[mythtv-users] Pull my hair out over DVI->HDMI for my HDTV

Robert Denier denier at umr.edu
Fri Oct 14 01:26:47 EDT 2005

One thing I find interesting is that
1920x1080=2073600 and
1600x1200=1920000 (common dvi resolution for lcd displays.)

So from a pure bandwidth prospective DVI might be able to handle it.
I'm not sure this is useful but I figured out a combinations that should
take similar bandwidth to 1600x1200 and are the same aspect ratio as

1920x1080 = 2073600     <-- HDTV res
1920/1080 = 1.777       <-- HDTV pixel aspect ratio

[A smaller resolution that should be similar bandwidth to 1600x1200]
1848 x 1040 = 1921920
1848/1040 = 1.777
%screen utilization = 1921920/2073600 = 93%

[Slightly smaller still.]
1840x1032= 1898880
1840/1032= 1.78
$screen utilization = 92%

I suspect either the dvi spec just doesn't support it, or maybe the
chips used can't handle that rate.  Still if someone was bored and could
enter an arbitrary resolution, I'd be curious what is the highest dvi
resolution obtainable was.  I suppose the results are not terribly
interesting other than from an academic standpoint since most people
wouldn't want to give up a significant amount of screen area regardless.

-Robert Denier

On Thu, 2005-10-13 at 22:27 -0600, Greg Grotsky wrote:
> John, it is a DVI limitation because your video card is sending a
> digital signal to the TV and it's displaying 1:1. meaning one pixel
> from the video card to one pixel on the TV.  You won't be able to
> adjust the overscan or scale the picture since it is a digital signal.
> Using a digital signal will give you the clearest possible picture and
> it was what I wanted but I changed my mind mid-purchase (and actually
> returned two TVs).  I went analog (D-sub) so I could scale the screen
> down to fit on the TV, I play lots of games on my TV and in order to
> see the status bars on the edges of the screen I had to switch to
> analog mode anyway (the DVI port cuts about an inch off all four sides
> of the picture).  Besides, I'm happy that I went analog because I got
> Sammy's new 5678W which does 1920x1080p, the thing they don't
> advertise is that you can't get a 1080p transmission over anything but
> the D-sub plug.  DVI/HDMI doesn't support those high bandwidths
> (yet?).
> Good luck, and if you need more modelines, I have all the ones for my
> TV from powerstrip.
> -Greg
> On 10/13/05, John Clabaugh <bubbaslash at gmail.com> wrote:
>         Here are a few that work for my Sammy DLP via the DVI port:
>                 ModeLine     "1280x720" 74.2 1280 1390 1430 1650 720
>         725 730 750
>                 ModeLine     "ATSC-720-60p1" 74.2 1280 1320 1376 1648
>         720 722 728 750
>                 ModeLine     "ATSC-720-60p2" 74.2 1280 1320 1376 1650
>         720 722 728 750
>         I still get overscan that I can't adjust out with
>         modelines.  Is that
>         is a DVI limitation?
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