Problems with interlaced output on a Nvidia 6600

[sbrushey]

Hi,

I have tried a Gigabyte 6600 connected to my LCD TV with varius inputs...

1) VGA @ 640 x 480 (native res of LCD)
2) Component @ 720 x 576 progressive - 576p
3) Component @ 720 x 576 interlaced - 576i
4) SVideo @ 720 x 576 interlaced - 576i

The two progressive options (1 and 2) give a great picture (with component looking the best to me) but I notice minor de-interlacing issues with some scenes.

When I use the interlaced outputs (3 and 4) I get good playback initially but after a while trails start to appear on any movement. Sometimes this also happens if you jump forward or back or use pause... but the same buttons can get everything running smoothly again.

I really want to use the component output interlaced and set the PureVideo decoder to film mode (no deinterlacing) as this gives me the best picture.

I read this post http://forums.nextpvr.com/showthread.php?t=15673 where someone is trying to do the same and noted Csy's comment at the end of his first post that "the TV-out encoder chips on Nvidia and ATI video cards appear to free-run, resulting in periodic dropping or gaining a field. The problem is each field slip results in swapping the field order presentation to the SDTV, therefore resulting in double-difference interlacing jaggies seen on the TV when motion occurs. So this shows up as say 2 minutes of smooth motion then 2 minutes of juddering motion, repeating."

This seems exactly what I am seeing here. Does anyone else successfully run the SVideo or Component interlaced outputs to a TV?

Many thanks
Simon

[daza67]

Simon,

What your describing sounds like the dx9c quartz.ll bug, see here http://forums.nextpvr.com/showthread.php?t=5600

Daza

[daza67]

Set your resolution to the native resolution of your display to get 1:1 pixel mapping. Let the graphics card do the scaling, this will avoid the crappy scaler built into most tv/monitors.

Also make sure you set the refresh rate to a multiple of the frame rate of the video material your trying to display. 75Hz or 50Hz is a good option in PAL land for interlaced material at 25fps, this will ensure stutter free smooth pans.

Daza

[csy]

LCD displays are progressive format therefore you MUST deinterlace. If you send an interlaced signal to the LCD display then it will deinterlace anyway (and very poorly, as you have experienced). The only way of getting good quality video is to use a progressive format interface linking to the display (your quoted options 1 & 2)

What is physical number of horizontal and vertical pixels on your screen (native resolution). I don't believe it is a low as 640x480 unless it is a very old first generation LCD display and even then I would be surprised.

Your best quality interface is VGA running at true native resolution.

Your deinterlacing issues on options 1 & 2, are due to either poor deinterlacing in your PC or slow pixel response time. You can quickly check the pixel response time by opening a page of black text on white background (eg MS-Word doc) and using the right-hand scroll bar to move the text up and down really fast. If the pixel response time is poor you will see the text bluring or changing colours. With respect to your PC deinterlacing functionality, you need a graphics card supporting hardware deinterlacing and configure your PC to use that.