Standard-definition television

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SDTV redirects here. For Arizona State University's campus channel, see Sun Devil Television.

Standard-definition television or SDTV refers to television systems that have a resolution that meets standards but not considered high definition. The term is usually used in reference to digital television, in particular when broadcasting at the same (or similar) resolution as analog systems.

In ATSC, SDTV can be broadcast in 704 pixels × 480 lines with aspect ratio (40:33 rectangular pixel), 704 pixels × 480 lines with aspect ratio (10:11 rectangular pixel) or 640 pixels × 480 lines with ratio (and square pixels). The refresh rate can be any of 24, 30 or 60 pictures per second.

Digital SDTV in aspect ratio has the same appearance as the regular analogue TV (NTSC, PAL, PAL2, SECAM) minus the ghosting, snowy images and static noises. However, if the reception is poor, you may encounter various other artifacts such as blockiness and stuttering.

Standards that can broadcast digital SDTV include DVB, ATSC and ISDB. The latter two were originally developed for HDTV, but they have proved to be more often used for their ability to deliver multiple SD video and audio streams via multiplexing, than to use the entire bitstream for one HD channel.

Digital video resolutions
Designation Usage examples Definition (lines) Rate (Hz)
Interlaced (fields) Progressive (frames)
MP@LL LDTV, VCD SIF) 24, 30; 25
Standard; MP@ML SDTV, SVCD, DVD, DV 480 (NTSC, PAL-M); 60; 24, 30;
576 (PAL, SECAM) 50 25
Enhanced EDTV 480; 576 60; 50
High; MP@HL HDTV, HD DVD, BD, HDV 720 24, 25, 30, 50, 60
1080 50, 60 24, 25, 30

This table illustrates total horizontal and vertical detail via box size. It does not accurately reflect the screen shape (aspect ratio) of these formats, which is always stretched or squeezed to 4:3 or 16:9. The table assumes an average vertical detail loss of .75x due to interlace. The actual loss is variable due to content, motion, opinion on acceptable levels of flicker, and possible success of deinterlacing. 1920 × 1080i is not included because all common use of 1080i is filtered to 1440 or less.

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Designation	Usage examples	Definition (lines)	Rate (Hz)
Designation	Usage examples	Definition (lines)	Interlaced (fields)	Progressive (frames)
MP@LL	LDTV, VCD	SIF)		24, 30; 25
Standard; MP@ML	SDTV, SVCD, DVD, DV	480 (NTSC, PAL-M);	60;	24, 30;
Standard; MP@ML	SDTV, SVCD, DVD, DV	576 (PAL, SECAM)	50	25
Enhanced	EDTV	480; 576		60; 50
High; MP@HL	HDTV, HD DVD, BD, HDV	720		24, 25, 30, 50, 60
High; MP@HL	HDTV, HD DVD, BD, HDV	1080	50, 60	24, 25, 30

This table illustrates total horizontal and vertical detail via box size. It does not accurately reflect the screen shape (aspect ratio) of these formats, which is always stretched or squeezed to 4:3 or 16:9. The table assumes an average vertical detail loss of .75x due to interlace. The actual loss is variable due to content, motion, opinion on acceptable levels of flicker, and possible success of deinterlacing. 1920 × 1080i is not included because all common use of 1080i is filtered to 1440 or less.

Standard-definition television

See also