Ext. Video scaler necessary/ Calibration?

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jasonc

Ext. Video scaler necessary/ Calibration?
« on: 3 Dec 2005, 03:27 pm »
There seems to be a fair amount of people over in the AVS forum using a video processor (such as DVDO iScan) in their HT system to convert a signal to either 480I, 480p, 720p, 1080i or 1080p in order to find the best resolution on their display.
To those of you here who know more about scalers and or are currently using one, do you feel they make a big improvement and are necessary in getting the most out of your HT experience?
I'm currently using my Acram DV29 with an HDMI connection to my display and the picture is pretty amazing.  The consensus over at AVS from what I've read is that 480i over HDMI seems to be the best picture which seems to be only achieved by one of these scalers.

Calibration-
This one I know is needed on every new set, my question is should I buy a do it yourself disk such as Avia or should I hire a pro to do it?  Is hiring someone overkill?  My TV is a Sony KD-34XS955 CRT.
Any thoughts welcome.
Thanks.

wshuff

Ext. Video scaler necessary/ Calibration?
« Reply #1 on: 3 Dec 2005, 03:58 pm »
There was a time when all displays and sources were 480i only.  Even then, people with front projectors, who were blowing the picture up to very large sizes, found that they needed some kind of video processing to avoid seeing the scan lines.

Now we have HDTV and digital displays which use chips with a fixed number of pixels used to display the images, so all sources must be scaled to match the number of pixels available.  CRT-based displays can now accept a higher scan rate (i.e., 1080i) -- some can do multiple scan rates, but I think that these days some upconvert all signals to one rate.

Unfortunately, the processing built into a display is not always the best.  My understanding is that a progessive image is needed for scaling, so if the input is 480i, the display electronics must first deinterlace to 480p, then scale that 480p image to the native rate, i.e., 1280X720 pixels for a 720p micro-display.  If the deinterlacing is not up to par, it creates artifacts which then get magnified with the scaling.

An externsal scaler allows one to avoid using the video processing built into the display.  I've got one in my system that I use to scale VHS, LD, and a DVD player to my TV's native 720p.  Compared to the scaler built into the TV, the picture is smoother, with less of what I can only describe as a digital quality using the TV's processing.  The deinterlacing is better, so fewer jaggies and artifacts.  I've also been able to calibrate each input individually, so that makes a difference.  The difference is subtle, but when I use a source that isn't connected to my scaler so that the TV does the processing, the difference is apparent.

I also have an upscaling DVD player that I use and let it do the deinterlacing/scaling.  If it were my only source, I wouldn't worry about the external video processor.

The reason that people are now talking about 480i over HDMI is because some of the newer external scalers now accept that as an input.  Before, quite a few people had their DVD players modified with an SDI output (a digita, 480i output).  That allowed them to get the video into the processor digitally, without any D/A-A/D conversions.  The video processor could then work its magic and output to the display.  Avoiding those unnecessary conversions resulted in a better picture, but came at a price since it required the modification to the DVD player.

Now that players can output 480i over HDMI (also a digital output that does not undergo a D/A conversion) and scalers can accept that input, there is no need to pay for an SDI modification.  The benefit is that some of the newer video processors have improved deinterlacing/scaling engines.  So, for someone who wants to stay on the bleeding edge, a DVD player (even a cheap one) outputting 480i over HDMI gives them a way to get the digital video into the new video processor.  It's not that 480i over HDMI is itself somehow better, it is just that it allows the video processor to get the digital video data straight from the DVD player.

If you are still using a smaller CRT display and have a decent upscaling DVD player, my guess is that you wouldn't see much of an improvement with an external scaler, or at least not enough to justify the expense.  Once the screen sizes start going up, the differences become more apparent.  What is acceptable on a 34" CRT might be unwatchable blown up to 106".

Hope that helps.

John151

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Ext. Video scaler necessary/ Calibration?
« Reply #2 on: 3 Dec 2005, 04:42 pm »
I asked a very similar question on AVS when I built my HT last year.  The answer I got was not to worry, unless I am unhappy with the PQ of my system.  I have a JVC SX21 PJ throwing onto a 116" 4:3 screen, and have no issues with the PQ. HDTV from the cable box looks outstanding, and most DVD looks very good (a noticable step down from HDTV, but still very good).    It seemd to me that my PJ has a very good scalar,  so I did not even look into the scalars (they aren't cheap).

I recently upgraded my DVD player to the Oppo unit, which has a Faroujda chip that makes the most of the data on the DVD.  My PJ shows that the output from the Oppo is 1080.  The resulting picture is very good, and cuts the quality gap between the prev DVD player and HDTV roughly in half.


I totally don't understand the 480i being the best solution over HDMI, unless that is for displays with a lower native resolution.  

