Hi, can someone tell me whether the current Apple TV 4K (1080p SDR Blu-rays encoded in x264 10-bit) is decoded/played back via hardware (GPU) or software?
Yes, it is supported via hardware decoding.
SDR video with AVC/HEVC (Main/Main 10 profile) up to 2160p, 60 fps
This has been true for all versions of the Apple TV 4K:
That doesn’t mention 8bit vs 10bit though
Yes it does. Main 10 is the profile that supports up to 10-bit per channel. That’s why there’s a 10 in the profile name. That’s the explicit difference between Main profile and Main 10 profile.
Thank you for the information. Unfortunately, I can only encode x264 using the High10 profile, and some videos with higher bitrates stutter. That’s a shame.