In my android tv device, Screen Resolution is displayed as 1920 x 1080.
In fact, our screen resolution is 4K, but the OSD is displayed by 1080P, playing video can reach 4K resolution.
You may get the resolution by DisplayMetrics, but this method has some limitations. You can refer to Google's solution(get the real resolution by read sys.display-size/vendor.display-size)：
Link is :https://github.com/google/ExoPlayer/blob/release-v2/library/core/src/main/java/com/google/android/exoplayer2/util/Util.java#L1836
For reference only, thank you！