Originally Posted by sspears
In a perfect world it would mean less. All of our sources today are 420. That needs to be converted to 422, 444 and then RGB. However, many ASICS work in 422, so if you send in RGB it may get converted back to YCbCr and even 422.
We talk about some of this in our choosing a color space article.
Using the LG as an example, even sending in 422 is greatly improved if you set the display to PC / 444 mode in terms of chroma resolution. Of course the bit depth is reduced in this mode, which is too bad. But while in this mode several options are disabled. I believe those options are all done in 422, which is why they get disabled.
Darn. I thought I was starting to understand this but it looks like I got it backwards...again. I'll start by saying this is a subject that for whatever reason, I have just had the hardest time getting my head around so please bear that in mind.
I know that sources are 420 so why is that not a good option to set the Apple TV to? If sources are 420 and you start with that, wouldn't that match up things 1:1 and thus make it...simpler?
I saw your post above replying to someone else and you had said given the choice between 420 or 444, 444 is the better choice.
I have an LG C8 and my only other source is a Panasonic UB820 and that also only gives me the choice of 420 or 444 and for that of course, I have it set to 444.
Interesting note about the Apple TV. (Mine is the 4K box, by the way.) I have mine set to SDR 4K with Match Range and Frame rate ON. In this mode, the only chroma options are 420 or 444. However, if I choose it to outupt 4K HDR, the chroma options become 422 or 420. I wont even pretend to know why this is. Would I be better off outputting the 4K signal at all times and choosing 422?
I had switch my Apple TV to default to SDR awhile ago due to an app I was using that did not flag itself to turn off HDR (since it wasn't an HDR app.) I no longer use that app but had decided to keep the ATV in 4K SDR since I just don't need my Apple TV menus in 4K all the time and that I was better off leaving it in SDR and having HDR kick on when it needs to via automatic detection. Figured it was better wear and tear on my C8 as well. I wouldn't be opposed to switching it back to HDR 4K if 422 is a better chroma setting to use.
An interesting thought I just had. Since the apple TV offers different chroma options depending on whether you have it set to SDR or HDR, what happens when you use content that switches the Dynamic range fom say SDR to HDR or even HDR to SDR? If you had chosen your chroma as 444, in SDR mode, when HDR content kicks in does it stay at 444 or switch to something else? When I have my ATV set to 4K SDR 420 and watch something in Dolby Vision isn't DV 10 bits? But 420 is 8 correct?
What is ASICS by the way? (Besides a shoe of course.) Haha.