Dealing with banding in fades on YouTube

NickHope wrote on 6/1/2012, 4:59 AM
I'm cooking up a slomo video based on some of my HDV underwater shots, deinterlaced and slowed down to 50% speed in AviSynth.

, without, as yet, a successful outcome.

So, help please!...

1. As I now have visual indigestion with this video, what do you guys think of the first versus the second opening?
2. Any other inventive editing suggestions for avoiding a fade but keeping the mood?
3. Any technical suggestions for pre-emptively reducing the banding on YouTube?

(by the way, I've already decided that the fade would need to come in a little sooner after the titles)


farss wrote on 6/1/2012, 5:19 AM
1. First is better.
2. Maybe an iris opening.
3. The banding is probably because the color is only in one (blue) channel. I'd have to look at on scopes to verify that though. Maybe shifting the color would fix the problem. You could also try adding noise to the blue channel to dither it.

NickHope wrote on 6/1/2012, 5:37 AM
Thanks Bob. I did start to make an attempt at an elliptical iris, opening from around/in the diver and expanding slowly out to fill the screen. I had trouble in Vegas creating an accurate ellipse with splines, or finding a transition that would let me move the iris off-center. I suppose I could do it with a .png mask made in Photoshop. Also a little difficult to avoid cheesiness with that?

In the meantime, am still working on the dithering.
farss wrote on 6/1/2012, 6:42 AM
"Also a little difficult to avoid cheesiness with that?"

Indeed but it's about all I could think of.
TBH the banding really isnt repugnant to my eyes. It only happens when the image is fairly dark and goes away pretty quickly.

"In the meantime, am still working on the dithering."

Might be hard to fix, I'm no wizard on how to use dithering, where is Glenn when we need him :)

I'd suggest trying using Secondary CC to shift the blue towards green just during the first part of the fade up. If that fixes it at least we know where the problem is coming from. Blue also has the worst chroma sampling, that is also probably not helping. Adding in some green might help.

TheHappyFriar wrote on 6/1/2012, 7:19 AM
Branding happens because you're dealing with 8-bit color per color. That's 256 shades of red, blue & green, max. That's a lot of colors but not all of them. That's one of the things HDR solves. There's not that much you can do about it, it's on everything but film & HDR digital.

Can't notice it to bad though.
Tim L wrote on 6/1/2012, 8:33 AM
Unfortunately, I read your description before I watched the video, so I don't know what my first impression would have been. Part of me wants to say that I would have noticed the banding but would have blamed YouTube for it and not thought much about it. On the other hand, it doesn't bother me much because banding also looks like ripples in water -- like a raindrop hitting the surface of the water. Had I not read your post first, I wonder if I might have thought it was an intentional effect.

I loved your titles, Nick -- very well done and fitting. Especially how the fadeout of the first title blends into the second title. It makes me wonder if you could hide the banding problem in the video by applying a slight "waves"/ripple effect to the video as the video fades in.

NickHope wrote on 6/1/2012, 8:59 AM
Thanks for the replies. I'm encouraged that the banding doesn't seem to be too objectionable for anyone.

Bob, I'll try your suggestion to add a little green.

TheHappyFriar. I take your point, but I'm still hopeful that some large amounts of dither/noise might be able to lessen the impact. Trying some stuff along those lines at the moment.

Tim, the titles took me ages as I'd never used PTT before. It was an absolute crashfest as PTT seems to object to large amounts of gaussian blur. To disguise the banding I did have a quick play with a waves/ripples "dream sequence" effect. I aborted because I couldn't get what I visualised and it seemed a bit cheesy, but perhaps that's just because I was using the Vegas' native FX and not a more sophisticated plugin.
TheHappyFriar wrote on 6/1/2012, 10:48 AM
I don't believe you'll be able to get rid of the banding. The difference between the shades is to small so there's not many colors to eliminate. It's like converting a 24-bit image to 8-bit, you'll get banding. I'd say look at your original footage with the brightness way up and see if it bands. You might be able to render that part out to uncompressed & then re-compress the whole video for youtube.

Adding noise/dithering doesn't get rid of it, just spreads it out. It might look better but it could also look like a bad camera instead. Worth a shot though.
mudsmith wrote on 6/1/2012, 11:44 AM
As someone who is not that well versed technically in all the different compression methods, but who has also been watching satellite TV starting with the old full res CBand through all the iterations of Dish and DirectTV, I have to tell you that ALL DirectTV pictures fall apart in this sort of banding way when things are dark with subtle variations in the color and luminosity.......darkening skies, etc. The compression just doesn't handle it well.......The more hi def it is, the less the effect, but I have seen it on every channel at every resolution at one time or another.

If the quest is to minimize it, even in the face of the universal problem, it is probably worth thinking about, but I guarantee you that most TV watchers are getting used to it by now.

