[mythtv-users] Objective IVTV quality measurement instructions

Jay R. Ashworth jra at baylink.com
Sat Aug 14 11:31:25 EDT 2004

On Sat, Aug 14, 2004 at 10:55:42AM -0400, Cory Papenfuss wrote:
> > *Ghod*, I love grad students.
>  	... that would rather work on fun stuff like mythtv than their 
> research, no less... :)

Well, Hell, Cory; if you can't find a way to make your MythTV *be* part
of your research, you're not much of a damned grad student, are you?  ;-)

> > I'll be trying this out in the next day or three, Cory; thanks.  Does
> > the image have any other useful test patterns on it?  I align a fair
> > number of TV's and projectors in a year...
>   It's just a work in progress. I collected a few more test images.
> I don't really believe the colorbars' accuracy (not sure if you can
> even *generate* a true colorbar pattern with COTS hardware like a
> DVD player). There's a B&W gamma pattern, and a simple aspect-ratio
> geometry pattern. I was mainly after the resolution test pattern.

You can't guarantee linearity -- you're actually *testing linearity* --
but the only think I don't know that you can do reliabily is PLUGE
bards; I don't know if the bits go to 7.5IRE or 0.  It's the usual
problem in digital video gear; consumer gear usually opts for 7.5, but
th einconsistencey causes apparent gamma errors between program

>   Shortly after I announced this a few months back, someone asked for
> a PAL version. I think I tried to generate it and put it up there. All
> of this comes with a HUGE YMMV disclaimer... :)

Remember, on DVD, the only different is the frame rate and the
resolution; the *player* does the color.

>   Actually, for my own resolution tests, I hacked up a modeline and
> had the computer generate the test signal at 1800x480. A DVD player at
> 720x480 is not too bad, though.

We'll see in a couple days.
-- j
Jay R. Ashworth                                                jra at baylink.com
Designer                          Baylink                             RFC 2100
Ashworth & Associates        The Things I Think                        '87 e24
St Petersburg FL USA      http://baylink.pitas.com             +1 727 647 1274

	"You know: I'm a fan of photosynthesis as much as the next guy,
	but if God merely wanted us to smell the flowers, he wouldn't 
	have invented a 3GHz microprocessor and a 3D graphics board."
					-- Luke Girardi

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