Posts by jd17

    Is there any reason you couldn't just create a sync delay rule in advancedsettings?

    I think you might have misunderstood what my issue is about.
    It's not about audio/video being out of sync.


    My AVR does not "like" the output signal of the S905X and causes a weird flicker in the lower grayscale range.
    This flicker is not there when I connect the box directly to the TV.
    johngalt initially thought it might be a pixel clock/sync issue.

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    A pixel freq or vertical/horizontal freq issue.

    ...but it could be a sync issue of some kind (though if you also get it on 50/60hz, then possibly not).

    Wow, I just tested 50Hz and 60Hz at 422,8bit and 444,8bit - no flicker whatsoever!
    (I just disabled refresh rate switching and enabled sync playback to display instead to test on the same 23.976fps movie...)

    I know this is a lot to ask since I seem to be the only one affected by this - but is there something you could do about this sync issue?
    That would be so amazing!
    Of course I understand if that does not interest you though....


    Edit:
    If I play a 10bit video in the same environment (8bit output, 60Hz) the flicker is there. So I guess the 10bit to 8bit dithering has an impact as well?

    ...and I'm also not sure if it would help.

    Me neither... But I'm desperate, grasping for straws.


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    The 10-8 dithering is disabled on 10bit output, but it could be a sync issue of some kind (though if you also get it on 50/60hz, then possibly not).

    I get this on regular 1080p / 8bit / AVC stuff too (the only kind I can compare to RPi2)...
    This is what makes it so weird. I had the box basically set up as a 1080p-only device in my last tests (422,8bit / rgb,8bit / 444,8bit).
    I even disabled deep color on the TV's HDMI input, anything to delete noise.

    However, I have not tested 50/60Hz yet - will do!

    What do you mean by sync issue?


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    Damn! Will fix. Thank you for reporting. I also believe that "macro blocking" issue you reported might be related to a color range bug if we fall back on hdmi mode from an edid parsing failure.

    Good man! :)
    It sounds like you have some compelling ideas.
    Just let me know when there is a build in which I should test those samples for the macroblocking again. :)

    Thanks johngalt! :)

    I have a question on a side note, maybe you can help me out...
    As you maybe remember, I complained a few times about weird lower grayscale flicker.
    It turns out that my AVR adds that to the signal. :(
    I am bypassing the AVR's video processor and it still messes up the signal - even if I "dumb down" the S905X output signal as much as possible (422, 8bit / rgb,8bit), I tried everything.

    The flicker is not there with the RPi2, however - the image quality of that is also inferior in the lower grayscale range.
    My assumption is that the S905X generally uses some kind of dithering that the AVR does not like...
    I don't know. It happens with MM kernel as well, so it's independent of build.

    Anyhow, long story short, as a last grasp - do you know if it is possible to "boost" the HDMI output signal on AMLogic devices?
    I am asking because the RPis have that function:

    Code
    1. config_hdmi_boost=0-11

    While that is strange, you still have a clear indicator that your 15m cable is a limiting piece in the chain - your own test confirmed that.

    Additionally, most other experiences agree with how difficult high bandwidths are with long distance, passive cables.

    Everyone else who tested john's builds eventually made them work, after upgrading the cables in some cases too.


    This is why I still believe it is more likely that something in that egrat box's signal is off than believing the fault is with john's build.


    Ideally you should use a UHD Blu-ray player to confirm, but I assume you don't have one...

    Do you know what chroma subsampling the egreat box puts out?


    For 10bit, 4:2:0 is officially only supported at 50 Hz and 60 Hz, while 23.976 - 30 Hz are only supported at 4:4:4 by HDMI 2.0:
    HDMI :: Manufacturer :: HDMI 2.0 :: FAQ for HDMI 2.0


    If your cable cannot pass a 23.976 - 30 Hz signal at YCbCr 4:4:4, it does not comply with the HDMI 2.0 standard. For me, that would be reason enough to consider a replacement.

    With the same setup, using egreat box A5, 4k hdr 10 output all is okay, so I think that there are some problems with testing version.

    That should not be your conclusion from the experience.

    It is far more likely that this box is just passing a lower bandwidth due to either not passing BT.2020 correctly or 10bit correctly or......


    I think the JVC beamers have a tab in the menu to show the specifics of the input signal...
    Please check if that actually confirms the signal from this egreat box is 2160p / BT.2020 / HDR10 / 10bit.

    Don't do it...
    You might get lucky, but in my experience, finding a 15m cable that can pass the full 18gbps is very difficult to come by.
    Is there a chance for you to use two shorter cables and a signal amplifier in between?
    As far as I know, even 10m cables are not such "divas" as 15m ones... Maybe you can use one 10m and one 5m cable or two 7.5m cables?

    Sorry for the delay...

    I finally had the time to test 12bit and look for the artifacts.


    Result:

    - 12bit does not change anything... Vertical lines are still there in 10bit videos.

    - I definitely see the weird artifacts in the "Sony Camp" video as well, it is 59.94 fps. At ~1.03min over the mountain (sky). It looks like heavy compression artifacts you get at low bitrates... Macroblocking... The video has a very high bitrate though and the artifacts are not there when I play via the TV's internal media player.

    I will look for the artifacts in different framerate demos today.


    Apart from that, everything seems to be very good in "testing1". :)
    BT.2020 and HDR10 are properly passed and look right.

    You are right, the lines are barely visible at normal distances.
    However, I don't want to accept that nothing can be done about them. ;)

    I will try to force 12bit and see if they are still there...