HDR to SDR tone mapping is broken (many comparison screens!)

Hello,
I’m testing latest Apple TV 128Gb with infuse as replacement to my android device. I really like Infuse interface and it is true that it is fast and intuitive, but i have some problem with the most important thing for the player - picture quality.

I noticed that HDR to SDR tone mapping looks really bad in comparison to other competitors. It has significant loss of details and some problem with color gradation in red, yellow and green colors. Also it has some strange saturation bugs.

I did many comparison screenshots through my capture card to show the difference between my current player and Apple TV with latest version of infuse.

I’m a new user and can’t upload screen to my topic. First pic is always Apple TV and second the other player.

Here’s comparison screens

As you can see there is something definitely not right with red, yellow and green color gradation.

I can live without bitstream audio and other stuff, but quality of video playback is the main feature of any media player. And current implementation of tone mapping definitely needs some rework.

6 Likes

Hello.
I confirm the existence of these problems. I own an Apple TV 4K of all three generations. I have seen the problems indicated by the author on all of them.
As far as I understand, players with VS10 support do tonemapping correctly, without these problems.

When disabling VS10 algorithms, problems are present on all media players. This means that the problem is software-based and is solved with the help of software.

If infuse fails to fix this problem, I suggest considering the possibility of introducing VS10 algorithms into infuse.
Or, try sending a ticket to Apple from the FireCore developers to solve this problem.
@james, please pay due attention to this topic. Thanks.

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Yes, I have had to stop using Infuse for tone mapping.

2 Likes

Infuse HDR to SDR tone mapping needs some improvement.

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I thought this was at first a level mismatch. That is, the 16-235 video from my server was getting mapped to 0-255 in Infuse, and then converted back to 16-235 for output. But looking more closely, it appears that it might relate more to the PQ EOTF tracking.

I don’t have the tools to dig in deeper than the visual comparison.

More examples:










What player are you comparing InFuse to?

I would not expect InFuse to do dynamic tone mapping or frame by frame (or even scene by scene) analysis…though that would be very cool!

But I would expect InFuse to follow the PQ EOTF up to 100 nits in the original signal, to track the SDR section of the signal accurately, kind of like the Panasonic disk players do.

It’s a Zidoo Z9X Pro, which has much slower SOC than Apple TV. 2 days ago i received new Dune 8k+ and it has exactly the same tone mapping with VS10 as Zidoo. No difference at all. So problem with tone mapping of infuse is not hardware, but software side.

What is this HDR to SDR tonemapping in Infuse? Is this something you can turn on? What are the uses of it?

It’s useful If you have projector, 1080p SDR TV or 4K TV with bad internal tone mapping.

True. It is particularly useful for projectors. Even those that claim to support HDR typically a better tone mapping solution is to convert to SDR in the player.

Of course, the conversion between REC2020 and REC709 color space may be much of the issue that we are seeing here.

Thanks for the tip.