1. No user installed addons are supported, python or otherwise.
2. No, they really are not supported.
3. They are not coming back
4. Read from 1. again

Any mention of illegal streaming sites, addons or any pirated material will not be tolerated. This is not democracy and any offenders will be banned and posts deleted immediately without warning.

Other than that, we hope you enjoy MrMC so far and we welcome any input and feedback you might have.

Team MrMC.

Incorrect HDR Tone Metadata

Any issues that are tvOS specific
-wyld-
Posts: 16
Joined: 04 Jun 2019, 00:41

Incorrect HDR Tone Metadata

Post by -wyld- » 04 Jun 2019, 02:45

MrMC always sends Max CLL = 4000 nits and Max FALL 1000 nits. Where are these numbers coming from? It causes my JVC RS1000 to crank down the picture tone as it expects the content to have a much greater brightness than it does. I believe this might be a contributing factor in why many are complaining that MrMC does not handle HDR correctly on Apple TV and why the picture is too dark and washed out. Can the app either send the proper Metadata from the content (ideal! Other apps like Netflix and Amazon do this correctly) or not send the metadata at all so that it defaults to "---/---" which will leave the picture tone at default values instead of reducing them for the scene improperly (in MrMC case, the scene = entire movie since it never changes).

User avatar
davilla
Team MrMC
Posts: 4078
Joined: 26 Oct 2015, 17:01

Re: Incorrect HDR Tone Metadata

Post by davilla » 04 Jun 2019, 12:35

-wyld- wrote:
04 Jun 2019, 02:45
MrMC always sends Max CLL = 4000 nits and Max FALL 1000 nits. Where are these numbers coming from? It causes my JVC RS1000 to crank down the picture tone as it expects the content to have a much greater brightness than it does. I believe this might be a contributing factor in why many are complaining that MrMC does not handle HDR correctly on Apple TV and why the picture is too dark and washed out. Can the app either send the proper Metadata from the content (ideal! Other apps like Netflix and Amazon do this correctly) or not send the metadata at all so that it defaults to "---/---" which will leave the picture tone at default values instead of reducing them for the scene improperly (in MrMC case, the scene = entire movie since it never changes).
The AppleTV4/4K sends a fixed value for Max CLL/FALL. tvOS does this, nothing we can do about it.

-wyld-
Posts: 16
Joined: 04 Jun 2019, 00:41

Re: Incorrect HDR Tone Metadata

Post by -wyld- » 04 Jun 2019, 14:51

But this is not true for other apps. Why is it only MrMC that does this? The base Apply TV UI, Amazon, Netflix all send different values.

User avatar
davilla
Team MrMC
Posts: 4078
Joined: 26 Oct 2015, 17:01

Re: Incorrect HDR Tone Metadata

Post by davilla » 04 Jun 2019, 16:20

-wyld- wrote:
04 Jun 2019, 14:51
But this is not true for other apps. Why is it only MrMC that does this? The base Apply TV UI, Amazon, Netflix all send different values.
Because they are using private APIs that are not available to 'normal' apps.

-wyld-
Posts: 16
Joined: 04 Jun 2019, 00:41

Re: Incorrect HDR Tone Metadata

Post by -wyld- » 04 Jun 2019, 22:39

This doesn't make sense that only MrMC sends 4000/1000. I don't know what you mean by "normal app" but setting base Apple TV to 4k HDR and then launching Channels DVR sends 250/100 which results in much brighter / appropriate Gamma. Only MrMC is sending 4000/1000 which results in cranking down the gamma. I believe this is contributing to poor HDR performance of MrMC.

For example, Vudu does not seem to do dynamic Max CLL/Max FALL like Amazon and Netflix do but launching the UDX version of Coco from Vudu switches to HDR and sends Max CLL/Max FALL of 250/100 just like the other default AppleTV UI settings. I believe the defaults you are referring to are 250/100 which would be much more appropriate for most media. Only MrMC seems to be sending 4000/1000.

User avatar
davilla
Team MrMC
Posts: 4078
Joined: 26 Oct 2015, 17:01

Re: Incorrect HDR Tone Metadata

Post by davilla » 05 Jun 2019, 00:39

It's well known that tvOS uses a fixed value when decoding using avplayer. That's the only API that is public and can handle HDR. AVFoundation decoder (in MrMC) uses avpayer API's.

If Apple's native app, Amazon and Netflix are sending values that come from the media, then they are using private API's. That means they a special relationship with Apple that goes beyond the normal app developer relations.

And use of private API is forbidden (and checked) when submitting Apps into the Apple store.

I assume you are using something like the HDFury for checking.

