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I've been reading lots of posts about scalers and their ability to de-interlace and all of the difference outputs they provide, but what's the deal with this 72Hz stuff? Some scalers say they output 72Hz, but is it the same as this True Rate stuff that Extron is advertising on the DVS 406?

http://www.extron.com/technology/archive.asp?id=ta0731


This article they have wrote makes it sound incredible, but can you really even see a difference?


Is any other scaler out on the market doing this kind of processing?


Thanks
 

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The reason for wanting 72hz output is that its an even multiple of the 24/sec frame rate of film. 60hz output is not, and therefore requires a 3/2/3/2/3/2 type of field repeat in order to make 24fps map to 60 updates per second. This can cause a kind of micro-juddering effect during pans. There is LOTS of talk about this subject on this forum, so do a search on '3/2 pulldown' and 72Hz refresh and such.
 

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Hi,


A good test scene is the Titanic flyover scene, about 35 minutes into the Titanic DVD. Most people can REALLY tell the difference between 60 Hz and proper 72 Hz when presented with the proper test material in an A/B test.


I know that some 72 Hz scalers don't properly keep the same number of frames. In some of these, you see many situations where 2 repetitions of one frame is followed by 4 repetitions of the next frame. Rather than 3 repetitions of each. Not properly timed and synchronized 72 Hz.


A proper 72 Hz scaler needs to keep track of the frames and time them properly.


The ROCK+ is also another scaler that can do 72 Hz output properly. (Actually closer to 71.928 Hz since NTSC is actually 59.94 Hz rather than 60.00 Hz). I suspect that there are other scalers as well that can do the proper timing and synchronization.
 

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Hi Mark,


what happens when you have bad film edits and the

3:2 cadence has broken up. I understand that a 72 Hz refresh would not do any good then.I never read anything about

this and does the ROCK software take care of that ?
 

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Hi spatz,


Good morning!


You are very right in that bad edits are certainly an important part of the strategy. Obviously, the reliability of the 3:2 pulldown lock is very important too. How well a scaler handles, and recovers from, bad edits, can be pretty important to a scaler's ability to do 72 Hz without judder (or minimized, unnoticeable judder) during bad edits.


Obviously, I can't go into details on how the ROCK+ does it, but we are most certainly aware of the bad edit issue and take it into account.
 

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Quote:
Originally posted by Mark Rejhon
A good test scene is the Titanic flyover scene, about 35 minutes into the Titanic DVD. Most people can REALLY tell the difference between 60 Hz and proper 72 Hz when presented with the proper test material in an A/B test.
Hi Mark,


Don't see you post much lately. I miss the good old days in the HTPC fourm! :)


After watched a few PAL DVD with 50hz 2/2 pulldown, I can now see the 60hz 2/3 stuttering on NTSC source clearly. But the stuttering really don't bother me. Actually I think I like it! The stuttering ensure me I'm watching film source and don't need to bother with video deinterlace artifact! In fact I can't stand the PAL 2/2 pulldown "odd" motion!


72hz is nice, but the good old 60hz is nice too! :)


regards,


Li On
 

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>>"I can't stand the PAL 2/2 pulldown "odd" motion!"


Actually, I think the oddness comes from the 4% speedup? At 72 Hz, film DVD's can look more like the cinema when played back through a scaler that can do proper 72 Hz synchronization.
 

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But at 72Hz video which is 60Hz becomes all screwey. No?


Bogdan
 

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Bogdan: Yes, it does.


I have found that some things look better at 72, most others do not and I have never seen any scaler that can do stuff made for 60 at 72 and have NO shudder or skipping whatsoever throughout an entire film.
 

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The opening Sequence to Star Trek Insurrection is good as well for showing Judder.


The issue that is missed allot of the time is that in the world of Digital Display devices (all the CRT folks... back off) a large percentage of the devices are unable to display anything other than 60 hz. And as a result, if you feed them 72 they will drop 12 frames and you may end up with some other type of artifact presenting itself. So if you are concerned about this feature and consider it a must, make sure your display device can actually put it to use. Otherwise you end up with a great feature... that can't be used.
 

