480i and 480p Systems
Interlaced Analog Composite Video
(M) NTSC and (M) PAL are analog composite video signals that carry all timing and color information within a single signal. These analog interfaces use 525 lines per frame.
Interlaced Analog Component Video
Analog component signals are comprised of three signals, analog R′G′B′ or YPbPr. Referred to as 480i (since there are typically 480 active scan lines per frame and they are interlaced), the frame rate is usually 29.97 Hz (30/1.001) for compatibility with (M) NTSC timing. The analog interface uses 525 lines per frame, with active video present on lines 23–262 and 286–525, as shown in Figure 3.1.
FIGURE 3.1. 480i Vertical Interval Timing.
For the 29.97 Hz frame rate, each scan line ...