Scanlines Again


subin

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well today i was browsing in dixons with a friend, and saw some personal media devices (like archos's and stuff, i think..), running videos, and noticed something! they suffer from pretty much the same scanline problem as the gp2x does, or it would seem so (i believe the problem varies based on your brain's interpretation of the image, and such.) so yes, they looked fine, then i moved my head slightly and i could see the scanlines - an identical situation to what happens on my gp2x.

comments?
 

Leshrac

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My GBA SP's screen does it too, less severely but you can notice it when moving the screen or when showing certain color patterns.
 

subin

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My GBA SP's screen does it too, less severely but you can notice it when moving the screen or when showing certain color patterns.

i was pretty surprised to see the same effect, i was quick to put it down to the gp2x's somewhat less-than-perfect reputation :p
 
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Vimacs

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Actually, the GP32 does it as well, but the scanlines are vertical rather than horizontal, so you don't really notice them unless you're looking for them.
thats couse the gp32's screen is rotated 90° :)
but honestly inever noticed that at my flu, is that maybe only on blu's?
 
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Paradox

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i dont have any lines on my gp2x screen, can someone explain what im looking for?

my screen has been pretty much perfect since i got it
 

Tobriand

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I definitely noticed it on the GP32 (FLU and NLU), but I must say, I never really associated it with the same thing as is happening, probably simply because the screen drawing the wrong way round there.

I recall on the GP32 that the problem became almost impossible to detect using higher voltage batteries - which means this may be the only argument yet that I've come across to recommend modding the 2x to take chargeable 3v Lithium batts instead of sticking with NiMh.

That said, using the LCD tweaker, the effect's almost invisible anyway, so hey... I'll manage :)
 

subin

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Same here, get some horizontal lines in fast zoom ins (in videos and such), but it's practically nothing..

yup, i don't really see any problem with it either, but it does depend on the person. some people describe it as headache and nausea inducing :blink:
 
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Radek

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i dont have any lines on my gp2x screen, can someone explain what im looking for?

my screen has been pretty much perfect since i got it

It's bassically an interlacing where the screen is refreshed in two phases - first the odd lines, then the even and again. That is unlike the PC monitors what are using a progressive mode - whole screen is refreshed at once.

Some people can detect it, some don't. It's a matter of personal perception. I can see them and it should be most visible for very fast moving objects. That's so because they will split into odd and even lines being in different phases.

It's both puzzling and somewhat sad than other devices have it too... There was speculation that it's just a bug in gp2x's firmware as gp2x's chipset (the MMSP2) has support for progressive modes. But if it is so common then it might be hardware related unfortunately...
 
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subin

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It's both puzzling and somewhat sad than other devices have it too... There was speculation that it's just a bug in gp2x's firmware as gp2x's chipset (the MMSP2) has support for progressive modes. But if it is so common then it might be hardware related unfortunately...

its no biggie though. the PSP's screen, is a different matter.. so blurry and weird. it jsut looks wrong.
 
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Leshrac

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Actually, the GP32 does it as well, but the scanlines are vertical rather than horizontal, so you don't really notice them unless you're looking for them.
thats couse the gp32's screen is rotated 90° :)
but honestly inever noticed that at my flu, is that maybe only on blu's?
I think this is only caused because the scanlines are easier to see on backlit screens, I've got a front lit GBA sp as well as a backlit one and the effect is far more noticeable on the backlit one with brighter screen, also, it magically disappears from both screens when I toggle the light off. It's just a matter of perception, so the birghter the screen is, the most obvious will it be.
 
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Dr Cain

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But seriously, has someone gotten in contact with the company that makes the LCD?
Last I've heard it seems that GPH almost guessed the right settings for the LCD, which isn't very odd of them.
Anyway, it would really be nice if we could get or hands on specifications on the LCD screen so we can see for ourselves.

And on another note, the image you see before U-boot loads (usally white, or a strange pattern incase you have garbage in VRAM), isn't interlaced. So the LCD does support progressive modes it seems.

All this should get sorted once we get the current uboot and kernel source though, and specifications on the LCD screen.
I can hardly wait.
 

DaveC

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I had scanlines on my GP32 that were just as bad when running an LCD gamma testing program. This program tested all modes including the intensity bit. It did weird things to the screen which caused this interlace effect severely, including pronounced scanlines. It looks exactly the same as the Gp2X. Since it was software that did it, it is likely that software is causing it here too. Someone just has to find out exactly how to fix it and then put it into the FW.

I don't like the scanline problem but it isn't bothering me as much as it should. I know my brain and it usually hates screen stuff like this. Honestly too bright gamma (black level) bothers me more. The gamma on the GP2X (under FW 1.01 at least) is perfect.
 

second exodous

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I haven't noticed scan-lines, maybe it's how the video you were playing was encoded? I definitely don't see it on any of the games, and I used handbrake to encode Heman, 640x480, and no scan lines. I also watch tv shows on my GP2X that are wide screen and look really good on my 20 inch iMac, no scan lines there either.

A few questions for people noticing scan lines: does it do it on everything, or just videos, and all videos or just some?

Thanx,
Stan
 

DaveC

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I haven't noticed scan-lines, maybe it's how the video you were playing was encoded? I definitely don't see it on any of the games, and I used handbrake to encode Heman, 640x480, and no scan lines. I also watch tv shows on my GP2X that are wide screen and look really good on my 20 inch iMac, no scan lines there either.

A few questions for people noticing scan lines: does it do it on everything, or just videos, and all videos or just some?

Thanx,
Stan


I don't watch video. Scan lines are apparent on everything.
 
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ThorC

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I haven't noticed scan-lines, maybe it's how the video you were playing was encoded? I definitely don't see it on any of the games, and I used handbrake to encode Heman, 640x480, and no scan lines. I also watch tv shows on my GP2X that are wide screen and look really good on my 20 inch iMac, no scan lines there either.

A few questions for people noticing scan lines: does it do it on everything, or just videos, and all videos or just some?

Thanx,
Stan

Easiest way to see them for yourself is using DrMDx if you have it. Open it up and watch the moving background - you can clearly see the scanlines. When you open a rom or do an action and the background stops, you can see the background as it should look.
 
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Mark1970

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well today i was browsing in dixons with a friend, and saw some personal media devices (like archos's and stuff, i think..), running videos, and noticed something! they suffer from pretty much the same scanline problem as the gp2x does, or it would seem so (i believe the problem varies based on your brain's interpretation of the image, and such.) so yes, they looked fine, then i moved my head slightly and i could see the scanlines - an identical situation to what happens on my gp2x.

comments?

Could also be accredited to optical interference from tube lighting above used in a lot of stores.
 
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