2160p and 1080p bitrate difference

[iKron]

it's just for educational purpose. lets say if a 1080p Bluray bitrate is 10mb/sec what should be a 2160p bluray bitrate.

1. consider both are using x264.
2. 1080p x264 and 2160p x265. i don't know if we can compare x264 and x265 but just an estimate idea if you have experience about compare the video quality.

[Selur]

my 2cents of thoughts,...

Assuming you have questions, phrase them as such.

regarding 1.: I considered it and don't get it. UHD Blu-ray can't use H.264.
1080p Blu-ray usually uses 8bit calculation precision and AVC.
2160p UHD Blu-ray usually uses 10bit calculation precision and HEVC
If you want to produce a (UHD) Blu-ray you are restricted by the (UHD) Blu-ray standard and can't use some advanced encoding options.
So encoding to UHD Blu-ray with x264 isn't really an option.

regarding 2.: We compare what we want, whether it makes sense depends on the goal we have.

General speaking, just about resolution and using the same encoder:
Roughly speaking if you double the resolution you usually require ~75% more bitrate when using the same encoding method.
Since you quatruple the bit rate increasing the bit rate by 150% to get the same detail preservance level is what I would expect.
So if you used 10 000 kBit/s for 1080p, I would expect 25 000 kBit/s for 2160p.

You are not asking about detail preservance, but about video quality and give no hint to what that means for you.

Cu Selur

[jagabo]

Why don't you just use CRF encoding? Then you'll always get the right bitrate for the quality you want.