480p
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480p is the shorthand name for a video display resolution. The p stands for progressive scan, i.e. non-interlaced. The 480 denotes a vertical resolution of 480 vertically scanning lines, usually with a horizontal resolution of 640 pixels and 4:3 aspect ratio or a horizontal resolution of 852 pixels and 16:9 aspect ratio. The frame rate (hertz) is usually 30 or 60 progressive frames per second and can be given explicitly after the letter p. The frames are displayed progressively as opposed to interlaced. 480p was used for many early Plasma televisions.
480p does not qualify as high-definition television (HDTV); it is considered Enhanced-definition television (EDTV).
[edit] 480p24 and 480p30
The ATSC digital television standards define 480p with either 704x480 (non-square sampling) or 640x480 (square sampling) pixel resolutions, at 24, 30, or 60 progressive frames per second. A 16:9 aspect ratio is defined at 720x480 pixels, using non-square, anamorphic sampling.
Both 480p24 and 480p30 are more common in countries that use or have used the interlaced NTSC system like North America and Japan (these formats are somewhat compatible with that system, when used to broadcast progressive film content).
[edit] 480p60 (480p59.94)
With doubled temporal resolution, 480p60 is considered enhanced-definition television (EDTV). It can be transported by both major digital television formats, ATSC and DVB.
SMPTE 293M defines a 480p59.94 standard with twice the data rate of Rec. 601, using 720x480 active pixels. ITU-R Rec. 601 is the specification for component digital interlaced video (480i) commonly used in standard definition television production.
[edit] See also
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