Problem watching sports with TBS6981

[fobos8]

Hi all

I recently started using the following setup;

TBS6981, Windows Media Centre, Windows 7, 12GB RAM, I7 processor, NVIDIA GeForce GTX660 graphics.

System requirements are surely met.

Watching the majority of TV is great but watching football is no fun at all. When the ball is kicked it apears like there are gaps as it is moving. It kind of reminds me of one of those match stick man flick books you made when you were a kid http://www.youtube.com/watch?v=-CKDwDEN0dk

I have tried many things to put it right;

varying settings in the graphics card
pressing 411 in windows media centre to get debug reveals a constant 50 frames
attaching a flatscreen TV
attaching a PC monitor
driver version is 2.0.1.5

Anyone got any ideas on what the problem is?

Any suggestions warmly recieved!

Regards, Andrew

[foxwood]

At a guess, the NVidia drivers are using a 60Hz refresh rate.

http://www.thegreenbutton.tv/forums/vie ... f=5&t=2010

[LuckyDay]

pressing 411 in windows media centre to get debug reveals a constant 50 frames

Well that can't be right can it? I assume you're watching a PAL channel, that should be 25fps right?

[fobos8]

Many thanks for the link to that thread.

I had the resolution and refresh rate (85Hz) of the graphics card set far too high. I'm using Intel 4000 HD graphics (I don't know why I said NVIDIA). I ran the wizard for setting the resolution and refresh which queries the monitor/tv and sets resolution and refresh to suit it. The resolution is much lower now and it has selected a refresh rate of 60Hz.

Sports is a lot better now - still not as good as my old set top box.

Any other tips on how to further improve things - it is still a bit juddery.

I've tried to set the refresh rate at 50 Hz as recommended in the thread link but there's no improvement.

Kind regards, Andrew

[CyberSimian]

Any other tips on how to further improve things - it is still a bit juddery.

Have you performed screen setup in Media Center? It is quite possible for Media Center to use settings different from those used for the Windows desktop, i.e. you may have used your graphics-card Control Panel to specify 50Hz for the desktop, but Media Center may still be using 60Hz for full-screen TV. You can certainly configure Media Center to use a different resolution compared to the desktop, but I am not sure whether that extends to being able to use a different refresh rate.

If you watch live TV in a window (i.e. not full screen), the TV image must be using the same refresh rate as the Windows desktop. Do you notice the same adverse effects on the TV image when viewed in a window?

-- from CyberSimian in the UK

[fobos8]

Hi CyberSimian and many thanks for your input.

Setting the refresh rate on my graphics card (Intel 4000 HD) to 50Hz is not an option in the list provided - however you can make a customized setting at 50Hz.

I didn't think you could adjust the refresh rates in WMC. The first time I tried to adjust the resolution settings I didn't see any refresh rates so I assumed you couldn't and that the refresh would be set to 60Hz. However at the bottom of the list of resolutions you can select "List all modes" which allows you to select many different refresh rates for various resolutions. So I now have it set to 50Hz.

Now I just need some sport to come on the TV!! I think there's some at the end of the week - I'll let you know how it goes.

Should the cable I used between the monitor and PC make any difference to how live video is presented from a PC? I'm using VGA to VGA as that's the only choice I have on my old Panasonic Plasma.

Kind regards, Andrew

[CyberSimian]

Does the cable I used between the monitor and PC make any difference to how live video is presented from a PC? I'm using VGA to VGA as that's the only choice I have on my old Panasonic Plasma.

The type of connection that you use between PC and screen can make a difference to what modes are supported (resolution and refresh rate).

With my screen (a Toshiba LCD TV), a DVI->HDMI connection allows me to choose 50Hz as the refresh rate, but a VGA->VGA connection does not -- I can pick only 60Hz or higher. The Nvidia Control Panel allows customised modes, and when I first set up my HTPC I did try creating a customised mode with 50Hz refresh on the VGA connection, but it resulted in a black screen, i.e. it was a mode that the screen did not support. I suspect that 50Hz may be a non-standard mode for VGA, and so it is up to the screen manufacturer to decide whether his products will support it. Evidently your Panasonic does, but my Toshiba does not.

-- from CyberSimian in the UK

[fobos8]

Hi all

Well just watching the Brazil - Italy football match. The flow of the football is a lot better now I have the refresh rate set to 50Hz - there is no juddering I can see - so I massive improvement.

However... when there is not much action such as the goalie pacing back to do his kick, camera showing manager, players walking around, views of the subs bench the picture looks great. But when the camera show a lot of the field and there is a lot of speed and action I have a awfull lot of blurring.

Is there anything I can do about this?

My TV is a very old Panasonic Plasma 42" (TH-42PWD6). In the spec the resolution for TV input is 1024 x 768 but it says that the max resolution for PC input (I'm using VGA as that's all there is) is 640x480 in 4:3 or 852 x480 in 16:9.

When I get my Intel 4000 HD grahics card to "query" the TV in its Wizard mode the closest resolution it offers is 800x600 so this is what I've been using.

So in Media Centre I have the resolution set to 800 x600 and this does give the best picture quality.

Do I need to get a TV which offers higher resolution for PC inputs or is there a less costly option?

Back to the football - great game by the way!

Cheers, Andrew

[LuckyDay]

I'm not familiar with this tuner card, is the signal you're receiving from the card an analog or HD one?

Analog channels sometimes display like this on higher resolutions. I have a problem with one of mine (also a football channel) where it does exactly what you're describing.

[fobos8]

I just noticed that when the camera is fixed and there is play going on even if the play is fast it is fairly clear. The blurring starts to get bad when the camera moves as the play moves up or down the field.

