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Discussion Starter · #1 ·
does 1280x720 mean it is 720p?

Wayne
 

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Just curious - does the digital standard even allow for 1280x720 interlaced?
 

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Quote:
Originally posted by kharvel
720 interlaced = 360 progressive. Lower than NTSC quality (480 interlaced)
say what ????


methinks you're boogling the math here.... :D
 

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Quote:
Originally posted by dandrewk
Just curious - does the digital standard even allow for 1280x720 interlaced?
ATSC standards call for 1280x720 progressive. However, you could certainly do this with Powerstrip and a Radeon card.

-------------------------------------------------------------------------

PowerStrip timing parameters (for 1080i HDTV):

1280x720i=1280,125,120,139,720,180,1,224,56160,280


Generic timing details for 1280x720:

HFP=125 HSW=120 HBP=139 kHz=34 VFP=180 VSW=1 VBP=224 Hz=30

interlace +hsync +vsync

-------------------------------------------------------------------------
 

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Discussion Starter · #7 ·
I guess i should of really expanded on my question.


I currently have an Nec 6PG and really trying to find out what is the sharpest resolution to set it to.

I have been using powerstrip and tried some crazy res of 1366x86somethin and the desktop was not sharp at all.

I am using a radeon 7200 and winDvd 4.0 with xlobby as my frontend.

I have to assign for each res on my PJ and was hoping someone could tell me what is the best so i could just go straight into converging for that instead of messing around for hours to dial in the sweet spot.

TIA

Wayne
 

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Problem is 'sweet spot' resolution depends on your projector not on the PC...


What you need to have will depend on how tight a beam spot you can achieve... An incredibly tight beam spot allows for a higher resolution.. The looser the beam spot (or scan line) the more overlap you get at the same resolution between pixels (scan lines) and hence the more gaussian blur or visual softness you see...


One side note is that many people find that exact multiple of the DVD resolution allows for a cleaner scaling of the source... Hence people sometimes use non square pixels to allow for this 1440 x 480 is precisely 2x the horiz dimension and single the horiz and seems common... Of course then you have issues with scaling for sources (such as PAL / HD / Etc) that can make a headache...


I would suggest polling in the CRT forum for what people would expect a good condition 6PG to be able to cleanly resolve and then using that as a basis to work from and experiment with...


BTW I do not and never have owned a CRT so take those words with the appropriate pinch of salt...
 

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Karnis, you seem to have every model of ATI Radeon cards in hand. :) So do the newer ATI Radeon cards (9000+) have a default setting for 1280x720? Or do I only get that with PowerStrip? I'm interested in the 9700 specifically. Thanks.
 

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Keep track of refresh rates too... True 720p is 60hz refresh, but PCs can generate different rates.

For CRT displays a higher refresh might be preferrable.

For digital projectors 60hz is fine.
 

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My 1080i RPTV cannot do 720p native so I sometimes use 720i to display HDTV recordings I have re-encoded in a 720p format.


- Tom
 

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Can anyone suggest to me what kinda timings on powerstrip I could use to run an older pj that scans 37hz max.


So it has to be less than 37hz horizontal so as not to push it too hard. Also it only uses rgbs not h+v.


Currently, its on a doubler that does not do a really good job. I would appreciate if I could get better than 480p but less than 37hz horizontal sr .
 

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Quote:
do the newer ATI Radeon cards (9000+) have a default setting for 1280x720?
I have a 9700Pro, and you have to use Powerstrip to get 1280 x 720.
 

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ATI has some hidden resolutions, which I believe 1280x720 may be one of them. I don't have the file at work so I can not be sure.
 

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Quote:
Can anyone suggest to me what kinda timings on powerstrip I could use to run an older pj that scans 37hz max.
37 Khz at a progressive 60 Hz would allow a max of about 616 lines. So you might get close to 600 lines if there was not too much overscan. But I don't know which resolutions your video card would accept with Powerstrip.


It is a bit easier and more foregiving with my old G400 card to add most any resolutions within the horizontal refresh rate limits just using the Matrox utility. But my TV shouldn't go over 33.75 Khz, which limits me to maybe 540 or 544 lines.


The horizontal resolution is very foregiving on most TV's if your video card will accept it. The TV mostly can't even tell.


- Tom
 

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Quote:
Originally posted by trbarry
It is a bit easier and more foregiving with my old G400 card to add most any resolutions within the horizontal refresh rate limits just using the Matrox utility. But my TV shouldn't go over 33.75 Khz, which limits me to maybe 540 or 544 lines.


- Tom
Tom,

_____I have a spare g450 that I can use. So what am I lookin at?

Is it possible to get something better than 540p and still be under 37khz.?


How do I determine number of lines and how to reduce overscan if applicable?

Should I just use the Matrox utility or use together with ps.?


Any suggestions highly appreciated.
 

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Quote:
Originally posted by eggz
I have a 9700Pro, and you have to use Powerstrip to get 1280 x 720.
On a 9000, you do have to set 1280x720 via Powerstrip initially, but once you have applied the setting and rebooted, you no longer need Powerstrip (the resolution automagically gets added to the Display settings.)


I presume it's this way for all 9XXX's.
 

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Quote:
Originally posted by jkaiser
ATI has some hidden resolutions, which I believe 1280x720 may be one of them.
Yep -> 1280 x 720 is supported by the Raedons. It can be enabled through a registry entry, or there's a tweak program that does it automatically. If anyone can get the search engine for this forum to work right, you'll find the specifics. There's also a nice writeup over at (3drage.com???)
 

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Quote:
_____I have a spare g450 that I can use. So what am I lookin at?

Is it possible to get something better than 540p and still be under 37khz.?


How do I determine number of lines and how to reduce overscan if applicable?

Should I just use the Matrox utility or use together with ps.?


Any suggestions highly appreciated.
On my G400 it looks like ...


Go to the Matrox site and download the MTSUxxxx (x=release) utility. Run it and create, say, a 592 line resolution like 1056x592. Reboot. I think the matrox cards may prefer width multiples of 32 and height of 16 but don't know if it's mandatory.


Be sure your monitor type definition (inf, what do you call that) allows the horizontal refresh rate you are asking for. You may have to lie about this.


Go into display_properties/settings/advanced/monitor_settings.


Make sure "Use Customizations ..." is checked and "Use Simplified ..." is not checked. Choose "Adjust a different resoluton". From the list choose you new resolution in 32 bit color, even though it has a red bar through it. Say you want to allow this and that you want to adjust it.


On the screen that pops up it will show the horizontal refresh rates and you can adjust the sizes, front and back porches, etc to get it the right screen size, position, and refresh rate. Adjust the horizontal front and back porches to over at least over 100 and test the resolution. When you get it where you wanted you are done.


Not all resolutions will lock in and you may get an error msg, keep fiddling, but make sure the vertical & horizontal refresh rates are not over your limit for your display.


At this point you can always hit escape to back out if your display loses picture for more than a couple seconds.


- Tom
 
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