On Feb 10, 2009, at 6:21 PM, jonas ulrich wrote:
> What is "Deinterlacing"?-Jonas Video images are described in 'Lines' from the olden days when each line was a scan of the electron gun in the CRT horizontally across the phosphor mask. Television was interlaced, meaning that each frame only displays every other line, so the TV screen is scanned line 1, 3, 5, 7...on to the end, then it comes back and scans 2, 4, 6, 8.... This meant that the circuityry could operate at half the frequency that would normally be required, making television possible in the beginning, and cheaper later on. Since it was codified as a standard, TV never changed, (until next week.) Persistence of vision, and the slow decay of the phosphors meant that we saw the whole picture, not two half pictures in a row. (for grins, if you ever run across one, hook up an old green high-persistence monochrome monitor like an Apple III to a video source. It's...interesting. :-) HD video does the same thing, 720i or 1080i is interlaced, 720p and 1080p is 'progressive' or de-interlaced. This gives you a sharper picture, but at the cost of display speed, which is why on older 'p' sets, you get smearing and fuzziness when there are large, fast changes on the screen, such as games or sports events. De-interlacing in DVD Player is displaying each line sequentially line 1, 2, 3 , 4 etc. For HD this can be a MAJOR factor in performance. What this means is that the DVD player application has to decode TWO half frames at once, and display them simultaneously. It doubles the CPU load, and can lead to stuttering just like you saw. -- Bruce Johnson University of Arizona College of Pharmacy Information Technology Group Institutions do not have opinions, merely customs --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed Low End Mac's G3-5 List, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to g3-5-list@googlegroups.com To unsubscribe from this group, send email to g3-5-list-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/g3-5-list?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
