Best picture quality: Video Processor vs HTPC?

[clarkc]

I am pretty new to the home cinema world but I am keen to learn ! I anticipate investing soon in a new high-end plasma or LCD screen (still thinking hard) and want to ensure the very best picture for both SD and HD in all circumstances. It appears that video processors offer some benefits, depending upon the situation. I am also attracted by the apparent flexibility of a HTPC.

But my question is this: Does a HTPC plus a video-processor make any sense? (I don’t want to waste money). Can a HTPC with the right software (which s/ware?) make a video-processor irrelevant? For example, the German company Sonavis (http://www.sonavis.de/) offers a media centre (Sonavis One) and claims that it makes any video-processor obsolete because it handles all the scaling itself. I have read in this forum about wonderful things like ‘cadence detection’, ‘PreP’, ‘combing’ Are certain functions exclusive to the world of video-processors or can a HTPC do everything with the right s/ware? And how important are these special functions?

Any thoughts much appreciated !

[spooney]

If a PC does the scaling you will not need an additional scaler.

I'll leave the controversy regarding picture quality to other folks

[Nic Rhodes]

http://www.avforums.com/forums/showt...08#post3612508

[choddo2006]

If you're using a HTPC then effectively software can do everything a video processor can do but with a bigger box and more to go wrong

Combing artefacts are introduced when a TV or processor thinks it's getting a film source (complete frames @ 24fps split into 2:2 or 3:2 cadence) when really it's getting a video source (50/60 interlaced fields, each one separated in time) and pulls two fields into a single frame, so you get movement showing on alternate lines. So getting cadence detection right is very important, whether it's your VP working out what it's being sent or your HTPC playing back an interlaced source and working out what's in it. Unlikely you'd want to send an interlaced signal out of the HTPC so adding a VP after that makes little to no sense. The HTPC can also scale very well.

Of course, if you can't get the HTPC to handle every source (Sky?) then you might want to include a VP anyway. In which case PReP might help anyway as it could re-interlace the progressive signal from the HTPC and deinterlace it again which it might or might not do a better job of, but it's a DVDO vp50 exclusive for now (when they ship the firmware that has it!) so I don't think it ought to be a major consideration, it's real application is for DVD players and SkyHD where you get 576p over HDMI and really want 576i.

[clarkc]

Many thanks for the useful answers.

I am still trying to understand whether the algorithms embedded in the better video processors are fundamentally superior to those found in the best available s/w solutions. Perhaps the dedicated processors have an advantage simply as a result of focus?

If the s/w solutions are comparable (which are the best by the way?), would it not make sense to go the s/w route as this can always be upgraded / exchanged to the latest and greatest?

Thanks

[choddo2006]

The algorithms are patented so chances are there are differences and also modern video scalers are FPGA based which means they can also be updated with improved algorithms, while being faster than software.

dScaler has an impressive array of deinterlacing algorithms. Not sure if there are better altenatives, I forget the name of the other popular one.
http://deinterlace.sourceforge.net/downloads.htm

and more flexible. You can't easily plug a PS2 into a HTPC and get a result worth looking at

[Barcoing Mad]

HTPC can be interesting and effective for SD sources. I used Dscaler with a Sweetspot capture card happily for a couple of years. It performed on par with a Centerstage CS1 scaler for a fraction of the price (given you've already a decent PC in the house).

However, a good secondhand SD scaler can be bought for a few hundred these days.

If you're into HD, then HTPC goes out of the window, except for playabck of ripped HD files. There are no capture cards for HD or scaling software to my knowledge, and at present HD scalers are expensive.

[welwynnick]

You can now get HD DVD players and PC capture cards with HD-SDI interfaces. Probably the best picture ever, but quite expensive.

Nick

[Gordon @ Convergent AV]

Nick,

Glad you added probably....although as I've never seen an HTPC do judder free 48Hz from HD or have as good scaling or calibration features as the best of the external processors I do fail to see why you think it could be so good..... i do agree it'd be expensive...last HTPC I saw that was commercially available and was desigend for ultimate video playback and media streaming was £10,000 + and couldn't even play back 1080i streamed HD at 1080p@60 without dropping frames...

Gordon

[welwynnick]

You may have noticed that I'm not such a great fan of scalers as I used to be, but my motives for promoting HTPCs probably aren't what might be expected. Lets just say that I didn't have 1080p in mind.....

Buying a Lumagen has been the only logical thing for me to do, yet perversely, that's the only thing I haven't done!

Nick