Home Theater PC and cable options

[stringplucker]

Hey Guys,

I have been reading around on this topic but haven't received a definitive answer so I figured I'd ask you guys.

I currently use a desktop computer as a HTPC. It is hooked to my HDTV via DVI-to-HDMI feeding out of my Geforce 4 TI @ 720P. I have an analog TV tuner card, the ATI TV Wonder Elite. I currently have Comcast analog cable which pipes directly into my TV Wonder Elite and is piped out to my HDTV. Using Snapstream Beyond TV I have full DVR capabilities and am relatively pleased with the results. However, the TV picture is a little more distorted than if I directly piped the analog signal to my HDTV. For the record my HDTV has an extremely good analog tuner so viewing analog channels is actually very good.

Let me preface my actual question by saying that I have already adjusted the settings on my software and hardware, checked my signal strengths, and tried sending the video signal to the TV at 480P.

My question is whether or not changing my cable service to Comcast digital cable would improve my situation. The TV Wonder Elite has an S-Video input which works extremely well when hooked up to say a DVD player or nintendo. The Motorola Set Top Box which comes with Comcast digital cable has an S-video out, among others. Do you think this would buy me any increase in picture quality? Am I correct in believing that, when using this kind of setup, the cable signal is pure digital until the set top box, at which point it is converted to analog and sent over s-video, which is converted to digital via the TV Wonder Elite, and then piped to the HDTV as digital? Or is this extra conversion step going to cost me additional quality?

I know I could just get digital cable AND Comcast's DVR but I have the complete solution on my PC, running DVD software / media libraries, game emulators, internet, etc.

Thanks for the help in advance!

[AllGamer]

I've a feeling it's a simple Resolution issue

4:3 vs. 16.9

or along the lines of 800x600 (or 1024x748) vs. 3000x2000 or whatever your HDTV resolution size is supposed to be.

remember that on PC the default is 4:3 and it outputs in 4:3 as well, if you are using a TV OUT option

also when you DVR, in 4:3 it will display back only in 4:3

so if you want to see the widescreen 16:9 or whatever... then you better set your DVR recordings to 16.9

So that even when the output is 4:3 displaying a 16:9 to your HDTV will make it look back to normal again.

That's what i do


Cheers

[stringplucker]

Thanks for replying AllGamer,

First off, I am not using a TV-out option. I am using DVI-out (digital) which can correctly compensate for 480P, 720P, and 1080i HDTV signal broadcasts. As such my desktop is displayed in the correct widescreen format. If it was a resolution issue, my entire desktop would be skewed. The nvidia drivers are actually quite good at handling HDTV output.

If you are refering to the loss of quality due to upconverting from 480i (analog TV broadcast) to 720P, I have already tried adjusting the output resolution of my computer to 480P which uses the same effective resolution as 480i and looks identical to the 720P settings.

On an additional note, if I hook my computer up to my LCD monitor also via DVI, which is a 4/3 aspect ratio monitor, I get the same picture quality.

I really believe the issue lies either in the quality of the analog-to-digital conversion of the TV Wonder Elite via coaxial, or the software configuration of the related components. This is why I wondered if having a digital signal transmitted via an analog s-video cable into my TV card (through its svideo input) would look better than the simple analog coaxial transmission.

Any thoughts?

[AllGamer]

if you have the necessary cables

it's worth a shot to use SVIDEO or RGB cable to the HTDV and see how it looks using those.

and if the Size / Resolution is good (not distorted) then you might be right about the Digital - to analog - Digital thing screwing up the quality

[stringplucker]

See thats the thing. I have no way of using the SVIDEO input of my tuner card because all I have is a coaxial cable input. I would have to upgrade to digital cable in order to use the SVIDEO output of a cable box. I dont want to upgrade until I am sure that this change will make a difference.

[stringplucker]

I have read a few articles which make me wonder if my issues are due to deinterlacing. Apparently converting from 480i to a progressive signal inherently creates many artifacts. Dscaler looks like a promising software tool which remedies this situation. Does anyone have any experience with it?

