A stubborn intent to render yuv444 10bit video

[Amadian]

Hi guys. I decided to try a project of my own after watching you work on the amazing things here. For a long time, I have the idea to collect all deleted scenes for a particular movie + use the comics that are happening during the plot of the movie, to animate them (crude but effective for me), and create an uber extended version that probably only I can appreciate...

'Started with the Star Wars Episode I, a guilty pleasure of mine.

Anyway, it's going to end up being a 5h+ long video, so I'm doing it in chunks, and then I will merge it all at the end.

It goes as expected atm, and I have done AI upscaling, editing, colour correcting and all that jazz, and exported 1st section as TIFF RGB 16bit colour sequence. Time to render it to H265 with Nvenc.

I can do yuv420 SDR 10bit 4K without any issue, cranking the bitrate around 100mbps and it's fine. It's a standard so I know I don't have to use more.

The thing is, that I am noticing a slight difference in colour and yuv444 video looks better to me (placebo or not), and my ocd is not giving me peace.

I'm trying for days now to figure out what is the bitrate that that I can use to encode this with, to avoid insane bandwith that required for playback of such file. Got down to around 70mbps video but still in some more busy places in the video a stuttering occurs that even playback from the M.2 SSD is not helping with.

So I am turning to you for advice (other than the most obvious one, "just stop insisting on 444 you crazy bastard"...). Indulge me if you can.

Did anybody try this? What is the bitrate you would go, or be OK with? How low do you think it would be OK to go for 4K SDR 10bit? I do want to kinda future-proof this project, since I'm spending so much time on it.

[deleted user]

I also like to render at 4:4:4 (though 1080p) for projects that are important to me. Strongly saturated edges and such are sharper with it and stuff like colored text on black backgrounds remain sharp. I don't know about 4K but in any case I would say, don't use NVENC. I haven't thoroughly tested the newer versions of it but in my experience it doesn't even come close to a good solid encode with x264 or x265. Those are infinitely slower of course but the quality is worth it imo.

[Amadian]

Hey thanks man. Yeah, you are right, I usually agree that x265 looks better at lower bitrates. I don't usually make a point to go low with bitrates, at 100-150mbps I found that render looks pretty much identical to source with NVENC, so I went with that. It's significatly faster, and I am not doing many of these, so even if they take up more space, I was OK with that.

This is the fist time I'm trying 444, just because I surprised myself how good my colour correction process went, and I'd hate to loose portion of that with 420. Thank you by the way for confirming that I'm not crazy noticing the sharper result in full yuv colourspace.

I'm just not sure how low I can go with bitrate? Added sharpness in 444 makes it seemingly easier to go lower in bitrate ( which I would not do either way it it is not for this stuttering in more busy frames, I would keep it at 150mbps and be happy with it.

Trying now with 60mbs to 4K, will see how that will go. If not, 'will try 50 on average, next, and see... Guess nothing else, but make/fail, make/fail...

[deleted user]

Does NVENC have a constant rate factor mode? In x265/x264 there's a CRF mode where you set a number representing the quality you want to achieve and the encoder will pick the bitrate necessary to achieve it. A fixed bitrate will give too much bitrate to slow scenes and too little to fast. But to achieve a fixed bitrate whilst allocating correctly to fast and slow (or high and low detail) scenes, you would need 2 passes, so crf is a nice alternative, where the final bitrate might not be specifically what you wanted, but it will be consistent quality, more or less.

[Amadian]

Yeah, NVENC does have CRF mode. I never used it, because in the past I did not have good experience with it. So I always opt for VBR, and constant quality option chosen on top of that (StaxRip, is showing it as an option) so that it allocates bits to frames based on that, but from the overall max allowed bitrate I determined. I have up on 444 for this project 420 at the average 150-190 mbps looks pretty darn good. It's insane bitrate, I know, but I decided to go with it...