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Discussion Starter · #1 ·
Got my Cox cable box installed today. The SA3100HD outputs all HD video in 1080i. If the original broadcast was 720p, my understanding is the box outputs it at 1080i...which then flows into the component input of my DLP. Am I then stuck watching it at 1080i? Does the set automatically reconvert it to 720p? What if I want to watch it in 720p (for sports for example)...any way to force the issue?


By the way, the PQ is terrific. Very pleased.
 

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The Sammy has a native resolution of 720. That means anything you put into it will get scaled by the DLP to that native resolution. If you feed it 1080i the Sammy will still convert it to 720p. I do not know if you can change the resolution output on the 3100....I do not believe you can. On HD D* receivers, most will allow this. It is always best to try to output as it is input into the box and let the Sammy do the scaling. The DLP should do a much better job at scaling than any set-top. This will also allow for the least amount of scaling and should give the best PQ.
 

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Discussion Starter · #3 ·
Thanks. So if I've got it right (finally), the only time the set would actually display 1080i would be if I played a DVD and sent the output as 1080i via the DVI. Any other HD source (nonDVI) would be 720p.
 

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The monitor will never "play 1080i"--it has a fixed set of pixels, 720x1280 and will always display in progressive scan mode. If it receives a 1080i signal, component or DVI, it will scale it to 720p. If it receives a 480i or 480p signal, it will scale it to 720p. The only time that it won't scale is if it receives a 720p signal.


There are a few DVI-output DVD players on the market which scale to HD resolutions in the digital domain before transmitting to the television; if you bought one of those and set it to 720p, the television wouldn't have to scale the data. Some HD cable boxes can be set to 720p (the Pioneer 3510, for example, though I think that you have to do it through the maintenance menu). The Samsung OTA HD tuners can scale their output to 720p. And last, but not least ;), about 15 Xbox games (and counting) can output 720p.


If a source can scale its own output to 720p, like the ones I mentioned above, its better to do it there, since there are advantages to doing scaling and deinterlacing during MPEG decoding. It's particularly not good, at least conceptually, to let the television rescale a digitized analog component video signal. Of course, any artifacts introduced in the tortuous scaling-D/A conversion-analog-transmission-A/D conversion-scaling/de-interlacing process might not be bad enough to bother you.
 

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I would always try to send 720P into the set (when possible), rather than letting it convert 1080i into 720P internally. I have tested this with many sources, including my HD pattern generator. When the set converts 1080i to 720P it can introduce anomalies.
 

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Discussion Starter · #6 ·
Thanks Mike (fellow San Diegan) and Seth. The SA3100HD only outputs in 1080i. I'd have to change boxes to one that allows otherwise.

I've got the DVD player (Sammy 931) already set to 720p.
 

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I wish they would pass through the HD matterial via 8vsb so the Sammy STB's could decode them.
 

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I find with my HD cable (SA 3250HD from TWC), it doesn't do a good job converting 1080i video-based material to 720p at all. The Sammy does a much better job. So I keep the 3250 set to 1080i for 1080i sources, and 720p for Monday Night Football. :)


My 931 over DVI is definitely set to 720p, and does an excellent job of it. By SRT-151 is set to 720p, but there's a dearth of OTA HD I can pick up yet until stations stop messing around in low-power.
 

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Speaking of MNF, I watched my first MNF game last night on my new 5065W set. Completely blown away I must say. I"m new to the HD world, and trying to understand something. A CBS football game that I watched in HD on Sunday, showed what I'll call "pixleation" as the scenes changed. It's almost like it took a fraction of a second to get focused. However on the MNF game, I did not notice any of this. Crisp, bright picture that seemed to stay in absolute focus continuously. Reading this 720P and 1080i info, would CBS be xmitting their game in 1080i format, and MNF in 720p, which may be why I was noticing this difference?


I also noticed that the ABC,CBS and NBC HiDef stations showing the standard stuff like CSI, or any of those other shows, that I notice the "pixelation" effect in a big way as the screens changes camera shots. Just curious if differenct stations xmit in different formats. Thanks - hp
 
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