Fraps colorspace issues (wrong color, faded, dark etc) - part 2

raffriff

Moderator
Staff member
Site Contributor
How to keep consistent color, from Fraps all the way to the viewer.

My first attempt to talk about this went over like a lead balloon, so I'll start over, and try be be more readable.

In short:
  • There are four basic color shift problems:
    (note sometimes I use the term "color shift" to include brightness shift as well)
    • If black is low or white is high, you have high contrast (y+ for short)
      Colorimetry-errors-4-y+.jpg
    • If black is high or white is low, you have low contrast (y-)
      Colorimetry-errors-5-y-.jpg
    • If green is high but red is low, you have "green push" (g+ for short)
      Colorimetry-errors-3-g+.jpg
    • If red is high but green is low, you have "red push" (r+ for short)
      Colorimetry-errors-2-r+.jpg
    • (here's the image with correct color)
      Colorimetry-errors-1-normal.jpg
    • Normally you fix the luma levels first, before worrying about the green or red.
      ...
  • Different media players can show the same video with different color shifts. There is no "gold standard." You must decide which player to use as your "standard." Use the player that most of your audience will use. Right now, that usually means Flash Player on YouTube.
    ...
  • Your eyes (aided by measurement) must be the judge, not abstract theories.
    ...
  • Check for color shift at every step in the signal chain. Check when importing into an editing program and again when exporting, then again when viewing on line (YouTube) or with another device (iPad, Xbox).
    ...
  • Test with color bars, not regular images. The color changes are too subtle to see reliably with normal program sources. A good source is my Frafs Test Pattern version 0.5.
    ...
  • To check colors precisely, measure the screen. Use a screen color tool like ColorPic.
Now in more detail...
  1. Start Fraps. Play your Fraps test pattern. Get a screen grab.Open in your favorite image editor.
    • Compare the original colors of your test pattern to the colors reported by the image editor.
    • If any colors aren't correct, STOP and let me know so the problem can be fixed.
    • If you are reporting a color problem, post a reply with...
      • Your OS, graphics card, GPU color settings.
      • The nature of the color shift, as listed above: y+, y-, g+ or r+....
        ...
  2. Capture a short movie clip and open it in your favorite video editor. Check the preview window with the screen color tool.
    • If any colors aren't correct in preview, make a note of it.
    • Ideally preview should match the final output. It probably doesn't right now. You can address that later if it's a problem. For now, let's move on...
      ...
  3. Make some color bars with your video editor's internal generator, if you can. Edit the two together.
    ...
  4. Render your test clip and open it in your favorite media player.
    • If any colors aren't correct, make a note of it.
    • Try several media players. The colors can shift from player to player.
      ...
  5. Assuming your viewers will see your finished videos on YouTube, upload your test clip and play the video in your browser.
    • Note: before checking screen color of any Flash player window, close all other Flash player windows and any media players or video editors, or the colors may change. This is because (I think) hardware rendering only works on one video window at a time.
    • Play your video.
    • Use your color tool to measure the screen display.
    • You could also capture a full screen image with Fraps or the PrintScreen key, and examine it in your image editor. But make sure the captured image matches the screen!
    • If any colors aren't correct, stop. Find and fix the problem.
      Post a reply with:
      • The nature of the color shift, as above: y+, y-, g+, r+.
      • The program you are using to compress the original Fraps clip.
      • The colors as they appear in your preview window: y+, y-, g+, r+.
      • The settings you used to import, render & encode the test clip.
    • Compare your on-line color to the colors you saw in your video editor and in your media players. Knowing the quirks of each player is the key to getting a good final product.
      ...
  6. If your viewers will see your finished video in some other way (Xbox? Network TV? Giant outdoor screen? Subspace hologram?), you'll have to change your methods accordingly. By this point you should be able to look at your test pattern and spot the four types of color shift by eye.
    ...
  7. The action you need to take to correct a color shift depends on the application and type of error. I can help you with most color shift problems - I think. I've fixed a lot of them. Many solutions are listed in my previous post on the subject. No one (I assume) has read that post, since it's just too long, so maybe we'd better discuss each situation as it comes up, one at a time; please post your questions!
 

ETAdmin

Administrator
Staff member
I didn't think your previous post was that bad, but since it is so thorough in terms of "if this situation-do this" there really isn't a need for additional questions if someone who is looking for information actually goes through and reads it.