I would expect that DVI/HDMI output on DVD players will be the norm by this time next year, and HDTV programming on cable is increasing, so the quality of video sources is increasing rapidly.  Assuming your main video sources are cable/sat and DVD, I would recommend investing in very good DVI/HDMI DVD player instead of a scalar (either the Oppo, or wait for another brand to leapfrog them).

I have never calibrated a display unit (my PJ was optimized by William Phelps), so I can't speak to how easy it is, but I can say that a display should be calibrated.  I would say try it yourself, and see how it goes.  If you don't like the results, hire a pro.

Just my $0.02.  I am far from an expert, so take my opinions with a grain of salt.

wshuff

Ext. Video scaler necessary/ Calibration?
« Reply #3 on: 3 Dec 2005, 05:04 pm »
Quote
I totally don't understand the 480i being the best solution over HDMI, unless that is for displays with a lower native resolution.


No, it isn't for displays with lower resolution.  It isn't that the video is going to be displayed as 480i.  480i over HDMI is just a way to get the digital video into the video processor without it having to go through various D/A-A/D conversions.  The video processor, whether external or in your TV, is going to need to have the video in digital form to do the processing.  If you use component out from a DVD player, that is analog, so the digital video will go through the MPEG decoder and deinterlacer in the DVD player, it will go through a D/A conversion and then out via component as an analog signal.  At the video processor, there will be an A/D conversion in order for the processing to take place.  From there, the video processor may or may not have to conduct another D/A conversion before the signal finally gets to your screen.  480i over HDMI (as 480i over SDI) allows those steps to be eliminated.  The digital video can go straight into the video processor, be it in the display or an external box.

John151

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Ext. Video scaler necessary/ Calibration?
« Reply #4 on: 3 Dec 2005, 09:16 pm »
wshuff - I understand why DVI/HMDI will be better than analog component connection, but why specifically 480i? Why not something in a higher resolution?

jasonc

Ext. Video scaler necessary/ Calibration?
« Reply #5 on: 3 Dec 2005, 09:18 pm »
Thank you very much for the responses!  
I think the biggest thing I've learned is because I have a smaller monitor I won't see big gains with an external scaler.  
Cheers!

wshuff

Ext. Video scaler necessary/ Calibration?
« Reply #6 on: 3 Dec 2005, 11:28 pm »
Quote
wshuff - I understand why DVI/HMDI will be better than analog component connection, but why specifically 480i? Why not something in a higher resolution?


Because if you send a higher resolution, be it 480p, 720p, or even 1080i, that means that the DVD player itself has performed the deinterlacing and scaling.  If you are going to use an external scaler (or if the video processing built into your display is better than that used in your DVD player), then you want to let it do the deinterlacing and scaling, presumably because it is better than your DVD player.  For instance, some of the new video processors that are soon to be released use new chips (like the HQV chip found in the upcoming Algolith processors) that are supposed to surpass the capabilities found in the vast majority of current DVD players.  If you have a DVD player than can output 480i over HDMI, then you can send the pure digital video signal directly to the video processor, avoid the D/A conversion and any superfluous processing in the DVD player, and allow the video processor to work its magic for the best possible picture.  The new video processors will work with higher resolutions like 480p, and they accept analog component inputs, but for the highest quality, the direct digital feed is considered better.

I hope that helps.

John151

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Ext. Video scaler necessary/ Calibration?
« Reply #7 on: 4 Dec 2005, 05:02 am »
Okay, so the 480i only holds true only for DVD signals, and NOT for HDTV signals, such as a cable box?

wshuff

Ext. Video scaler necessary/ Calibration?
« Reply #8 on: 4 Dec 2005, 05:29 am »
Right.  DVD starts life as 480i, so it has to be scaled up to a display's native rate.

You wouldn't want to downrez an HD signal to 480i for display on an HDTV.  Keep HD as HD.

bubba966

Re: Ext. Video scaler necessary/ Calibration?
« Reply #9 on: 4 Dec 2005, 06:07 am »
Quote from: jasonc
Calibration-
This one I know is needed on every new set, my question is should I buy a do it yourself disk such as Avia or should I hire a pro to do it? Is hiring someone overkill? My TV is a Sony KD-34XS955 CRT.
Any thoughts welcome.


I'd say no, hiring someone is not overkill.

You're got a real nice display there. And it will be even better with a proper ISF calibration. Sure, you could borrow or buy a copy of either Avia or Digital Video Essentials. You'd get an improvement in your picture going that route, but it won't be as good as an ISF'ing.

If you do go the ISF route, make sure your set has a few hours on it. At least 200 hours. This is where the Avia or DVE disc can be handy as you can do a basic calibration by yourself & touch it up as the set settles/burns in.

