2018-04-21, 12:27
This issue is still present in the latest nightly 04/21 . I could narrow the prolem down to the Setting "Allow hardware acclereation - MediaCodec (Surface)" . When this setting is enabled, HDR 4k content shows with grey bars, when disabled, the bars are full black but the video files are stuttering with ~1fps.
I will roll back to Nightly 02/20 again.
I will roll back to Nightly 02/20 again.