[_Spook_]

From this article at Anandtech: http://www.anandtech.com/show/10610/inte...-january/3

"The Video Quality Engine also receives some tweaks for HDR and Wide Color Gamut (Rec.2020) support. Skylake's VQE brought in RAW image processing support with a 16-bit image pipeline for selected filters. While Intel has not discussed the exact updates that enable Rec.2020 support, we suspect that more components in the VQE can now handle higher bit-widths. Intel pointed out that the HDR capabilities involve usage of both the VQE and the EUs in the GPU. So, there is still scope for further hardware acceleration and lower power consumption in this particular use-case.

Intel claims that Kaby Lake-U/Y can handle up to eight 4Kp30 AVC and HEVC decodes simultaneously. HEVC decode support is rated at 4Kp60 up to 120 Mbps (especially helpful for premium content playback and Ultra HD Blu-ray). With Kaby Lake-U/Y's process improvements, even the 4.5W TDP Y-series processors can handle real-time HEVC 4Kp30 encode."

"One of the disappointing aspects from Skylake that has still not been addressed in Kaby Lake-U/Y is the absence of a native HDMI 2.0 port with HDCP 2.2 support. Intel has been advocating the addition of an LSPCon (Level Shifter - Protocol Converter) in the DP 1.2 path. This approach has been used in multiple motherboards and even SFF PCs like the Intel Skull Canyon NUC (NUC6i7KYK) and the ASRock Beebox-S series. Hopefully, future iterations of Kaby Lake (such as the desktop and high-performance mobile parts coming in January) address this issue to simplify BOM cost for system vendors.

In summary, Kaby Lake-U/Y resolves one of the major complaints we had about Skylake's media engine: the absence of hardware-accelerated 4Kp60 HEVC Main10 decode. There are a few other improvements under the hood that enable a more satisfying multimedia experience for consumers. The software and content-delivery ecosystems have plenty of catching up to do when it comes to taking full advantage of Kaby Lake-U/Y's media capabilities."

If that applies for Kaby Lake you know that it will be the same for Apollo Lake. So it does get HDR and REC.2020. But it will not be delivered via native HDMI 2.x. They have to use a seperate chip like in the NUC6i7KYK. That means that for linux systems they have to implement this in the i915 driver for the kernel to be able to get HDR or any other "fancy" features. At this point this seems to be something they might get into the 4.9 or 5.0 kernel it seems. But time will tell...

Kaby Lake has an updated video engine. Apollo lake don't have the same gpu. Both are gen9, but only kaby lake has those new features

No. If you look at the second table here:
http://www.anandtech.com/show/10635/inte...o-lake-soc

You see that Apollo Lake also has an updated video engine. It does not have HEVC Main10, but it does have HEVC.