Many DolbyVision Titles Dropout on HDR10 TV’s

Discussion in 'Apple TV and Home Theater' started by SamEdwards, Nov 21, 2018.

  1. SamEdwards macrumors newbie

    Joined:
    Mar 22, 2010
    #1
    The AppleTV 4K has dropouts on HDR10 TV’s when playing many DolbyVision Titles.

    The Random singnal loss on DolbyVision titles come from Apple’s improper conversion to HDR10 from DolbyVision for non-dolbyvision displays. This is something that ‘just works’ on 4K BluRay players, and was better pre-TVOS12.

    HDR10 is supposed to have static metadata for the entire title. That’s the main difference between the two HDR formats.

    Even though the AppleTV correctly determines that a display is not DolbyVision compatible, it still sends dynamic metadata to those displays. Many displays just have a brightness pop at those changes. Some dropout audio or have crackle and pops. Others, like Sony projectors drop picture.

    Here’s a YouTube video that shows the problem causing Audio dropouts. I get image dropouts at the same spots in thsee clips.



    I’ve spent more than the cost of an AppleTV on various cables recommended by Apple ‘geniuses’ trying to fix this problem. It would be great if they would fix their faulty firmware instead of twisting every conversation into an excuse to sell you something. Since this problem varies with software versions, they obviously can fix it, if they care.

    Before you buy more cables trying to fix this, check and see if your problems occur on DV titles, and if they happen at the same time on repeated viewings.
     
  2. BODYBUILDERPAUL macrumors 65816

    Joined:
    Feb 9, 2009
    #2
    Can you list the makes and models of TVs that are having this problem as it certainly has not been reported by tech sites or others on this site.
    Because I use Apple TV for everything, it was 100% the reason that I choose to buy the LG OLED. It's been a wonderful pairing and everything 'just works'. Never been a fan of SONY products along with their non existent customer service which dates back many decades.
     
  3. SamEdwards thread starter macrumors newbie

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    Mar 22, 2010
    #3
    I’m very curious what other models may have these issues. The Lumagen processor in the YouTube clip obviousy looses sync and has an audio glitch...
     
  4. Cell-666 macrumors 6502a

    Cell-666

    Joined:
    May 3, 2011
    #4
    Sam, where did you get the information that the ATV 'coverts' DV metadata into HDR10. I'm under the impression that this should be done by the set and not the ATV?
    You maybe best look at the stream's data via the developers menu which will show you what is happening on the actual ATV unit's output.
     
  5. SamEdwards thread starter macrumors newbie

    Joined:
    Mar 22, 2010
    #5
    I've looked at the streams data with the HUD and it indeed reports that it's sending Dolbyvision, even though the display does not support that format.
    Dolby Vision is supposed to be backwards compatible with the older HDR10 format. According to the HDR10 format specs, that includes static metadata. In the clip you can see that the metadata is not static coming from the stream in the demo.
    I don't know how a tv or projector manufactured before the Dolby Vision spec was finalized could do this conversion. It's up to the playback device to provide the backwards compatible stream.
    --- Post Merged, Nov 27, 2018 ---
    All of the current Sony 4k projectors loose sync on the metadata change, and black out for about 5 seconds each time. I have the 285ES and about 30% of the Dolbyvision content in the apple store and on netflix is unwatchable.
     
  6. priitv8 macrumors 68040

    Joined:
    Jan 13, 2011
    Location:
    Estonia
    #6
    This can and will not happen. Lack of DoVi support of screen is known to aTV via display id metadata over HDMI. A source shall not send unsupported signal formats to sink. So the burden to provide acceptable to sink video signal is with the source (aTV).
     
  7. ActionableMango macrumors G3

    ActionableMango

    Joined:
    Sep 21, 2010
    #7
    I can only lamely suggest trying to turn off "Match Frame Rate" and "Match Dynamic Range" to see what happens, (but admittedly you've probably already tried that).

    Sort of. Dolby Vision has many profiles. The Dolby Vision profile used by Blu-rays include a requirement to have HDR10 fallback on the disc itself. The profiles used by streaming do not, so the device has to do translation on the fly and it sounds like ATV's translation is problematic.

    I suggest everyone with this problem file a bug report here:
    https://www.apple.com/feedback/appletv.html
     
  8. SamEdwards thread starter macrumors newbie

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    Mar 22, 2010

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