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Discussion Starter #1
Does the JVC RS1 have problems deinterlacing a 1080/60i signal properly? A review I read indicated it did not handle this correctly, but since it uses the Gennum chip I would assume that was a bug that has been or will soon be squashed.
 

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Quote:
Originally Posted by uzun /forum/post/0


Does the JVC RS1 have problems deinterlacing a 1080/60i signal properly? A review I read indicated it did not handle this correctly, but since it uses the Gennum chip I would assume that was a bug that has been or will soon be squashed.

I don't see any problems with 1080i/60. In fact it does an outstanding job and passes the MI3 HD DVD Vatican Wall "Moire" test with flying colours.


What was the review ?


Dazzer
 

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Discussion Starter #3
Home Theater magazine June 2007 page 44, "In another shock, it doesn't pick up the 3:2 sequence with 1080i material. This is a shock becuase JVC is one of the few companies whose projectors consistently pass this test"
 

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Quote:
Originally Posted by uzun /forum/post/0


Home Theater magazine June 2007 page 44, "In another shock, it doesn't pick up the 3:2 sequence with 1080i material. This is a shock becuase JVC is one of the few companies whose projectors consistently pass this test"

Not something I've observed.



Dazzer
 

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Quote:
Originally Posted by anbjornk /forum/post/0


The RS1 doesn't do inverce telecine on 1080i60 film-material, which is probably why it is mentioned in the test.

What does it do with HD DVD or BD at 1080i/60 ?


Dazzer
 

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So you basically need a video processor to handle 1080/60i film based material, such as from an HDTV movie from your cable box, or from a Toshiba HD-A1 or A2 HD-DVD player? I mean it won't process it correctly on its own, when every other projector in the world basically does just fine?


I have to assume this is something of a bug, that JVC will soon fix, correct?
 

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Greg Rogers, in his review of the RS1, stated:


"The Gennum processor handled most 3-2 pulldown cadence tests and bad edit tests (disruptions in the 3-2 cadence) at 480i and 1080i, but it doesn't include

processing to detect other unusual cadence sequences, such as those used in animation or anime. . .


It appeared to work perfectly with vertical camera movement over fine lines and edges in Grand Prix and other HD DVD movies that it deinterlaced from 1080i

to 1080p. Vertical detail was sharp and exceptionally well defined during slow movement."


I haven't checked this myself, but I tend to trust Greg more than HT magazine.
 

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When I asked JVC about this, they told me the Gennum chip didn't do anything with 1080i60 film-material. According to them it was handled by the LSI unit. (I'm not familiar with "LSI")
 

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Seems you have to differentiate between 1080/60i (30i) material such as live football broadcasts (or 1080/60i taped documentaries/travelogues) and 1080/60i delivering 24p film/tape programming with 2-3 pulldown. The Widescreen Review/Rogers excerpt above covers 2-3 pulldown reversal handled by the Gennum chip. Such reversals 'toss out' extra TV fields added to 24p material in order to match the 1080/60i broadcast rate, then weaves the original TV fields together to recreate each 24p frame.


By contrast, live or recorded 1080/60i has 1/60-sec (540-line) TV fields captured at different moments in time requiring more complex deinterlacing, with digital interpolation by the Gennum circuit. Deinterlaced 1080/60i becomes 1080/60p, while deinterlaced/reverse 2-3 pulldown 1080/60i becomes 24p that's best displayed at multiples, such as 96 fps, (although some fixed-pixel pro projectors in theaters display at 24 fps without flicker problems).


LSI means large scale integration, representing certain transistor counts in microcircuits, while VLSI is very large scale integration, no doubt used for the Gennum chip. JVC engineers would know the difference, but not less-technical JVC reps. -- John
 

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Quote:
Originally Posted by anbjornk /forum/post/0


When I asked JVC about this, they told me the Gennum chip didn't do anything with 1080i60 film-material. According to them it was handled by the LSI unit. (I'm not familiar with "LSI")

LSI (LSI Logic) is a manufacturer of deinterlacing and other video processing chips used in DVD players, recorders etc. I assume they mean that they're also using an LSI chip to handle the 1080i deinterlacing? That doesn't make any sense as the Gennum chip can easily handle it.


Again, per Greg's review: "The RS1 uses a Gennum GF9351 VXP Image Processor. The 10-bit video processor performs 1080i and standard-definition inverse-telecine deinterlacing for film-source video and per-pixel motion-adaptive deinterlacing for original interlaced videos."
 

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Quote:
Again, per Greg's review: "The RS1 uses a Gennum GF9351 VXP Image Processor. The 10-bit video processor performs 1080i and standard-definition inverse-telecine deinterlacing for film-source video and per-pixel motion-adaptive deinterlacing for original interlaced videos."

Now I'm a bit confused. In other words this mean that the RS1 does 3:2 pulldown detection and de-interlacing on 1080i film-material. But since it cannot show it in a multiple of 24hz, what's the point? Converting from 1080i60 -> 1080p24 -> 1080i60 -> 1080p60 ??
 

