Digital Video and DSP: Instant Access

Video timing

Although it looks like video is continuous motion, it is actually a series of still images, changing fast enough that it looks like continuous motion, as shown in Figure 1.1. This typically occurs 50 or 60 times per second for consumer video, and 70–90 times per second for computer displays. Special timing information, called vertical sync, is used to indicate when a new image is starting.

FIGURE 1.1. Video is composed of a series of still images. Each image is composed of individual lines of data.

Each still image is also composed of scan lines, lines of data that occur sequentially one after another down the display, as shown in ...