Handbrake "slower" setting: a nuclear option to remove color banding artifacts without huge filesize

[krausfadr]

Color banding ( https://en.wikipedia.org/wiki/Colour_banding ) refers to artifacts that take the form of noticeable color gradient changes where there should be a solid color or a gradual smooth gradient change. This can be very noticeable in backgrounds and areas of solid color, usually in darker scenes. The most professional studio released bluray discs will have no banding at all.

Some movies have footage that can be really difficult to remove color banding when re-encoding even at higher bitrates. In Handbrake, HEVC (H265) 10bit encodes are a great way to help eliminate banding that readily happens in AVC (H264), but sometimes there can still be troublesome spots even in HEVC. I learned that for HEVC 10bit encodes in Handbrake changing the encoding setting to "slower" can produce great results in these troublesome areas that once had banding. The ugly artifacts simply vanish.

The "slow" setting will not achieve the same results. The trade off to a small filesize that looks perceptually perfect is that the encode takes a really really long time. I have a relatively fast machine, and a 2 hr movie is about to take me more than a day to encode at 1080p.

 

[The Scribbling Man]

I always use the slowest option (bar placebo) on handbrake. I see no reason not to. File size and quality are more important than speed.

 

[krausfadr]

Placebo? Wow! Well it can't hurt anything except your CPU, the diminishing law of returns still gives returns.

 

[The Scribbling Man]

Placebo? Wow! Well it can't hurt anything except your CPU, the diminishing law of returns still gives returns.

As in "placebo" is where I draw the line. I've tried it and can't tell the difference. But apart from that I have it on the slowest setting.

 

[krausfadr]

@The Scribbling Man using slowest, are you typically encoding in AVC or HEVC?

 

[The Scribbling Man]

@The Scribbling Man using slowest, are you typically encoding in AVC or HEVC?

AVC. I have considered using HEVC, but I know it's not as widely compatible, which is a turn off.

 

[ParanoidAndroid]

Up to now I've merely outputted H265 directly from DaVinci Resolve free edition, but on seeing this thread I did a couple of tests and saw for myself that indeed a much better image is obtained for the same file size by outputting in a less compressed format then re-encoding in Handbrake.

The issue that results from this (beyond the greater time, which is more of an acceptable annoyance) is of course the large interim file size, from the size of a few short test clips it appears that a whole feature could end up occupying several hundred GB.

In order to get the good results from a very slow 10-bit H265 re-encode, are there any suggestions regarding NLE output settings? I hope that DNxHR 444 is overkill for 1080p, or maybe I just need to just get yet another external hard drive!

 

[krausfadr]

@ParanoidAndroid if you can output to Cineform (film 2 setting) your hard drive will thank you for the reduced filesize and increased visual quality. Still though a 1080p 2hr movie might be around 150 - 200 GB (depends on content though since Cineform uses variable bitrate). DNxHR will be much larger filesize without an increase in quality.

 

[ParanoidAndroid]

Thanks for the tips, but the only option for Cineform I can see (specifically "GoPro Cineform" under AVI and QuickTime) are YUV 10 bit, no Film 2 as far as I can find. Is this a limitation of the free version of Resolve?

 

[krausfadr]

If you are using Resolve, the default quality setting of YUV 10 bit at quality "Best" uses the Codec's Film 2 setting. GoPro Cineform is the official name.