[bbeattie]

I've been asked how someone can get 1080i output for a HDTV. The person has been unable to get an nvidia card to do the 1080i. So what can people recommend? I only deal with my 1024x576p custom resolution.


Thanks,


--Brandon

 

[dododge]

Quote:

Originally posted by bbeattie I've been asked how someone can get 1080i output for a HDTV. The person has been unable to get an nvidia card to do the 1080i. So what can people recommend? I only deal with my 1024x576p custom resolution.

Does it have to truly be interlaced?


My finicky first-generation display only accepts 1080i, but I've managed to trick it into taking 540p from my Linux machine (with GeForce2 GTS at the time). I used a Key Digital KD-VTCA1 to convert the output to YPrPb. Horizontal resolution didn't matter much since this was analog output and what the display mainly cared about was the sync rates being close enough to 1080i. In my case the display could only truly resolve 480 lines anyway, so dropping the interlacing didn't really damage the image quality.


Here's some XF86Config data that the display could sync to, though my notes say there was a lot of overscan and some tearing on the right edge. I don't know if the image problems were with the timings or the equipment:


Mode "960x540"

DotClock 37.26

HTimings 960 976 1008 1104

VTimings 540 542 548 563

Flags "+HSync" "+VSync"

EndMode


Other options: if you can find a set-top box, tuner, or maybe DVHS player with Firewire input, you might be able to send a transport stream directly to it and offload the MPEG decoding and scaling as an added bonus.


An 8VSB output card would provide the same functionality with pretty much any terrestrial set-top box, but I've yet to find such a device at a non-astronomical price.


Occasionally a high-end scaler that can produce HDTV output will show up cheap on eBay, so that's another option though it might involve multiple analog-digital-analog conversions.

 

[hdtv_moron]

I would recommend the following modelines to deal with overscan. This works perfectly with my Pioneer SD532-HD5 RPTV.


Modeline "856x480p" 36.547 856 920 952 1080 480 506 512 564

 

[jarodwilson]

Quote:

Originally posted by dododge Does it have to truly be interlaced?

The answer would appear to be no. I'm the one who asked bbeattie about what I needed to feed my TV. A bit more on my setup:


-Panasonic 47" rear-projection HDTV (model PT-47WX49E, mfg April 2001)

-Linux HTPC w/GF4MX video card

-Audio Authority VGA->Component adapter


Quote:

My finicky first-generation display only accepts 1080i, but I've managed to trick it into taking 540p from my Linux machine

This does appear to do the trick, or at least provide vastly better results that I'd been getting previously... Not sure why I never got powerstrip on my XP box to work at that setting though (perhaps I skipped it for some stupid reason).

Quote:

Here's some XF86Config data that the display could sync to, though my notes say there was a lot of overscan and some tearing on the right edge. I don't know if the image problems were with the timings or the equipment: Mode "960x540" DotClock 37.26 HTimings 960 976 1008 1104 VTimings 540 542 548 563 Flags "+HSync" "+VSync" EndMode

I've tried this, with some slight variations. With the exact setup you spec'd, I also get lots of overscan, and some slight tearing on the top right of the display. I've eliminated the tear, but I'm still working on the overscan...


Oh, and the 856x480p modeline suggested by hdtv_moron as a possible fix doesn't have desirable results on my display (the original version is much better). I'll keep reading and tweaking...

 

[ddennedy]

Do the new NVidia cards do interlace output at all? I thought I read they do not; only some older models do.