Apple TV 4K + Samsung = Worst Combo?

I did a LOT of hours reading and testing. 

The picture on my Samsung seems reasonably good when watching DolbyVision titles on my Samsung TV’s built in smart apps but worse when I watch the same title via the Apple TV’s apps. I was expecting it to be better

Does anyone know what the Apple TV actually does when receiving a title listed as HDR DolbyVision while connected to a Samsung? 

It appears to accept the DV stream and then it seems that it either passes it to the Samsung unchanged and the Samsung “copes” with it or that the ATV reformats it to some format which it feels is acceptable to the Samsung. 

What it doesn’t seem to do is reject the DolbyVision stream and request an HDR10 (not plus) stream instead. If there is such a thing. Which is perhaps what the Samsung apps do. 

I connected a 12 year old monitor to the Apple TV and the Apple TV reported “HD DolbyVision”  and the picture was not good. So it seemed to be passing on the DV stream in some form. When I switched the box to SDR the picture was very good. (On 22” !)

Netflix say it provides DV titles in DV or HDR10 but do they mean that two separate streams are available or that they supply one stream that “fits all”? 

I rang Netflix about that and they said “No one at Netflix has that information” which took me aback! 

It seems that DV support can be added to a TVs firmware, if the TV’s processing is powerful enough. So, maybe Samsung will stop ignoring Netflix, Apple and Disney. 

Thank for the help, Vazandrew.

1. My Samsung TV’s specs list HDR10+ and HLG as supported but makes no mention of DolbyVision. Perhaps it can “play” DV videos even though it doesn’t “support” DV. So, maybe my ATV4K box sees it as DV “capable” as it passes the box’s HDR tests?

2. Is there any way of telling whether what I see on the screen is HDR10, HDR10+ or DV?

Netflix shows DV in their listings. Amazon just shows “HDR” for all HDR listings. 

The ATV4K’s UI pull-down info shows only “DV or HDR”

Samsung’s Netflix and Prime smart apps show only “HDR” in the tv’s UI info. 

My Samsung TV shows Gamma ST2084 for all HDR types and Gamma BT1886 for SDR (from my ATV4K box) and for UHD non-HDR as specified in listings. 

3. I don’t think my equipment is faulty as the DV/Samsung problem is documented by others on the internet. 

4. I note that for the same DV video from Netflix (“Chef’s Table”) I see:

a) A poor quality picture via ATV4K set to HDR. Gamma defaults to ST2084 (Possibly the ATV4K is accepting a DV stream?)

b) A better picture via Samsung smart Netflix app. Gamma defaults to ST2084 (Presumably the app requests an HDR10 stream?)

c) The best picture via ATV4K set to SDR. Gamma defaults to ST1886. Possibly the ATV4K requests HDR10 and strips out the dynamic metadata - I don’t know what I am talking about here! - before passing it to the Samsung? Or can Netflix be supplying a UHD SDR stream for what they list as DV?

5. Why would the picture obtained via the ATV4K (set to HDR)  be worse than that obtained from the Samsung built-in smart app?

Possible answer:

Netflix claims to stream its HDR videos in either DV or HDR10 depending on the capabilities of the receiving device. (Is there a third option of UHD SDR?)

So, possibly, if the receiving device is a DV-capable ATV4K, Netflix will serve DV. 

Maybe, instead of rejecting that DV stream, the ATV4K either converts it to HDR10 and passes that to the Samsung or it passes the DV straight to the Samsung which can convert/play it, but badly. 

Sorry to rabbit on!

Thanks jefbak. I have been giving them a try. They seem to work OK, just a bit dark, in (edit) HDR10 (presumably) for Netflix DV, Apple+ DV and Prime 10+.

They are usually better than from the ATV set to HDR but similar to the ATV set to SDR.

I have been doing a LOT of testing but just recently have foolishly let watching TV programs get in the way of testing.

I’d like to use my expensive, powerful ATV box do everything but, at the moment, its coming second. I’ll try to finalise my thoughts soon though I’m starting to really regret buying a Samsung.

Unfortunately, although Samsungs don’t claim to support DolbyVision, they will play it. Albeit badly. I wish the Apple TV *would* resort to HDR10 when served DolbyVision while attached to a Samsung. I have to manually switch it to SDR.

As it is, I am prevented, by the combo, from getting enhanced HDR from *any* of the main sources.