HLG processing is terrible on the Z9X

Discussion in 'HDD Media player(RTD 1619DR)' started by cucnz, Jan 9, 2023.

  1. cucnz

    cucnz Active Member

    Been suffering thru watching His dark Materials which is an HLG tv series

    I had tried watching it in HLG mode originally but colours are just all over the place ,and blacks are just murky greys
    Switching to VS10 mode is just as bad with blacks still being non existant (and we know vs10 works excellently in SDR and HDR modes)

    With just a couple episodes to go i finally clicked ,and watched them via the Panasonic OLEd USB port totally by passing the Zidoo

    Finally the pictures came out in what id say was close to proper "DV" quality viewing ,with nice deep blacks,good shadow detailing and good colours all around

    While there isnt a lot of HLG content ,more TV manufacturers like LG and Samsung have added it to their newer tvs

    I have mentioned this in the latest firmware thread and added some pics showing the vastly differing qualities of images ( thou only via cellphone camera so not super ,but still easily noticable) but pages jumped fast and it got missed i think,so thought id start a thread for it

    ive added pics from HDM epi1 (one is like 1/5 sec early but thats the pana oled HLG one so youll see the huge improvement in black levels very easily over the Z9X HLG and VS10 prcessing

    Just wondering if Dev team will be sorting out this ,since it is a feature sold as part of the product line ,and one which atm is incredibly substandard

    cheers Thomas :)

    Attached Files:

  2. Markswift2003

    Markswift2003 Well-Known Member SUPER Administrator Beta test group Contributor

    Not quite sure what's going on here, but I just tried my test file from His Dark Materials.

    Played natively in HLG, my Vertex confirms the file plays in HLG BT.2100 and colours are correct and blacks are inky black as they should be.

    Played natively in SDR (using an SDR EDID), the SDR layer is played correctly and colours are correct, blacks are inky.

    However, if played with VS10 in either SDR, HDR10 or DV, the colours fade and black level is raised.

    Arguably this could simply be that VS10 does not support HLG since Dolby have a habit of ignoring rival HDR protocols, and HLG is a direct, if inconsequential, rival to Profile 5.

    So I'm not getting the same results as you for native HLG - on my setup it works fine (Samsung TV)

    Two things strike me, and I'm guessing a bit here:

    Firstly HLG was designed by NHK and the BBC for streaming only so it's possible that the TV you're using does not process HLG properly on the HDMI input because it was never expected to do that.

    Secondly, I do remember ages ago that there was an issue with native HLG playback on the Zidoo so what firmware version are you using?

    I'll query the VS10 behaviour with the devs but as I say, native HLG is fine here.

    (as a bit of a litmus test, my Dune behaves the same - ie HLG native is ok, but in VS10 is not correct)
    xskip likes this.
  3. xskip

    xskip Active Member

    Played His.Dark.Materials.2019.S01E01.2160p.HLG.WEB-DL, file is 8GB
    great picture, inky black, no problems. (settings HDR Auto)
  4. cucnz

    cucnz Active Member

    cheers for answers

    im on latest .42 f/w

    not sure why DV VS10 are working in everything else but for HLG its murky greys in both Auto or VS10 modes and as shown in pics ,perfect direct to tv on usb
  5. Markswift2003

    Markswift2003 Well-Known Member SUPER Administrator Beta test group Contributor

    Like I said, HLG is designed purely for streaming (well, broadcast actually!) so it's possible your TV just doesn't like HLG via HDMI because that's not the way it's supposed to come in. Playing off USB is a completely different signal path.
  6. cucnz

    cucnz Active Member

    ta luckily the number of HLG tv etc is low still ,thou as i said above ,it is something thats been added to most tv brands now as it is used more often

    ill just try to remember to watch them via tv unless a fix can be added
  7. Markswift2003

    Markswift2003 Well-Known Member SUPER Administrator Beta test group Contributor

    Nothing to be fixed really (other than possibly VS10 processing, but the more I think about that and Dolby's walled garden, the less likely I think that will be) - it's the TV that processes HLG, not the source - the source just provides the signal.
  8. cucnz

    cucnz Active Member

    Technically it should work over HDMI since it was added as part of the HDMI 2.0 standards in 2016
    and both the TV and the Z9X recognise it as an HLG signal
    Last edited: Jan 9, 2023

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