HDR too dark on TV

Ugh that sucks… I may just continue to use the Vero for 1080p Blu-rays, and find something else for UHDs. At least for the timing being I’m using the Apple TV 4K for UHDs via Plex Direct Play.

This is way too big of an issue to leave not addressed, though, so I expect Sam will do some of his wizardry-figuring-out-of-things to fix it. You’d think that since it appears it’s ONLY the Vero with this specific UHD issue that it would be “simple” to figure out, right?

Nothing is simple when you have two or maybe three devices sniffing around each other like dogs trying figure out what each is capable of and which is responsible for doing translations.

I’m no programmer, but when one device out of zillions is behaving completely differently to those others, it FEELS like it should be something of an, “OOPS!” moment, and not something crazily hard to find.

Of course, it might be literally the opposite of that. In which case, I present my sad face. :smiley:

:sob:

I must say that this topic is starting to make me paranoid. I orderd the vero 4k+ specifically to play uhd & uhd hdr remuxes on my new lg oled c8 and from what I read here it’s having problems doing that very thing :frowning:

We’ll work it out. This issue was only reported less than a week ago though, so it might need a small bit of time to resolve it.

HDR content is generally well tolerated on Vero 4K +. There will always be corner cases; so we will work on those.

Sam

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With the Coco sample provided, Vero 4K is outputting incorrect mastering display metadata. Instead of 1000/0.000 nits, the output metadata is 5000/0.005 nits. It’s correct on the Shield (haven’t checked any other device). I’m not sure what is triggering this because I wasn’t able to reproduce this with other clips even when I change the metadata similar to the Coco one (P3, D65, 1000/0.000 nits, no maxCLL/maxFALL).

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Well that’s interesting…

I will add some pr_info messages to amcsc later to see if we can work out where in the chain this is happening.

Sam

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I mean, that “Enable HDR Autoswitch”-option only works like 30% of the time for me. In most cases I have to restart the movie at least 3 times until it actually switches to 10bit. Sometimes even five times. In some rare cases (seems movie dependent) even trying it 10 times and a fresh restart doesn’t work, so I have to SSH into the Vero 4k and do the echo 444-thingy. Kinda annoying to be honest that this is still an issue.

You can just enable it permanently for now unless you keep swapping between SDR and HDR displays. I think this is what most people do.

There will be a build with improved HDR autoswitching shortly.

I further checked the Coco clip on two other Amlogic S905X devices (LE nightly on a M8S Pro+ and Mi Box 3 Android Oreo). The output metadata was correct on both the devices. I also noticed that I could simply overwrite the SEI messages for this clip in the commercial program that I use to edit SEI and the new clip would play with correct metadata. This makes me wonder whether there is something odd with SEI message parsing on Vero 4K (? HDR autoswitching code).

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That’s useful to know. I’ll check latest 3.14 drop from AML for any core changes. It may just be that simple; although I understand that LE’s current 3.14 kernel has some regressions re. HDR.

If it’s OK on Android it suggests that we’re lacking something, rather than having broken something.

Sam

Mi Box 3 has 4.9.54 kernel, but LE is 3.14. So, if it works fine on LE, it may be something that can be fixed easily.

Great detective work. I wish I were more understanding of this sort of metadata so I could contribute. I feel like all I’ve been successful in doing is yelling, “FIX IT!!” :smile:

4.9 seems to be the minimum mandated kernel version by Google for Android TV.
We are considering a move to 4.9 in the interim before mainline is ready as it is still maintained by AML.

We’re looking in to this further.

Cheers

Sam

Cheers, Sam, for being on top of this. It’s a good thing these issues only affect movies I want to watch, lol.

OK, you are right, it is simple in a way. For some reason Vero is not reading the master display data in your clip but is able to read it in all the other clips which have that same meta.

Also, as @wesk05 has spotted, the default max luminance in Vero is 5,000nits. So, either those other devices can read the mastering display data which vero can’t or their default max luminance is closer to the one on the original BD.

We can change that default to 1000. Coco should then play OK. But other rips with different max lumi will be too bright or dark if their master display data cannot be read.

The not so simple bit is finding out why your clip and vero don’t get along.

I’ll build a kernel with these changes shortly.

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Retail Ultra HD Blu-ray titles are mastered either on the Dolby Pulsar or the Sony X300. The max. luminance can be 4000 or 1000 nits depending on the grading monitor used. I haven’t been able to figure out why Vero 4K is changing it to 5000 nits for this particular clip and possibly for the few others that have this luminance problem.

IIRC it’s only Disney titles that have the issue. Steps back for hail of objections