I stream 4K MKVs from my phone (an iPhone) to my Apple TV 4K using AirPlay all the time. It used to be a challenge getting the codecs right, but there's broader support now. It took awhile to find a good iOS app that supports this, but once I found nPlayer[0] I've never gone back. It's faarrr better than the VLC iOS app.

It works quite well even when my phone is streaming media that's on cloud storage somewhere (nPlayer supports many). But for optimal playback I download the file to my device first.

Of course if you want Dolby Atmos sound, I think you're out of luck. I think HDR should work but not sure.

[0] https://apps.apple.com/us/app/nplayer-plus/id539397400#?plat...

edit: You can also install app on the ATV that accesses files stored over the network/internet as well, like VLC for ATV. Though I've never found a great one.

App to access files over the network. I think Infuse is pretty good. It supports NAS and if your files are well named then pulls in meta/artwork. Can also be a front-end for Ember/Jellyfin/Plex, but for my LAN media I’m currently going with DLNA.

Infuse is fantastic!

Fun fact, Dolby Atmos support is very much pushed now, not sure how long it has been like this but it says it on the box so perhaps a software update?

I did not realize this was an option, thank you for your comment

So what exactly is the system? You transfer the MKVs to your phone via a cable somehow? Is there any quality hit?

I use nPlayer to access my files over the network/sftp/Dropbox/WebDAV/put.io/HTTP and download to my local device. But like I said, streaming directly from the network works too. But for a high bitrate 4k file downloading first is better since the server=>phone=>ATV transfer can be too slow. (Resolution doesn’t matter, it’s all about bitrate. Some 4k HEVCs are lower bitrate/smaller files than 1080p h264s)

Having an excellent with Infuse and macOS inbuilt SMB!

You can get VLC on Apple TV which makes streaming most things on the LAN simple enough but yeah, just using the USB port on the TV would probably work for that use case. The UI is miles better on the Apple TV and the remotes are very good, but you do need to create/use an Apple account in order to download things (like Netflix, YouTube, Amazon Prime etc.) from the App Store.

Not sure about the Plex flack here, 4k is fine if not transcoded and sits happily in its own library.

I own both, and the Roku is slow, buggy and has really horrible UX. It doesn't get used at all.

>streaming 4K MKVs over the network

Isn't that covered by your airplay requirement?

I couldn't work out how to do this. I usually just use IINA and an HDMI cable but it's non-ideal - I figured it would require re-encoding or something and sucking on quality.

If you have a solution I'm all ears!

I use Airflow to stream 1080 to a chromecast from my MacBook . Works flawlessly with a simple UI.

My understanding is that it supports 4k and a range of streaming devices but I can’t say if it handles it flawlessly because I don’t have hardware to try it.