4k HDR issue

Discussion in 'Apple TV and Home Theater' started by bp1000, Jan 28, 2019.

  1. bp1000 macrumors 65816

    Jul 7, 2011
    I’m seeing really bad blocking / low res patches when watching HDR content.

    It’s native HDR in Netflix

    My ATV4K is set to SDR 4k @ 60hz (uk) but with range and frame match content set to on

    When watching a HDR show with a bright scene (like a white sky with a gradient) I get terrible blocking / low res patches with some colour banding

    Watch exactly the same scene via the Samsung TVs inbuilt app also in HDR, everything is fine.

    So that rules out the panel and picture settings.

    My HDMI input is set to UHD colour and the only other thing is the cable. I don’t have any new cables. All the ones I have at 2-3+ years old. But they do say high speed with Ethernet.

    Any ideas what it could be?
  2. Audit13 macrumors 68040


    Apr 19, 2017
    Toronto, Ontario, Canada
    I would try different inputs on the tv, connect atv directly to the tv, use an Ethernet connection, and/or change the HDMI cable.
  3. priitv8 macrumors 68040

    Jan 13, 2011
    I would also start with HDMI cable (must at least be able to put through 18Gb/s. 48Gb/s HDMI 2.1 would be even future-proof for some time to come), then check every HDMI port on the TV. They may not all be created equal.
  4. Michelasso macrumors 6502


    Feb 20, 2012
    Treviso, Italy
    In my experience pixelation is caused by a low bitrate. I'd check with Speedtest (there is the app in the App Store) if you're getting the right bandwidth (and latency/ping) with your connection. Also if the ATV is wired I'd tried via WiFi (just for testing). And vice-versa. Unfortunately I don't know the way to check what's the current bitrate in Netflix while streaming on the ATV 4K, if there is any.

    Then it would help to know which Netflix show(s) is causing the issue (unless it is all shows/movies you tried). I mean, just to check if we get the same issue ourselves.
  5. bp1000 thread starter macrumors 65816

    Jul 7, 2011
    Thanks, I will double check the bandwidth, but i'm very confident all that is fine.

    I run 5ghz wifi with no interference and i have a fibre connect at around 70Mbps with a throughput of at least 60Mbps at all times.

    I ran a netflix bandwidth test too, in the account/support settings via the app and the speed came out fine.

    It maybe the cable so i've ordered a newer HDMI cable from amazon. Fingers crossed!
  6. Cardiff25 macrumors member

    Sep 10, 2015

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