Calibarate Overlay Mode Colour

[mridang_agarwal]

Hey guys,
This might be tad complicated but I still hope I get a solution. Its like this - I formatted my PC yesterday and the rest of the day went in installing and tweaking stuff. At the end of the day, I installed all my Codecs (K-Lite Codec Pack) and began watching a DivX movie. The moment the movie began, I could see that all the color settings were haywire. I concluded that it must be the Overlay mode color settings that were messed up. This was because, no matter which Media Player i used to watch the movie - i got the same old discolored video. I began fiddling around a bit and found the place where I Could rectify it - the Nvidia control panel. Now its asking me to set all sorts of things such as Gamma, Hue, RGB, Saturation and all the other jargon. I have basic idea of what each one does but I'm not able to calibarate it cause i need something as a benchmark. How do set it? When i try to watch a small video clip and set I dont get good results as i dont know what figures to feed into the different boxes.How do i do this? The moment i slightly increase the Gamma, the whole video becomes one big flash of light and the moment i reduce it, it goes pitch dark. What values should i use for the settings?
Thanks in advance guys.

[jagabo]

Video drivers often mess up the overlay settings when first installed. So first disable overlay and exit the dialog. Then go back and reenable overlay. That may be enough to fix the problems you are encountering. Then you can fine tune all the settings if necessary.

[edDV]

No substitute for doing it right.

THX alignment patterns are availalable on many DVD discs.

List of DVDs
http://www.thx.com/mod/products/dvd/dvdFind.html
http://www.thx.com/mod/products/dvd/optimizerIntro.html

Or,
start with a color bar pattern
http://www.belle-nuit.com/testchart.html

and adjust by the normal technique
http://www.videouniversity.com/tvbars2.htm
http://www.indianapolisfilm.net/article.php?story=20040117004721902

In your case, follow PAL settings.
The most basic adjustments are.
- Set black level with "Brightness"
- Set white level with "Contrast"
- Adjust gamma so all ten luminance steps are visible and about equal
- Adjust color "saturation" to taste
- Adjust "Hue" to get correct colors.

[mridang_agarwal]

Video drivers often mess up the overlay settings when first installed. So first disable overlay and exit the dialog. Then go back and reenable overlay. That may be enough to fix the problems you are encountering. Then you can fine tune all the settings if necessary.

How do I disable overlay? I have a Nvidia 5200FX and the regular Nvidia drivers. I cant seem the find the setting anywhere.


Hey edDV,
How would I be able to get a colour bar pattern into Overlay mode in Media Player Classic. My desktop colours are fine so I'd i have to view the image in Overlay mode but how do i do it?

[edDV]

Hey edDV,
How would I be able to get a colour bar pattern into Overlay mode in Media Player Classic. My desktop colours are fine so I'd i have to view the image in Overlay mode but how do i do it?

See if you can encode it into a video format assciated with the player. Uncompressed AVI maybe?

Rec-601 levels 16 black, 235 white as used in MPeg2, MPeg4. The chart also shows 0-255 markers.

[Richard_G]

Isn't it generally accepted that the worst thing you can do is install a codec pack? Most recommend ony installing individual codecs one at a time as needed. There have been a number of threads on here where people have had display problems which were cured by uninstalling codec packs.

[jagabo]

How do I disable overlay? I have a Nvidia 5200FX and the regular Nvidia drivers. I cant seem the find the setting anywhere.

If there isn't an explicit enable/disable overlay go to the Troubleshoot tab and turn Hardware Acceleration all the way down. Exit the dialog (a reboot might even be necessary), go back to the Troubleshoot dialog and turn Acceleration all the way back up.

How would I be able to get a colour bar pattern into Overlay mode in Media Player Classic. My desktop colours are fine so I'd i have to view the image in Overlay mode but how do i do it?

Convert the TIFF image to a BMP file. Then drag it onto Windows Media Player or Media Player Classic.

If you convert the image to an MPEG file be aware that most encoders will compress the luma range of an RGB source so that all YUV luma values fall between 16 and 235. So the patch labeled 0 will become 16, 4 will become ~19... 255 will become 235. On conversion back to RGB (loading into a program like VirtualDub) the opposite will happen. YUV luma 16 will become RGB 0, etc.

[edDV]

I agree the BMP is the most direct and least error prone way to go.

If you pull the tif or BMP to full screen on your desktop (no overlay), you can also see how close your computer monitor brightness, contrast and RGB levels are set.

If for just watching, your goal is to get close and adjust it for your personal taste.

The first things to check are black and white levels. Black is most sensitive. A computer monitor desktop should be seeing 0-255. If you see no difference between 0, 4, 12, 20 then you need to adjust "brightness" up*, then tone down contrast until 255, 251, 239 show difference vs. 235.

For overlay, you should see little or no difference between 0, 4, 12 and 16. 20 should show some difference moving from black to very dark gray. Adjust until you see a little difference. Otherwise you have crushed black levels. At the white end 231 to 255 steps should be visible.

If you are producing video for others to watch, you need to get very anal about getting these set precisely. Otherwise the user of your video will see shifts vs. commercially produced material.


* If you can't get there, make sure the 16 to 21 step is adequate. Fine black level sensitivity is a sign of a quality monitor.

[edDV]

How do I disable overlay? I have a Nvidia 5200FX and the regular Nvidia drivers. I cant seem the find the setting anywhere.

Why would you want to disable overlay? You want overlay if you want live video on your display. You don't want the cpu to do this work. It would need to calculate each pixel. Frame rate would drop to next Tuesday.

Read this.
http://en.wikipedia.org/wiki/Video_overlay

[jagabo]

Why would you want to disable overlay?

Because I told him to disable then reenable overlay. This often fixes overlay problems with fresh graphic driver installs.

I formatted my PC yesterday and the rest of the day went in installing and tweaking stuff... The moment i slightly increase the Gamma, the whole video becomes one big flash of light and the moment i reduce it, it goes pitch dark.

[mridang_agarwal]

I, reset my overlay mode (By first turning Hardware Acceleration all the way down, rebooting, and then turning it all the way up). The result - nothing!

Now, off I go to try the second way. I'll try it out and post the results here. Sorry for replying slowly guys, I've been kinda busy and I really appreciate all the help I've been getting from you. Cheers!