1080i

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1080i is a shorthand name for a category of video modes. The number 1080 stands for 1080 lines of vertical resolution, while the letter i stands for interlaced or non-progressive scan. 1080i is a high-definition television (HDTV) video mode. The term usually assumes a widescreen aspect ratio of 16:9, implying a horizontal resolution of 1920 pixels and a frame resolution of 1920 × 1080 or about 2.07 million pixels. The frame rate in hertz can be either implied by the context or specified after the letter i. The two frame rates in common use are 25 frame/s (in countries that use 50 Hz alternating current) and 30 frame/s (in 60 Hz countries), with the former (1080i25) generally being used in traditional PAL and SECAM countries (Europe, Australia, much of Asia, Africa), and the latter (1080i30) being used in traditional NTSC countries (e.g. United States, Canada and Japan). Both variants can be transmitted by both major digital television formats, ATSC and DVB. The European Broadcasting Union (EBU), prefers to use the resolution and field rate separated by a slash, as in 1080i/30 and 1080i/25, likewise 480i/30 and 576i/25.

1080i is directly compatible with CRT-based HDTV sets. 1080i is compatible with newer 720p- and 1080p-based televisions but must be deinterlaced first in order to be displayed on those sets.

Due to revision of the NTSC format when color became available, the frame rate of actual 1080i broadcasts is usually 0.1% slower than is implied. For example, a 1080i30 or "30 Hz" transmission actually displays about 29.97 frames each second. Both the straight 24/30/60 and 23.976/29.97/59.94 frequencies are supported by current standards.

Progressive format 1080p 50 or 60 (25/50 and 30/60 frame/s used in 50 Hz and 60 Hz countries) is foreseen as the future broadcasting standard for production[1].

For a comparison between 1080i and 720p, see the 720p article.

[edit] See also

Television Portal

[edit] External links

[edit] References

  1. ^ EBU Recommendation FUTURE HIGH DEFINITION TELEVISION SYSTEMS


v • d • e
Digital Video Resolutions
Designation
Usage Examples Definition (lines) Rate (Hz)
Interlaced (fields) Progressive (frames)
Low; MP@LL
LDTV, VCD 240; 288 (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, BD, HDV 720   24, 30, 60; 25, 50
1080 50, 60 24, 30; 25
Visual comparison of common video/TV display resolutions
This table illustrates total horizontal and vertical pixel resolution via box size. It does not accurately reflect the screen or pixel shape (aspect ratio) of these formats, which is either 4:3, or 16:9.