[CyberSimian]

when there is not much action such as the goalie pacing back to do his kick, camera showing manager, players walking around, views of the subs bench the picture looks great. But when the camera show a lot of the field and there is a lot of speed and action I have a awful lot of blurring.

It is not obvious what might be causing this effect. It is possible that it is caused by your elderly Panasonic with its limited resolution, in which case a brand spanking new TV would fix it. But it is equally possible that it is caused by the transmitted data stream being over-compressed, which is a problem that cannot be fixed by us viewers.

If you have access to alternative screens of a size similar to your Panasonic, you could try viewing football on them to see if they exhibit the same effect as your Panasonic. That might give you a clue as to the origin of this problem.

I am not a football aficionado, so I will have to leave it up to others to comment on the video quality of football on DVB-S/S2. Which channel(s) are you watching?

-- from CyberSimian in the UK

[fobos8]

I am not a football aficionado, so I will have to leave it up to others to comment on the video quality of football on DVB-S/S2. Which channel(s) are you watching?

When I used to watch football through my set top box the quality of the football was great so as the source is the same it should be the same through my PCIe tuner. The channels I watch are ITV and BBC in standard definition.

[milli260876]

Was your set top box scart? And on the same tv, ive had Intel graphics & tbs cards with no issue. I think the old tv/limited resolution suggestion is the winner....

[fobos8]

Hi there

Have tried same set up but with a 1080p TV and there is a big improvement.

Compared to using the TV's onboard FreeSat Reciever the picture quality is the same even on HD channels. However during sport when the camera moves to catch up with play moving up and down a field there is still some bluring of the image, eg the green of the grass blurs/pixelates during the camera movement and then corrects itself when the camera stops moving.

Any other ideas on what to try?

different graphics card? I'm currently using Intel's 4000 HD

Regards, Andrew

[milli260876]

Did u set the refresh rate correctly for the new tv?

[fobos8]

yes 50Hz and 1080p. Double checked in debug (411 Ctrl D) native video and display both 1920 x 1080 pixels and refresh 50Hz

[CyberSimian]

Have tried same set up but with a 1080p TV and there is a big improvement. Compared to using the TV's onboard FreeSat Reciever the picture quality is the same even on HD channels. However during sport when the camera moves to catch up with play moving up and down a field there is still some bluring of the image, eg the green of the grass blurs/pixelates during the camera movement and then corrects itself when the camera stops moving.

Am I right in thinking that the 1080p screen using its built-in Freesat tuner shows the same "blurring" in this situation as Media Center using the TBS tuner? If so, then you are probably seeing the visual artifacts produced by compression of the TV signal when it is transmitted.

UK TV runs at 25 frames/sec (50 interlaced fields/sec, where a field is half a frame). But digital TV does not transmit 25 complete frames every second. Instead, digital TV compresses the data by transmitting one complete frame (called a "key frame", I think), and then for the next "n" frames transmitting only the differences from the previous frame. If you think about a news reader sitting in a studio, most of the image in unchanging, so only the small movements of the news reader need to be transmitted for each frame. This gives a very great reduction in the size of the data stream transmitted. But when a camera pans quickly on a football pitch, virtually every frame is different from the preceding one, so (in principle) every frame transmitted needs to be a complete frame in order to reproduce all of the detail present. The broadcasters do not do this of course -- instead detail is discarded to reduce the data rate to a level that will not impact the other channels residing in the same MUX. As soon as the camera stops panning, the detail re-appears.

If your screen has any controls for sharpness or other similar-sounding settings, you could try varying those to see if that will produce an image that is more to your liking. But that may not be "maximum sharpness". I recently purchased a new smartphone, and was trying out its 8Mpix camera. It has three sharpness settings, and the one that produces the fewest visual artifacts is (to my eyes) minimum sharpness(!)

-- from CyberSimian in the UK

(who is wondering why Opera with its UK dictionary is highlighting "artifact" as being misspelled)

[fobos8]

Hi CyberSimian

Thanks for the detailed and interesting explanation. With the built in FreeSat tuner there is a small amount of blurring. With the TBS tuner there is noticeably more.

There is some more football on tonight so I will try adjusting the sharpness. I'll also try my PC (which has a super duper video card) instead of my HTPC to see if that makes any difference. I'll report back tomorrow.

All the best, Andrew

[milli260876]

Freesat is 1080i i think. Also itv is still dvb-s on some channels opposed to dvb-s2 there is a noticeable difference in quality in them as well. I'm sure i had my Intel rig set to interlaced...

[fobos8]

Well some good news!!

Watched some football again tonight on ITV HD. Managed to get a really good picture using the TBS card in my wife's PC. She has a Nvidia Geforce GTX660 card that she uses for CAD software. The picture is a lot crisper and less blurred. There is a little bit of blurring when the camera moves quickly but this almost instantaneously corrects itself. Pretty much the same quality as the TV's onboard Freesat HD.

At half time I switched the TBS card back into my HTPC with Intel 4000 HD graphics. There's more blurring which takes a longer to settle after camera has stopped moving. In general the picture quality and whole viewing experience is worse. I tried all manner of settings for the graphics card; noise reduction levels, sharpness levels. I also played around with the sharpness settings of the TV with no joy.

I also tried the Intel card on Interlaced mode and everything went purple!!

Thing is how do I now manage to get a graphics card in my Streacom case? I already have a soundcard in there which is definately not coming out and the TBS card. The printed circuit board will take another PCIe card but there is no extra "proper" slot on the case. There is space in the case though - so do I get a drill out and some self tapping screws and get it on there??

Of should I get another case with 3 slots?

Kind regards, Andrew