So I just woke up with an interesting idea, and I thought I would share it with the bunch. It could possibly allow for HDTV quality projection. The idea is using multiple screens, like they have at video stores and some electronics places. Here in the US, they do this at blockbuster and Best Buy. The concept is having 4 screens, with 1/4 of the total picture on each screen. This would make it higher quality because each screen is only being stretched 1/4 size of the whole screen. You could use 4 mid-quality 2" lcd's to get a good image, or 4 high-quality lcd's to get possible HiDef.
The concept is simple, but I've searched the forum and not found anything dealing with this. Perhaps this would be best suited for a rear-projection big screen tv? Let me know what everyone thinks, its dinner time.
The concept is simple, but I've searched the forum and not found anything dealing with this. Perhaps this would be best suited for a rear-projection big screen tv? Let me know what everyone thinks, its dinner time.
Very interesting thought!
Getting the optics to line up would be a trick, but I think it definately would be do-able. 🙂
I'm looking forward to seeing more discussion on this...
--Clint
P.S. This might help with the brightness problem... if we could have basically 4 DIY projectors and combine them all, we could use cheaper, smaller light sources and get the same kind of image as a more expensive setup...
Getting the optics to line up would be a trick, but I think it definately would be do-able. 🙂
I'm looking forward to seeing more discussion on this...
--Clint
P.S. This might help with the brightness problem... if we could have basically 4 DIY projectors and combine them all, we could use cheaper, smaller light sources and get the same kind of image as a more expensive setup...
Sorry to bring bad news, but the device that spilt the video into four different channels usally costs serveral thousand dollars, and most output just standard video. There are those who have been able to make there own video-wall boxes with a pc running linux, but you would need a very fast computer to handle doing it with Mpeg-2 HDTV, also I don't believe the current HD-turner cards come with drivers for linux. In the end, in all odds, I could be done, but it would not be worth it.
Another idea down the toilet
Unfortunately you are absolutely correct mike, they are thousands of dollars. I found some info on a DIY multiple video output if anyone is interested in building a Video Wall. It may even be possible to take the info from these webpages and reconstruct it so that it is cheaper. It is relatively simple to implement as is; one computer for each row of video output.
<a href="http://www.linuxdocs.org/HOWTOs/Xinerama-HOWTO.html" target="_blank">Xinerama How To</a>
<a href="http://www.gstreamer.net/apps/vw/" target="_blank">Video Whale Project(pics)</a>
<a href="http://www.gstreamer.net/docs/video-wall-howto.html target="_blank">DIY Video Wall</a>
Unfortunately you are absolutely correct mike, they are thousands of dollars. I found some info on a DIY multiple video output if anyone is interested in building a Video Wall. It may even be possible to take the info from these webpages and reconstruct it so that it is cheaper. It is relatively simple to implement as is; one computer for each row of video output.
<a href="http://www.linuxdocs.org/HOWTOs/Xinerama-HOWTO.html" target="_blank">Xinerama How To</a>
<a href="http://www.gstreamer.net/apps/vw/" target="_blank">Video Whale Project(pics)</a>
<a href="http://www.gstreamer.net/docs/video-wall-howto.html target="_blank">DIY Video Wall</a>
not only very expensive equipment, but useless for now- there would be no use to make an hd set since you don't even have the media to use the full resolution of one 15" lcd, let alone 4 of them- think about a dvd on your compute- to make it full screen, the computer must strecth the image if the monitor is above 800x600. u can take advantage with widescreen dvd movies, for example, since the computer monitor, even though at a 4:3 ratio, is still capable of displying the entire widescreen image in its native resolution without cropping- or squeezing if it's anamorphic. any true hdtv out there HAS to be widescreen. the progressive image cannot be trully called hd if it isn't on a wide screen. for our projecting purposes, a monitor supporting a resolution at about 1024x768 can be considered hd
These guys sell the equipment for multiple screen setups (computer as well as video).
http://www.9xmedia.com/index.html
I'm sure this stuff is a fortune though.
http://www.9xmedia.com/index.html
I'm sure this stuff is a fortune though.
even so...
the lcd's would have to be compatible with HD format...and most arent, and i bet you couldnt find that 2" size like that. See, the HD format can't be on any type of lcd or tube screen. It HAS to be compatible with the higher pixel density that HD is. That would be a hitch. Wouldnt it?
the lcd's would have to be compatible with HD format...and most arent, and i bet you couldnt find that 2" size like that. See, the HD format can't be on any type of lcd or tube screen. It HAS to be compatible with the higher pixel density that HD is. That would be a hitch. Wouldnt it?
