Feedback Color issue thread - Discussion 2

Discussion in 'ZIDOO X9S' started by n_p, Jun 30, 2017.

  1. n_p

    n_p Active Member

    Major Correction - the brightness level in ZDMC is OK.

    It was a fault on my part - a recent greyscale calibration I've done has dropped the black level significantly. I've now checked multiple sources and they all suggest +6 ticks on brightness.

    So that entire point is mute.

    - The remaining two points Zidoo can address as they see fit. I would not categorize them as major issues.

    --
    Also - dont touch brightness in the picture parameters setting in the X9S, if you dont have to, moving it away from default messes with gamma reproduction.
     
  2. boblo

    boblo Member

    @n_p: So what is the proper mode to see the user interface and to play video? I'm very confused. My TV is an old Pioneer LX-508D Kuro plasma display (2007 generation). Thanks.
     
  3. mirror

    mirror Well-Known Member SUPER Administrator Zidoo TECH Supporter

    @n_p
    It happened on YCbCr or RGB mode?
     
  4. PacoRabanne

    PacoRabanne Well-Known Member Beta test group

    n_p, because you (like me) use a LG OLED TV, which is the best configuration to use with 1.4.12 release (my TV HDMI ports are set for "UltraHD Deep Colour") ?
    TIA!
     
  5. mentsm

    mentsm New Member

    Was I wrong?
     
  6. mentsm

    mentsm New Member

    You said my method was wrong, so please tell me the correct way.How do zidoo x9s (firmware1.4.8 and 1.4.11) + SONY TV (kd-x9000e) get the correct gray scale
    thank you!
     
  7. mentsm

    mentsm New Member

    I tried RGB 444 YCbCr422 YCbCr444, also tried the HDM change I (auto \ all \ limited) of the TV, and the color was the best when the llimited, but the grey order did not change

    I have to change the TV to get the correct gray order

    I was puzzled: was my operation wrong?My x9s are defective?My TV doesn't match?Is the firmware flawed?

    I like the shape, manufacturing process and function of x9s very much.


    No one has ever told me.
    Zidoo's staff told me that using firmware1.4.12 gray order would get good gray-scale, but how would the previous version of firmware1.4.12 do not have an answer
     
    Last edited: Aug 22, 2017
  8. wesk05

    wesk05 Member Beta test group

    I haven't checked the 1.4.12 firmware and I won't be able to until later this weekend.

    @mentsm: I am not sure where you got the test pattern from. It seems to be from a Blu-ray disk. I checked the levels in the H.264 elementary stream and they are not what the numbers say. 1 is 18, 2 is 20.... 32 is 56. Did you reencode the video?
     
  9. mentsm

    mentsm New Member

    donwluod url
    https://www.jdbbs.com/forum.php?mod=viewthread&tid=5763957&highlight=super+hivi
     
  10. nikos_a

    nikos_a Active Member

  11. n_p

    n_p Active Member

    Its actually good, that its not there anymore. Or at least that its not there anymore in the implementation it was before.

    x.v.Color is a color space, closely associated with Sony - used in maybe a handful of Bluray movies that were marketed as "mastered in 4K" but then put out in a 1080p format with an wider color space. It was a thing in 2013, and by 2016 it was dead in the water (presumably, I dont know much about the format to be frank).

    The issue here was, that the X9S would output a wide color space, when the box was set to auto and 1080p resolution. Regardless of the content. Almost NO content (with the exception of maybe a handfull of bluray movies out of Sony) is encoded in that color space. So the vast majority of what you were watching would be displayed incorrectly - if this was the output.

    (The X9S just expanded every color to a wider color space. Even though 99.999% of 1080p content ist encoded in rec709.)

    If 4k "wide color gamut" (rec2020) still works (I havent tested it, but I presume it does.) in the interest of "the many" this was the right decision to make. You cant optimize "auto modes" to cater to a format that maybe 0.001% of 1080p movies were mastered in.

    The only instance where it would have made any "tangible" sense for you to use this, was if you used to watch 4K HDR movies on a 1080p set that "only" supports 1080p (in x.v.Color space) and even then the color mapping probably wouldnt have been "exact" because the gamma mapping is different. Or if you were watching isos of the handfull of movies that were encoded in xvYCC.

