peaks and valleys of analog video signals must be converted into digital "0" or "1" by an analog-to-digital (A/D) converter. This conversion process is what we call video capture (or acquisition process). If you want to watch digital video on TV, you need a digital-to-analog converter to decode binary information into analog signals before playing them.

The digitalization of analog video includes many technical problems, such as TV signals have different formats and adopt composite YUV signal mode, while computers work in RGB space; Television is interlaced scanning, and computer monitors are mostly progressive scanning; The resolution of the TV image is different from that of the display, and so on. Therefore, the digitization of analog video mainly includes the conversion of color space, the conversion of raster scanning and the unification of resolution.

Analog video generally adopts component digitization. Firstly, the brightness and chroma in the composite video signal are separated to get YUV or YIQ components, and then these three components are digitized by three A/D converters, and finally converted into RGB space.