[mobo57]

Descaler is really for cleaning up video for viewing on a PC. As to the video cables, HDMI/DVI is your best output. Component followed by s-video and composite next.
I do not think it is your input/output that is causing your problems. I have or had just about every ATI AIW and tuner/capture card. Without a doubt, some are good, but some are junk. The one you have is a good one. Right now I have a 550 & a 650 and love them. BUT, to make them work best I do not use that pile of steaming brown matter called MMC or anything else from the ATI software numbskulls, they are just one step above ATI support in regards to knowledge IMO. It is amazing how bad this software is, almost as bad as the Pinnacle software. I use virtualdub for capture along with different codecs.
Seeing as how you are trying to output to your TV via DVI, effectively using it as a monitor, Descaler might work at cleaning up the picture for you. Can't hurt to try it.
And as a FYI, I do have digital cable. I have feeds going into my cards through both the box and straight off the cable. It has taken quiet a bit of tuning, but I have finally gotten it to where my play back on my TV is almost as good as what goes directly to it.
Your question about "converting" from 480i to P. Your TV probably plays in progressive format, especially if it is plasma or LCD. The issue of interlaced and progressive are related to the signal coming into the set. The signals coming in are usually interlaced (480), old CRT's, guns, blah blah..., and then processed into progressive (LCD/plasma don't use line scans- the reason for interlace). The processor determines the quality of what you see. Most HDTV's have a very good processor, usually better than those found in DVD players (won't go into up conversion).
Coming to the point and avoiding a dissertation of digital video, the processor in your TV Wonder is very good, it is the rest of the "stuff" that brings it down a bit. Unless you have really shoddy cables, going s-video is not going to help. I'd concentrate on trying different software packages. You may also try creating a custom profile and capture in uncompressed format (AVI), if you have the space. Problem with capturing in uncompressed is it does put a bigger load on the system during playback then MPEG etc do.

[stringplucker]

Thanks for the reply mobo57.

I wasn't refering to the output to my HDTV. I was refering to the output to my pc from a digital cable box (coax, composite, svideo). Which output on your box do you use to connect to your pc?

I completely agree with you on the software aspect. I don't even have the PVR software that came with the card installed. I have used a multitude of titles including GBPVR, MediaPortal, etc. I have settled on BeyondTV by snapstream. VirtualDub sounds interesting but I don't think it fits my purposes. Do you know of any PVR software which handles deinterlacing and filtering issues?

I gave Dscaler a go last night. When it first fired up everything was going well, the picture looked better than in BeyondTV. However, as soon as I applied any of the filters for tuning it crashed and rendered my TV card useless until I restarted. I'll have to search for a how-to on Dscaler, but it looks promising.

[AllGamer]

You lost me again....
How about this

Which Hardware are you using for Output? The ATI <insert name> wonder, or your NVidia video card?

most ATI <insert name> Wonders are only for Inputs
so the only way you can output to your HDTV is via your nVidia video card, either through Digital (HD), Analog (VGA), or S-Video

[mobo57]

I use the coax cable split off the main cable. As to the cable input to the card, the same holds true as to quality. You want the highest to match the signal. But I would suggest you try different combinations. What looks good for your eyes may not be the same for my eyes. The Wonder card treats the incoming signal differently when s-video, composite, etc. A good primer on it is here: http://www.hothardware.com/articles/..._Elite/?page=1
In our case, I believe that only the 650 PCIe has the capability to receive digital signals from cable. So we are taking a analog signal and converting it. So we want the best signal coming in. My setup is a splitter in from the main cable in, one going to the box, the other a direct line to another splitter. I then have a line coming off the box to the second splitter. That way I can record either from the box or straight off the cable. This allows me flexibility in recordings. What I have found by recording the same show on one line and then the other and comparing it on my tv is that the direct line has slightly better quality, for obvious reasons.

[stringplucker]

AllGamer,

The output from my computer to my HDTV is my Nvidia card via a 720P signal over DVI/HDMI. However, I was asking about the output from a digital cable box which is either coax, composite, or svideo, all of which my TV Wonder Elite can accept as input.

After playing with Dscaler a bit I am pretty satisfied with the quality I am getting. I can barely distinguish between a straight line input versus through the TV Wonder Elite. I downloaded the trial version of SageTV (which can use Dscaler as a deinterlacer) and the quality is superb with all of the PVR functions intact. I think this confirms mobo57's first inclination that it was a software configuration issue. Whether or not it was strictly deinterlacing-related I don't know, but who cares. Now its just a question of whether or not I'm willing to shell out the extra 80 bucks for SageTV, or if I will just keep playing around with different configurations. SageTV even works out of the box with my Remote Wonder. Cool!

[AllGamer]

interesting.... i've gotta check that out as well

[mobo57]

A comprehensive list/downloads of capture software and user ratings can be found here:
http://www.videohelp.com/tools/sections/capture
Stoik is also a good one to use. Both Stoik and vd are a little more difficult to use but have great features and controls to allow you to get the best capture possible.

[stringplucker]

Wow, that is a great reference there mobo57. Its gonna take me a while to run through all of those apps! I appreciate the responses, boy of you guys.