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Discussion Starter · #1 ·
Anybody know if there is a way to lock the internal scaler of a Davis DL450 clone to 800x600. I have been trying to create a 800x450 resolution with powerstrip, the internal scaler try to go to 640x480 and everything just go berserk (!) after that. I think my chance of success will be a lot better with the internal scaler lock to 800x600. Thank you!


Bruno
 

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I would like to do this so as the jump in boot time did not knock the projector out of whack...


If trying to do a PowerStrip 800x450 setup I had many many difficulties with this and in fact gave up as YxY top alignment + blanking works better as I can then have zoom out and full panel resolution for 4:3 sources and games... I emailed back and forth with Ashley many times and it was suggested that possibly the GeForce card did not like resolutions with less than 480 vert... This may make sense as 480 is the min expected these days with VGA and many apps just dont have enough screen real estate to handle a 450 vertical setup...


If you get it working please mail me... For me as soon as I went below 480 the display adapter dropped to 640x480 not the projector but the PC !!!


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This look like a question for...Larry Davis! Hello Larry, are you on-line?

}

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No such luck guys. The Davis will only recognize 640x480, 800x600 or 1024x768. The projector is a vesa standard fixed scan frequency unit, not multiscan so it cannot synch to other non-vesa signals.
 

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Jon,


Theoretically you should be able to get 800x450 working but using back and front porches with powerstrip, ie the signal 'looks' like 800x600 but there is only 800x450 active pixels. But as PP said about it looks like the Geforce has problems with less then 480.




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JonS as Lance has said the projector would be seeing a SVGA timed signal but what you are doing with PowerStrip is adding porches (of no info = black) to the signal to letterbox the active pixel array...


Many many other people with XGA projectors (that do not sync to widescreen either) will run a 1024x576 active pixel array with XGA timing + porches... In theory it should work down to the 800x450 but my gut feeling is its the Geforce not liking vertical rez less than 480 that does it (I had 800x480 working) anyway I need all the light output and resolution I can get... Hurry up with that Pannie http://www.avsforum.com/ubb/eek.gif


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Discussion Starter · #7 ·
Phat,


Can you give your settings for your 800x480 resolution (front and back porches etc..). So far I haven't been able to get anywhere that close. A print screen of your setting will be perfect. If the resolution is stable enough I think I could live with that. What I hate the most is my Viewsonic going full screen for the DVD menu than back to a 16X9 viewing area for the movie.


Bruno
 

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Discussion Starter · #8 ·
I SofaCinema,


I don't know for the others but my computer doesn't recognize my viewsonic and I use the standard 800X600 Microsoft drivers. I probably need to reinstall windows. I switch video card before Christmas and now I can't do 800X600 at 72 kHz, 60 kHz is the only refresh rate working. I guess if I really want to try 800x450 with powerstrip I need a cleaner system. thanks for the info.


Bruno


[This message has been edited by bgosselin (edited 04-26-2001).]
 

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Heya guys,

I run my projector at 848x480, not 848x600. As far as I know, all SVGA DLP's have an 848x600 DMD panel. The problem is that the single chip units have only 800 horizontal pixels available. I know nothing about tweaking the front and back porch settings in Powerstrip. Luckily, I don't need to. I hope SC's fix works for you. Remember I no longer own a Davis projector and I can't try this out on it. I think 16:9 desktops are overrated. Of course, I am running a 16:9 desktop, but that's just for DVD.


Bruno,

If I were in your shoes, I would just select a high res monitor in Display Properties and select 800x600 as my resolution. For NTSC I would use 72 Hz and for PAL, 75 Hz. In fact, this is what I did. No need to reinstall Windows just for this.
 

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Discussion Starter · #10 ·
I Larry,


I will try that. So far I try with the Microsoft driver 800X600 at 75kHz but 72kHz just did not stick. My main reason for wanting a 16x9 desktop is the following. My projector is in my main leaving room. I do not have a special theater room like most of the guys in this forum. I have a regular TV and all my electronic requirements below my screen. When I watch a DVD 16x9 the movie is just a few inches above the TV and the other furnitures like I want. But when I go on the chapter menu for example. Then my projector goes on a full 4x3 image projecting on my tv and stuff. It is really annoying.


I know I could project on the bottom of the screen but then the top on a full 4x3 will be projecting on the ceiling.


Bruno



[This message has been edited by bgosselin (edited 04-26-2001).]
 