I think the idea is to put 4 panels together, making it one HD panel. 640x480 time 4 is 2560 x1920. Well more than enough to get a true HD picture. You'd need 4 graphics cards, and you'd have to have an OS that could support 4 graphics cards. Maybe you could use two graphics cards that have dual outputs. Then you'd need software to tell the OS to output a different quarter section of the screen to each video card. In theory it makes perfect sense. But good luck finding or writing the software. Plus, I don't think it is physically possible to align them without having a black cross in the middle of the image. But hey, what do I know?
What about Multiple Monitor support under Windows??
I know you can easily do 2 monitors with many graphics cards. Adding another 2 would be the problem
Does nVidia's nView architecture have anything to do with this? If it is possible to run 4 monitors off a PC, then this is easily doable. The resolutions of each panel would probably need to be 640x480 minimum, but I reckon it might be doable.
Just need to see if 2 graphics cards = 4 displays with nView.
Ofcourse, the other plan is 2 PC's, each playing 1/2 the DVD, but the sync issues would be a nightmare (ie. custom software)
Just a thought,
Jonathan
I know you can easily do 2 monitors with many graphics cards. Adding another 2 would be the problem
Does nVidia's nView architecture have anything to do with this? If it is possible to run 4 monitors off a PC, then this is easily doable. The resolutions of each panel would probably need to be 640x480 minimum, but I reckon it might be doable.
Just need to see if 2 graphics cards = 4 displays with nView.
Ofcourse, the other plan is 2 PC's, each playing 1/2 the DVD, but the sync issues would be a nightmare (ie. custom software)
Just a thought,
Jonathan
Sweetrobot, your right that anything over 800x600 is useless for DVDs, but some people do get HD broadcasts, Xboxes can output HD, and people like to play computer games in high resolution (especially if it's on a big screen). I like 1600x1200 on my 19" monitor. I'm definately not wanting to settle for 1024x768 on an 80" screen.
ilikenwf, I'm a little confused about what your saying. There is no such thing as LCD's that are or aren't compatible with HD. That has to do w/ the controller card, if it has component inputs. But if it has computer inputs, then you've got an HD compatible panel already. Even some (not many) DTV decoder boxes use a VGA output .
There is no such thing as an "HD format". ATSC are digital signals sent over the airwaves in a variety of formats. A decoder is required to..... decode the signals, and then it spits out an analog signal (yes, analog) via 3 component coaxle cables. There are many ATSC signals that decoders will recognize. Standard definition or SD, like 480i (same as NTSC), 480p (same as a DVD) are also broadcast on "HD" channels. 720p and 1080i (what is mean when people say "high definition"). 720p, for example, is no different than a computer desktop monitor running at a widescreen resolution of 1280x720.
If you watch a movie on HBO HD, 9 time out of 10, the movie was never transfered from film straight to an HD video recorder (called D-5 machines). It was probably transfered from a D-1 or Betacam, which are old-school NTSC formats. So even then your not getting high definition.
Most HD TV's you see in stores have a much lower native resolutoin than 720p or 1080i. I have yet to see a Plasma TV that has anything higher than 1184 vertical lines or whatever. Yet they charge thousands and call them HD-ready because they have 1080i component inputs on them. This is one of the main reasons I want a DIY projector- because I can achive a much higher resolution that any manufactured item costing less than $50 grand.
ilikenwf, I'm a little confused about what your saying. There is no such thing as LCD's that are or aren't compatible with HD. That has to do w/ the controller card, if it has component inputs. But if it has computer inputs, then you've got an HD compatible panel already. Even some (not many) DTV decoder boxes use a VGA output .
There is no such thing as an "HD format". ATSC are digital signals sent over the airwaves in a variety of formats. A decoder is required to..... decode the signals, and then it spits out an analog signal (yes, analog) via 3 component coaxle cables. There are many ATSC signals that decoders will recognize. Standard definition or SD, like 480i (same as NTSC), 480p (same as a DVD) are also broadcast on "HD" channels. 720p and 1080i (what is mean when people say "high definition"). 720p, for example, is no different than a computer desktop monitor running at a widescreen resolution of 1280x720.
