[mythtv-users] [OT] 1080i

[Brad Templeton]

On Tue, Mar 01, 2005 at 09:50:01AM -0500, Andrew Gallatin wrote:
> Brad Templeton [brad+myth at templetons.com] wrote:
> > > So this leaves me with the Audio Authority 9A60.  Does going out
> > > the VGA port work around the nvidia interlace bug?  I've seen
> > > this implied, but I don't think anybody has actually come out and
> > > said it.   If this works, why are people (from the 6600GT thread)
> > > so eager to ditch their 9A60?
> > 
> > The VGA port will not have the interlace bug, you can make it work
> > using the Audio authority.
> 
> Great.  Thanks.
> 
> > Your TV may be one of the ones that actually has 1080 lines so if that's
> > true you will want the full res.  For 720/768 line TVs, running at that
> > resolution and having xv downscale is actually a good choice.
> 
> I wish there was some way to know.  The TV itself offers 1080i
> (actually 1920x540p) and 480p modes via ddc.  But the docs say it
> supports 720p also via DVI.
> 
> The interesting thing is that my powerbook finds 2 modes. 1920x540p
> (which looks awful, and there is no way to get a mac to interlace), 
> and 720p.  I wish I knew where it was getting the 720p mode from.

It seems to be the case that most TVs over the EDID do not report interlaced
resolutions and instead offer 1920x540.

Almost every HDTV will take 1080i input, and that is what many set top
boxes do as their output.

Remarkably, only some TVs will take 720p, even a few of the TVs for which
that is the native resolution!!!   This is improving.

Very few TVs actually can handle 1080 lines.   The Sony XBR and some other
traditional CRTs do.  (After all, we have had 1080 lines on traditional
CRTs for ages, I am typing this on one.)

If there are plasma or LCD TVs with 1080 lines they are very rare and
very, very expensive.   Ditto DLP or LCoS.

If you paid less than about $7,000 for a non-CRT it is probably not
1080 lines.

Rear CRT projection I am less sure of.  They have little 7" and 9" CRTs
inside, and the number of lines they can do depends on their electronics etc.
but they could be capable of it.  However, my own examination suggested
that whatever their electronics can do, their optics might not be up to it.

Somewhere your tv's manual should talk about its native resolution, though
there are cases of tvs that lie about this, and call the native res the
format they convert all signals to.   For example, a TV that converts 480i
to 1080i first before scaling it to 1280x720 might well pretend that
1080i is the native res.