On 1/25/07, <b class="gmail_sendername">Nick Morrott</b> <<a href="mailto:knowledgejunkie@gmail.com">knowledgejunkie@gmail.com</a>> wrote:<div><span class="gmail_quote"></span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
1080p60 has twice as many pixels/s as 1080i60, as Jarod stated earlier:<br><br>1080i60 = (1920x540 pixels per field) x (60 interlaced fields per<br>second) = 62,208,000 pixels/second.<br><br>1080p60 = (1920x1080 pixels per frame) x (60 progressive frames per
<br>second) = 124,416,000 pixels/second.<br><br>1080p30 will have the same datarate as 1080i60 however, and fast<br>action scenes may look smoother using the 1080i60 format.<br></blockquote></div><br>Right. For fairly static scenes the field rate is less important and 1080i will approach 1080p in quality. For rapid movement field rate makes more difference and so 1080i will not look as good as 1080p at the same field rate, but will look better than 1080p at the same data rate (
i.e. 1080p60 is better than 1080i60 is better than 1080p30). Really interlace should be considered to be a lossy compression scheme.<br><br>But keep in mind the source material. Movies are (generally) shot at 24 fps, so Xp60 contains alternately duplicated and triplicated frames,
i.e. 60% of the data rate is completely wasted. Xi60 has more than enough bandwidth to transmit all of the source pixels without any loss. If accurate inverse telecine is possible the 1080i60 signal will result in exactly the same output as 1080p60. I think this is what Steve Adeff was trying to say. Of course this doesn't apply if the source is Xp60 material.
<br><br>Steve<br><br>