Resolution Help (Stuttering)

[Evil_Attorney]

Ok, I need some help regarding which resolutions I should have my pc set to, because I suspect it is causing "micro stuttering" or frame dropping.

First, the problem is slight, but can be seen on horizontal scrolling on TV. For example, the CNN ticker micro stutters almost every second. Panning on DVD's shows the same problem, however it's not every second...more like once every few seconds. This leads me to believe that my problem relates to frames being dropped because of a mismatch between the framerate of the MPG file and the TV resolution.

I have a BFG 6600gt oc for a video card and an a 30 inch Syntax Olevia http://www.syntaxgroups.com/products..._productd.html connected via DVI. The Syntax supports all sorts of computer resolutions and has the 3/2 pulldown.

Currently, my card is set to 1040x768 @60. I've tried to set the NVIDIA drivers to an "HDTV" setting, such as 1040i, but they don't seem to stick.

Can anyone suggest how and what resolution to set my card to? Thanks.

[Kanati]

Sounds like "tearing" to me... On games tearing is caused by tossing video at the screen without regards to the refresh rate. So while the video in memory is getting updated very very fast, the screen refresh happens to catch it mid-refresh in memory. So you get a slight "ripple" or stutter in the picture.

Look in the nvidia drivers for a "force vertical sync" or something to that effect. That will cause the picture in memory to only update with the veritcal sync of the monitor or tv in this case.

That might not be your problem, but that's what it SOUNDS like.

kanati

[Evil_Attorney]

My driver has the vsync set for application control. I've tried it in the forced on mode, with no changes.

Am I wrong in thinking that this is a problem? I think tv is 29.97fps and movies are 23.976 fps. Therefore, unless Sage somehow adjusts the refresh rate, some frames will be lost, causing a stutter.

[blade]

Are you running overlay or vmr9?

I have a 6600GT running at 17xx*1006 (I forget the exact resolution) and I can not run vmr9 at all due to the stuttering.



Also are you using the default, nvidia, or nvidia post processing for your decoder?

Even using overlay if I try to use the nvidia post processing I sometimes get stuttering on the fox news ticker .


I run my settings on overlay, with the default decoder (the nvidia decoder)

[Evil_Attorney]

It shows the exact same micro stuttering with any decoder (nvidia, cyberlink, intervideo, sage) with any resolution (640x480 through 1280x1024) in overlay. With nvidia vmr9, it microstutters and tears, so I stopped messing with that a while ago.

[bartley9]

Have you tried running task manager and checking your cpu.

[Kanati]

try copying one of the shows in question to another computer and playing it on a monitor to see if it's frames getting dropped from the encoding or during playback. If it looks fine on another computer then it's not the encoding. If it's fine, then play it on your sage box with an external player and see if that screws up as well. Try it on a monitor hooked to your sage box... You just have to start eliminating things logically.

[Evil_Attorney]

My CPU it around 10% while sage plays shows. I haven't tried them on another computer, but I'll try that tonight.

Last night I was searching around and found a program called reclock. http://reclock.free.fr/ That made a big difference. The picture is VERY smooth now, much like a normal TV. You can see microstutters are there on horizontal motion, but they are much less perceptible. I'm going to play around with the settings tonight to see if I can improve it even more. Here's Reclock's description from the website:

Description:
The purpose of ReClock is to definitely get rid of jerky playback of AVI and MPEG material on a PC (or a PC connected to a TV). It's a DirectShow filter which is loaded in place of the default directsound audio renderer.
It provides a new reference clock that is locked to the video card hardware clock, in order to ensure that frames are played at the exact speed of what is expected by the video card vertical sync.
It also provides a frame rate adaptator for media files that do not match a multiple of the video card refresh rate (ex: playback of 23,976fps IVTC NTSC on a PAL TV).
Finally it is an audio renderer with hardware or software rate adaptation in real-time, multi-channel audio, and dynamic range compression capabilities.
For a full description of ReClock, please read carefully the README file in the distribution. There is also a little FAQ at the bottom of the page that answers common questions.

[Evil_Attorney]

I've been playing around with reclock and it has drastically improved the micro stuttering, although it hasn't completely eliminated it. The other interesting thing is that vmr9 gave me bad tearing before, but after reclock it works with just a few little microstutters.