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Mark mentioned the Titanic scene as a good scene to demonstrate the juddering effect. Another great scene to test for judder at 60HZ or the benefits of 3:2 pull-down is the opening scene of Shakespeare in Love. The movie opens with a slow circular pan through the Globe Theatre.


Do a "before" and "after" test with this scene set at 60HZ and 72HZ, with and without a scaler with 3:2 pull-down and observe the differences.


This scene is a challenging one and will be a great test for the performance of a scaler.
 

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Extron makes some great stuff, high build quality, good integration capabilities, etc., but my recollection from prior threads is that their deinterlacing solution is not up to par with the Rock+, Sil503/504 or Sage chipsets. The single most important feature of any scaler is its deinterlacing ability; if that is substandard, other benefits may not outweigh it. I haven't seen SDI and can't comment on it, but I would sure rather have a device that has top-shelf deinterlacing performance -- that is my primary criterion for a scaler.


If someone can shed light on Extron's deinterlacing solution, that would be helpful information for those forum members otherwise interested in it.


Cheers.
 

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i seem to recall reading in another post that it is their own patented solution.

Quote:
Originally posted by DPincek
:) It’s nice to see that some of our processors are starting to get some attention on the AV Science forum. There are a few points that came up on this thread that I would like to clear up…


The DVS 406 Processing…

The decoder is a Philips 7118. Hands down the best quad standard decoder we’ve found. As for the de-interlacing and scaling, it really is ours. We have a proprietary 3:2 and 2:2 pulldown detection process that is patent pending.


DVS 406 vs. System 7sc…

The DVS 406 is a better scaler than the System 7sc. It has improved motion detection, better handling of scene cuts, cleaner frame rate conversion, a new horizontal scaling technique, SDI input, full variable aspect ratio conversion (with 3 memories per input) [that means you can run your DVD anamorphic and use the scaler to compress the image yourself vertically], and it has True Rate. For a full explanation of True Rate go to this link http://www.extron.com/technology/archive.asp?id=ta0731
As far as pricing on the unit... i seem to recall that AVScience is a dealer. Call them and they should be able to give you a price.
 

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Quote:
Originally posted by karos
Mark,


Where s a good place to purchase the rock+? price?


The TAW site is a little defective.
Rock+ is 5k and for whatever reason TAW doesn't list on their website or provided anyone with a dealer list. You'll have to contact them to see if there is a dealer in your area.


Jim
 

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Hi,


At the TAW site, click PRODUCTS and you'll see the ROCK+ and the price listed there. If you found some defects on the TAW site, please email me immediately at [email protected] ... Something may have slipped through the cracks. Are you using Internet Explorer or Netscape, and which version?


harlock is correct - To find out where to buy ROCK, you need to call TAW for the nearest dealer.
 

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What's really disappointing is that there weren't free Rock+ for all the visitors of their booth at CEDIA ;-)


It was an amazing experience to sit down and watch Stacey and Mark look at various scenes from Stacey's torture disc collection.


Stacey would put on a disc, he'd find a problem, show Mark, and Mark would take notes.


Not that there were a ton of problems, but I don't know of anything that can pass EVERY torture test disc Stacey has.


Regards,
 

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I have grown up with pal 100Hz TV:s and to me NTSC is almost unwatchable. I notice 3:2 stuttering without any A/B camparison.


Progressive NTSC looks better but still I cant stand the stuttering the worst thing is diagonal pans.

I remember one 007 movie that sean connery climbes over a wall at the begining of the movie. The camera pans diagonally to follow his moves and I had to stop watching.


I think that people from NTSC land are so used to it that they dont notice. Like we in PAL land doesnt bother to much about the 50Hz flickering. Now day almost 90% have 100Hz and widescreen so its a no issue any more.



///CF
 
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