Why am I seeing colors bleeding shaped like a staircase?

[killerteengohan]

I noticed when I went to clean my Blu-Ray up if you look along most of the black lines, it looks there's gray/black color bleeding in the shape of a staircase or something over the lines.

Here are a few screenshots to show what I am talking about.


https://forum.videohelp.com/images/imgfiles/jlpfhPh.png

https://forum.videohelp.com/images/imgfiles/NiRUqBH.png

https://forum.videohelp.com/images/imgfiles/1nE6UpS.png


What can I do to get rid of this?

[jagabo]

It looks to me like the filter that converts YUV 4:2:0 to RGB 4:4:4 is duplicating chroma samples rather than interpolating them. Your source has a 1920x1080 luma channel but the colors are encoded at 960x540. When converting to RGB the 960x540 colors are upscaled with a nearest neighbor filter. Try using different software.

You can clean it up a bit in AviSynth with a sequence like:

MergeChroma(BicubicResize(width/2,height/2).BicubicResize(width,height).aWarpSharp(depth=10 ))

[killerteengohan]

Try using different software for what? Playback of the file or encoding?

Those screenshots are from MPC-HC directly from the untouched .M2TS they are not from my encode. The company that released it has got to be stupid or something to do a thing like that.

I generally don't like to downsize and then rescale back up because it blurs footage, but if that's my only option, okay Ill give it a try.

[smrpix]

Do you actually watch these videos or simply inspect them frame by frame? These artifacts should become completely invisible if you view the files normally in motion.

[jagabo]

Those screenshots are from MPC-HC directly from the untouched .M2TS

Try a different player -- or a different h.264 decoder. But I suspect the problem is a little more than what I described earlier. Can you provide a short un-reencoded sample of the video?

I generally don't like to downsize and then rescale back up because it blurs footage, but if that's my only option, okay Ill give it a try.

Only the chroma channels of the resized video were used. The luma channel remained at its original resolution.

[killerteengohan]

Sure I will get you a sample asap, working on it now.

It does this on both my Blu-Ray Players and PS3 as well, so its not just my computer media players having the issue.

[jagabo]

It does this on both my Blu-Ray Players and PS3 as well, so its not just my computer media players having the issue.

So it's more than just a decoding problem. If you look at the chroma channels you'll see they're badly aliased. Here the U channel (the V channel has the same problem) with a big contrast stretch (to make the problem more visible):



That's a pretty bad screw-up.

[killerteengohan]

Heres the sample

https://mega.co.nz/#!s4RHXLgL!1lS5sXW6mV9Jtygfju_Hg80lBLlBFfQqeGQrVsQnkhA

[jagabo]

I'm heading off to bed. I'll check it out tomorrow.

[killerteengohan]

Alrighty, goodnight and thanks. I will check back tomorrow.

[jagabo]

The problem is definitely in the source, not your processing. The chroma channels are like the image I posted last night. It's as if they removed every other column and resized what was left, leaving terrible aliasing artifacts. I don't see any good fix other than something like what I posted earlier.

[killerteengohan]

Well I tried this and it looks better. While not a perfect fix, it doesn't look near as obvious unless you know to look for it.


MergeChroma(BicubicResize(width/2,height/2).BicubicResize(1920,1080).aWarpSharp(depth=8))
LanczosResize(1280,720)
maa2(ss=2.80)
LimitedSharpenFaster(ss_x=1.0, ss_y=1.0, strength=8, overshoot=0, undershoot=0, soft=0, edgemode=0)


I at first I couldn't decide whether to resize to 720p and then do the mergechroma or do it first then downsize to 720p. I just went with fix it at 1080p then downsize to 720p because it seemed like it would be the better option.