576i and 576p Systems
Interlaced Analog Composite Video
(B, D, G, H, I, N, NC) PAL are analog composite video signals that carry all timing and color information within a single signal. These analog interfaces use 625 lines per frame.
Interlaced Analog Component Video
Analog component signals are comprised of three signals, analog R′G′B′ or YPbPr. Referred to as 576i (since there are typically 576 active scan lines per frame and they are interlaced), the frame rate is usually 25 Hz for compatibility with PAL timing. The analog interface uses 625 lines per frame, with active video present on lines 23–310 and 336–623, as shown in Figure 3.14.
FIGURE 3.14. 576i Vertical Interval Timing.
For the 25 Hz frame rate, each scan line time (H) is 64 ...