I am using Infuse on an Apple TV 4K 3rd gen, connected to an LG G5.
I was doing routine checks to confirm correct Dolby Vision RPU handling when I came across something… interesting.
On this test Dolby Vision video for example (played in Infuse from a network share), I noticed that the cyan color ramp is showing unexpected “dark blotches” that look somewhat like video compression artefacts (blocking) at the bright end of the ramp.
I tried to take a picture (4:00 into the test video), sorry it’s a bit hard to see due to my camera and the moiré pattern - in real life it looks much more obvious:
These artefacts are only visible on the middle cyan ramp. What makes this worrying is that these artefacts do not show up when playing the test file using the TV’s internal video player (from a USB stick connected to the TV), suggesting that they are not caused by the TV’s own response but rather something to do with the Infuse/ATV setup.
In both cases (Infuse/ATV and TV internal player), the LG G5 picture mode was set to Dolby Vision FILMMAKER mode with no other adjustments. All framerate/dynamic range matching options are enabled in the Apple TV settings.
I’m a bit surprised by this phenomenon, as my understanding is there should be zero difference between players when it comes to this stuff. I’m wondering if this could be some kind of HEVC decoder issue, or some kind of numerical precision loss somewhere in the pipeline?