TV frame

According to an PAL standard, SDTV broadcasts in three ways. First, at ratio of length and width 16:3 and resolution 1080x500. Second, at ratio 4:3 and resolution 704x500 Lastly, at ratio 4:3 and resolution 480x500. The first one has best quality, second one is next, and the last one is the worst. There are 50 per second.

Merit

SDTV has a similar state of resolution compared to analog TV. But SDTV is more vivid than analog TV because it has less noise. And it has better sound. The point that SDTV uses a digital broadcasting system makes SDTV have many accompaning functions. For example, multitasking, electronic program guide, and so on. This functions are impossible at analog TV. Compared to AmeriTV, it has lower resolution.

Comparison

Generally, there are three types of TV. They are analog TV, SDTV and HDTV.

• Price : AnalogTV < SDTV < HDTV
• Quality : AnalogTV ≒ SDTV < HDTV
• AnalogTV only can be compatible with analog signals, but both SDTV and HDTV can be compatible with not only analog but also digital signals.

Digital definition resolution

Video Format	Resolution	Pixel Aspect Ratio	Equivalent square-pixel resolution
PAL 4:3	704×576	12:11	768×576
PAL 4:3	720×576	12:11	786×576
PAL 16:9	704×576	16:11	1024×576
PAL 16:9	720×576	16:11	1048×576
NTSC 16:9	704×480	40:33	854×480
NTSC 16:9	720×480	40:33	872×480