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Hi Bruno,

I know what you mean. That used to bug me just a little bit. If you were to use an anamorphic lens, you would have an effectively 16:9 display. Your desktop would appear slightly "squished" down, but for DVD it would look great. After awhile, I got completely used to a 16:9 appearance to my desktop with my ISCO and now with my 16:9 resolution (848x480). If you can afford it, go for the lens. Hopefully the Panamorph will be the king of anamorphic video lenses. We'll see when it comes out. Remember reading the phrase "it's like getting a new projector"? I coined it from my own experience with my anamorphic ISCO lens and projector and it's true - it IS like getting a new projector! http://www.avsforum.com/ubb/biggrin.gif Good luck.
 

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Its 5:55 with me and I am late for work but this can be accomplished very easily without custom resolutions....


Use YXY to create a 16x9 window at the top of your screen and blank the rest... 16x9 will fill the window 4:3 will automatically pillarbox....


I have this working so that all my sources are correctly AR'ed within my 16x9 screen


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Guys this can be done. The problem is with the computer not the projector. You must have "standard VGA monitor" driver installed not DL450 or your PC monitor in order for the 800x450 w/ 800x600 T&R to take. The way I made this work with the LP340 was to turn the plug and play off therefore windows could not detect a monitor. I don't know if the davis has this option, if it doesn't you could remove the pins that send the information or use a 5 bnc breakout cable. here are the Powerstrip timings:


PowerStrip timing parameters:

800x450=800,56,128,72,450,76,4,98,40025,2048


Generic timing details for 800x450:

HFP=56 HSW=128 HBP=72 kHz=38 VFP=76 VSW=4 VBP=98 Hz=60


Linux modeline parameters:

"800x450" 40.025 800 856 984 1056 450 526 530 628 +hsync +vsync
 

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Of course, Phreddy is correct. If you want a 16:9 desktop, that's not so easy for an SVGA DLP owner. But a 16:9 window for DVD viewing is easy with YXY. Download YXY here . It's easy to use. To set up a perfect 16:9 window for DVD, open WinDVD (if you have it, doh) and select properties. Select the display tab and unlock aspect ratio. Close WinDVD (important!). Reopen WinDVD and insert the Avia disc. Select the widescreen enhanced circle hatch patterns. Make the circle as short as it is wide, via YXY. You will have to "squish" the circle down. You will need a tape measure for this.


Another option (which I wouldn't do, but it could suffice until you get the AVIA disc, which is indispensable) is to take an anamorphic DVD which you know has a 1.78:1 aspect ratio. Squish the height of the image until it perfectly fits the height (maintaining the full width, of course) of your 16:9 screen. If you don't have a 16:9 screen, divide the width of your screen by 1.78. The result is the correct height of your 16:9 window.
 

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OK well SofaCinema came to the rescue (when PowerStrip would not do what I wanted I took it off the machine) with T&R info for you but...


If it is just the menu's and 4:3 switch then why not use YxY to hold a 16:9 window (and blank the window frame and external) this is what I do and I also top align it... This way I have pillarboxed full panel resolution and light output for games, apps, dTV, web etc etc and when I do DVD viewing then I zoom (this downshifts the image in my setup) and YxY top aligns to that it still fits my 16x9 screen..


There are some slight problems due to image shift during zoom but combinations of stretch and (god forbid) crop means all my vide formats fit my 16x9 screen with the best of all worlds... I need all the light output I can achieve..


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Discussion Starter · #16 ·
Hello Larry,


I will try YXY in the next few days.


I try yesterday to play a little bit more with powerstrip custom resolution. I was able to obtain a perfect 16x9 screen using 1024x768 (1024x576) on my other computer. My idea was to feed my HTPC with that resolution and to find out how my Viewsonic was going to deal with it. The Viewsonic being a SVGA I was curious to find out how it was going to behave. I thougt it was going to try to fit that resolution in a 800x600 window and not a 640x480 like it always seem to go back to.


I was not able do complet the test. My video drivers are really corrupted. I try to change my monitor from the 800x600 default video driver to 1024x768. But my HTPC refused to go above a 640x480 with those drivers. I do not want to reinstall windows. My HTPC is really stable at this point and I do not want a blue screen of death in the middle of a movie, like I had with my previous system. I will try to solve my problem using YXY.


