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  1. I have seen a lot of videos that look yellow, some nude bathroom scene, most look to be a result of lighting or camera settings.

    Is there a simple white balance edit that would go some way to correct?

    Second question, how do you reduce red and green or increase blue to correct a cast?

    Thanks
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  2. Member
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    Try virtualdub2. You'll find some color correction tools in
    the filters
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  3. Originally Posted by davexnet View Post
    Try virtualdub2. You'll find some color correction tools in
    the filters
    I want to keep the file original, some mp4, just found others are mpg.
    virtual dub would only be good if I am saving to lagarith between process?

    Here is what I have found so far, just not sure if the Shadows/Midtones/Highlights options should be used for the task, or otherwise edited to work.
    default 0.0, seems pretty simple to use.
    Any ideas on how to aproach it?

    Code:
      $ ffmpeg -i input.mp4 -vf "colorbalance=gs=.5:bh=1" -pix_fmt yuv420p output.mp4
    Code:
    colorbalance
    	Indicates the color balance filter name
    
    rs, gs, bs
    	Indicates adjustments to red, green and blue shadows or darkest pixels (1.0 to -1.0 with default 0.0)
    
    rm, gm, bm
    	Indicates adjustments to red, green and blue midtones or medium pixels (1.0 to -1.0 with default 0.0)
    
    rh, gh, bh
    	Indicates adjustments to red, green and blue highlights or brightest pixels (1.0 to -1.0 with default 0.0)
    
    
    pl
    	Indicates preserve lightness when changing color balance (1.0 to -1.0 with default 0.0)
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  4. Member
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    No. Since I don't have the video to look at.
    That's why I suggested vdub2, you can preview the filters and see adjustments in real time.
    Vdub2 can save your modifications to a mp4 or mkv
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  5. No worries Dav, thanks for dropping by
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  6. So for the FFMPEG Users, here is the next snippet I found:

    Quote from https://www.dpreview.com/forums/post/61575417
    Code:
    Maybe you can use the eq filter? ("Set brightness, contrast, saturation and... gamma")
    
    For instance, to reduce blue cast and increase color saturation, call video filter (-vf) with eq items, while copying the audio track (-c:a).
    
    ffmpeg -i orig.mp4 -vf eq=gamma_b=0.8:saturation=1.6 -c:a copy PitNew.mp4
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  7. Member
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    Hey, I use FFmpeg too. I think you'll just have to try some of these filters and see what gets you close
    to what you want. There are many possibilities in the FFmpeg filter reference doc.

    Were these videos taken with your own camera, presumably with lighting issues?
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  8. Can you just use the r,g,b commands as needed?
    This is probable wrong, I strung together bits from internet!

    Code:
    ffmpeg -i IN.mp4 -vf eq=gamma_r=0.8:gamma_g=0.8  -c:a copy OUT.mp4
    Or:
    ffmpeg -i IN.mp4 -vf eq=gamma_b=1.2  -c:a copy OUT.mp4

    The value must be a float value in range 0.1 to 10.0. The default value is 1.

    gamma=1:
    gamma_r=1:
    gamma_g=1:
    gamma_b=1:
    gamma_weight=1

    I am just interested in the correct code.
    ffmpeg is very fast and simple to look at results and re-adjust

    Edit: Think the code will be correct now, can gamma_weight be used so the other gamma_(Letter) edits have reduced effect, like more resolution?
    Last edited by Tom4; 26th May 2022 at 23:17.
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  9. Originally Posted by davexnet View Post
    Hey, I use FFmpeg too. I think you'll just have to try some of these filters and see what gets you close
    to what you want. There are many possibilities in the FFmpeg filter reference doc.

    Were these videos taken with your own camera, presumably with lighting issues?
    The video in bathroom is porn, wish I did take with camera LOL.



    I have the complete set of codes for ffmpeg and every UI that could be found online.
    Love the programs power and use

    First attempt to correct yellow/lighting/cast issue worked perfect

    First really good solution:
    Code:
    ffmpeg -i IN.mp4 -vf eq=gamma_r=0.8:gamma_g=0.8  -c:a copy OUT.mp4
    When I say perfect, like Just wow and that simple
    Last edited by Tom4; 26th May 2022 at 23:37.
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  10. Last edited by Tom4; 26th May 2022 at 23:36.
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  11. Anybody has ffmpeg tips for lighting cast issues, please add
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