Obsolete analog video woes
February 14, 2012 5:31 PM Subscribe
I have a media box plugged into a 480p widescreen TV. How can I get Windows to use the correct aspect ratio?
So, I have a media box running Windows 7, with a Radeon HD 4870 sending component video to an older 16:9 TV that doesn't have a digital input.
The best available resolution for component output is 720x480 (the native resolution of the TV, as far as I can tell -- it's a plasma). This stretches to the edges of the screen and looks pretty good.
My problem is that Windows seems to assume that the 720x480 resolution is in square pixels. This led to an aspect ratio problem on a CRT TV I had the same media box connected to earlier, because the 3:2 aspect 720x480 was squished into a 4:3 picture. Now I seem to have the opposite problem, where the 3:2 desktop is stretched to 16:9.
Oddly, when I switch the resolution to 640x480 (the only other option), the screen switches to 4:3 mode and everything looks correct, but of course I lose the widescreen.
How can I force Windows to recognize that my screen is 16:9 and not 3:2? Barring that, is there a way I can virtualize the display somehow so I can "pretend" to have an HD-resolution TV? This would come in handy with using Windows, it's barely operable at 720x480.
So, I have a media box running Windows 7, with a Radeon HD 4870 sending component video to an older 16:9 TV that doesn't have a digital input.
The best available resolution for component output is 720x480 (the native resolution of the TV, as far as I can tell -- it's a plasma). This stretches to the edges of the screen and looks pretty good.
My problem is that Windows seems to assume that the 720x480 resolution is in square pixels. This led to an aspect ratio problem on a CRT TV I had the same media box connected to earlier, because the 3:2 aspect 720x480 was squished into a 4:3 picture. Now I seem to have the opposite problem, where the 3:2 desktop is stretched to 16:9.
Oddly, when I switch the resolution to 640x480 (the only other option), the screen switches to 4:3 mode and everything looks correct, but of course I lose the widescreen.
How can I force Windows to recognize that my screen is 16:9 and not 3:2? Barring that, is there a way I can virtualize the display somehow so I can "pretend" to have an HD-resolution TV? This would come in handy with using Windows, it's barely operable at 720x480.
I think you're out of luck for displaying the Windows desktop in the correct aspect ratio. However, a lot of video playing software has an aspect ratio override. What are you using to play your media?
posted by zsazsa at 6:02 PM on February 14, 2012
posted by zsazsa at 6:02 PM on February 14, 2012
720x480 is the native encoding format for NTSC DVDs, and that encoding does not use square pixels; the encoded pixels are widened for 16:9 movies or narrowed for 4:3. In fact your actual display panel probably has 853x480 physically square pixels and that's what you should be aiming to set the Windows output resolution to.
posted by flabdablet at 7:59 PM on February 14, 2012
posted by flabdablet at 7:59 PM on February 14, 2012
Agree that the non standard pixel setting might fix the problem. You could also see if your video card settings window lets you configure overscan.
But where exactly are you seeing the issue? Are you running the Media Center app? The settings in there have a different way of affecting the output than the settings in control panel.
posted by punocchio at 9:10 PM on February 14, 2012
But where exactly are you seeing the issue? Are you running the Media Center app? The settings in there have a different way of affecting the output than the settings in control panel.
posted by punocchio at 9:10 PM on February 14, 2012
Does the plasma have a VGA/RGB port? If so, use that rather than component. Flabdeblet is right that the plasma's resolution is 8XX by 480, although the exact horizontal pixel count often varies by display.
What's the exact model name of the display?
posted by The Lamplighter at 11:19 PM on February 14, 2012
What's the exact model name of the display?
posted by The Lamplighter at 11:19 PM on February 14, 2012
Powerstrip will set your output to anything you want. Do find out the native resolution of the tv first though.
posted by defcom1 at 7:45 AM on February 15, 2012
posted by defcom1 at 7:45 AM on February 15, 2012
Response by poster: Component video is my only real option here. All the inputs are analog (S-Video, composite, antenna).
720x480 is the native encoding format for NTSC DVDs, and that encoding does not use square pixels; the encoded pixels are widened for 16:9 movies or narrowed for 4:3. In fact your actual display panel probably has 853x480 physically square pixels and that's what you should be aiming to set the Windows output resolution to.