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This was posted (either by tstites or some other JVC engineer, I forget who) some time ago:


The HD1/RS1 frame doubles 1080p24 to 1080p48 and this is displayed at 96Hz. 1080i60 is deinterlaced to 1080p60 and displayed (with 3:2 progressive frame cadence) at 120Hz.
 

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Quote:
1080i60 is deinterlaced to 1080p60 and displayed (with 3:2 progressive frame cadence) at 120Hz.

Where does 3:2 cadence come in for 1080/60i deinterlacing to 1080/60p? Shouldn't 60p just be shown twice (for 120 Hz)? -- John
 

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There are two ways to de-interlace film sourced i60 feeds - using inverse telecine (3:2 pulldown) to convert it back to the original 24p - or - just doubling the fields into 60p. The former method removes the telecine judder - the later does not. So film to 1080p60 has inherent judder - is then doubled to 120 with the judder still in there. The ideal way to deal with i60 film sources would be to do IVTC back to 24p then display at 5:5 cadence (120 hz).
 

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Quote:
Originally Posted by usualsuspects /forum/post/0


The ideal way to deal with i60 film sources would be to do IVTC back to 24p then display at 5:5 cadence (120 hz).

Or in case of the RS1 use a 2:2 cadence to end up with 48Hz, internally doubled to 96Hz.
 

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It says in the manual that if you input a 1080i signal to the RS-1 the Genum chip will process it up internally to 1080p. ( isnt that what a lot of displays do if you run less then native resolution to them. Thier internal processor is supposed to up convert to the panels native pixel resolution so they say )


I just completed a second install today with another RS-1 and a Lumigen Vision Pro Scaler.


The saler is set to RGBS (there is no HDMI so dont ask) and at 1080i. The projector looks much sharper at 1080i then it did at 720p so thats where it stayes and according to the manual is what the PJ wants for the Genum to do its magic. I was getting some waves in the image at 720p that initially didnt show up right away and Im not sure what that is all about. At 1080i the picture is perfect and shows what the RS-1 is all about.


This installation went smooth as its the right PJ for this theater room unlike the other install I was trying to pull off and needed a little keystone correction which the RS-1 doenst have, despite the H and V lense shift I needed a bit more. ( OTHER POST ) As I have been ridiculed about that and refuse to talk to any one over in that post now since Ive been made out to be an inexperianced prick! My middle finger is up to you fine folks!


I have a local AVS member comming out to see this RS-1 install so he can decide if he wants to purchase one. He will post his thoughts on the install and picture quality.
 

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"The saler is set to RGBS (there is no HDMI so dont ask)"


Use a DVI to HDMI cable or a simple DVI/HDMI adapter on the Lumagen.


"The projector looks much sharper at 1080i then it did at 720p so thats where it stayes and according to the manual is what the PJ wants for the Genum to do its magic."


The Vision can be set to pass-through 1080i inputs. You might want to consider setting it to do that. Or feed the JVC 1080p directly when you get the proper cable.


Shawn
 

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Why pass through 1080i when there is NO Native 1080i sources in this theater thus the scaler in the 1st place, thank you very much.


The scaler is also needed as a switcher becuase his almighty MERIDIAN Preamp doesnt touch video.


There is a 5 mini cable to the PJ ONLY NO WAY to MAKE IT DVI HDMI OR any other Digital BS feed. You know Analog is not a bad thing. The walls in this room are solid PLASTER covered w/ red velvet. NO ATTIC space and the equipment is in a closet about 60 feet away. HDMI cables that long are ungodley expensive, and CANT be retrofitted in this room. It was wired back before DVI and HDMI existed so RGB is the ONLY way!
 

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"Why pass through 1080i when there is NO Native 1080i thus the scaler in the 1st place, thak you very much"


Get that owner some HD. You would pass through 1080i so you don't go through de-interlacing it twice.... once in the scaler and again in the projector. It also bypasses the scaling engine in the Lumagen for maximum sharpness.


"You know Analog is not a bad thing. "


No, but it has more noise and other artifacts then you would have digital and I believe also prevents you from feeding the projector 1080p (24 or 60) directly.


Put up the Lumagen every other vertical line test pattern and you should see some. That should be a good pattern to use to adjust the pixel clock on the JVC. On my older JVC G10 the pixel clock settings would show banding and such on those patterns when they were mis-set and even still a little when dialed in as well as possible. The RS1 may be better in that regard. None of that to worry about when fed digital.


And if/when the owner hooks up a HDCP encrypted digital source the analog output is going to shut off.


". NO ATTIC space and the equipment is in a closet about 60 feet away. HDMI cables that long are ungodley expensive"


About $78 dollars for a 75' cable with built in equalizer.


"It was wired back beofre DVI and HDMI so RGB is the ONLY way!"


Fine, I thought you were complaining about the lack of HDMI on the Lumagen.


Shawn
 
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