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Adjust the brightness

Discussion in 'NEO U9-H' started by vincenz0, Mar 13, 2017.

  1. Villa

    Villa Administrator Administrator

    You broke my box! :(:eek:o_O

    I click play and full screen and got this...

    Screenshot_20170323-161507.png


    Then pressed Home...

    Screenshot_20170323-161526.png

    Then a message to say Chrome has stopped working! :mad:
     
  2. WeK05

    WeK05 Audio Visual Master Specialist

    You can use this test pattern for checking: https://mega.nz/#!RJ8iDAha!pSuHDw77TKku0B0Mn0TSjNHY2qPBFxkMvNyapcgV5zk

    If you have adjusted the brightness on your TV correctly, you will see gray bars 16 and above flashing. Depending on your TV, you may also see several of the bars above 235 also flash. To adjust the brightness of your TV, play the clip in "Movie" player and adjust the brightness on your TV, such that no bars below 16 flash.

    The brightness issue being discussed here makes none of the black bars visible. As for white bars, you may see 230-233 flash, but not above it.

    What I have now seen is, after you play any clip in "Movie" player, the brightness issue is fixed. The issue does return after a reboot. I tried clicking on different parts of the screen as you have suggested, but that didn't help.
     
    Villa likes this.
  3. Az3w0ra1

    Az3w0ra1 New Member

    Wek,

    Is the issue solution only for.video playback?

    When i click thru settings of device if its 80 to 90% darkarea it will dim down
     
  4. WeK05

    WeK05 Audio Visual Master Specialist

    After I play a clip in "Movie" player, the brightness issue is fixed globally, i.e, for both system graphics/menu and video playback.

    I was going through freaktab posts and it looks like other S905X/912 boxes also have the same issue. Users have reported playing a clip in "Movie" player or a 4K clip fixing the issue temporarily. There are also some custom ROMs for S905X that apparently fixes the issue by changing permission on some "vpp_brightness" file.
     
  5. Villa

    Villa Administrator Administrator

    I think that was my case too. Clicking on the screen did nothing!
    While a video was playing in BBC iPlayer the issue wasn't fixed until I backed out of the video and started it playing again.
     
  6. WeK05

    WeK05 Audio Visual Master Specialist

    Have you tried the "Movie" player "fix"? I have tried 1080p clips and it seems to work.
     
  7. KellyND1

    KellyND1 Member

    Try the minix launcher, not the wretched custom one.

    Sent from my XT1254 using Tapatalk
     
  8. pusb87

    pusb87 Well-Known Member Trusted Helper

    oops :whistle:
     
    Az3w0ra1 likes this.
  9. MINIX - Ken

    MINIX - Ken Former MINIX Team Member Administrator

    We need to know how to make it "abnormal" first.
     
  10. MINIX - Ken

    MINIX - Ken Former MINIX Team Member Administrator

    No, it removes an invisible warning message which darken the screen.
     
  11. MINIX - Ken

    MINIX - Ken Former MINIX Team Member Administrator

    Yes, move the cursor around and click anywhere when it happens should become bright again.
    That's what we have fixed so far.
     
  12. MINIX - Ken

    MINIX - Ken Former MINIX Team Member Administrator

    Thanks for all the info provided, we have applied 3 fixes on the coming FW004, going to check with your file soon.

    One fix is about grey scale, the other one is about HDR OSD menu, and the last one about the invisible warning message that I mentioned.
     
    Runge, Az3w0ra1 and skynet like this.
  13. MINIX - Ken

    MINIX - Ken Former MINIX Team Member Administrator

    so if we see 16-25, 234 and above flashing, the problem can be assumed fixed?
     
  14. WeK05

    WeK05 Audio Visual Master Specialist

    If you have set the brightness on your TV correctly, then if you can see 16-25 flash, the problem can be assumed to be fixed. You can also check this with Minix Metro or Kodi splash screen.

    Minix Metro - Incorrect output

    [​IMG]

    Minix Metro - Correct output

    [​IMG]

    Kodi Splash Screen - Incorrect output

    [​IMG]

    Kodi Splash Screen - Correct output


    [​IMG]
     
    Last edited: Mar 24, 2017
    Runge and skynet like this.
  15. MINIX - Ken

    MINIX - Ken Former MINIX Team Member Administrator

    Are we talking about 2 separate issues?
    I'm confused.
    And I tested the video you provided:
    In Kodi, Shield and U9-H are giving the exact same result - can't show all blocks
    In U9-H movie player - can display up to 253
    In Shield native player - can display up to 240 something

    We can fix/have fixed the brightness issue but the gradients thing is another problem not limited to our device?
     
  16. pusb87

    pusb87 Well-Known Member Trusted Helper

    Well then, since saying i had not seen this issue i have for the first time turned my U9 off completely and restarted.
    I can now see that the screen is a little darker, and by using black and white test patterns confirm all is not as it should be. I then played a 4K movie clip and returned to the test patterns and as others have reported it all seemed much better again and i could see more or less the correct black gradient bars flashing.

    I guess I must have played a 4K clip very early on when i first got the U9 which had me thinking i did not see this issue.

    I stand corrected !! :oops:
     
    Villa likes this.
  17. Villa

    Villa Administrator Administrator

    It doesn't need to be 4K! I played something in BBC iPlayer, backed out, then to Home screen and all is brighter!

    Edit: Played 720 in Movie Player, all bright again!
     
    Last edited: Mar 24, 2017
  18. pusb87

    pusb87 Well-Known Member Trusted Helper

    well weird..sure @MINIX - Ken will be on top of it though (y)
     
  19. WeK05

    WeK05 Audio Visual Master Specialist

    There is only one issue. Incorrect YCbCr output. I am calling it as that now because it is not clear whether the issue is due to incorrect RGB-YCbCr conversion or due to an invisible warning message like you mention.@wrxtasy mentions that this same issue is seen with LibreELEC on S912. This suggests that it is actually a Amlogic decoder problem. Surprisingly, this issue is not present on Xiaomi Mi (S905X).

    With the black and white test pattern, it is important that you first set the brightness on your TV correctly. Without doing that, interpreting the results are really meaningless. If brightness is set correctly on the TV, you will see bars 17-25 flashing. White clipping depends on your TV. On some TVs you may be able to see bars above 235 flash even when you set contrast to the maximum. Ideally, you are not supposed to see those with YCbCr input. You have to use "Movie" player to adjust the settings on your TV. There is no issue with "Movie" player output.

    With this brightness issue, you will not see bars 17-25 when the test pattern is played in Kodi/SPMC etc. The upper half of the pattern will look uniform black. This is because YCbCr 16,128,128 is displayed as 0,128,128 and everything below 16 is also 0. 18 becomes 1, 19 becomes 2 and so on.

    As for comparing it with the Shield, it depends on whether you are on Nougat or Marshmallow firmware. It is different on the two firmwares. On Nougat, Shield does pass the full YCbCr range (0-255).
     
    Last edited: Mar 24, 2017
    Runge likes this.
  20. Runge

    Runge Member

    Correct me if I'm wrong but I don't think we are talking about failure displaying gradients? The screens WeK05 provided gives a good impression of how the home screen looks like before and after the correct display/brightnes profile has been applied (using the 4K video trick or similar). I see the same thing happening here before and after 4K trick.