Well, that's the rub. I'm not sure if I can change the output resolution. Didn't know about the extra pixels on my display, though. If it's really square pixels and I can manage to tweak the output rez this might work.
I'm not sure if I'll be able to tweak the resolution for the composite output, but I suppose if composite can handle HD resolutions it can handle slightly-wonky resolutions, maybe? (I don't think I can turn GPU scaling on either.)
Powerstrip will set your output to anything you want. Do find out the native resolution of the tv first though.
I'll have to give this a try.
posted by neckro23 at 8:30 AM on February 15, 2012
720x480 is the native encoding format for NTSC DVDs, and that encoding does not use square pixels; the encoded pixels are widened for 16:9 movies or narrowed for 4:3. In fact your actual display panel probably has 853x480 physically square pixels and that's what you should be aiming to set the Windows output resolution to.
Well, that's the rub. I'm not sure if I can change the output resolution. Didn't know about the extra pixels on my display, though. If it's really square pixels and I can manage to tweak the output rez this might work.
I'm not sure if I'll be able to tweak the resolution for the composite output, but I suppose if composite can handle HD resolutions it can handle slightly-wonky resolutions, maybe? (I don't think I can turn GPU scaling on either.)
Powerstrip will set your output to anything you want. Do find out the native resolution of the tv first though.
I'll have to give this a try.
posted by neckro23 at 8:30 AM on February 15, 2012
Give us the exact model name of the display.
Composite cannot handle HD. Neither can s-video.
posted by The Lamplighter at 10:56 AM on February 15, 2012
Composite cannot handle HD. Neither can s-video.
posted by The Lamplighter at 10:56 AM on February 15, 2012
Response by poster: I was backwards. I meant component.
posted by neckro23 at 1:46 PM on February 15, 2012
posted by neckro23 at 1:46 PM on February 15, 2012
Best answer: You can probably send any valid HD resolution to the display via component - it will then handle the scaling. Those are 480p (640x480 progressive, or 720x480 progressive), 720p (1280x720 progresive) and 1080i (1920x1080 interlaced). You'll likely be happiest with 720.
It's really surprising that the display doesn't at least have a VGA/RGB input. Older plasmas were usually pretty full-featured when it came to inputs.
If you won't at provide the model at least provide the brand.
posted by The Lamplighter at 3:14 PM on February 15, 2012
It's really surprising that the display doesn't at least have a VGA/RGB input. Older plasmas were usually pretty full-featured when it came to inputs.
If you won't at provide the model at least provide the brand.
posted by The Lamplighter at 3:14 PM on February 15, 2012
Response by poster: It's a Sylvania set. Cheap and bare-bones even when it was new (the remote looks like it's for a hospital bed or something) but the picture is decent and hey, it was free.
I intend to try changing the resolution tonight and will report my findings...
posted by neckro23 at 8:25 AM on February 16, 2012
I intend to try changing the resolution tonight and will report my findings...
posted by neckro23 at 8:25 AM on February 16, 2012
Best answer: Is it this set? Connect via component and have the PC output 720p (1280x720).
posted by The Lamplighter at 12:26 PM on February 16, 2012
posted by The Lamplighter at 12:26 PM on February 16, 2012
Response by poster: As a matter of fact, it's exactly that set! I should've mentioned the model earlier.
...and I should've tried 720p earlier, too. I'd forgotten about disabling the HD resolutions in Catalyst Control Center, and assumed the maximum resolution was fixed. 1280x720 does the trick, and it's only slightly fuzzy! Thanks!
posted by neckro23 at 5:32 PM on February 16, 2012
...and I should've tried 720p earlier, too. I'd forgotten about disabling the HD resolutions in Catalyst Control Center, and assumed the maximum resolution was fixed. 1280x720 does the trick, and it's only slightly fuzzy! Thanks!
posted by neckro23 at 5:32 PM on February 16, 2012
It's fuzzy because your TV is interpolating the 1280x720 image your video card is sending it onto a display without enough pixels to represent that image accurately. The upside is that Windows should be pretty much completely operable given a desktop 720 logical pixels high; in fact this is exactly the "display virtualization" you were asking for.
