Poor Live TV Quality....Why?

[dazza]

Hi All,

I have a Nova DVB-S2 HD tuner card and a Sky subscription. The quality of live TV (SD channels) through W7 MCE compared to that of the Sky HD box is poor. Can anyone advise why and what I can do to bring it to at least the same as the Sky STB if that's possible?

I have an Nvidia graphics card.

Thanks
Dazza

[newfiend]

By poor quality do you mean poor picture quality? As in the video looks less vibrant? Or are you having tuner issues where the picture is having problems tuning?

Sent from my SGH-i937 using Board Express

[newfiend]

And FYI.. SD channels will always look bad compared to an HD source and box, although media center can display both types well.
what NVIDIA card do you have?
Sent from my SGH-i937 using Board Express

[dazza]

The picture quality is reminiscent of what I have before the direct tuners where I used a PVR 150 capture card via composite scart adaptor connected to the Sky box. Perhaps a little better than that but not much!

The GPU is an Nvidia 8400 GS

[STC]

What settings and tweaks do you have your Nvidia video output set to?
Its common practice to disable all of the video processing settings. Dynamic contrast being a main culprit.

[holidayboy]

^ +1

Check all options in the graphics driver utility, my Freesat picture is pretty awesome.

Are you running 1080p @50HZ, with the TV set to 1:1 scaling (maybe called just display, or no scaling or similar wording)?

You can try playing around with the graphics settings in order to add or lose some sharpness etc, that can help with the "blocky" look of SD channels - you will find that the HD channels don't look as good if you play around too much though.

The Sky boxes probably handle video scaling 'better' in that the channels look better to us, there is maybe some enhancement going on behind the scenes, or it could just be that the video scaler built into the box is doing a better job (I'm sure that Mr Murdoch wouldn't scrimp on component quality in order to raise profit margins )

[dazza]

running at 1920x1080@60HZ. Don't see a 50HZ option in Nvidia control panel. TV is on Just Scan.

[holidayboy]

50HZ might help a bit.

Try right clicking on the desktop, click screen resolution>advanced settings>monitors tab and see if you can find 50HZ there.

You will need to set Media Center to 50Hz as well, there is a 7MC reg key to disable refresh rate change so that it matches the desktop setting. I'll try and find it later.

You can try setting a different resolution and refresh rate in MC (720p@50HZ maybe) and preview the setting before finishing, then set to 1080p@50 in order to force the change (60HZ tends to stick if you don't preview the change).

[dazza]

I've created a custom resolution of 1920 x 1080 @ 50HZ. That reg key could be handy. Once I have that I'll plug the coax back in to the tuner card and give it a roll but if the picture quality isn't as good then the wife will veto it!

[holidayboy]

Here it is, set it to 0 while Media Center is closed and the desktop is set to 50HZ.

A reboot can't hurt either I guess but I don't think it's absolutely necessary.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Media Center\Settings\DisplayService\EnableRefreshRateChange


You can also set the logical and physical sizes as well as the refresh rate (50 decimal) in the same key.

[richard1980]

Also, calibrate the GPU...brightness, contrast, gamma, etc. I use two tools, one to calibrate the desktop and one to calibrate video. Calibrate the desktop first using the different pictures available here. For video calibration, I use the MP4 files found here.

[CyberSimian]

running at 1920x1080@60HZ. Don't see a 50HZ option in Nvidia control panel. TV is on Just Scan.

I do not have Sky, but I was under the impression that high definition from Sky is in fact 720p (or maybe even 720i), bit not 1080i.

If Sky is 720p, it means that the HTPC will be doing the pixel remapping from 720p to 1080i, in order to send 1080i to your TV. In contrast, if you connect the Sky box to the TV, it will be the TV that does the remapping from 720p to 1080i. Would this explain the difference? I note that HolidayBoy receives an excellent picture, suggesting that the Media Center or graphics card pixel remapper is not lacking in quality.

-- from CyberSimian in the UK

EDIT: On re-reading your original post, I see that you were in fact complaining about the quality of standard definition TV, which is... 576i ? So there is still the issue of the pixel remapping being done in different places.