If you watch a movie on HBO HD, 9 time out of 10, the movie was never transfered from film straight to an HD video recorder (called D-5 machines). It was probably transfered from a D-1 or Betacam, which are old-school NTSC formats. So even then your not getting high definition.
Most HD TV's you see in stores have a much lower native resolutoin than 720p or 1080i. I have yet to see a Plasma TV that has anything higher than 1184 vertical lines or whatever. Yet they charge thousands and call them HD-ready because they have 1080i component inputs on them. This is one of the main reasons I want a DIY projector- because I can achive a much higher resolution that any manufactured item costing less than $50 grand.
Just tossing up ideas now....
Here are 4 ideas I recently came up with dealing with video splitting:
Ok maybe there is some way to use a tv signal generator to split an output signal 1/4? I have no idea how these work or what they are used for...where is <b>remp</b> when you need him..
Take 4 lcd's of the same make and model and wire them all to the same lcd controller card so that the controller thinks it is outputting to one lcd, but each lcd is outputting 1/4 of the full image.
Macintosh OS-X has a zoom feature resident in its programming that allows the user to zoom in on any program, application or even the desktop. Maybe this could be used in conjunction with 2 dual output video cards so that the bottom 2 screens are zoomed into the bottom half of the screen, and the top into the top half.
I have an Nview graphics card. I know it allows multiple desktops each with different programs running, but I am not sure about using it in conjunction with multiple video output. I will look into this some more.
All of these ideas are very simple in nature, and are only intented to get everyone's gears turning. Maybe a solution can be derived using one, or all of these ideas somehow. Who knows? Never Stop Pondering!!
Here are 4 ideas I recently came up with dealing with video splitting:
Ok maybe there is some way to use a tv signal generator to split an output signal 1/4? I have no idea how these work or what they are used for...where is <b>remp</b> when you need him..
Take 4 lcd's of the same make and model and wire them all to the same lcd controller card so that the controller thinks it is outputting to one lcd, but each lcd is outputting 1/4 of the full image.
Macintosh OS-X has a zoom feature resident in its programming that allows the user to zoom in on any program, application or even the desktop. Maybe this could be used in conjunction with 2 dual output video cards so that the bottom 2 screens are zoomed into the bottom half of the screen, and the top into the top half.
I have an Nview graphics card. I know it allows multiple desktops each with different programs running, but I am not sure about using it in conjunction with multiple video output. I will look into this some more.
All of these ideas are very simple in nature, and are only intented to get everyone's gears turning. Maybe a solution can be derived using one, or all of these ideas somehow. Who knows? Never Stop Pondering!!
hdtv
hdtv ready sets which aren't widescreen- ie- sony wega xbr, etc, are not even hd- the wider spread on the horizontal in widescreen equals more pixels. all the 4:3 displays have is the same number of pixels for the area they would take up if you were to overlay them onto a widescreen. therefore, the image would be just as sharp on either, with the exception that the 4:3's image has less pixels overall, and thus, is not capable of displaying what by definition is an hd source- a widescreen- since the format has more pixels than can be physically fitten onto a 4:3 screen. you may also notice that all plasma displays- basically have same size pixels and dot-pitch as crt's- are all widescreen.
Now, there are two types of hdtv signals- 1080i, and 720p, intrelaced and progressive, respectively. The 1080i has 540 active lines and refreshes @ 60hz. i trust most know what interlacing is, but for those who don't, the system basically does every other line in the first scan, therefore 540 lines/scan, then scans the other set of 540- this all happens so quick, many will not notice. the second type is the 720 progressive- this is much better as it does all 720 lines progressively- ie scans all lines in one refersh, and therefore eliminates ghosting as may occur for the interlaced mode- if you've encoded avi's from a dvd source with divx or xvid, you know exactly what it looks like unless u put on a deinterlace filter- which blurs the interlaced image.
about resolution, the 1080i system has 1920 pixels per line, which is 1080x1920, but remember that it only really does 540 x 1920 per every refresh, while the 720p has 1280 pixels per line, and therefore a constant resolution of 720x1280.
