If you just don’t like ads AppleTV works great.

That said if you’re set on something less locked down you might look into Dune-HD boxes. They have some that have a dual OS. One is Android TV (not sure how mod-able) the other is Linux that can have other kinds of apps. They’re virtualized and accessible without a reboot. They have great codec support. Just realize only some of their models have the Android TV dual system thing.

As far as I can tell there are two separate worlds, with close to no overlap.

On the one hand the mainstream stuff, proprietary, DRM compatibile, interner dependet, non moddable, no privacy, no way to own your content, tracking you from asshole to appetite, often ad-infested.

Best you can hope for is some Android TV streaming box, but the moment you start to do stuff like root it or unlock the bootloader some streaming apps might decide to stop working, or degrade your quality. DRM-protected streaming services will completely refuse streaming high-quality content to any hardware you really control.

On the other you have self-hosted, often open source, tweakable, local, customisable, technology, compatible with all codecs you want, but functionally blocked from DRM. There is essentially no way to legally acquire video content for the second one. You could get a libredrive compatible BD reader and rip your own movies, but that’s still illegal in many countries, certainly the US, and is a ton of work.

If you have sufficiently powerful hardware, you might be able to stream low-bitrate 720p with software decoding. They won’t serve you better stuff. Anything better than that, you should consider it accidental and likely to stop soon.

I believe the Apple TV to be (still) quite decent in that respect, but judging from the post that’s not an option?

Personally I just run a ThinkCentre mini pc with Fedora. Bluetooth keyboard/trackpad; Sorted. Not as convenient as a remote but don’t need to fiddle with stuff.

You can get them cheap used on eBay

Following on this, I’d like some sort of dongle capable of running Lineage OS. I only need it to run Jellyfin and some other fdroid apps. Any suggestions?

ugoos box with coreelec. I use the am6b+. Only format it can’t play is av1

stock runs a stripped down version of android with 0 ads that is very barebones so if you just want streaming apps this is for you. I use this part for my IPTV client but basically any streaming app available on the play store or that can be side loaded with an apk works

You can also flash coreelec and run kodi natively. You can just use the android build of kodi but using the coreelec build has many advantages; it can boot directly to kodi, it’s much snappier within the ui, and most importantly there are far less (basically no) issues with content playback. This option can basically play any file you throw at it natively. You can also set it up to stream files from a pc/nas with jellyfin/plex/emby but this is really the setup for weirdos like me that refuse to subscribe to streaming services (aside from an iptv provider).

Notably the ugoos is the only device, currently, that is licensed to playback Dolby vision content and actually does so properly.

Literally every other option, amazon stuff, shield, chromecast, appletv, pc directly connected to tv, the internal players of TVs, etc don’t play back Dolby vision content correctly in some way. Either they fail at playing certain profiles, they have issues with color accuracy, they flicker, etc. obviously this depends on your setup though, if you have a Samsung dv is meaningless unless you plan to get an oled at some point. That said even if dv is pointless for you it still does hdr/hdr10+ and all the lossless audio stuff/audio pass through

If Dolby vision and av1 are important to you the coreelec team have extended their work to other devices that have av1 support. Do research though because not all of them are fully supported, like some you need a usb Ethernet/wifi adapter which is dumb

Downsides are that it’s tough to set up, like you should be a tinker type person. This is a bit more of a pain than an apple tv or a shield. Also it’s not the easiest thing to get support

But if you’re like me and you’re super paranoid about streaming services harvesting your watch data and selling it, plus super frustrated that they continually fragment and want yet another $17 to access another library that you only want 3 shows of while increasing prices every year and still shoving an excessive amount of advertising in despite having you pay for the service, I would highly recommend just pirating media and using kodi/jellyfin to locally stream.

As an added bonus you get a noticeably higher image quality if you download stuff sourced from physical media because most (tbf not all) streaming networks have shit quality, much less likely to have issues with buffering or the stream dropping from 4k to 480p because the bandwidth wasn’t there for 4 seconds, often can get much better subtitles that are timed and syncd (and in the case of anime like animated and shit), etc. plus no ads, ever, no data harvesting (disconnect your tv from the internet so it doesn’t use brightness patterns and power usage to determine what you’re watching!), no corporate censorship (my collection has Daria with the original music and not the “soundalikes” because mtv couldn’t be bothered to relicense the music. It also has all the blackface episodes of various shows like community and it’s always sunny because I can decide whether something is offensive or satire for myself without netflix or disney to act as a nanny)

Depends on what you want to watch. Streaming services do limit DRM content even if you’re on a windows machine and using HDMI. If your sailing the seas then there should be no problem with the raspberry pi. You could install a container with Jellyfin or plex and Tailscale and access it from wherever you want

I’d say put your RPi4 in a Flirc passive case and use Kodi via LibreElec.

The Argon One connects the fan control in a funky way so your OS must have some way to configure the fan controller. I know Batocera v41 has Kodi 21 built in and their wiki says how to get an ArgonOne working properly. You can then have it set to boot into Kodi and have retro emulation as a secondary option.