Atrium — a native tvOS app for your Emby server

[vdatanet 1657]

Hi all,

I've been building Atrium, a native tvOS app for home media servers, and as of version 1.2 it
works with Emby. It's on the App Store, it's free, and it stays free: no in-app purchases, no
subscription, no ads, no tracking, and no Atrium account — you point it at your own server, sign in
with your own user, and that's it. (It speaks to Jellyfin servers too; the app doesn't ask you
which, it works it out when you connect.)

--- With Emby, HDR video is tone-mapped to SDR ---

Here is why, as precisely as I can put it.

On Apple platforms the player decides the display mode from the multivariant playlist *before* it
downloads a single segment. It reads the attributes on #EXT-X-STREAM-INF — VIDEO-RANGE, CODECS —
to work out what the stream is and to configure the display. Emby's transcoding manifest currently
carries neither, so tvOS has nothing to act on and never switches the TV into HDR mode.

But an app can't use that. If it just plays the stream, the display stays in SDR, and PQ content
shown on an SDR display looks washed out — worse than not trying. So Atrium does the honest thing
instead: it tells the server it accepts SDR, the server tone-maps, and what you see is correct.
Less than the file holds, but right.

One thing that makes this cheaper than it sounds: the transcode currently comes out 8-bit
(yuv420p) even when the command line asks for main10, and PQ at 8 bits bands visibly. So what is
actually being given up is smaller than "no HDR" makes it sound.

--- What would change it ---

Populating VIDEO-RANGE and CODECS on #EXT-X-STREAM-INF (and SUPPLEMENTAL-CODECS where Dolby Vision
applies), reflecting what the stream really is. That's the whole ask — it isn't a change to what
the transcoder produces, only to how it's described.

On my side the HDR path is already written and shipping; asking for HDR again instead of SDR is a
one-line change and a release. I'd be glad to test any build against a 4K HDR/DV library and report
back with player-side measurements: which variant is chosen, what the player reports the range as,
and whether the display actually switches.

--- Everything else ---

Libraries, search, Continue Watching, the Apple TV top shelf, subtitles through the native tvOS
picker, music with a proper queue. If something doesn't work the way you expect, I'd genuinely
like to hear about it — this is the first release Emby users have had their hands on, and you'll
find things I can't.

https://apps.apple.com/app/atrium-media-player/id6777638751