Hi everyone, I’m totally aware of the many discussions on this topic, but they all seem to stray from the original problem into a debate about why do it rather than how to fix it.
There IS an issue with HDR Tone Mapping, but it’s pretty minor. Bright scenes look amazing and better than their non-HDR counterpart. Dark scenes are too dark. Some of the data is getting lost and I believe it’s due to the HDR Tone Mapping Algorithm.
There are 6x algorithms for converting the HDR color map to an SDR color map (that I’m aware of):
clip
mobius
reinhard
hable
gamma, and
linear
It’s possible that depending on the SDR screen or content, it may be necessary to switch. I’m honestly not sure, but I can definitely say that all HDR movies and shows that I watch have the problem I described above on 2x SDR screens that I’ve tested. To be clear, the content looks perfect on my HDR screen.
James, would you be open to implementing an option that allows the user to choose which method is used?
I think this will end the frustration that I’m sure at least a small population of Infuse users are having and it will end the need for people to continue to debate the why.
Unfortunately, there’s no perfect solution for HDR > SDR mapping. Each method features different strengths and weaknesses, and generally there isn’t much variance between how one type manifests on different TV models. In essence, you have a choice between the 3 major attributes: luminance, color, and detail - and you only get to pick 2.
We’ve done a fair amount of testing for what works well with the Apple TV when paired with a handful of different SDR sets (ranging from an entry-level LG all the way up to Sony’s $8,000 flagship 4K SDR set from 2015), and the recipe we currently have Infuse seems to be the best compromise we could find.
We made a number of changes towards the end of last year in the 5.8.1 update (Infuse Release Notes | Firecore). Right now, we’re not aware of any outstanding issues.
FWIW, converting HDR to SDR is not a 1:1 process, so there will almost always be some differences between a converted HDR video and its SDR counterpart.
Last night, with the latest version, bright scenes look great and dark scenes are too dark. The balance isn’t right. On Plex, the dark scenes are brighter, but the light scenes don’t look as nice as Infuse. This is due to different choices in the tone mapping algorithm, right? If so, please use a different one that’s not so punishing to dark scenes.
Getting better blacks is possible, but it comes at the expense of loss of quality in light scenes, with bright colors having an overexposed effect.
If you’d like to compare, a link to a set of samples can be found at Dropbox - File Deleted These images show the ‘before’ level (5.8.0 and earlier), ‘now’ level (5.8.1 and later), and a hypothetical ‘other’ level. As you can see there was a noticeable improvement in the reworked algorithm in 5.8.1 - with darks being displayed better, without much change in light scenes. The ‘other’ level does better with darks, but degrades lighter colors.
Our goal with the changes added in 5.8.1 was to provide a balance of light, dark, and color accuracy, and display a picture that is generally pleasing to the eye. The feedback we’ve received from these changes has been overwhelmingly positive, though I can understand different people may have sensitivities to different things.
James, you nailed it. These screens look almost like you took them from my home theater. I remember seeing the change from before to now and feeling hopeful that it would continue to move in that direction.
For my setup, I’m trying to compare the true SDR version of each film to the HDR>SDR conversion to figure out what is most accurate. On (now) 3x different screens that I’ve tested, the HDR version always comes out darker on dark scenes in Infuse on Apple TV 4K, but closer (still a bit darker) on the Plex AppleTV 4K App. On Plex; however, I’m not seeing brights being blown out… they just don’t like as vivid (or maybe bright). It seems like they crushed the spectrum instead of offsetting it.
Is there no mapping that can crush the spectrum a bit so that we can get brighter darks, but not blow out lights? How is Plex doing it?
Yes please !
My projector is actualy HDR capable, but I find the extra dynamic you can get is not worth the added fan noise and the reduced lifetime of the lamp, so I like to keep my AppleTV set to SDR.
Like others, I noticed that there is something wrong with black levels in the BT2020 to REC709 conversion in Infuse.
Really hoping 6.1.6 will help !
Any release date ? Or maybe a beta ? Would love to help If I can !
And FYI, in the 3-set of images you linked to, I would always go for the « other » choice. On a calibrated REC709 projo it does a very decent job on light tones and is much better in the dark tones than the current setting. No doubt.
6.1.6 is waiting for tvos 13 gm which hasn’t been released yet. potentially they are releasing it alongside ios 13.1, or maybe saving its release for October event…
Apparently, tvOS 13 is supposed to come at the end of the month, while iOS 13.1 is now supposed to be released on September 24th. God knows what bugs exist in iOS 13.0 that they had to reschedule the release of 13.1 a week early.
