Color banding occurs in AVI output.

[YuK1_Works]

AVI output will cause banding.

PC:

OS: Windows11 23H2, CPU: AMD Ryzen 7 3700X, GPU: NVIDIA GeForce RTX 2060

Project Color Settings:
Bt Depth; 8bpc, Working Color Space: None, Assume Working Gamma: 2.4 (Rec. 709)

Options used:

Example: TIF, AVI, TIF - AVI(Levels are applied for clarity) 

This problem also occurs with Adobe Media Encoder.

[nishu_kush]

Thanks for writing in and sharing the screenshots. I don't see the banding in the Ae project file unless I zoom in and look for it. I exported the file as MOV and I can see a bit of banding in the Quick Time player and was fixable by applying the Noise effect with the Amount of Noise set to 1%.

Let us know if that works for you. I am moving this thread from Bugs to Discussions for now.

Thanks,

Nishu

[YuK1_Works]

I am not sure I understand what you are saying.
I am saying that AVI export increases banding.
Uncompressed MOV does not cause banding.
The reason you see banding in the original image is because of the 8 bpc gradient.
AVI export clearly increases the banding more than that.
This problem does not seem to occur with CPU processing, which makes it seem more like a bug.

[Rick Gerard]

If you compress color as 4:2:2, basically you average color in blocks of 4 pixels. This causes color banding in subtle gradients. If you use 4:2:0, the banding is worse. The solution is to introduce a little noise or grain in the footage. When you are stuck with 256 maximum luminance values and a color gradient that goes from something like 18 to 24 over an entire frame, there are only seven possible values for the frame, and without noise or grain, those are going to show up as 7 different lines. The noise/grain hides the lines.

Your best option when dealing with subtle colors is to set the project to 16-bit, add a little noise or grain, and then use one of the presets or a preset in the Media Encoder to render an H.264 4:2:2 deliverable for viewing on the net or in a media player. Unless you have a very good understanding of video codecs and compression algorithms, coming up with your own settings can often cause problems that the presets avoid. 

If you are rendering for further editing and processing, including re-compressing for distribution, it is always a good idea to render to a frame-based codec like ProRez at least 10-bit color. MPEG formats are unsuitable for production or archival masters. You don't want the codec to be predicting the movement of pixels between frames like MP4 formats do by default.

[YuK1_Works]

I have specified "None" as the codec for AVI. Is 4:2:2 or 4:2:0 still used in this case?
We consider the word "None" to mean "no degradation". This means that I want the image to be saved in 4:4:4 or RGB format.
Also, since banding occurred even when using the non-degraded codec UtVideo T2 RGB, I do not think this is a codec issue.

[Rick Gerard]

Even with no compression, you will get banding in subtle gradients using 8-bit color. Just a tiny bit of noise or grain will hide the artifacts. 

I don't use AVI formats at all. AVI is old, developed in 1992, and no longer an industry-standard format. ProRez is probably the most widely adopted industry-standard format. If you use the highest quality, you get 4:4:4 compression. Even that will not always fix the banding you get with subtle gradients and 8-bit color. I believe AVI from the Render Queue's Output Module is only 4:2:2, but I'm on a Mac and can't check it.

An AVI can contain many compression codecs, even MPEG. I would avoid it. AVI is not supported on a Mac. 

Just a bit of grain (Add Grain set to about .4 or less for Intensity, Size, and Softness) or Gaussian Blur set a little less than 3.5 will hide most banding and maintain clarity.

[YuK1_Works]

I'm not talking about not using AVI or anything like that, I'm saying that as long as this phenomenon occurs only with AVI, it is a bug.
The MOV format does not cause banding beyond that caused by the gradient, and there is no error when the difference is taken from the TIF.
Only when the AVI format is used, an error occurs in the difference from the TIF, so this is a bug no matter how you look at it.

[Rick Gerard]

It's not a bug. It's a problem with a format developed in 1993 that has limitations that were never addressed. 

[YuK1_Works]

“Mercury Software Only” (i.e. CPU processing) and AVI exported, no additional banding occurs.
Additional banding only occurs when “Mercury GPU Acceleration” is specified and AVI export is used.
Even when “Mercury GPU Acceleration” is specified, MOV and TIF do not cause additional banding.
In other words, this is not a problem caused by the codec or container, but a bug in Ae.