The second generation Fire TV has been out for over a month now, yet there haven’t been any 4K capable video apps other than the ones from big names like Netflix. Amazon’s Media Specifications page for developers lists the Fire TV platform as only being capable of “up to 1080p” with no mention of 2160p (4K) capabilities or the newer h.265 codec used by the 2nd-gen Fire TV. I inquired about 4K playback on Amazon’s developer forum and was told that “at this time, 2160p output is not available to developers on the 2nd-gen Fire TV” by an Amazon representative.
It appears an app needs special consideration and/or approval from Amazon to initiate 4K video playback. It’s not clear what it takes for an app to be allowed 4K playback, like with the Netflix app, but an average developer cannot simply create an app that takes a 4K video file or stream and play it back at full resolution on the new Fire TV. This means it’s unlikely for media player apps like VLC or Kodi to be able to play local 4K video files until this policy changes. It may be possible for unofficial apps that require sideloading, like Kodi, to reverse engineer the Fire TVs 4K playback capabilities and support the feature. Official apps in the Fire TV appstore, however, have an extra hurdle to overcome if they want to be granted 4K video playback privileges.
The decision to limit 4K video on the Fire TV to approved partners is likely related to the new Fire TV’s need to switch the device’s output resolution from 1080p to 2160p before playing 4K video, and then back again once video playback has ended. The Fire TV’s processor is not capable of displaying its user interface or apps at 4K resolutions, so that output must be reserved for specific h.265 encoded video only. Amazon may not be ready to give all developers the ability to switch the Fire TV’s output resolution at will.
With 4K video still being a relatively new advancement, and 4K video sources being far and few between, there are bound to be hiccups and limitations for early adopters. For the time being, 4K video playback on the 2nd-gen Fire TV will likely be limited to big names like Netflix who can work closer with Amazon’s Fire TV team than most developers.