TV video safe modes!

earlz · Post by **earlz** » Wed Mar 21, 2007 9:20 pm

I have recently got a S-Video cord to hook my old pc to my TV(preventing switching monitor cords)
and well...IT SUCKS! I can barely read anything! the text is so small and hard to see, even on my huge TV, at 800x600 resolution(on windows btw)

the only way to make it all mostly readable is to make text size "extra large" and even with this, some things are hard to read..(like most normal window text)

when implementing your OS, you should really consider this stuff! make a TV safe setting, and with this, you can override all font sizes to 2x or 4x size(even on fonts exclusively listed!)

now, all VGA text modes(there are 5 of them I think) I tested my OS with them, and the worst thing that happened was in a high resolution mode(like 90x60) it was a bit unreadable(though still pretty good) and in a few modes it had the text repeating, like it had one copy of the text on both the right and left side, which is OK, just kinda confusing

AndrewAPrice · Post by **AndrewAPrice** » Wed Mar 21, 2007 9:50 pm

what sort of TV? NTSC? PAL? High definition? Digital or analogue?

Have a look here http://en.wikipedia.org/wiki/List_of_common_resolutions

uglyoldbob · Post by **uglyoldbob** » Fri Mar 23, 2007 8:20 am

I think that this is the norm for tv-video cards. I'm not sure the TV can handle the recolution that is being pumped to it by the video card. 720 x 480 seems to be the largest that the most common tv's will have according to the wikipedia. I have used two different tv-video cards before and it was very difficult to read text unless it was greatly magnified. Movies, graphics, and non-text go through great.

GLneo · Post by **GLneo** » Fri Mar 23, 2007 8:38 am

i have one of these cables, text does suck, but quake is great! TV's just don't have the pixel accuracy of monitors, i have yet to find a resolution that can display text.

800x600 is good.

AndrewAPrice · Post by **AndrewAPrice** » Sat Mar 24, 2007 7:12 am

Modern TV's (my LCD anyway) have a VGA connector, so I can plug it in like any normal monitor.

Candy · Post by **Candy** » Sun Mar 25, 2007 1:32 pm

uglyoldbob wrote:I think that this is the norm for tv-video cards. I'm not sure the TV can handle the recolution that is being pumped to it by the video card. 720 x 480 seems to be the largest that the most common tv's will have according to the wikipedia. I have used two different tv-video cards before and it was very difficult to read text unless it was greatly magnified. Movies, graphics, and non-text go through great.

*cough* NTSC tvs have a vertical visible resolution of 480, total resolution of 525, being interlaced (so if you alternate white horizontal lines with black horizontal lines your customers will probably be taken to the hospital within a few minutes). PAL tvs have a vertical resolution of 576, total resolution of 625, also interlaced (same thing on black/white). The former run at 60Hz, the latter at 30Hz.

The horizontal resolution SHOULD be 720, but if your driver is a bit noisy or underpowered (or too unprecise or something similar) it'll be less. The horizontal/vertical ratio is fixed though. In theory, you could put 1920 pixels in the horizontal direction and monitors capable of changing that quickly would show you 1920*480 pixels. In practice, most TVs don't care and just sample it 720 times a second for manual deinterlacing and upping the display frequency to 90/100 Hz, performing 3/2 downsampling or something similar making the image quality better than what it would've been in the 1970s.

carbonBased · Post by **carbonBased** » Sun Mar 25, 2007 2:42 pm

MessiahAndrw wrote:Modern TV's (my LCD anyway) have a VGA connector, so I can plug it in like any normal monitor.

It'll still be nowhere near the resolution (See Candy's response).

Text on an LCD *should* have more definition then an analogue CRT, though, even at the same resolution... which would make it easier to read.

Also, as a general note, 640x480 (VGA) is the closest (std) res you'll find that'll closely match a (non-hd) television. Those that have mentioned that 800x600 looks okay should realize that there is definite aliasing occuring even in this mode.

--Jeff

AndrewAPrice · Post by **AndrewAPrice** » Sun Mar 25, 2007 6:23 pm

Standard definition CRTs were never designed for text, only for moving images, that's why they seem to blur the image - fine for video, but not for text. You could use a 200x150 (or something similar) resolution like them old Commodore computers.

Candy · Post by **Candy** » Mon Mar 26, 2007 11:32 am

MessiahAndrw wrote:Standard definition CRTs were never designed for text, only for moving images, that's why they seem to blur the image - fine for video, but not for text. You could use a 200x150 (or something similar) resolution like them old Commodore computers.

Ahum. Even the really old C64 computers used 320*200 or 160*200 in high-colour mode. Using assembly you could get up to 16 colors at the same time in 320*200 iirc!

CRT's are designed for photorealistic images in the way that they'll blur anything you won't notice in a typical photorealistic scene - exact horizontal lines, white/black crossovers and so forth.

On the subject of high-def TV's, most don't even make the 1080i resolution - they go for 1300 something by 800 something pretending to be full HD. While we're at it - 1080p really won't be much better than 1080i if only because of the quite decent deinterlacing techniques that modern TV's already use.

mystran · Post by **mystran** » Mon Mar 26, 2007 2:40 pm

Well computer CRTs don't blur nearly as much as TVs do. You'll notice the difference immediately if you take an old monitor maxing out at something like 640x480, and compare the image with a modern TV; you'll almost certainly notice that text on the old monitor is much easier to read.

For displaying video, which is what TV are designed for, it kinda makes sense to avoid too sharp image anyway. The reason TV cards often look crappy compared to a normal cheap TV is specifically because computer screens are far too good and display all the imperfections in the image too sharply.