I'll get my 30" 16:9 CRT ISF'd as soon as I've got the spare $ for it. I'll be spending a good $250 to ISF a set that I paid $500 for (gotta love a close out deal), but it'll be worth it.

As far as the external scaler goes, I don't think you really need it. Use the $ that you'd use for a scaler getting an OPPO DVD player, and an ISF calibration.

And if you still have some spare $ left over, send the OPPO to Bolder Cables and get it modded.

Then you're looking at $200 for the OPPO, $400 or $500 for the mod (depending on what's done), and $200-$300 or so for an ISF calibration. Not sure how that stacks up pricewise to a nice external scaler. But you'll see a lot better results with that than you will by just adding a scaler.

John151

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Ext. Video scaler necessary/ Calibration?
« Reply #10 on: 4 Dec 2005, 03:07 pm »
wshuff - Thanks, that all makes perfect sense now.

Eric5676

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Ext. Video scaler necessary/ Calibration?
« Reply #11 on: 4 Dec 2005, 05:17 pm »
I have the Sony KD34XBR960, which is essentially the same TV as the XS, and I can assure you: An ISF calibration is WELL worth it!

Eric5676

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Ext. Video scaler necessary/ Calibration?
« Reply #12 on: 10 Dec 2005, 06:37 pm »
wshuff and others:


What's your all's feeling and take on a device like the HDMI Mosquito?

Once yet again, I'm sure this would be massive, supreme overkill on a display like mine, but certainly, IF that product lives up to billing, I could see that being an item to watch out for some day.

Algoith seems to have a nice corner on the market right now, in terms of noise reduction and the like.

Comments?

wshuff

Ext. Video scaler necessary/ Calibration?
« Reply #13 on: 10 Dec 2005, 07:33 pm »
Q,

All I know about the Mosquito is what I've read in a few threads on AVS.  I'm sure that you've seen the same ones.  Still, I'll take a shot.

My only experience with video processing has been with the CS-1 I got a few months ago and then with the processing built into my DVD players.  I found that the Sil504 chip in my Denon 2900, and the Faroudja in my Pannie RP82 made a noticeable difference compared to the chips used in my previous DVD players.  I now have an Oppo, which uses the Faroudja chip, outputting  720p into my TV.  I have the Denon connected to the CS-1, also outputting 720p, but over component.

The differences I see between the Oppo and the Denon are slim.  In fact, I'm not convinced that I'm seeing real differences as much as I just THINK I'm seeing differences.

Now, I do see a noticeable difference with other sources, like cable TV, using my CS-1.  Compared to the cable box alone, the CS-1 produces a smoother picture.  For lack of a better way to explain it, the cable alone looks very harsh and digital, more like a WMV video on a computer.  Still, the degree of improvement, at its best, is really small in absolute terms, and of course, there is the old adage about garbage in, garbage out.  Given the rather poor quality of many channels and sources, there is just not much that the CS-1 can do to improve things.

From what I've read about the Mosquito, it may be able to help in those situations where the CS-1 is really helpless.  In fact, I think I remember reading a thread on AVS where a guy was thinking that he would get a bigger improvement from adding a Mosquito than with a video processor (I don't remember if it was the Dragonfly or not).  If the Mosquito can help clean up some of the artifacts in some of those poor sources, I could see it making a much bigger difference than even the best video processor that is simply deinterlacing and scaling those artifacts.  And I'd imagine that the cleaner picture would look better no matter the size of the screen.

But that's all just conjecture on my part, taken mostly from the thread on AVS where the potential buyer was considering a Mosquito over a scaler.

As for being overkill, even with your current TV I'd think the Mosquito might make a very nice difference, possibly even more than the VP30, especially since you already have the Onkyo.  Of course, even if it is overkill now, you can still use a Mosquito and/or VP30 with whatever display you might end up with down the road.

Eric5676

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Ext. Video scaler necessary/ Calibration?
« Reply #14 on: 11 Dec 2005, 01:04 am »
Quote from: wshuff
Q,

All I know about the Mosquito is what I've read in a few threads on AVS.  I'm sure that you've seen the same ones.  Still, I'll take a shot.

My only experience with video processing has been with the CS-1 I got a few months ago and then with the processing built into my DVD players.  I found that the Sil504 chip in my Denon 2900, and the Faroudja in my Pannie RP82 made a noticeable difference compared to the chips used in my previous DVD players.  I now have an Oppo, which uses the Faroudja chip, o ...


Something to keep an eye on. If I ever bought something like that, it would be the intent of something that I would use and keep for years to come.

I'll need to see a LOT of glowing feedback and hopefully, some professional reviews, before I'd really feel confident about it, but it's definitely an intrugiing product.