    Otherwise you (and certainly Zidoo) were using it wrong. Especially as a "feature" that would activate in an auto mode.

    edit:
    This is a posting from 2015:
    https://www.hometheaterforum.com/community/threads/blu-ray-disc-association-completes-ultra-hd-blu-ray™-specification-and-releases-new-logo.340691/page-13#post-4287111

    I struggle to find 15 movies that were ever encoded in that format. And remember as soon as someone ripped the movie from those Bluerays (and they arent in iso format anymore), they almost certainly used the rec709 color space again (not xvYCC (= x.v.Color)).
     
    Last edited: Aug 25, 2017
    nikos_a and leonkoum like this.
  12. n_p

    n_p Active Member

    I think both, but I can double check, give me a day.
     
  13. n_p

    n_p Active Member

    To all the people asking what would be the "best" setting to choose for your TV and then naming the model:

    The correct one. :)

    Probably auto. At least after the next firmware.. ;)

    So here is the full explanation.

    Regarding Color bit rate (10bit, 12bit, ...) higher is better, if your TV supports it (but not if it doesnt ;) ), and the transcoding in the X9S is correct. It may be the single hardest thing to tell (for a couple of reasons you dont want to know.. ;) ). Higher bit levels are mostly a "thing" for 4K HDR content. Leave it on auto. (Strong recommendation.)

    Signal level (YCbCr 4:2:2, YCbCr 4:4:4 and RGB 4:4:4): It depends. ;) Almost all video content is encoded in YCbCr 4:2:0 . Both 4:2:2 and 4:4:4 are "better" (more chroma information in the signal), but since most movies are encoded in 4:2:0 it mostly doesnt even matter. In principal 4:4:4 is better, but it actually depends on the "signal space" your TV "thinks in(/displays it to the display in)". So sometimes YCbCr 4:4:4 can be less accurate, because some TVs only downconvert it to 4:2:2 to be able to display it. The safe bet here is YCbCr 4:2:2.

    RGB 4:4:4 mainly is used for displays that are primarily computer screens and were produced a few years ago, because nowadays almost everything supports both YCbCr and RGB.

    Color range (auto, limited (16-235), full (0-255)): It depends. :) The correct setting for most TVs is limited. The correct setting for most PC monitors is full. Some current TVs even have a setting that might auto adjust for it - but if you want to be sure - take the AVS HD 709 Contrast/Black level test pattern (download for free from http://www.avsforum.com/forum/139-display-calibration/948496-avs-hd-709-blu-ray-mp4-calibration.html ) and check it yourself. The aim here is to get the black level close to correct (as dark as possible, without sacrificing too much near black detail).

    Also some monitors/TVs might not support YCbCr full modes. If you find out that you need full in those cases, and the only way to "get it" is to switch to RGB full, switch to RGB full. (The reason why we would like to stick to a YCbCr mode is, that almost all video content is encoded in YCbCr and we want as few color level conversions as possible (normaly they arent "lossy", but still...)).

    The full/limitede switch actually shifts the black level by 16 stops ("levels"), which is a huge difference, and you have to find out which one is correct for your TV(/TV Setting). The reason is, that essentially all movies (up to and including 1080p) only use a limited signal range (16-235), but some TVs and mostly monitors could also expect full signal range (0-255) in which case you would have to switch the setting (either on the X9S, or on the TV/Monitor (not always possible there)).

    Its most easy to "spot" which one is expected by looking at black (the contrast/black level test pattern in the pattern collection linked to above).

    The correct setting in most cases would be limited, but I cant tell you for each and every monitor/TV, so you have to use the test pattern and check for yourself.
    -

    There is also also whiter than white which is information in the encode at 236 and above - which isnt "standard" but sometimes is there. If you want to optimize for that (and some people tell you you should), you'd have to put both the X9S and your TV/monitor in a full (0-255) mode.

    There would also be the option for Zidoo to integrate a "Superwhite" toggle (16-255) so you could leave the signal at YCbCr limited, (16-), but also enjoy the "whiter than white" parts of the signal (-255).

    This would actually be the best of both worlds - but Zidoo hasnt implemented it yet. :)

    Using a full signal range instead (0-255) means that most content (movies) go through one or more color range conversions until the signal gets displayed - which isnt optimal, but here we are talking serious nitpicking.. ;)
    -

    So full/limited mostly depends on your monitor/TV('s settings). To find out you have to use a test pattern (or a meter device).
    --

    Also ZDMCs Kodi Player (named DVDPlayer, although it has nothing to do with DVDs) in the current builds finally supports auto framerate switching (if enabled in the Kodi settings), so use ZDMC as often as possible. :)
     
    Last edited: Aug 25, 2017
    ton_dahlia, neo2017, leonkoum and 3 others like this.
  14. vadergr

    vadergr Member

    Your latest comments/suggestions have to do with the latest beta 1.4.12 fw?
     
