RPi4 testbuild with HDR support

  • Hello @all , have installed the latest Nightly but have the problem that the sound format is only displayed as a PCM at the Ambeo Soundbar. Atmos is not available for selection. TV is an LG GX 4k

    A LOT of Dolby Atmos content out there is overlaid on top of Dolby Digital Plus. I also have the exact same TV as you, (althought different audio setup) and passed through that codec fine. If you don't enable DD+ passthrough (which after deciphering your German UI, you didn't check that) if you play anything with DD+ (or DD+ with Atmos metadta on top) it will simply convert it to PCM with whatever channel configuration you set it to (in this case 5.1).

  • Maschingun thanks for the logs!

    Can you please run the following command via ssh/putty and post the output URL?

    od -t x1 /sys/class/drm/card0-HDMI-A-1/edid | pastebinit

    Also: did you connect the RPi directly to the TV or via the soundbar? Which soundbar are you using?

    so long,


  • It Works now. It shows Dolby or Dolby +

    DTS or DTSHD do not work.
    Atmos is apparently not available for selection?

    Problem was with the number of Channels 5.1
    now have 2.0

    And I also had to activate converting Dolby Digital.


    The RPi is directly to TV.

    Soundbar is Sennheiser Ambeo

    Edited once, last by Maschingun ().

  • Maschingun thanks for the info! I'd still be interested in seeing your edid, if you have time please run the command I mentioned in post 155 RE: RPi4 testbuild with HDR support

    so long,


    As mentioned I have the same TV as Maschingun albeit in English and the US model.

    It supports Dolby Atmos metadata in both Dolby Digital+ and True HD, along with as standalone codecs without the Atmos metadata, and DD...at least passed via HDMI (so obviously technical limitations prevent it from being passed via SPDIF since it can't support the bandwidth requirements beyond plain DD). You don't specifically set Dolby Atmos in Kodi, you just select passthrough for both Dolby Digital+ and TrueHD.

    Maschingun to see it in action, just select the "Input" button in your remote. For some bizarre reason LG left out DTS support ENTIRELY (for any variant, including the old school DTS) for that TV. Bit annoying but I live with it because I rely on the TV for only video display duties, personally. If your Soundbar supports HDMI video passthrough I suggest instead connecting it as Kodi->soundbar->LG TV.

    If you see that in the TV info but not the Soundbar, it's possible eARC is either not supported by it, or possibly if it is it's not enabled. IIRC, plain old ARC basically is technically equivalent in capabilities as a plain old SPDIF connection. So you need eARC specifically. Again if your Soundbar supports HDMI video Passthrough to your TV, you're better off connecting as I mentioned.

  • HiassofT, Couple of


    I also own a 2019 Shield TV pro, a 2016 era Roku Ultra, the Panasonic 820 UHD player, a 10th gen NUC, a mini Lenovo ThinkCentre with 8th Intel mobile U-series CPU and Xbox Series X. Along with a 65" LG GX OLED TV. For every other device that supports at least HDR10 (the Shield and UHD 820 player and XSX also support Dolby Vision in conjunction with the TV), they all output in BT.2020 (Rec.2020)... at least according to my TV. With the nightly 03/16/2021 build, Kodi does in fact trigger HDR10 as my TV indicates it, but unlike the other devices it doesn't output in BT.2020 as my TV doesn't mention that like all the other sources. As a result the color looks washed out--comparing the shield to the Kodi, it looks more greyish. I looked around briefly to see if I could force it to BT.2020 in some config variable but didn't find anything promising. Imo that's definitely the missing piece to get proper HDR10 support.

    It appears that if you enable both HDMI ports that it behaves similarly to Displayport MST, and you are limited to 30hz @ 4K. Perhaps I suggest making the dual audio output something that can be configured for those who don't need it?

    Also my setup is somewhat interesting since the GX TV is a very recent purchase made this year and my first 4K display. The rest of my existing gear was actually from 2007 in addition to my receiver that I'm still using it for audio duties in both powering my speakers and decoding audio codecs (currently not interested in expanding my 7.1 speakers to Atmos/DTS:X). I'm pretty sure it's only a HDMI 1.3a receiver. The 4K HDMI passthrough is being handled with both an HDMI 2.0b and an HDMI extractor device. An interesting observation is if I connect the pi 4 directly to my receiver the receiver itself goes a little nutty and starts randomly switching to operational modes I didn't expect. So I had to connect it directly to my HDMI switch. Might be a clue for some folks having issues I'm their setup...

    All in all, a great first accomplishment in working to get HDR10 support! The pi4 device is actually serving as a Retro Pi and my Shield is the device I use for Kodi, but I'm more than happy to beta test to assist!:)

  • All of my HDR content is washed out. Is there a setting I need to get hdr working? I've tried the nightlies from the last few days only.

    EDIT: I just noticed its a known problem, but I don't understand why it works for some people and not others.

    I think some people may not see the gamut mismatch - where Rec 2020 content (which is pretty much all the HDR10 and HLG out in the wild apart from DIY stuff) designed for much wider gamut primaries is displayed with Rec 709 primaries (giving you far less vibrant colours)

    If you aren't comparing with the content displayed properly - you may not see it as an issue. (Or maybe some TVs automatically go into Rec 2020 mode, incorrectly, when they see an HDR EOTF flagged over HDMI, even if there isn't a Rec 2020 flag present)