Apple TV 4K HDR to SDR Tone Mapping Issue

Hello all, was watching The Batman yesterday and noticed every 20ish seconds the video would freeze for about 1-3 seconds while the audio kept going. I have observed this behaviour in the past with other movies but always chalked it up to the fact I was using a networked HDD connected to my router to watch movies and that might be the bottleneck. After looking into deeper I only have this issue with HDR movies and SDR ones play just fine. My set up doesn’t support HDR so the Apple TV 4K does tone mapping to convert the HDR video to SDR. To confirm this suspicion, I played the same movie with all the same AV specs expect its an SDR version, and it played without a hitch. I believe this may be a bug or I may be overworking my Apple TV by having it play a large 4k file while also tone mapping.

My set up is as follows: Segate 4tb USB 3.0 HDD connected to a Asus Rt-Ac3100 - FTP - Wired Apple TV 4K. The file I am playing is a 4k H.265 Dolby Atmos 5.1 MKV HDR file.

Apple TV 4K running Infuse Pro 7.3.10
Streaming Cache Auto
Speedtest to Networked Drive is ~500Mbps

Welcome to the forum!

First what version number of Infuse are you using and under the Settings, what do you have set for the Streaming Cache?

Ha yes forgot to include that info I am running Infuse Pro 7.3.10 and stream cache is set to auto

Just to confirm this is infuse Speedtest? And can you test on both SDR and HDR files?

Yes this is a Speedtest through the infuse app and both HDR and SDR files have about the same speeds give or take 20-30Mbps

Could you run the speed test on the hdr version and let it run for at least half the movie? It should be pretty fast since it’s not real time, then click over to the graph and post a screen cap of that. Looking for a dip to match the stalls.

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Will do, will post results in about 1.5 hours.

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Here are the results


Just to verify, you’re TV can’t do HDR? If this is correct and you have the time, try this.

As a test, on the ATV settings, go to Video and Audio, Match Content, turn off Match Dynamic Range. You probably have the verified format of 2160p SDR so leave that.

Yes that is correct my projector doesn’t support HDR.

I already have match dynamic range set to off and have match frame rate set to on.

Do you by any chance have a Mac?

Yeaup 2 and both have Infuse on them

Do you know how to use QuickTime Player to view your ATV?

Do you mean play the file on QuickTime off my Mac and AirPlay go to my ATV?

No, you can actually use QTP to view the output of your ATV.

What I’m wondering is if the projector may be causing the freezes for some reason. If you can look at the output of the atv on your mac then you can check if you see the freezes there. It’s pretty simple as long as their all on the same network. Got time to try it?

I will have time in about 45 mins. In the meantime I will see if I can figure out how to do that myself. Otherwise I’ll ping you!

Edit: think this link may be what I need to do, basically screen record?

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Just start the ATV, then launch QTP, go to File, new movie and when you get the selfie view on the mac and the floating record button on the screen the little down arrow next to the record button, click that and you should get a pull down menu that lists your ATV. Select that and you should get a feed from the ATV.

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yup, that 's it. :wink:

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Yeaup still freezes when viewing the ATV off my Mac

So did some more testing, this time played the HDR file on my iPhone which has an HDR display. Still freezes interestingly… maybe this isn’t a tone mapping issue then after all