Hopefully I’m hoping someone can weigh in on the workflow I’ve posted below. I’m trying to learn about colorspace and bit-depth and how they interact between my device and display so feel free to poke holes in it. I’m using an Apple TV4K and an LG C7. I try to avoid any “artificial” enhancement of data, meaning adding data (on the device) that is not present in the source file. I’m using 60Hz for everything because it runs the UI smoothly, and I can reverse the present 3:2 pulldown to 24Hz accurately using Real Cinema controls.
Firstly, my understanding is that a typical SDR file is delivered to the content provider at 4:2:0 colorspace, 8-bit color depth. A typical HDR file is delivered to the content provider at 4:2:0 colorspace, 10-bit color depth.
My Apple TV 4K allows me to pick 1080p SDR@60Hz, YCbCr 4:4:4 for SDR content, and this format would probably be my first inclination since the resolution isn’t being upscaled right off the bat. However, the colorspace is being upsampled and my C7 apparently cannot “properly” display a 4:4:4 signal outside of PC mode anyway (I haven’t been able to find out exactly what goes wrong here), and this mode locks the refresh rate at 60Hz, which I won’t choose because I don’t enjoy the look of 3:2 pulldown. That brings me to my next option for SDR: 4K SDR@60Hz, YCbCR 4:2:0. This seems to be the best option for my setup, since I can choose the native colorspace of 4:2:0 which my display has no issues with, and it should still be an 8-bit file, so no device-added data.
As far as HDR goes, I can choose 4K HDR@60Hz, YCbCr 4:2:0 or 4:2:2. I believe 4:2:0 to be the correct colorspace here since the file is encoded as such and this format is going to give me a 10-bit color depth.
Next up would be Dolby Vision which I have no choices for (though I believe it’s a 4:2:0 12-bit file)?.
Is there ever a reason, as far as source bit-depth fidelity goes, to choose a 24Hz refresh rate? I’m in the process of testing some chroma patterns on my set to get the best result - just looking for some insight about my thought process and understanding of these topics.
Apple TV 4K