in all, a 1080i image has a total of 2,073,600 pixels, but only half are active at any gven time, while the 720p has 921,600 pixels active simultaneously. although for every refresh the interlaced is faster since it does only half of the 2,073,600 pixels, which is fewer than 921,600, it only does half a frame in this amount of time, and must do another refresh for the other half of the frame - so two refreshes /frame. because there are fewer pixels to trace PER FRAME in the 720p mode, the less time it needs. this enables for greater frame rate, and therefore smoohter playback.
i hope this clears the fog a bit.
hdtv ready sets which aren't widescreen- ie- sony wega xbr, etc, are not even hd- the wider spread on the horizontal in widescreen equals more pixels. all the 4:3 displays have is the same number of pixels for the area they would take up if you were to overlay them onto a widescreen. therefore, the image would be just as sharp on either, with the exception that the 4:3's image has less pixels overall, and thus, is not capable of displaying what by definition is an hd source- a widescreen- since the format has more pixels than can be physically fitten onto a 4:3 screen. you may also notice that all plasma displays- basically have same size pixels and dot-pitch as crt's- are all widescreen.
Now, there are two types of hdtv signals- 1080i, and 720p, intrelaced and progressive, respectively. The 1080i has 540 active lines and refreshes @ 60hz. i trust most know what interlacing is, but for those who don't, the system basically does every other line in the first scan, therefore 540 lines/scan, then scans the other set of 540- this all happens so quick, many will not notice. the second type is the 720 progressive- this is much better as it does all 720 lines progressively- ie scans all lines in one refersh, and therefore eliminates ghosting as may occur for the interlaced mode- if you've encoded avi's from a dvd source with divx or xvid, you know exactly what it looks like unless u put on a deinterlace filter- which blurs the interlaced image.
about resolution, the 1080i system has 1920 pixels per line, which is 1080x1920, but remember that it only really does 540 x 1920 per every refresh, while the 720p has 1280 pixels per line, and therefore a constant resolution of 720x1280.
in all, a 1080i image has a total of 2,073,600 pixels, but only half are active at any gven time, while the 720p has 921,600 pixels active simultaneously. although for every refresh the interlaced is faster since it does only half of the 2,073,600 pixels, which is fewer than 921,600, it only does half a frame in this amount of time, and must do another refresh for the other half of the frame - so two refreshes /frame. because there are fewer pixels to trace PER FRAME in the 720p mode, the less time it needs. this enables for greater frame rate, and therefore smoohter playback.
i hope this clears the fog a bit.
Blah blah blah blah blah
Perhaps a better name for this thread would be "High resolution using multiple lcd's"
I honestly could care less about all this useless jibberish everyone seems to post to make themselves feel smarter. This has turned into a real nice ******* contest guys.
The point is, I am trying to use multiple screens to project a MORE CLEAR PICTURE.
Perhaps a better name for this thread would be "High resolution using multiple lcd's"
I honestly could care less about all this useless jibberish everyone seems to post to make themselves feel smarter. This has turned into a real nice ******* contest guys.
The point is, I am trying to use multiple screens to project a MORE CLEAR PICTURE.
nem0, if this were a ******* contest...
... u'd be ******* against the wind. this "useless jibberish" has all to do with your intentions on breakin up an image over multiple displays.
i mean no hostility, but please carefully read the posts in this thread. the whole thing comes down to your media source/ resolution. assuming the highest definition media you have is a dvd, by spreading the image over more pixels does not magically input more pixels per frame. in reality, u would be just stretching the same number of pixels you can fit onto one display. since you yourself stated that you are "trying to use multiple screens to project a MORE CLEAR PICTURE", or a higher definition picture, there would be no use to use more screens since the picture will retain the same clarity/ number of pixels as before. in essence, all you would be doing is making the same image larger, but not more clear- kind of like zooming in, u just get more pixelized. this is the whole point of projecting an image, to make it bigger, and by doing so, you would not make it sharper.
the only real advantage i would see in your setup is the fact that 3d models will have sharper resolution, but their textures as they are definitely finite. no matter how much u zoom into an edge, it still is an edge, but it is different for textures. also, vector art, and ither things like that will be bigger and sharper.
i hope this information better explains the relevancy of the previous posts.
