Originally Posted by mcl
...or it could be the line doubler in the computer providing the signal. Computers don't typically produce interlaced video these days. It's 480p because the computer's outputting 480p. The bandwidth for 480i and 480p is identical; the only difference is the scanline sequence. One's interlaced (i), one's progressive (p).
You need look no further than any progressive DVD player for evidence. They output 480p day and night, over S-Video. You do not need component connections for 480p, because the bandwidth's the same as that of standard NTSC.
How is that possible? NTSC is 60fields/second interlaced, or 30 frams per second. 480p is 60 frames per second. 480p should take about twice the bandwidth of 480i.
Progressive scan DVD-players do not output 480p through S-Video. One must use Component video to use the Progressive scan feature. I am quite sure of this.
I don't think the component video output of the 8790 is just a conversion of the S-Video signals. It must be a 2-mode connector to support s-video and component video. It is impossible to separate the R-Y and B-Y channels from the C channel of S-Video without the use of sophisticated equipment. Which means that when in Component video mode, the connectors are no longer carrying the Y/C of s-video but rather YPrPb.