14 posts / 0 new / Last post
#1  July 15, 2018 - 12:04pm
Ashkaan's picture
Offline
Joined: Dec 2017
Posts: 28
Kudos: 2

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.

      July 16, 2018 - 2:42pm
    james's picture
    Staff
    Offline
    Joined: Jun 2008
    Posts: 13,681
    Kudos: 1,130

    Good question!

    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.

    Infuse 6 for iOS and Apple TV is now available!

      July 16, 2018 - 2:45pm
    Ashkaan's picture
    Offline
    Joined: Dec 2017
    Posts: 28
    Kudos: 2

    Is there no way to allow users to adjust these things in options (with a button to reset back to FireCore Preferred)?

      July 16, 2018 - 2:47pm
    james's picture
    Staff
    Offline
    Joined: Jun 2008
    Posts: 13,681
    Kudos: 1,130

    Not at this time. Sorry.

    Infuse 6 for iOS and Apple TV is now available!

      July 21, 2018 - 5:21am
    Feahnor's picture
    Beta Tester
    Offline
    Joined: Apr 2018
    Posts: 15
    Kudos: 2

    I think this is necessary. I have films I can't watch in my calibrated non-HDR tv because they are are almost black, like Harry Potter 1.

      May 17, 2019 - 7:16am
    Feahnor's picture
    Beta Tester
    Offline
    Joined: Apr 2018
    Posts: 15
    Kudos: 2

    Any updates to this? Last weekend I tried watching my HDR Aquaman rip and it was very dark compared to the SDR version.

      May 17, 2019 - 7:30am
    Ashkaan's picture
    Offline
    Joined: Dec 2017
    Posts: 28
    Kudos: 2

    Sadly, I had to go back to the Plex app (latest beta). It does a slightly better (still not great) job of HDR tone mapping than Infuse.

      May 17, 2019 - 12:42pm
    james's picture
    Staff
    Offline
    Joined: Jun 2008
    Posts: 13,681
    Kudos: 1,130

    We made a number of changes towards the end of last year in the 5.8.1 update (https://firecore.com/releases). 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.

    Infuse 6 for iOS and Apple TV is now available!

      May 17, 2019 - 12:50pm
    Ashkaan's picture
    Offline
    Joined: Dec 2017
    Posts: 28
    Kudos: 2

    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.

      May 20, 2019 - 11:42am
    james's picture
    Staff
    Offline
    Joined: Jun 2008
    Posts: 13,681
    Kudos: 1,130

    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 https://www.dropbox.com/sh/yxq3rrsqtp2hq47/AAD... 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.

    Infuse 6 for iOS and Apple TV is now available!

      May 20, 2019 - 2:40pm
    Ashkaan's picture
    Offline
    Joined: Dec 2017
    Posts: 28
    Kudos: 2

    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?

      August 29, 2019 - 10:27am
    james's picture
    Staff
    Offline
    Joined: Jun 2008
    Posts: 13,681
    Kudos: 1,130

    Quick update.

    We have another round of tone mapping improvements coming soon in 6.1.6. Smile

    Infuse 6 for iOS and Apple TV is now available!

      August 29, 2019 - 10:30am
    Ashkaan's picture
    Offline
    Joined: Dec 2017
    Posts: 28
    Kudos: 2

    Thank you!

    I promise that it's a worthy investment for the long term.

      August 29, 2019 - 1:45pm
    bl4ck's picture
    Offline
    Joined: Aug 2019
    Posts: 17
    Kudos: 1
      james wrote:

    Hello,
    I noticed problem with bad looking font in Infuse
    This is infuse vs plex:
    https://imgur.com/a/ckIKZCW