I will start a new thread in the computer section to find out if there is a way to correct my video drivers without reinstalling windows.


Thank you for your help.


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bgosslin, I would say that feeding the SVGA unit a XGA timed signal + porches that bring you down to a 16x9 XGA desktop will look really ugly... Running anything other that 800x600 gives an unusable (in any HT sense of the word) image in my setup... Try it by all means but only for curiosity value...


As to the display drivers have you tried removing them completely... a reboot or two into VGA then installing fresh current drivers ??? I would say this is likely to succeed and should not nix your partition... I hope its not too late to suggest a drive image backup tool like PowerQuest's Drive image pro... It gets me out of sticky situations and allows me to throw whatever I want (Game demo's, flaky SW, test stuff, etc etc) on for the weekend in total confidence... Highly recommended...


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Discussion Starter · #18 ·
I Phat,


I did find a complete instruction of how to remove display drivers on the manufacturer website. I will try that. Your suggestion to buy a Drive image pro is really interesting. I will look into it. Thank you for your help !


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Larry, I just re-read your post above Re: resolution of DLP... I take it your 3 chipper will handle a 848x480 resolution fed by PowerStrip equipped PC ?? But you state ALL DMD panels are 848 x 600 ?? I have noticed the extra pixels left and right of my panel and when I have absolute darkness tonight I will also check above and below for some 'extra'...


When you say that they are not addressable would you believe this is HW limited or SW (firmware) limited.. If a Davis Firmware could 'unlock' these pixels, you would think that the Cinema series of machines would have the 848x480 in use as this is so close to perfect 16x9 as to be very desirable... Would also mean that the full 480 resolution of DVD's would not need to be downscaled (pixel perfect DVD mapping may be interesting complete elimination of scaling all together)...


This is a very interesting possibility... has this idea not been discussed in the past ?? Of course I start to think about this at a piont that (I hope) is close to the final shipping of the Pannie which will nix a 16x9 panel being required for me, but if there is more vertical as well then 848x636 would be 12-15% more light and resolution (who doesn't want that ??)..


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Originally posted by Phat Phreddy:


"Larry, I just re-read your post above Re: resolution of DLP... I take it your 3 chipper will handle a 848x480 resolution fed by PowerStrip equipped PC ??"


Yes. I'm using it with great results.


"But you state ALL DMD panels are 848 x 600 ??"


As far as I know, that's a fact.


"I have noticed the extra pixels left and right of my panel and when I have absolute darkness tonight I will also check above and below for some 'extra'..."


The way I understand it, all SVGA DMD panels are 848x600. That should mean you will not see any unused panel above and below your 800x600 desktop. The 16:9 window within an 848x636 window is 848x480, so for widescreen movies, 848x480 is effectively the same as having an 848x636 DMD.


"When you say that they are not addressable would you believe this is HW limited or SW (firmware) limited.."


I think something like this would probably be software, but I think I read that TI may have done this to the chips, so I don't know. There are at least a few people here who would know the answer for sure. I think we have an occasional poster here who works for Davis. He would know or could find out.


"If a Davis Firmware could 'unlock' these pixels, you would think that the Cinema series of machines would have the 848x480 in use as this is so close to perfect 16x9 as to be very desirable... Would also mean that the full 480 resolution of DVD's would not need to be downscaled (pixel perfect DVD mapping may be interesting complete elimination of scaling all together)..."


Since I'm running at 848x480, I can say the image is sharper and more detailed. It just looks better. By going from 800x450 to 848x480, projector resolution increases by 13%. It's not a lot, but enough to notice it. It would be great if single chip units could work at this resolution.


"This is a very interesting possibility... has this idea not been discussed in the past ??"


Yes, it was brought up several times. From what I understand, TI themselves may have locked the DMD's somehow (don't know how) to 800 horizontal pixels.


"Of course I start to think about this at a piont that (I hope) is close to the final shipping of the Pannie which will nix a 16x9 panel being required for me, but if there is more vertical as well then 848x636 would be 12-15% more light and resolution (who doesn't want that ??).."


848x480 + 2.35:1 movie + Panamorph, would give you nearly nearly 50% more projector resolution than you get from 800x600 + 2.35:1 movie and no anamorphic lens. The reason being that on an SVGA projector with no anamorphic lens, you use only 340 vertical lines, instead of 600, as you know.


[This message has been edited by Larry Davis (edited 04-28-2001).]
 
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