Author Topic: Reference guide for spotting encoding problems  (Read 34204 times)

Offline anonymlol

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Re: Reference guide for spotting encoding problems
« Reply #60 on: January 22, 2013, 11:12:09 am »
Screenshots taken with avsp.

Aliasing | fixed (Ixion Saga DT, .m2ts)

Ghosting (not deinterlaced) | fixed (Tamako Market, .ts)

Cross Conversion | fixed (Jinrui, .m2ts)

Offline jackoneill

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Re: Reference guide for spotting encoding problems
« Reply #61 on: January 22, 2013, 06:36:59 pm »
Ghosting (not deinterlaced) | fixed (Tamako Market, .ts)
I'm not sure you could call this ghosting.

Cross Conversion | fixed (Jinrui, .m2ts)
You should show that in glorious 1080p. Downscaling hides the ugly.

Offline anonymlol

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Re: Reference guide for spotting encoding problems
« Reply #62 on: January 22, 2013, 09:43:05 pm »
I'm not sure you could call this ghosting.
I'm not sure either. What should I call it?

Cross Conversion | fixed (Jinrui, .m2ts)
You should show that in glorious 1080p. Downscaling hides the ugly.

Cross-Converted 1080 | Fixed 1080 (Jinrui, m2ts)

Online Krudda

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Re: Reference guide for spotting encoding problems
« Reply #63 on: January 23, 2013, 08:33:23 pm »
Not really sure if this is an encoding 'problem' or just a problem I usually like to fix, but frames that have an identical frame before/after and yet the encoder leaves something like this in the image:
Bad|Good

Like I said, its more a matter of caring then an actual encoding error. Its very easy to delete a frame and duplicate another to replace it, though it does take a considerable amount of "caring and effort" to find every issue in every frame.

Also, can't see if you already have this, but ghosting due to incorrect field matching:
bad
Fixed 1
Fixed 2

Everything here from R2J's of "Pokémon de English! (2007)"

Edit:
Yes, as Lillymon states below, it was after every single cut.
« Last Edit: January 28, 2013, 04:40:58 am by Krudda »

Offline Lillymon

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Re: Reference guide for spotting encoding problems
« Reply #64 on: January 24, 2013, 03:31:11 am »
Not really sure if this is an encoding 'problem' or just a problem I usually like to fix, but frames that have an identical frame before/after and yet the encoder leaves something like this in the image:
Bad|Good
Funny that the server went down as I was typing this message and wiped it out when it went to preview and both the server and my browser were too fucking incompetent to save it and now I have to type all of it out again and take the same care I did last time and paste all four links back in and waste another 15 minutes and oh god I'm doing it again...

Now where was I? Oh yeah, I found the same problem in Wedding Peach DX a little while ago and I might as well try to post that again:

1 | 2 | 3 | 4

Somehow whoever mastered this was able to make it so this happens at the bottom just before a cut then at the top just after a cut, manage to do this on every cut, and keep it up for all four episodes even though they came out over the course of a year and probably cost an arm and a leg. I was going to try and fix it, but first off that was too much like, second I spotted at least one instance in the intro alone that had no matching 'good' frame, and third... well, every cut. No idea how many that adds up to, but I'm guessing it's a question of whether it's three figures or four, and it's not even going to fix all of them so nuts to that.

Offline Firesledge

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Re: Reference guide for spotting encoding problems
« Reply #65 on: February 05, 2013, 12:15:50 am »
I have a couple of video samples showing "aliasing or moiré in slow motion".

1. Problem | Fixed
2. Both on the same clip

I'm not sure they meet the technical specs for video samples but I can reencode them if required.

Offline the_E_y_Es

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Re: Reference guide for spotting encoding problems
« Reply #66 on: September 22, 2015, 01:17:50 am »
What kind of video problem is this:

Sorry but you are not allowed to view spoiler contents.

you can see it around the plane

Sorry but you are not allowed to view spoiler contents.

and around the dog & the railing

What's it called?

Offline OnDeed

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Re: Reference guide for spotting encoding problems
« Reply #67 on: September 22, 2015, 03:39:41 am »
Ah, I recall that from the oldest shit rip I have seen of GitS... I believe that is an actual animation artifact, not a video fault.

P.S.
I am pretty late to the party, but for future readers,

@Lillymon and @Krudda
Those are so called burn marks (the bottom of frame) and glue marks (bright stuff on top). They are present on the actual film from the process of cutting. You get that on lots of old cel anime DVDs, unless they are overcropped enough to dispose of them, or the authoring people used some software to hide them (motion compensation from neighbour frame, I noticed that on Andromea Stories, man I would like that software).
Sometimes they are left on DVDs because they counted on them being hidden in overscan area.

Poor man's solution is to freezeframe such. If there isn't an identical duplicate, it is a tradeoff. In simple pans the unique frame might be sarificeable, in some cases the lost frame (especially if it is a lot fo them in row) might be too precious though... sometimes, the ideal solution i to photoshop, but that is such an effort, that it is not reasonable to require it.
« Last Edit: September 22, 2015, 03:49:09 am by OnDeed »

Online Krudda

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Re: Reference guide for spotting encoding problems
« Reply #68 on: September 22, 2015, 03:42:27 am »
If you want to name it I guess the closest match is a halo.

Offline OnDeed

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Re: Reference guide for spotting encoding problems
« Reply #69 on: September 22, 2015, 03:49:56 am »
If you want to name it I guess the closest match is a halo.

That would be confusing, because halo is actual filtering artifact that is very unrelated.

Offline Koby

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Re: Reference guide for spotting encoding problems
« Reply #70 on: September 22, 2015, 04:04:28 am »
You sure it isn't some sort of chroma-shift or field blending? Can't really tell from just a screenshot, but it kind of looks like stuff blended in from another frame.

Online Krudda

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Re: Reference guide for spotting encoding problems
« Reply #71 on: September 22, 2015, 04:06:04 am »
I never said to name it a halo, just the effect is similar and thats the closest from whats available to call it.

It comes from scanning IIRC.

Definitely not a blend.

Offline OnDeed

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Re: Reference guide for spotting encoding problems
« Reply #72 on: September 22, 2015, 04:11:54 am »
You sure it isn't some sort of chroma-shift or field blending? Can't really tell from just a screenshot, but it kind of looks like stuff blended in from another frame.

Nope, it is an area aroudn the plane that keeps moving with it. Basically some transparent paper or foil on which the plane was drawn... that didn't turn out to be compeltely transparent when the composited frames were shot on film.

Actually I am not compeltely sure in the second case with the bridge and dog frame, but it is likely to be tha same shooting issue.
« Last Edit: September 22, 2015, 04:13:44 am by OnDeed »

Offline the_E_y_Es

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Re: Reference guide for spotting encoding problems
« Reply #73 on: September 23, 2015, 03:10:26 am »
Thanks for the replies, I guess it's from the scanning, then. It makes sense that matte compositing would produce stuff like this. The plane and the dog are separate layers on top of a background layer, so yeah... I thought it was haloing, too. Maybe scan aura, scan shadow or matte aura/shadow would be a more appropriate name.