Wednesday, December 5, 2012

The Artifacts

The artifacts I see from the Mac->Belkin->Monoprice->Sony->DVDO hookup described in last few posts, as viewed on my Samsung, are clearly interlacing artifacts, specifically the artifact known as combing.

http://www.neuron2.net/LVG/interlacing.html

This might or might have nothing to do with the Apple and it's output, which I have suspected is far from perfect, in 480i.  But perhaps there is nothing wrong with the Apple 480i at all.

In fact, I have another bit of evidence, this combing grows and shrinks over time, perhaps a second or so.  This suggests a possible ground loop in the connection between the Sony and the DVDO.  This would not have changed with the new Mac Mini (which, like the laptop, has two prong power connection which avoids ground loops).  Maybe...it was previously there and I just never noticed it before.

That wouldn't necessarily explain the added softness I seem to sense compared with the S-Video output of my Titanium Powerbook.  Though perhaps I didn't pay enough attention to that before to compare fairly.  I do know that on still images especially the DVDO upscaling (as with most upscaling) gives a smoother, film-like quality compared to the brisk sharpness of 480i.

Though, I may have improved that a bit by adjusting the Underscan control in the Mac Display Preferences. Funny I did not see this control at first, and I was aggravated that it wasn't there.  Because it wasn't there, or I overlooked it, I spent more than an hour fiddling with the adjustments on the DVDO to no avail.  (For some reason, with 1080i output, the DVDO was not able to apply this underscan effect to compensate for the monitor overscan.  The Zoom and similar features could only expand the image, not make it smaller.  And changing from 16:9 and 4:3 didn't help either.

This puts more of the image on my TV screens (I've adjusted it now so you see everything) and thereby shrinks the image a bit, which makes it seem like better focus.

Still much room for improvement, and I still think the Powerbook display at 480i was much better.  The digital output to component that I am using now should be about 50% better still than the S-Video hookup, but it seems like the opposite.

I need to get some test patterns I can play through the Mac.


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