So, for those of you who haven't been able to get vmr9 working without tearing, try reclock on the "auto" setting with your monitor set to 60 hz refresh. The 60 hz refresh appears to be important because reclock adjusts the fps to be a multiple of the refresh rate, and 30 is the closest multiple.

[Kanati]

I'll have to give this a try as I am running 1080i which is 30hz anyway...

[g-man]

Thanks for the input Evil_Attorney, I actually had the same exact problem you were having and fixed it also with ReClock. I have the same Olevia 30" LCD with a VGA connection from a Volari V3XT. I still see micro-stutters, but nothing like I was seeing without reclock.

I use VMR9 with FFDShow from a s-video connection through Directv. I actually get better quality than with a direct connection from Dtv to the LCD. I also switched down to 60hz and the picture is as good as it gets from stv.

Thanks for the research!

[Evil_Attorney]

The question is, is that as good as it gets? Is everyone else getting the occaisonal microstutter and just doesn't know it? Or do they have some hardware component that prevents the stutters. At one point or another I've upgraded almost everything on my machine, like the HD, memory, video board, sound card, etc, except the motherboard. So, either some motherboards are causing problems or other people aren't as sensitive to the stuttering.

BTW, one of the added benefits of reclock is the sound compressor that you can activate, which will level out the volume. It's especially nice with cable where some channels are quiet and some are louder or with quiet shows and commercials.

[Kanati]

I think I know what you are talking about now... I never noticed it on anything but divx files, and thought it was just the file itself. But now I understand. And no, I haven't found anything yet that fixes it entirely but reclock does a good job of reducing it.

[Evil_Attorney]

According to reclock, the problem is imperfect time of the sound board. I originally had SoundBlaster Live, but my system wasn't getting good air flow, so I removed it for an external USB SB Extigy. I didn't notice that changing them made a difference.

What sound cards are others with micro stutters using?

[g-man]

I am running the on board sound from an Abit VA-10 (VT6106: 6-ch Audio on board with digital S/PDIF output). I want to keep my slots open for more tuner cards and the digital out straight from the MB works very well.

As far as "as good as it gets", I get a great picture from every channel even sports. I would like to clear up the microstutter as I am sure it is there on all the channels but only noticable with the scroll. Currently that is my only complaint, well except for the OSD from Directv. When changing channels I would like to get rid of the delay from the Directv OSD as changing channels becomes very clunky. If anyone has a suggestion please let me know.

[Evil_Attorney]

G-man, I compared the specs on your MB and Mine: http://www.ecsusa.com/products/PM800-M2.html

It looks like they have some similarities, such as a similar integrated SB (which I disabled in the bios), similar integrated graphics cards (which I also disabled in the bios), and VIA chipsets.

I wonder if some VIA boards have timing issues.

[g-man]

Hmm, have you tried connecting a reqular TV to the media center instead of the LCD? If I get a free minute later I may try to do that to see if it goes away. This would at least narrow down the issue.

[Evil_Attorney]

Last night I tried a recently recorded show on another Dell computer I have. Since Sage isn't installed, I used PowerDVD to play it. It didn't appear like there were microstutters, but I'll record some sports and give it a better test.

I have not tried a regular TV. My video card only has DVI out, so it's a little difficult. However, maybe I'll try another monitor I have. I could be the Olevia that's causing the problem.

G-man, does your motherboard have SATA? This was causing me major problems a few months ago. Apparently the SATA hard drives are treated like RAID drives, which prevented Sage from recognizing my PVR cards. Apparently there were conflicts, because in one configuration, I got the blue screen of death.

[Evil_Attorney]

Holy crap. I think I finally found my problem. I just connected an old 15" Dell monitor to my PVR machine. Guess what...no microstutter. No microstutter on sports, no microstutter on CNN/Fox/MSN scolls. The problem is the Olevia. I don't know why this would be. Maybe the 3/2 pull down doesn't work right? Maybe the "monitor modes" are very innacurate in their refresh rates.

[g-man]

I have heard that the larger LCD screens have some milliseconds issues that cause artifacting etc.. This is all off the top of my head, but we are heading down the right path.