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Discussion Starter · #1 ·
i cant get my head around this anomally, can someone help

my display handles full levels 0-255, when i run a test disk(sd DVE) sometimes i see BTB other times not

using an ati card i see btb but after running the reg hack it dissapears. WHY?

using an nvidia 8200 board its not their at all
 

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Well that's exactly what the reg hack does on ATI.

ATI cards automatically expand HD to 0-255 clipping BTB and WTW but this will look correct on a display that supports full range video. So in order to get SD to match HD content you have to hack SD to clip as well.


With nvidia via DVI w/o HDMI connection you should get BTB and WTW if you use the setting in the nvcp for limited range. If you set it to full range then it expands the video.


With a DVD or TV in digital format the space from 0-16 is blacker than black, and 236-255 is whiter than white. This means theoretically these values don't have any effect on the image and shouldn't be displayed. So if your TV is set to full range 0-255, you want to clip BTB and WTW. If you have your TV set to normal mode then passing BTB and WTW is fine, but you still shouldn't see it.
 

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Discussion Starter · #4 ·
still not understanding

so because i have an sd dve test disc the btb disapears why?

do i therefore need an hd dve disk to set upthe btb ans wtw and then exept that sd will be the same because of the hack or can i still use the sd version?

also why do i know get a pop up balloon whenever i run hd saying (cant remember exactly) color is being set to windows vista basic levels? this wasnt there before i changed my motherboard

oh, is there a downloadable hd test?

soory to appear dumb
 

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I think there is some confusion about BTB and WTW.


If your display - whether it is 0-255 or 16-235 - is correctly calibrated, you shouldn't see BTB. It is there to ensure picture quality is retained upstream in the production chain (particularly stuff from analogue sources, or routed through analogue paths). If your display is correctly calibrated, then black content should be the darkest thing you see, BTB should be below black and thus not visible. If you can see BTB then your display is showing raised blacks (i.e. they are grey not black)


BTB can be useful for display calibration purposes - as mis-calibrating your brightness (aka black level) control lets you see the BTB (sub-black) content on PLUGE, and you can therefore correctly set your black level by making this disappear.


If your display is a 0-255 DVI model - where black is input at 0, then it isn't possible to feed this display sub-black (you can't go into negative numbers in 8 bit integer video representation)


I'm not sure why anyone with a 0-255 display would expect - or want - to see sub-black?


(This is with my broadcast video background - am I missing something?)


Sure you could feed 16-235 video (which has the capacity to carry BTB and WTW) video to a 0-255 monitor and you may have enough latitude in the black level (brightness) and video gain (contrast) controls to shift input 16 to black and input 235 to peak white, and when not correctly adjusted you will see sub-black and super-white (aka BTB and WTW) but in normal viewing conditions you wouldn't want to see BTB and WTW (it just makes display calibration a bit more of a pain)
 

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Confusion is right sneals. I see so many people here(not in this thread) crying about getting unaltered video from recievers. They're worrying about like you point out a black level you're not even supposed to be seeing. It just cracks me up. When no matter what display you have if you just adjust it properly it doesn't matter which level your gear can or can't do.


This issue has many people confused to no end I tell ya.
 

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Discussion Starter · #7 ·
on the DVE disk it says that if you cannot see btb then your source equipment is 'crushing' or clipping colours

i understand that you shouldnt 'see' btb or 'wtw' and that they arre there for easy calibration

so is it correct to assume that with the ati hack or nvidia output i have that dosnt show btb then the colours are not being clipped but purely adjusted correctly to 16-235 instead?

if so my display has the option to select both should i set it to 16-235 and use the above?

now without the btb how do you calibrate correctly?

i thought hd stuff used 0-255 and sd 16-235? correct?

why do i get the balloon message every time i run hd and what is it doing to my colours?

god this is confusing
 

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Quote:
Originally Posted by pacemaker /forum/post/15588066


on the DVE disk it says that if you cannot see btb then your source equipment is 'crushing' or clipping colours

i understand that you shouldnt 'see' btb or 'wtw' and that they arre there for easy calibration

so is it correct to assume that with the ati hack or nvidia output i have that dosnt show btb then the colours are not being clipped but purely adjusted correctly to 16-235 instead?

if so my display has the option to select both should i set it to 16-235 and use the above?

now without the btb how do you calibrate correctly?

i thought hd stuff used 0-255 and sd 16-235? correct?

why do i get the balloon message every time i run hd and what is it doing to my colours?

god this is confusing

Some things clip, yamaha recievers for instance are known for removing all signal below 16 and above 235, but black is still 16 and white is still 235.


Other things expand (I like this word better than crush, crush implies something wrong) with expanded levels 16 is at 0 and all the content is still there and still accurate, you just need to use a different TV calibration (specifically raising your brightness control) to get accurate levels.


BTB is mostly usefull for calibrating a display using video levels so that you can't see the moving bars on a pluge pattern. BTB is a relic of the analog world and not something that needs to be steadfastly preserved as it's eventual result will be to render exactly at 0 on a digital display.
 

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Quote:
Originally Posted by pacemaker /forum/post/15594272


can someone explain the balloon message in vista that pops up when playing hd

plus how to disable it

I'm not sure what exactly you are seeing, but I'm guessing it's the message that says aero has been disabled.


If your hardware can't run BD+Aero, your only real option is to disable aero all the time, otherwise just get use to the popup.
 

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Discussion Starter · #11 ·

Quote:
Originally Posted by sotti /forum/post/15594354


I'm not sure what exactly you are seeing, but I'm guessing it's the message that says aero has been disabled.


If your hardware can't run BD+Aero, your only real option is to disable aero all the time, otherwise just get use to the popup.

many thanks that was it

thought i had disabled that

weird it only happened with hd
 

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Quote:
Originally Posted by pacemaker /forum/post/15594987


many thanks that was it

thought i had disabled that

weird it only happened with hd

Right, that's because HD acceleration uses the 3d GPU shaders to do the accelration, regular SD accel just uses the DXVA portion of the card. So to process the HD video it drops aero to free up extra cycles on your GPU.
 
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