Darkness Issue In Avi's


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DarkMetroid

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Everything I encoded for GPCinema is always Extrememly dark in cetain scenes.
Even in ANime you cant even tell whats going on in some scenes. I tried useing level filter to brighten it up and lumni masking and it doesnt make any difference.
Everthing else looks ok but when theres a scene at night its impossible to see or kno what going on. Is it like this for everyone?? :blink:
 
Dozer posted on Jun 10 2004 said:
Hold up on the joystick to turn the brightness up.
Click to expand...
It waz the first thing I did when I noticed how dark my avi waz and it didnt help It still waz dark and it just made the scene look faded but u still couldnt tell what going on in the scene. Is there something wrong with my Flu cuz even BOR is extremly dark :(
 
Last edited by a moderator:
you might adjust the contrast when converting, but I guess that the best way is to view the screen with good light. But adjusting the contrast is easier...
 
Thanx, I definitely try adjusting the contrast hopefully that would
help. Its weird how everything looks so dark on my gp32 is it suppose
to be like that well im going to try adjusting the contrast hope it looks
good I got my fingers crossed
 
presumably you are using virtualdub. change the levels and click "preview" then use the right keyframe button to move throught the vid until you reach a frame that will look dark once encoded. First, slide the right hand slider to the left a little which will make the bright colours brighter, then move the middle slider left, changing the medium bright colours until you are happy, the preview will update as you slide them around.

this always works for me, it may take some getting used to
 
Yep, levels is the definate only right way to do it... I suggested this a year ago (in exactly that way ;)), so I guess they used this for their guide :)

Just the reason behind this:

You have a minimum video signal (0% = Black) and a maximum video Signal (100% = White).

If you use a brightness filter, you just lighten up everything.
i.e. if you brighten the picture 20%, everything that was black is now 20% grey.
Everything that was 70% is now at 90%.
The problem: It CAN'T be higher than 100%! This means, everything that was between 80% and 100% is now at 100% - pure white. Means: You lose a lot of the picture...

If you use a contrast filter, it makes the lighter areas more light and the darker areas more dark.
i.e. 0% black stays at 0%. 20% black goes down to 10%. 100% white stays at 100%, 80% white goes up to 90%.
Makes the picture look nicer on your GP32, but the dark places still stay dark.

Now onto the levels filter:
The levels filter "shifts" everything between 0% and 100% dynamically.
This means: 0% stays black, but (depending on how you adjust the levels), everything that was between 0% and 10% is now between 0% and 20% (it's expanded).
Thus, dark areas get brighter, but anything that was pitch black stays pitch black and won't turn to grey.
Same thing for the light areas: 100% white stays at 100%, but everything between 90% and 100% is now between 100% and 80%.

The value you're changing with the levels filter is called the gamma level.
And as each type of monitor (Plasma, LCD, TFT, CRT, etc.) has a different gamma curve, you need to adjust these levels to look good on you GP32.
(As the gamma curve is always the same, they could've implemented this into GPCi nema - but I guess it would take up a bit of processor time).

Any questions left?
 
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