480p is the shorthand name for a family of video display resolutions. The p stands for

progressive scan Progressive scanning (alternatively referred to as noninterlaced scanning) is a format of displaying, storing, or transmitting moving images in which all the lines of each frame are drawn in sequence. This is in contrast to interlaced video us ...

, i.e. non-

interlaced Interlaced video (also known as interlaced scan) is a technique for doubling the perceived frame rate of a video display without consuming extra bandwidth. The interlaced signal contains two fields of a video frame captured consecutively. Th ...

. The ''480'' denotes a vertical resolution of 480

pixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a Raster graphics, raster image, or the smallest addressable element in a dot matrix display device. In most digital display devices, p ...

s, usually with a

horizontal resolution Dots per inch (DPI, or dpiThe acronym appears in sources as either "DPI" or lowercase "dpi". See "Print Resolution Understanding 4-bit depth – Xerox" (PDF). Xerox.com. September 2012.) is a measure of spatial printing, video or image scanner ...

of 640

s and 4:3

aspect ratio The aspect ratio of a geometry, geometric shape is the ratio of its sizes in different dimensions. For example, the aspect ratio of a rectangle is the ratio of its longer side to its shorter side—the ratio of width to height, when the rectangl ...

( 640) or a horizontal resolution of 854 (848 should be used for mod16 compatibility) pixels for an approximate 16:9 aspect ratio ( 853.). Since a pixel count must be a whole number, in Wide VGA displays it is generally rounded up to 854 to ensure inclusion of the entire image. The frames are displayed progressively as opposed to

. 480p was used for many early plasma televisions. Standard definition has always been a 4:3 aspect ratio with a pixel resolution of at 60 Hz for

NTSC NTSC (from National Television System Committee) is the first American standard for analog television, published and adopted in 1941. In 1961, it was assigned the designation System M. It is also known as EIA standard 170. In 1953, a second ...

regions, and 720 or for

PAL Phase Alternating Line (PAL) is a color encoding system for analog television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 ...

regions (1024 wide for

widescreen Widescreen images are displayed within a set of aspect ratio (image), aspect ratios (relationship of image width to height) used in film, television and computer screens. In film, a widescreen film is any film image with a width-to-height aspect ...

displays). However, standard definition defines a 15.7k Hz horizontal scanrate, which means that interlacing has to be used for those resolution modes. The lowercase letter "p" in 480p stands for progressive, so the two must not be confused.

ATSC progressive mode standards

The ATSC

digital television Digital television (DTV) is the transmission of television signals using Digital signal, digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an ...

standards define 480p with 640×480p (4:3) pixel resolutions, at 24, 30, or 60 frames per second. When 480p30 is broadcast on air, it is frame doubled then interlaced to 480i60. In case of 480p24, it is processed using the 3:2 pulldown technique to 480i60. In both cases the spatial resolution doesn't change, but the conversion to a interlaced format allows a direct digital to analog conversion for eventual broadcast on the analog television network.

Resolutions

References

{{TV resolution Television terminology Video formats

ATSC progressive mode standards

Resolutions

See also

References