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Discussion Starter · #1 ·
Hi,

I am experimenting with my new HTPC and I observed that if I hook up my DirecTv directly to my Sony Wega (Direct View) then TV picture quality is much better than if I hook up the signal to my ATI AIW 7500 and then via S-Video to my Sony Wega.


This leads me to the following questions:

* Is ATI's comb filter so much inferior to what Sony uses?

* Are there other picture quality related processing features in a TV that are not present in a cheap TV card (like the AIW)?

* Is there a way to enhance the picture quality in my HTPC using equivalent software filters/processors?


Thanks, Thomas
 

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The problem here is that you are not adding anything to the setup. You start with a 480i picture coming in from the DirecTV and then you send a 480i picture out to the TV. All you can do reduce picture quality by the extra processing and cabling and noise in the PC.


HTPC is unlikely to ever give a better picture than dedicated devices/connections to the TV as long as you use Composite/S Video. Component connections like ATI does work better, with progressive scan via RGBHV or compnnent and a transcoder better still.


What are you trying to achieve here. PC on the TV or just improve PQ with HTPC processing ?
 

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Discussion Starter · #3 ·
Quote:
What are you trying to achieve here. PC on the TV or just improve PQ with HTPC processing ?
In the above scenario I am trying to use my HTPC for recording TV shows and for time shifting. So I was expecting a certain loss in quality when the TV signal runs through my HTPC, but the picture produced from my HTPC is really not nearly as crisp as the native TV signal.


The suggestion using component connectors doesn't work for me, because the best I can do with my equipment is using S-Video right now.


I am trying to figure out what other than cabeling can cause the loss in quality:


Is it ATI's comb filter? Because when I send the signal to my TV via S-Video I am bypassing my Sony's comb filter.


Is it the deinterlacing or other filters that are applied during the TV-in process? I hope the the deinterlacing is using Bob and produces 60 fields second, because I set my TV resolution to 640x480 60Hz. Then the TV-out module should create one frame with two fields at 30fps. How can I check that this theory actually is true?


Any ideas?


Thanks, Thomas
 

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Deinterlacing the input into the puter will mean nothing if you are just re-interlacing on the way out. Set your dScaler de-interlacing to scalerbob as that turns off de-interlacing
 

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I have a ATI AIW 8500 card that is connected to my HDTV using component cable. I have all latest driver and software installed. I notice the TV quality is much worse than before (I was using a composite cable, yes, "Composite".) There are lots of noise in the picture.


Anybody has any opinion on that?


Thanks a lot.
 

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I agree with SIMJEDI - unfortunately, the TV-out on most (all?) video cards, not to mention all reasonably-priced VGA->TV converters, is remarkably bad. Poor color saturation and blurry output.


And, for the price of a high-quality converter, you could buy a Tivo anyways :(


Iff your TV can't support VGA-input, stay away from HTPCs for high-quality (or even medium-quality) Video.


Andy K.
 

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I disagree with kromkamp, I use an ATI 8500DV with svideo in from my satellite receiver, run throuh dscaler and then out again through svideo to my standard def projection TV. I actually had to descrease the svideo output sharpness on the ATI becasue it was too clear and showed off all the compression artifacts that usually got lost in the signal. I now run it through some noise filters in dscaler and output it and it looks much better than the original.
 

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Discussion Starter · #8 ·
Kelmk,

you are bypassing the ATI's comb filter by using an S-Video connection from your receiver to your HTPC. This brings me back to one theory: ATI's comb filter may be much worse than the TV's comb filter.

I will definitely try your setup over the weekend, sounds encouraging.

Thanks, Thomas
 
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