I am using the Sony Android TV Amazon Prime Video APK on my NVidia Shield.
It works great, but from a bit of testing, nothing plays beyond 1080p resolution.
My TV is 4K capable, my internet is 250Mbit, and we know the Shield is 4K capable.
I tried testing it with The Grand Tour, but it won't go higher than 1080p.
Is this a limitation of the app?
If so I really hope we see real Amazon Prime Video Android TV support in the future.
im a developer, and one of my apps is android TV. a lot of the issues with 4k support have nothing to do with the devices. there is a huge web of studios demands and DRM support of the whole hardware chain, that have to be worked out. android tv definitely supports 4k and HDR etc, but a lot of content owners have much more difficult requirements to allow their content to be shown in 4k/hdr