Screen Flickering on Sony HDTV RP LCD

[jasmithvr6]

I originally had my HTPC hooked up to an old 32" beast using a digital coax cable for audio (through a Yamaha RX-V1000 receiver) and an S-Video cable (best connection the TV accepted) for video. Although the picture quality left a lot to be desired, the Sage box was rock solid for a good 3 months. No lockups, no crashes, nadda! I also was running VMR9 without a hitch (presuming VMR9 is with translucent menus). The HTPC box consists of the following:

Software:
Windows XP Pro (SP1a)
Sonic Decoder Pack
Catalyst 4.6 (previously running Cat 4.2 in old setup)
SageTV 2.02

Hardware:
P4 2.4ghz (533FSB)
Intel 865 PERL MB
ATI Radeon 9600 (non-pro)
SoundMax onboard sound
512mb Kingston running in dual channel
Lite-On 16x DVD Drive

After the old 32" tube finally bit the big one, I stepped up to a HDTV Sony 50" Rear Projection LCD. Awesome TV by the way, but that's besides the point. I hooked up the Sage box to the new set via a DVI connection and the same digital coax used before. I've set the TV monitor driver to Sony GWD-900 and pumped up the resolution to 1920x1080 using Powerstrip (previously not used under the old setup). Granted the overscan is a bit annoying under this resolution, but I've compensated for it in Sage. And seeing as I don't use the HTPC for anything other than Sage, which loads full screen at startup. I'm not too concerned about the overscan issue in Windows.

So the picture quality is out of control...well for about 18-24 hours anyway, at which time the screen flickers wildly to the point that I can't even see the screen to shut down properly. I've read that dropping the resolution to 1776x1000 may help, so I gave it a shot. Problem being is that when I restart the machine I'm faced with an entirely black screen. As a matter of fact, I get the same black screen on a few other screen resolutions, so I kept it at the 1900x1080. Then I did some research on ATI's website. There's a box that can be checked under Display Settings / Advanced / Options labled 'Reduce DVI Frequency on High Resolution Displays'. According to ATI's tech support, checking that box may help to prevent horizontal lines, flickering, and screen glitches, but goes on to mention that it should only apply to Radeon 7500 and 8500 cards.

http://mirror.ati.com/support/infobase/3992.html

So I checked the box anyway just for grins...still have the problem. I'm not sure what else to do at this point. I'm almost tempted to try running S-Video again to see if I can recreate the problem. Like I said before, this thing was as stable as stable could be before I switched over to the HDTV. It might also be worth noting that I have not been able to get VMR9 operational on the new setup and am currently using Overlay (which I'm not too crazy about). Any suggestions on the screen flickering problem?!?

[stanger89]

Your TV can't display interlaced resolutions natively, try dropping the resolution to 1280x720 or 1366x768 @ 60 Hz

[jasmithvr6]

Thanks for the adivce stranger89. I dropped the rez down to 1280x720 (couldn't get 1366x768 to work) and after 2 days the HTPC has been lockup free. But I had a few questions/concerns after changing over to the lower resolution:

1. There's a noticable deterioration in picture quality between 1900x1080 and 1280x720 displays settings (go figure!). The Sage menus, text and overall quality is not as crisp in 1280x720 as it was under 1900x1080. When I was running the higher rez, I didn't have any problems with screen flickering while watching TV, movies or listening to music. The only time it would crap out was when I would put it to sleep for an extended period of time (i.e. at night or while I was at work). When I would turn on the TV and go to bring it back up, the screen flickering would be going full strength. My question is, do you know if there's a way to force the 1900x1080 resolution or to maybe trick the HPTC into using this higher rez more reliably?

2. Under the 1280x720 rez I've noticed some ghosting and/or shadowing of images, especially when there's movement on the screen (mostly sports, but I've seen it with far less movement as well). Do you know anything about this or how to correct it?

3. Under both resolutions, anything that is white on the screen seems to be bleached out. I've tried messing with the 'picture settings' within the TV video adjustments, but it hasn't seemed to help. Before I go screwing around with any other settings, I thought I would ask if you had any suggestions.

4. And lastly...I mentioned that in running my old setup I had translucent menus within Sage (which presumably meant I was running VMR). With the new TV and DVI hookup, I'm not getting translucent menus, even though I have VMR enabled within the Sonic Decoders and Sage. I'm guessing it's only pushing Overlay. Any thoughts on how to force VMR?

Thanks again for your help!

[Ducky]

Originally posted by jasmithvr6
1. There's a noticable deterioration in picture quality between 1900x1080 and 1280x720 displays settings (go figure!). The Sage menus, text and overall quality is not as crisp in 1280x720 as it was under 1900x1080. When I was running the higher rez, I didn't have any problems with screen flickering while watching TV, movies or listening to music. The only time it would crap out was when I would put it to sleep for an extended period of time (i.e. at night or while I was at work). When I would turn on the TV and go to bring it back up, the screen flickering would be going full strength. My question is, do you know if there's a way to force the 1900x1080 resolution or to maybe trick the HPTC into using this higher rez more reliably?

That's actually expected -- LCD TVs have fixed resolutions. 1900x1080 is probably its native resolution, so 1280x720 is done by converting 1280x720 back up to 1900x1080, which would be less sharp because of pixel "stretching."

[salsbst]

<-- not familiar with this setup, but is there any reason not to go for 1920x1080p?

[stanger89]

I'm assuming that's a Grand Wega, those have a native resolution of 1366x768 (or something close). There are only a very few digital displays that are 1920x1080 native and they are all LCoS AFIAK.

You might want to look here:
http://www.avsforum.com/avs-vb/showt...hreadid=362324

[jasmithvr6]

That's actually expected -- LCD TVs have fixed resolutions. 1900x1080 is probably its native resolution, so 1280x720 is done by converting 1280x720 back up to 1900x1080, which would be less sharp because of pixel "stretching."

Just a quick clarification on my part. When I was referring to the 1900x1080i resolution, I actually meant 1920x1080i.

By running a 1280x720i rez, I figured it would be converting it to a 1920x1080i rez (presuming that's the TVs native resolution). I'm using a Sony GDW-900 driver, which supports rez up to 1920x1080i. I get an absoutely perfect picture for about 24 hours, but when I put Sage to sleep the screen flickering problem strikes again (not sure for how long Sage is asleep before it happens, since I can't bring myself to watch the screen saver for more than about 2 minutes).

I'm assuming that's a Grand Wega, those have a native resolution of 1366x768 (or something close). There are only a very few digital displays that are 1920x1080 native and they are all LCoS AFIAK.

Yes it's a 50" Grand Wega. I was running the 1280x720i rez for a few days without any screen flickering issues. Low and behold...screen flickering by the 3rd day. On both the 1920 and the 1280, I was watching TV, recording shows and enjoying all the functions of Sage. Once the screen is flickering, it's completely unusable (although shows are still recorded).

I'll give the 1366x768i rez a try and see what happens. I've been having problems changing resolutions (both in and out of PS), whereby the screen goes completely black. I took a look at the thread you sent, but haven't gone completely through everything. The only problem is all of the links to files that were hosted are no longer valid. I'll drop a message on the board to see what's up.

Thanks again for your help!

[stanger89]

No it's not 720i it's 720p. I know my desktop LCD (19" samsung) hate's interlaced resolutions, haven't had the pleasure of playing with an HT type LCD.

[kny3twalker]

enable 3d acceleration for VMR9 in SageTV
also I looked up this cause I had no idea what it was but here
LCoS
http://www.intel.com/design/celect/technology/lcos/
good article