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  1. Member
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    Hello!

    Does FFV1 and Huffyuv support full-range (0-255) color or limited TV 16-235 colors?
    The reason: Many camcorders record X.V. colors, which are the best with full range (0-255) colors.
    Thank you for Your reply!
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  2. Lossless without color space conversion imply 0- 255 (1-254).
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  3. If they receive YUV video and are set to compress in a YUV mode those codecs are lossless. If the source has excursions beyond the valid range they are retained. Where you have to be careful is what your editor is doing to the video before it gets to them. For example, if you are filtering in VirtualDub YUV will be converted to RGB with a rec.601 matrix by VirtualDub. That will lose super blacks and super brights. You will not be able to restore them by converting back to YUV and compressing with those codecs.
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  4. Yes, lossless codecs are lossless if used properly in the same colorspace/colormodel

    x.v. is a marketing name made by Sony for ITU rec.1361 or xvYCC . Is is a matrix or set of equations that govern Y'CbCr <=> RGB conversions

    Instead of using Rec.601 or 709 (the standard matrices) found in most equipment and software , where many colors and levels will not be displayed, the hardware will display more data in the Y'CbCr stream . Negative values in the transfer curve are allowed

    You need software and hardware that support "wide gamut RGB" or Rec.1361 in order to visualize those "extra" colors . Anywhere there is a "break" in the chain, you will not be able to visualize extended gamut (such as jagabo's vdub example)
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  5. I thought these days VirtualDub only converts to RGB if a filter/plugin is RGB only? Not that I use it much, so I could be completely wrong.
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  6. Originally Posted by hello_hello View Post
    I thought these days VirtualDub only converts to RGB if a filter/plugin is RGB only? Not that I use it much, so I could be completely wrong.
    Yes

    But some vdub filters can work in YUV (e.g. brightness), but most still cause a conversion RGB . If you checkmark "show image formats" in the filter list you can see the colorspace
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    Can you recommend a software which use the ITU rec.1361? Is it supported by the ffv1 codec?
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  8. Originally Posted by Stears555 View Post
    Can you recommend a software which use the ITU rec.1361?
    No consumer software that I know of supports it. You need a color managed workflow, with LUTs and ICC profiles. e.g After effects, DaVinci Resolve , NukeX . This also requires a Wide gamut display . A regular monitor or HDTV won't be able to display the extra colors

    Is it supported by the ffv1 codec?
    This question doesn't make sense . Lossless is lossless

    The proper question should be: "what software and hardware can convert FFV1 in Y'CbCr to RGB using Rec1361"


    8bit Y'CbCr can contain a lot more data than 8bit RGB. Look at this color cube representation . Notice the RGB cube is small and entirely fits within Y'CbCr space. Not all Y'CbCr values can be "mapped" to RGB (ie. you can't see some values because they lie outside the cube) . Wide gamut RGB is a standard to display more colors . Previously "illegal" or out of range (negative) values when using Rec601 or 709 can be visualized using Rec.1361 - that's all. Nothing else is changed. YCbCr is YCbCr. Lossless is lossless

    source: http://software.intel.com/sites/products/documentation/hpc/ipp/ippi/ippi_ch6/ch6_color_models.html

    Click image for larger version

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    Last edited by poisondeathray; 27th Dec 2012 at 12:10.
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    okay, but has a 12bpp XV.color AVCHD video wider gamut than the 8bit simple RGB video? Can a 12bpp planar setting of FFV1 codec reserve its full color range? Or the 32/24bit settings of FFV1 can preserve the original colors?
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  10. Originally Posted by Stears555 View Post
    okay, but has a 12bpp XV.color AVCHD video wider gamut than the 8bit simple RGB video?
    YCbCr will potentially always have wider gamut than RGB at the same bit depth . Just because it "potentially" has more doesn't mean all those color values are necessarily used . Even if you have xvYCC proper recoding AND decoding matrix with hardware - but record a dull, drab scene, or even something like black and white chart, values might not be out of range even with Rec601 or 709.

    12bpp is same thing as 8bits per channel , but the CbCr planes are subsampled (they are reduced in resolution w:h). Reducing chroma resolution does not affect gamut (at least not directly)

    Even 12bpp "normal" video potentially has wider gamut than 8bit RGB (look at the color cube chart)


    Can a 12bpp planar setting of FFV1 codec reserve its full color range? Or the 32/24bit settings of FFV1 can preserve the original colors?
    You already asked these questions. Go back to your FFV1 thread. Yes. Lossless is lossless. Whether or not your software or hardware can display those colors is another question . Whether or not your software or hardware can display even the original AVCHD in xvYCC is another question
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  11. Member
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    Originally Posted by poisondeathray View Post
    Originally Posted by Stears555 View Post
    okay, but has a 12bpp XV.color AVCHD video wider gamut than the 8bit simple RGB video?
    YCbCr will potentially always have wider gamut than RGB at the same bit depth . Just because it "potentially" has more doesn't mean all those color values are necessarily used . Even if you have xvYCC proper recoding AND decoding matrix with hardware - but record a dull, drab scene, or even something like black and white chart, values might not be out of range even with Rec601 or 709.

    12bpp is same thing as 8bits per channel , but the CbCr planes are subsampled (they are reduced in resolution w:h). Reducing chroma resolution does not affect gamut (at least not directly)

    Even 12bpp "normal" video potentially has wider gamut than 8bit RGB (look at the color cube chart)


    Can a 12bpp planar setting of FFV1 codec reserve its full color range? Or the 32/24bit settings of FFV1 can preserve the original colors?
    You already asked these questions. Go back to your FFV1 thread. Yes. Lossless is lossless. Whether or not your software or hardware can display those colors is another question . Whether or not your software or hardware can display even the original AVCHD in xvYCC is another question
    In 2012 utmost all modern HDTV knew the XV.color and Deep color too. Since I've a hdmi 1.4 output on my Nvidia card, therefore X.V. color is not a big thing nowadays! It is ferial thing today!
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  12. But how do you have it hooked up? Because most playback formats don't support xvYCC. blu-ray, flash doesn't . Most (all?) common software media players don't. Just because you click "XV" in the control panel doesn't mean you are getting XV color, because most of the time you're actually getting rec709 color . It's not a big thing because most people aren't actually using it (even if they think they are), and most content does not use it (most of the content shot by your camera will "map" to legal rec709 values)

    rec1361 is backwards compatible - anytime you have a "break" in the link, it falls back on rec709. (All values above "0" in the transfer curve are identical to rec709) . In order for xvYCC to work, the hardware has to know it's supposed to use xvYCC - there has to be a flag in the stream or some other indicator to tell it what to do, or you have to manually switch it.

    wide gamut displays have been available for many years (mostly due to graphics, adobeRGB color space), but actually use in video has been limited
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