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  1. Originally Posted by anachronon View Post
    The lossless master copies (of home videos) will not be for distribution---though I may send edited/restored/compressed clips to family/friends. In testing DVD's though, I have noticed a great variance in the settings of black/white levels. For example, the "black" of the letterbox area can vary as much as 8 levels, from one movie to another.
    Are you referring to RGB or YUV values? YUV should always be (16,128,128) for the black borders of DVDs. What you get for RGB on the PC monitor depends on the conversion matrix which is in place.
    How to you measure it?
    Last edited by Sharc; 10th May 2021 at 05:52.
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  2. I am referring to resulting RGB values. I made nearly a dozen tests on different DVD's, with the same settings, and got significantly different results, just in the letterbox "black" area.
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  3. Strange. I can imagine that rounding effects during YUV -> RGB conversion give +/-1 unit deviations, but 8 steps seem to be too much .....
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  4. Originally Posted by Sharc View Post
    Strange. I can imagine that rounding effects during YUV -> RGB conversion give +/-1 unit deviations, but 8 steps seem to be too much .....
    +/-3 for color

    +/-0 for black,white,greyscale where CbCr are 128

    Or home video can be +/- 50. Seriously.


    Originally Posted by anachronon View Post
    I am referring to resulting RGB values. I made nearly a dozen tests on different DVD's, with the same settings, and got significantly different results, just in the letterbox "black" area.

    But are you just ripping the DVD and measuring digital values directly, or contaminating the results through some capture chain ?

    The actual digital letterbox values will be Y=16,CbCr=128 . RGB 0,0,0 if using "computer RGB", or RGB 16,16,16 if using "studio range RGB"
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