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TVScreen 1.0.0 for Shake

for simulating a TV-screen

License
Button download
2,822 Downloads

Compatibility

  • 3.x, 2.x, 4.x

Operating Systems

  • Linux
  • Mac
  • Windows

History

Created:04/06/2005
Last Modified:03/22/2009
File Size: 73.3 KB

This TVScreen macro is based on entirely different fundamentals than the previous ones so the results are far more believeable (though not perfect).



It contains all the three picture tube types in use (inline, delta, trinitron - see example & what is what) and handles 4:3 and 16:9 aspect ratio as well.

 

I built in some typical errors (all off by default) like desynchronization, color purity and convergence error of the CRT (see what is what).

 


Restrictions:

 

If you look close the example file, the pixel colors are not red green and blue. That's because of the jpeg compression, on your screen there will be no problem.

 

Since the delta picture tube type shifts pixels by 0.5 in every second line (as seen on example) and you monitor cannot draw half pixels, you will see 0.5*red+0.5*green, 0.5*green+0.5*blue, 0.5*blue+0.5*red colors in every second line instead. (only when switching to delta CRT)

 

 

 

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What is what?

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Inline:

 

The three electron guns are placed along a horizontal line and the fluorescent material is photographed on the screen in vertical lines through a shadow mask. The shadow mask is a sheet-metal with slight vertical holes in it, and this is placed behind the screen to enable to one electron beam to reach it's own phosphor and disable that for the other two.
TVs since the 70s use this type of picture tube, because it's cheaper, simpler and less sensitive to vertical convergence error than the delta type.

 

Delta:

 

The three electron guns are placed in a triangle (or "delta") shape, so the phosphor points on the screen. The shadow mask has now point holes in it.
TVs before the 70s and most of the CRT monitors today use this picture tube.

 

Trinitron:

 

It is similar to the inline array, the only difference is that instead of shadow mask it usues an aperture grill, which is a thick vertical wire-net allowing more light to pass, producing a brighter image. The only drawback of this system is, that you can see 2 thin horizontal black lines at 1/4 and 3/4 height of your screen. These are two thin wires holding the wire-net.
TVs and monitors with "Trinitron" marking use this type of CRT (developed by Sony so usually Sony things).

 

Desynchronization:

 

When the picture begins slowly wandering up or down the screen and you see an ugly black line between the frames. The wandering is because the incoming frequency differs from the (PAL) 50Hz field frequency of your TV (NTSC - 59,97HZ). The black lines are because the (PAL) picture contains 625 lines (NTSC - 525), but only 575 (NTSC - 485) lines are visible on the screen. The other 50 (NTSC - 40) lines are during the blanking time, so they are out of the screen normally. But when the synchron goes wrong you will see those like they were black frame borders.

 

Color purity:

 

When an electron beam belonging to one color hits pixels belonging to another color instead of it's own pixels, causes color purity error.
For example the red electron gun fails by half pixel (say toward the green pixels), so only 50% of the red gun's light reaches the red pixels, the other 50% is added to the green pixels. If it fails by a whole pixel, there will be no red light on the screen, but the green (or blue) will be much brighter.

 

Convergence:

 

When an electron beam doesn't move together with the other two it causes convergence error. The wrong beam will over- or underscan the screen, so you will see a tinted double image showing itself increasingly toward the sides. There will be no convergence error in the center of the screen because the three beams will always cross this point at the very same time, independently of the convergence error.



Please use the Bug System to report any bugs.
Please use the Feature Requests to give me ideas.
Please use the Support Forum if you have any questions or problems.
Please rate and review in the Review section.