|
||||||||||||||||||||
|
||||||||||||||||||||
Due to a 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 1080p50 or 60 is foreseen as the future broadcasting standard for production[1]. For a comparison between 1080i and 720p, see the 720p article.
1080i vs 1080p
Current digital television broadcast systems and standards are not equipped for 1080p50/60 transmission. Also, the majority of consumer televisions offered for sale are currently not equipped to receive or decode a 1080p signal at any frequency. It is less bandwidth-intensive to broadcast a film at 1080p24 than 1080i30, since 20% less data would be transferred. In addition, when the source material is 24 frames per second, as are most films, it would be easy to convert a 1080p24 broadcast to an NTSC 1080i30 format using a 3:2 pulldown process (see telecine). Moreover, displaying a p24 broadcast on an i50 system (such as PAL) requires the speed of video and audio be increased by over 4% (to 25 frames per second). For movies the frames (25 or 30 per second) are segmented into two interlaced fields with equal time index (psf, progressive in or with segmented frames). The deinterlacer has to perform a simple weave only. This ensures compatibility with 1080i25/30 with only little less coding efficiency than 1080p25/30 and half the bandwidth requirement of 1080p50/60, but the SDTV problems of PAL speed-up and Telecine judder remain. It is less efficient to transmit any signal with a frame rate significantly higher than that of its source, which is 24fps for films; however, frame differencing in the compression standards used for HDTV transmission greatly reduce the wasted bandwidth in these cases. See alsoReferences
|
Sites |
Searched sites for "1080i" |
|
No sites found. |
Sorry, no matching site records were found. |
Want your site listed here?
|
||||||||||||||
|
Submit
your site |
|
Relevant quality search results and fast easy navigation throughout the
different sections of the site, make Americola.com |