When you play movies on this rig, your graphics card will be scaling the movie image up to fit 1280x720 pixels, and then your TV will be scaling that back down to fit its 852x480 physical display. This twice-over scaling will make the movie slightly fuzzier than it needs to be. If you can use PowerStrip or something similar to make your PC's video output signal match your display's actual native resolution, then the TV's inbuilt processor will scale at 1:1 which it can probably do just about losslessly. Also your GPU will end up generating its video output using about half the pixel clock rate, which should cut its power consumption some.
posted by flabdablet at 5:52 AM on February 17, 2012
When you play movies on this rig, your graphics card will be scaling the movie image up to fit 1280x720 pixels, and then your TV will be scaling that back down to fit its 852x480 physical display. This twice-over scaling will make the movie slightly fuzzier than it needs to be. If you can use PowerStrip or something similar to make your PC's video output signal match your display's actual native resolution, then the TV's inbuilt processor will scale at 1:1 which it can probably do just about losslessly. Also your GPU will end up generating its video output using about half the pixel clock rate, which should cut its power consumption some.
posted by flabdablet at 5:52 AM on February 17, 2012
Flabdablet - the TV isn't going to accept its native resolution via component. 720p is probably the best he can do.
You might be able to minimize some of the fuzziness by turning off any image "enhancement" features that the TV has - set sharpness to 0, noise reduction to 0, move the color control toward the middle setting, etc. The sharpness control will probably be the most essential.
posted by The Lamplighter at 10:56 AM on February 17, 2012
You might be able to minimize some of the fuzziness by turning off any image "enhancement" features that the TV has - set sharpness to 0, noise reduction to 0, move the color control toward the middle setting, etc. The sharpness control will probably be the most essential.
posted by The Lamplighter at 10:56 AM on February 17, 2012
Is there truly no 480-line timing that it can be persuaded to display at 16:9? I had the impression that that's what it was doing for 720x480, and that the issue was simply that 720:480 is not 16:9 so the Windows pixels end up stretched.
Or is it that its converter actually samples a 480-line timing at 720 points across each line and rescales from that for the display, rather than sampling at 852 points across each line? Because given the kind of control over the GPU timing that I know I can get with xorg.conf on a Linux box and which I'm presuming PowerStrip will let you get on Windows, coming up with an 852x480 analog signal with frame, line and blanking timings almost identical to those that the TV would normally expect for 720x480 should be completely feasible.
posted by flabdablet at 6:11 AM on February 18, 2012
Or is it that its converter actually samples a 480-line timing at 720 points across each line and rescales from that for the display, rather than sampling at 852 points across each line? Because given the kind of control over the GPU timing that I know I can get with xorg.conf on a Linux box and which I'm presuming PowerStrip will let you get on Windows, coming up with an 852x480 analog signal with frame, line and blanking timings almost identical to those that the TV would normally expect for 720x480 should be completely feasible.
posted by flabdablet at 6:11 AM on February 18, 2012
Response by poster: Heh, I just noticed the continued discussion here.
I tried to get Powerstrip working, I really did, but it simply wouldn't cooperate. I think the trouble is that the component outputs on the Radeon are treated differently by the driver compared to monitor outputs.
It's much more expedient to just send 720p to it. The TV display even says "720p", so it's obviously an intentional feature. When it was new, it was directly competing with 720p sets, so it makes sense in retrospect. The fuzziness is really not an issue, since it's mainly for Netflix viewing anyways.
posted by neckro23 at 4:27 PM on February 27, 2012
I tried to get Powerstrip working, I really did, but it simply wouldn't cooperate. I think the trouble is that the component outputs on the Radeon are treated differently by the driver compared to monitor outputs.
It's much more expedient to just send 720p to it. The TV display even says "720p", so it's obviously an intentional feature. When it was new, it was directly competing with 720p sets, so it makes sense in retrospect. The fuzziness is really not an issue, since it's mainly for Netflix viewing anyways.
posted by neckro23 at 4:27 PM on February 27, 2012
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posted by jozxyqk at 5:51 PM on February 14, 2012