Thinking of going Sage - Replace TV builtin Tuner?

[dandirk]

Seems like an easy question but one I could not find in FAQ or easily through search.

Is there a image quality drop with using a PC based DVR solution like Sage on a HDTV vs direct cable to the TV tuner? If so roughly how much, SD and/or HD?

My thought is if I were to go the HTPC DVR route I would want to replace the need to use my standard cable inputs on the TV entirely and only use my HTPC for TV viewing/recording 100% of the time.

My cable source is standard Comcast cable package (not digital package). My current TV has a QAM tuner so I get local stations in HD (not encrypted) with out using a cable box.


HTPC Specs and possible DVR equipment Comments?

Athlon 3.2Ghz single core
Nforce4 MB
7600GT (AGP)
Currently running WinXP and Meedio with 300 DVDs and ~250 CDs

Thanks for asking such a noob question.

[stanger89]

Originally Posted by dandirk

Seems like an easy question but one I could not find in FAQ or easily through search.

Is there a image quality drop with using a PC based DVR solution like Sage on a HDTV vs direct cable to the TV tuner? If so roughly how much, SD and/or HD?

For analog, there is a hit, because the video is lossy-compressed. How much is impossible to quantify. For me (HDTV) any loss in quality due to recording is more than offset by the improvements in deinterlacing/scaling.

For digital, not really, the bitstream is captured directly so there's no recording loss.

My thought is if I were to go the HTPC DVR route I would want to replace the need to use my standard cable inputs on the TV entirely and only use my HTPC for TV viewing/recording 100% of the time.

FWIW, I've always found the direct connection very nice for "surfing", or casual viewing, and using Sage for Favorites and the like.

[jdamore]

Do you have a tuner card?
If not, is there any specific cards you were looking at?

Oh- and welcome!

[dandirk]

Originally Posted by jdamore

Do you have a tuner card?
If not, is there any specific cards you were looking at?

Oh- and welcome!

Thanks...

I was thinking of getting a HDHomerun. It seems to dodge some issues that DVR software has with QAM. It also seems to be a good solution if you think you might change DVR apps.

I figure since Sage seems to be the best DVR app and from what I am seeing over at meedios, I should be able to integrate it to my current HTPC fairly seemlessly.

As for quality of SD... I recognize there HAS to be some degradation due to encoding/compression etc... but would you guys say its close to a direct TV connection (to an average person not a videophile)?

As I understand it HD, since it already is Mpeg2 the stream is just captured... does that mean no quality loss on the HD channels?

[GKusnick]

There's no quality loss during recording of HD. But the image you see during playback is a result of decoding and rendering the MPEG2 content. Your HDTV has a decoder/renderer built in, and your PC has its own combination of decoding/rendering software and hardware. Depending on the relative quality of those components, you may see a difference in image quality between direct TV viewing of broadcast HD content and Sage playback of recorded HD content. That said, with good decoding software and a reasonably high-powered graphics card, your PC output should be as good as or better than the TV's own decoder.

Whether you want to use Sage for live TV channel surfing is less a matter of image quality than of convenience. Since Sage is designed primarily as a recorder and mutli-user media server, it has some quirks in live TV viewing that take some getting used to. Some new users find them disconcerting. So as Stanger said, for casual channel surfing you may find you still prefer to use your TV's built-in tuner.

[jdamore]

Originally Posted by dandirk

As for quality of SD... I recognize there HAS to be some degradation due to encoding/compression etc... but would you guys say its close to a direct TV connection (to an average person not a videophile)?

As stranger said it hard to say..

I think my higher channels (like 16 and up) actually look better than a cable directly hooked into tv. As for the lower channels, it is more noticeable for me. Dont get me wrong, its nothing to worry about as its only really noticable with an A/B test or if you are really looking for it. In my case, the only lower channels I watch are availible in HD (unencryped). And even if it does degrade the picture quility, the benefits far out weigh that.

I actually just ordered a hdhomerun yesturday because it is supported by Sage for QAM and I can get rid of the huge attenna (wife calls it the dinosaur spine) on the roof.

Just try it.. You may never want to watch "Live" TV again!

[dandirk]

thanks for the input and replies...

I think I will try the HDhomerun, though I will have to research my comcast cable to see if all channels are QAM or not.

Hard to tell, I have just the basic cable package and not the digital package.

I have heard that most cable companies send both digital and analog signals to all subscribers and their digital box will tune the QAM digital channels (that is the one difference in the standard vs digital packages)....

Guess I have more homework.

Thanks again, I am sure I will be back once I get the HDhomerun and setup sage

[Halstead]

It's also worth noting that you may actually end up with better quality SD playback on your HDTV (MPEG artifacts not withstanding) depending on the quality of the deinterlacer/scaler in your TV.