It's 4:2:0. Thank God somebody at DJI was smart enough NOT to overload this H.25 HEVC CODEC with double the chroma resolution (4:2:2) while still leaving it at 100Mbp/s. It's already bad enough that they added 40+ times more color space with 10bit and didn't even add ONE single megabit to cover that overhead. Yes, HEVC is more efficient, but DJI is only using MAIN profile, not HIGH profile. So, DJI's H.265 HEVC is only uses a fraction of the H.265 HEVC tool set. It's a "light" version of H.265 HEVC!
10bit, 4:2:0 at 150mbp/s would have been perfect.
CT