-wyld-
Posts: 16
Joined: 04 Jun 2019, 00:41

Re: Incorrect HDR Tone Metadata

Post by -wyld- » 05 Jun 2019, 02:27

It seems that Vudu is not using data coming from the media, yet uses the same defaults as the ATV UI. It triggers HDR mode though, so I do not know if they are special like you say. I don't understand the private API concept but possibly I am a naive android user struggling with my first instance of the apple "Walled garden" everyone talks about. Many AV forums suggest AppleTV is best media player for 4k/HDR with frame rate and color space matching but it seems very limited to me.

I have looked through the documentation but cannot find if AVFoundation has the ability to adjust Picture Tone/Gamma of the output before sending up? If this could be implemented similar to how SDR media has brightness/contrast then at least I could compensate at the MrMC level for the poor tone mapping metadata being sent by the ATV OS. If you have any other suggestions for comparison apps or data sources I am willing to test them.

I am using JVC RS1000 which shows HDMI HDR tone metadata via the info UI.

User avatar
davilla
Team MrMC
Posts: 4078
Joined: 26 Oct 2015, 17:01

Re: Incorrect HDR Tone Metadata

Post by davilla » 05 Jun 2019, 13:29

-wyld- wrote:
05 Jun 2019, 02:27
It seems that Vudu is not using data coming from the media, yet uses the same defaults as the ATV UI. It triggers HDR mode though, so I do not know if they are special like you say. I don't understand the private API concept but possibly I am a naive android user struggling with my first instance of the apple "Walled garden" everyone talks about. Many AV forums suggest AppleTV is best media player for 4k/HDR with frame rate and color space matching but it seems very limited to me.

I have looked through the documentation but cannot find if AVFoundation has the ability to adjust Picture Tone/Gamma of the output before sending up? If this could be implemented similar to how SDR media has brightness/contrast then at least I could compensate at the MrMC level for the poor tone mapping metadata being sent by the ATV OS. If you have any other suggestions for comparison apps or data sources I am willing to test them.

I am using JVC RS1000 which shows HDMI HDR tone metadata via the info UI.
A private API is just that, private. You have to play coder games to get to the function as it's not listed in the available public file includes. tvOS is obj-c. There are a few ways to "hook" a private API. You can do the same thing under android with java. But Google cares less about private API usage.

With Apple, private API can and will change between os versions. They don't want apps to break between os versions so they ban the use of them. There are ways to hide the usage from normal detection methods but get caught using them and risk getting the app submission rejected or getting tossed out iTunes Store. It's actually a good policy, cuts down malicious apps and bad app misbehavior. Like I mentioned above, Google would care less as android is just a monetizing vehicle for them.

AVFoundation itself does not have a method to adjust picture tone/gamma. It's not it's job :) That falls to the renderer stage. With videoToolBox decoder, we are rendering in GLES where we do have control. HDR rendering completely bypasses the GLES renderer. To get control, MrMC would have to move to 'metal' rendering which is non-trivial but planned to happen at some time. No ETA.

-wyld-
Posts: 16
Joined: 04 Jun 2019, 00:41

Re: Incorrect HDR Tone Metadata

Post by -wyld- » 05 Jun 2019, 15:32

davilla wrote:
05 Jun 2019, 13:29
To get control, MrMC would have to move to 'metal' rendering which is non-trivial but planned to happen at some time. No ETA.
Thank you very much for the detailed explanation. I believe tweaking the brightness and contrast and then setting that as default for all media has resolved my SDR quality issue. If moving to metal rendering could give control over the tone in a similar manner, I believe it could resolve the HDR quality and make MrMC and Apple TV a complete media solution. I understand the move is non-trivial and I also understand to never ask for ETAs. Is there a feature voting forum though that I could cast my vote or possibly donate $ towards supporting such a feature? Like how bounties are handled in Android development...

User avatar
davilla
Team MrMC
Posts: 4078
Joined: 26 Oct 2015, 17:01

Re: Incorrect HDR Tone Metadata

Post by davilla » 05 Jun 2019, 19:39

-wyld- wrote:
05 Jun 2019, 15:32
davilla wrote:
05 Jun 2019, 13:29
To get control, MrMC would have to move to 'metal' rendering which is non-trivial but planned to happen at some time. No ETA.
Thank you very much for the detailed explanation. I believe tweaking the brightness and contrast and then setting that as default for all media has resolved my SDR quality issue. If moving to metal rendering could give control over the tone in a similar manner, I believe it could resolve the HDR quality and make MrMC and Apple TV a complete media solution. I understand the move is non-trivial and I also understand to never ask for ETAs. Is there a feature voting forum though that I could cast my vote or possibly donate $ towards supporting such a feature? Like how bounties are handled in Android development...
We don't do donations or bounties. You bought the app once, that's enough.
We also don't have feature voting via forums. We have our own agenda but do read each and every thread. If it's something several users want, it might get added to the list.

Post Reply