Also - Most users here (So far) have been pretty limited in how much they know about video formats... or even operating their computer at a basic level :|

Regardless of that... 10/10 for both threads!
 

Thalmor Wizard

Moderator
Staff member
Site Contributor
Also - Most users here (So far) have been pretty limited in how much they know about video formats... or even operating their computer at a basic level :|
As well as not knowing the 4 basic aspect ratios of 4:3, 5:4, 16:9 and 16:10 xD (5:4 and 16:10 are bad ratios D:)
 
raffriff,

Thanks for the enormous amount of time you put into this. I'm using Fraps to capture in Second Life and having some of the issues you describe. It's y- r+ as far as I can tell in both Window Media Player and Adobe Premiere. The following image is a print screen of Second Life (left) and the Fraps captured AVI playing in WMP (right).

fraps craps.png
I'm getting the opposite it appears when taking a still image in Fraps. The following image is a print screen of Second Life (left) and the Fraps captured still (right).

fraps craps 2.png
My equipment:

CPU: Intel(R) Core(TM) i7-2670QM CPU @ 2.20GHz (2195.08 MHz)
Memory: 8170 MB
OS Version: Microsoft Windows 7 64-bit Service Pack 1 (Build 7601)
Graphics Card Vendor: NVIDIA Corporation
Graphics Card: GeForce GTX 560M/PCIe/SSE2

Second Life Viewer: Firestorm 4.3.1 (31155)
Adobe Premiere CS6

Any light you can shed on my issue would be greatly appreciated.

Cheers,
Bungina
 

raffriff

Moderator
Staff member
Site Contributor
Thank you for your kind words. I am not sure what to advise at this point. I have never seen a Fraps screen shot looking so different to the movie. Fraps captures both in exactly the same way. The only difference in appearance would be on the decoding side.

First of all, it's hard to tell what's going on with a test image like that. Please try to find with a scene with bright whites, dark black, and fairly bright reds and greens if possible. I use one of the two test pattern generators I made - however, installation is not too user-friendly on either one of them, so if you can find a scene in Second Life like I've just described (like my sample image in the top post, or like the one I've attached, picked at random), that would be OK too.

A still frame so lacking in color - very odd. What format did you save as - BMP/JPG/PNG/TGA? How are you processing the image you posted? Please capture a a screen shot as JPG and post the original image with no alterations. If you're using the trial version of Fraps and can only take BMP, you'll have to post it on a hosting site, possibly ZIP compressed.

Does Second Life have a built in screen shot function? If so, please use it and post the original image without alteration. If it's not in JPG format, you will have to post it on a hosting site.

Thank you again - looking forward to your follow up.
 

Attachments

Some quick feedback before I run around looking for a test pattern in-world:

When I do a JPG screenshot in FRAPS, the original looks just like the one I posted for comparison. If I bring that image into Second Life and display it inworld it looks exactly the same (color/luma -wise) in the Second Life viewer as it does locally in an image viewer (IfranView) and Windows thumbnails as well. So...the color/luma shift doesn't seem to be viewer decode related OR at least they are all behaving the same way.

********edit to add********
Here is a snapshot taken in the Second Life (SL) viewer (Firestorm). The test patterns shown are: Left - your test pattern (.jpg) uploaded to SL and displayed on an object (prim box); Right - the web page showing your test pattern displayed as media on an object.
snapshot inworld_001.jpg

The next image is the same thing captured in FRAPS as JPG (original).
Firestorm-Release 2013-03-21 15-58-47-32.jpg

It appears to me that blue is increased somewhat, making the image appear more blue and slightly brighter (i.e. black is not really black). Red appears to be somewhat darker too.

The next is a print screen of FRAPS captured video playing in Windows Media Player:
print screen captured video.jpg
 
My solution was to buy mirillis Action. It captures AVI such that color remains consistent Second Life -> Abode Premiere -> YouTube . Thanks again for your help.

/B
 

billman

Well-Known Member
Site Contributor
Fraps capturing needs to be done with monitor calibration disabled (we need to make this more widely known)
Ah I understand now, even the Video driver has these sorts of tools to adjust the playback.

To solve my Dark problem I Increased the brightness of the game and lowered my physical screen brightness. Worked well enough for me.

But now I think about it my recording may not be darkened at all, however the number of times I transcode before uploading has a habit of darkening the video as well.

raffriff you continue to impress me with your knowledge, I really need to find time to read more of your posts.
 
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