On hi def real airwaves broadcast signals via antennae, I almost never see it, though other kinds of motion and dissolve artifacts are moderately common.....depending on the network and situation.
JJKizak wrote on 6/1/2012, 11:52 AM
On OTA I see it on the HD commercials but rarely see it on any other tv media.
robwood wrote on 6/1/2012, 11:54 AM
i'd try adding more saturation to the problem area, maybe animate the slider up as the fade goes down. maybe use a 2CC to isolate the saturation/chroma range with a nice fall-off. def a 32-bit project, not 8-bit.

or maybe i'd try to widen the blue; increasing the width would give the encode more values to vary between as it drops to black.

also, have you tried using inverse gamma to help with the fade? starting with inverse gamma and x-fading to black may help avoid some of the banding... then again, it could really increase them too :)
TheHappyFriar wrote on 6/1/2012, 12:20 PM
I've seen it from the major broadcasters, in theatre (SW: Episode 1 was HORRIBLE for this), satellite, cable, OTA analog & digital.

Mostly it comes from things shown in theatre's on film converted for broadcast (OTA, whatever). Film didn't have this, anything non-film does. Broadcasters pretty much avoid setting up a situation where this happens, that's why you don't see it often in TV.
Andy_L wrote on 6/1/2012, 8:18 PM
Nick, out of curiosity do you seem the same banding if you upload to Vimeo?
fldave wrote on 6/1/2012, 9:16 PM
#2 - I would overlap the fade out with the fade in, no gap. Just my first gut opinion.

#3 - What are your encode parameters? I've fixed some things like this with a higher peak bit rate, but keep the average the same. Maybe it can't resolve the darker shadows as well as the more common visual range. Your exceptional footage is probably pushing YT to its limits, as always!

edited: Scrap #2, I just realized there were two openings vs. the general transition. The second opening obviously doesn't have the fade in issue, so that is related to question #3.

Have you tried 720p upload and compare? I have scrapped 1080 uploads lately, seems to work better on older machines. Same bandwidth, but better quality. at 720
Steve Mann wrote on 6/2/2012, 9:15 AM
Nick, banding is an artifact from any compression method where there is a large block of the same color. YouTube's recompression just exacerbates the problem. Have you tried adding a touch of noise to the blue? Just enough to give the compressor in the CODEC something to work with.
Red Prince wrote on 6/2/2012, 3:06 PM

There is banding in both versions and there is little you can do about it because YouTube recompresses your video to a much smaller bit rate, which is the cause of the banding.

That said, banding or not, the first one is much better, both cinematicly and psychologically . The second one forces the viewer to move his eyes and to find what it is he is supposed to be looking at, which is distracting. As a result, the viewer is reminded he is sitting in a cinema or in front of a TV or computer, something you don’t want. There is no such distraction in the first one. The viewer is already looking where the action is because the opening credits were in the same position. The viewer forgets where he is. All he does is relax and watch. That is the psychological aspect. It is also much more beautiful, which is the cinematic aspect.

Forget the second opening. Stick to the first.


He who knows does not speak; he who speaks does not know.
                    — Lao Tze in Tao Te Ching

Can you imagine the silence if everyone only said what he knows?
                    — Karel Čapek (The guy who gave us the word “robot” in R.U.R.)

JJKizak wrote on 6/2/2012, 5:01 PM
You could try a mild radial blur to distract the viewer.
NickHope wrote on 6/9/2012, 2:02 AM
Thank you for all the thoughts and sorry I didn't reply sooner as I got dragged onto other projects.

I tried a few of the suggestions and ended up simply adding noise in Vegas to the clip, which I had previously deinterlaced and rendered to a 1280x720p lossless intermediate. I ticked all 3 boxes ("Monochromatic", "Gaussian Noise" and "Animate") and animated the amount from 0.020 at the start of the clip to 0.006 at the end of the fade up from black.

Not sure how successful it's been. The banding is reduced a bit but perhaps at the expense of more pixellation/noise/blockiness towards the end of the fade. In fact I feel the whole video might be a fine example of the type of footage and editing that highlights the shortcomings of YouTube's encoder. The "busy" footage of soft corals and anthias is a bit of mess. Anyway, here's the finished piece. Any feedback is welcome, +ve or -ve.

(Andy L, I'm afraid I didn't upload it to Vimeo as I want to maximise YouTube traffic. But I expect it would be cleaner on Vimeo. Maybe I could just upload that bit as a test)
farss wrote on 6/9/2012, 2:33 AM
The banding now looks like ripples which isn't so visually offensive, well done.

Munster1 wrote on 6/10/2012, 7:22 AM
Greyscalegorilla has a short AE tutorial for reducing banding artifacts, most of which can be applied in Vegas. The 4 colour gradient method might be worth trying.
Jim H wrote on 6/10/2012, 11:38 PM
You final version is improved and totally acceptable. I loved the vid and the colors really popped once you got to the fishes. The slow follow of the black and white snake was cool. Must be nice to have your whole body one big fluid head - really smooth. And the slow mo reverse entry shot at the end was a nice surprise. Well done all around.
NickHope wrote on 6/11/2012, 1:12 AM
Thanks guys. Munster1 that was a very useful tutorial.
apit34356 wrote on 6/11/2012, 1:53 AM
Nice work Nick! Enjoyed the video and workflow conversion! :-)