Apple TV 4K problem with Dolby Vision

Same problem here with a Sony OLED. I am pretty sure the problem only shows up with TV's that support TV-led Dolby Vision

I am also unable to enable Dolby Vision on my LG CX OLED using ATV4K.

Are you sure?

bad post, sorry

It’s too late for me to test that now, but I imagine it would be fine. But you would need a ultra high speed HDMI for the new one.

This has been an issue for years. Same canned messages from Apple.

I just have the Apple TV 4K 2021 connected with HDMI (the one in the photo) to my LG C9, and that’s it. :)

Definitely. I’ve tested a lot of movies now just to make sure — on multiple apps. I got a little scared when I tested Zack Snyder’s new movie on Netflix, Army of the Dead, because it shows slightly elevated blacks at the very beginning, but that turned out to just be the movie itself; it also looks that way on the C9’s internal Netflix app. So, based on what I’ve tested so far, it appears to be fixed. Maybe the fact that it’s a HDMI 2.1 device and requires a ultra high speed cable has made the difference, or maybe Apple has simply fixed it — I’m not sure.

@sciletto,

It sounds like to me that the AppleTV is sending the DV data in its RGB 8 bit wrapper as it should, but either the ATV or the TV isn’t properly decoding the Full RGB 0-1023 video levels (normally used for PC signals) to the RGB 64-940 Limited video levels (normally used for video signals) as it is supposed to. This would result in the hazy, raised blacks you report.

The DV processing uses the Full 0-1023, 10 bit range, but it’s supposed to change it for display in the final stage to Limited 64-940 video range because that’s what Home Video displays are designed for. Since the Dolby processing happens in the TV when DV is sent as RGB 8 bit, as opposed to when it sends LLDV’s YUV 10-12 bit, then it appears the LG TV is at fault actually for not decoding the full DV signal properly. It could be something missing in the AppleTV’s DV output as well I guess, in which maybe it doesn’t signal the LG TV to go into Limited Mode for display, idk.

You can try this yourself with other input signals if your TV has the option to switch from Full to Limited video signals. If you test by watching the same scene with something like the Bluray or an SDR version of the film, try changing from RGB Limited to Full and back and you’ll see the same anomaly.