Banding problem

Discussion in 'ZIDOO X10' started by ursiel, Mar 1, 2018.

  1. ursiel

    ursiel Active Member

    I originally posted this in the x9s v2.0.5 firmware thread, as I originally owned the x9s, but I was asked by several users to create separate threads highlighting some of the more serious issues with these players, to bring it to Zidoo's attention. Now that I own the x10, I see this player suffers from all the same issues as the x9s. There's a wealth of information on these issues in these 2 threads for the x9s:

    http://forum.zidoo.tv/index.php?threads/new-firmware-v2-0-5-version-beta-for-zidoo-x9s-release.7401/
    http://forum.zidoo.tv/index.php?threads/ycbcr-444-vs-ycbcr-422-why-the-difference.7216/

    So here goes:

    Banding

    I did some extensive testing today to try and pinpoint what modes were causing banding for me. I'll post the results here. The test file I used (due to it displaying heavy banding) was:

    The World In HDR 4K Demo.mkv
    http://4kmedia.org/the-world-in-hdr-uhd-4k-demo/

    This is with "Switch frame rate and resolution" selected.
    I used the native "Media Center" player, not ZDMC.

    HDMI mode: AUTO
    Color Space: AUTO / YCbCr 444 / YCbCr 420
    Deep Color Mode:
    - OFF - severe banding
    - 10bit - much less banding
    - 12bit - minimal/no banding
    - AUTO - minimal/no banding


    HDMI mode: AUTO
    Color Space: YCbCr 422 / RGB 444
    Deep Color Mode:
    - OFF - severe banding
    - 10bit - severe banding
    - 12bit - severe banding
    - AUTO - severe banding


    What this tells me is for me, deep color "Auto" is selecting 12-bit, as the results are the same between the two when using color space AUTO / YCbCr 444 / YCbCr 420.

    YCbCr 422 / RGB 444 both have severe banding with the above demo and other videos prone to banding, regardless of deep color mode. The only configuration I can use to reduce the banding to an absolute minimum is 12bit deep color in AUTO / YCbCr 444 / YCbCr 420.

    Unfortunately, because of the issue I posted yesterday with 23.976 files outputting at the wrong frame rate when in 2160p 4:4:4 mode with 10-bit or 12-bit color, this means I cannot use the YCbCr 444 configuration above to reduce/eliminate the banding, because it would introduce the 23.976 stuttering bug.

    Is this how the player should be handling banding or is something not right with what the player is sending out? Why do I need to select 12-bit to get the best results, when the TV is 10-bit and the files are processed as 10-bit? Also, I can play that demo above directly from my TV's native media player via USB 3 thumb drive, and it plays with minimal banding - it looks the same through the TV's media player as it does when setting the x9s/x10 to 12-bit color in AUTO / YCbCr 444 / YCbCr 420.

    Another big drawback of all this is, as I posted above, is I have an issue with the screen flashing back, which I narrowed down to deep color being enabled in AUTO, YCbCr 444 and YCbCr 420 - the very settings I need to eliminate banding. So I have a choice of the screen flashing black (which is unwatchable) or having heavy banding issues on some videos. That's the choice i need to make right now with my configuration.

    Can the team please look into these two issues? Right now I'm stuck with two choices, neither of which is good.
     
    Last edited: Mar 14, 2018
    HDTV1080p likes this.

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