... u'd be ******* against the wind. this "useless jibberish" has all to do with your intentions on breakin up an image over multiple displays.
i mean no hostility, but please carefully read the posts in this thread. the whole thing comes down to your media source/ resolution. assuming the highest definition media you have is a dvd, by spreading the image over more pixels does not magically input more pixels per frame. in reality, u would be just stretching the same number of pixels you can fit onto one display. since you yourself stated that you are "trying to use multiple screens to project a MORE CLEAR PICTURE", or a higher definition picture, there would be no use to use more screens since the picture will retain the same clarity/ number of pixels as before. in essence, all you would be doing is making the same image larger, but not more clear- kind of like zooming in, u just get more pixelized. this is the whole point of projecting an image, to make it bigger, and by doing so, you would not make it sharper.
the only real advantage i would see in your setup is the fact that 3d models will have sharper resolution, but their textures as they are definitely finite. no matter how much u zoom into an edge, it still is an edge, but it is different for textures. also, vector art, and ither things like that will be bigger and sharper.
i hope this information better explains the relevancy of the previous posts.
My bad
Well I do apologize. I guess I'm just more focused on the physical part of this idea. The actual nuts and bolts involved as opposed to the technical specifications. That and I'm sick of every single idea I have being shot down within a number of hours due to the "you can't do that" concept.
Well I do apologize. I guess I'm just more focused on the physical part of this idea. The actual nuts and bolts involved as opposed to the technical specifications. That and I'm sick of every single idea I have being shot down within a number of hours due to the "you can't do that" concept.
i hear ya
I understand what u're sating about the hands on. the cheapest solution is to get a gfx card supporting dual out, then work from that. i'm not posting to shoot your ideas down. i just like to share some knowledge, which may help people make better informed decisions- especially in this case, where things aren't exactly cheap. i am making a projector myself, and have been running into bad luck with a ribbon i cut in order to extend... not the place to talk about this though. good luck with your setup- keep us informed! ; )
I understand what u're sating about the hands on. the cheapest solution is to get a gfx card supporting dual out, then work from that. i'm not posting to shoot your ideas down. i just like to share some knowledge, which may help people make better informed decisions- especially in this case, where things aren't exactly cheap. i am making a projector myself, and have been running into bad luck with a ribbon i cut in order to extend... not the place to talk about this though. good luck with your setup- keep us informed! ; )
Re: Blah blah blah blah blah
I don't see any ******* contest. Everything we're saying has to do with the topic at hand.
Nem0 said:
I don't see any ******* contest. Everything we're saying has to do with the topic at hand.
Re: nem0, if this were a ******* contest...
I think it's been made clear that high def/high res is pointless for DVDs. But like you said, 3D images will benifit, computer games, Xbox games, and HD broadcasts will still benefit. Going the "video" route is not a good idea. Not gonna happen. It doesn't work like that. Going the "computer" route, might work (see my earlier post) because you could possible figure out a way to use multiple graphics cards.
Sweetrobot said:
I think it's been made clear that high def/high res is pointless for DVDs. But like you said, 3D images will benifit, computer games, Xbox games, and HD broadcasts will still benefit. Going the "video" route is not a good idea. Not gonna happen. It doesn't work like that. Going the "computer" route, might work (see my earlier post) because you could possible figure out a way to use multiple graphics cards.
multiple LCD panels for HDTV
It seems to me that it would not be difficult to accomplish the desired high resolution with only two LCD panels that had higher resolution properties. Windows can support multiple graphics cards and treat both monitors as one large monitor. The DVD playback window could be sized to expand over both monitors or LCD panels. This would make for an aspect ratio much closer to 16:9 without losing much of any of the monitors display resolution. The only problem as I see it is doubling the cost and engineering a method for aligning the two projected images. Because of the frame around the LCD panel you would have to align the two images externally unless there was some way to align the images inside the projector prior to image enlargement.
It seems to me that it would not be difficult to accomplish the desired high resolution with only two LCD panels that had higher resolution properties. Windows can support multiple graphics cards and treat both monitors as one large monitor. The DVD playback window could be sized to expand over both monitors or LCD panels. This would make for an aspect ratio much closer to 16:9 without losing much of any of the monitors display resolution. The only problem as I see it is doubling the cost and engineering a method for aligning the two projected images. Because of the frame around the LCD panel you would have to align the two images externally unless there was some way to align the images inside the projector prior to image enlargement.
- Status
- Not open for further replies.