  15. neo2017

    neo2017 New Member

    I'm assuming a projector also uses a limited Color range?
     
  16. drdwridav

    drdwridav New Member

    I'm also interested in what is perceived to be the best approach with a projector. I have a BenQ which allows me to change between full and limited (it calls full 'PC signal'). I'm still on fw 1.4.8 with zidoo settings on auto. I find the picture is much improved when I use the full setting on the projector (better gray details). Does this sound correct? Or am I going to find myself changing settings when I upgrade firmware!?!?
     
  17. n_p

    n_p Active Member

    Everywhere I've used the monitor/TV phrase you can replace it with monitor/TV/projector. Projectors most likely would use limited by default - but again, use a contrast/black level test pattern to be sure. (When you look at it, and switch between limited/full (on the most current firmware), it should be pretty obvious (because again, there are 16 steps (/levels) of difference).

    If you switch it (on the most current firmware) and see no difference, the monitor/TV/projector might actually auto adjust, based on the signal (some do).

    Also one more thing - the notion of preferably sticking to YCbCr (over RGB) only holds up, if the X9S outputs (close to) bitaccurate YCbCr, during Kodi playback. YCbCr is your best bet for accurate output on most AV devices, but on the X9S - it actually might not be. (Because Android and Kodi tend to natively run ("/think") in full RGB) So you would actually expect one color conversion to YCbCr at minimum. So if YCbCr is not output "bitaccurate", its actually a tossup between YCbCr limited and RGB full/YCbCr full (if your device support them all). You could choose whatever.

    To explain a little bit whats going on there and what you are trying to minimize - when converting from 16-235 to 0-255 (and the other way around) you get little rounding errors (because math). You'll actually get them everytime such a conversion takes place, so you tend to want to minimize them. But the differences are, very, very small. As in "not even visible" small. Its more a purist thing to do... ;) (If the math in the conversion is correct (looking at you - Zidoo from three months ago... ;) ))
     
    Last edited: Aug 25, 2017
  18. n_p

    n_p Active Member

    This is getting silly, but bare with me. :) It sounds like, in your case, on auto the X9S is outputting full, so when the projector is in limited you get black crush, and when it is in full - you get correct signal levels. With the most current firmware, this shouldnt change.

    But I've actually suggested, that Zidoo should think about always making limited the default (the way they do it currently is to read the projectors EDID (think of it as a text file with what the monitor/TV/projector can do), and if it says that it can do full - they are outputing a full signal (with the X9S on auto)), but as you found out before - just because your projector supports full, doesnt mean it is set to full by default - and you had to change that setting in the projector.

    If Zidoo chooses to go with limited by default (like most other TV box vendors, like f.e Amazon) - more people would have a chance of getting the "correct setting, without having to change anything", because most AV equipment (even if compatible with full), expects the signal to be limited by default.

    So on the most current firmware you most likely dont have to change the setting again, but maybe on the one after it.

    What you are doing with limited/full is setting up a matching chain. If the source device outputs limited, and the monitor/TV/projector expects limited, you are fine - if the source device outputs full, and the monitor/TV/projector expects full, you are fine also. If they are mixed up - you are not. :) (The entire signal then is off by 16 brightness levels.)
     
    Last edited: Aug 25, 2017
  19. n_p

    n_p Active Member

    It happens in YCbCr 422, 444, and RGB 444. When connected directly to a LG 2016 OLED and signal range (? the auto/full/limited setting, forget to check the name Zidoo has given it in the menu) is set to auto the X9S outputs a full signal in all three modes (Tested by switching from limited to auto in all three signal modes, black level shifted in all three instances.).

    The hdmi port settings on the TV are set to limited (= default setting on those TVs), and an "auto" option doest show up, when the X9S is connected. (It does, when some other devices are connected.) Just fyi. You dont have to act on that information (Find out why.) in my opinion. ;)
     
  20. drdwridav

    drdwridav New Member

    Thanks @n_p. Really helpful. I think you are right with your analysis. From my untrained eyes all I can say is that I was watching a film with many dark scenes and there was lots of black with no details. Changed to full and suddenly I could see edges to walls, patterns etc. Either that or my brightness settings are well off...or I just have no colour recognition ability :)

    I do still find that my projector's yellow is a tad too orangey but happy with all other colours. Not sure whether I should try to adjust the projector's hue/saturation/gain for yellow as I really wouldn't know which to start with!!!!!!!!!!!!!!!!!!!!!!!
     

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