Comblike artifacts in Babylon 5, explained

[Katie Boundary]

A LONG time ago, when playing around with Babylon 5 footage, I noticed that even when fields were assembled back into their correct original progressive frames, the CGI still had scanline-like artifacts. The mystery of exactly where these artifacts come from has been bugging me ever since, with many people blaming Amiga Video Toasters but not elaborating any further. About a week ago, I figured out what was really going on: it's vertical halation. I was able to replicate the effect in other TV shows with the following convolution kernel:

0 1 0
0 -1 0
0 1 0

Applied to Andromeda, the results look like this:



So with that mystery out of the way, I ask: why would anyone do this, and more importantly, what bob-deinterlacers would be best at restoring these shots, in terms of temporally softening repeat frames but not producing ghosting in non-repeat frames?

[StainlessS]

BabylonEp59 (S03DISK04-Ep03) PAL version has Perverse Telecine from about Frame 710->1073, perhaps more sequences (Only just found that one).
Sequence should be Progressive but every other field is from the wrong progressive frame, eg

    abcdefg
    bcdefgh

How many more sequences in the 110 episodes are likewise screwed, Oh Dear

[hello_hello]

The problem with CGI was discussed years ago. At least in respect to the NTSC version. From memory it was the result of interlaced footage being resized incorrectly, or something along those lines. There was a suggestion or two offered here. http://forum.doom9.org/showthread.php?t=155988
Seems like a lot of work to isolate and fix the CGI parts though.

I don't know if anything similar applies to the PAL version. If it's progressive but the fields are "out of phase", wouldn't TFM() fix it? Or maybe TFM(pp=0) to prevent it de-interlacing?

I can't say I've ever been a fan of Babylon 5. I've watched a couple of seasons but couldn't get past Kosh looking like an actor with a huge toilet seat on his shoulders, or Michael Garibaldi having a haircut like a muppet (I had to visit IMDB to remember the character names). I did get past Commander Sinclair looking as though went to the Keanu Reeves school of acting because Michael O'Hare left after the first season (didn't he start having paranoid delusions about being able to act?), but I never managed to become invested in Babylon 5. Should I try again?

[StainlessS]

but couldn't get past Kosh looking like an actor with a huge toilet seat on his shoulders

I loved that ol' dude with the lavvy seat sat on his shoulders

Should I try again?

Could do. I only liked the Shadow Wars middle bit, the rest was a bit too much like "lets all get along nicely with each other"
instead of "there's an alien, lets kill him".
(much like the earlier parts [at least] of Voyager, got a bit more interesting when 7 of 9 got un-assimilated).


I guess I could put the clip through TFM(pp=0), but having a play with it first.

This is what I got so far (not bullet proof I guess, but sort of works a bit).

GScript("""
    Function IsCombedStatus(clip c,int current_frame,clip Bobbed,int "Th",Bool "Show") {
        c
        Show=Default(Show,False)
        Th=Default(Th,18)
        # 0=Progressive, 1=Progressive:Interlaced next neighbour, 2=Interlaced, 3 Perverse Telecine
        if(IsCombed(Threshold=Th)) {  # Some kind of interlaced
            bn1 = current_frame*2+1                              # current frame odd field 
            c0 = RT_LumaDifference(Bobbed,Bobbed,n=bn1,n2=bn1-1) # current frame even field 
            n0 = RT_LumaDifference(Bobbed,Bobbed,n=bn1,n2=bn1+1) # next frame even field
            n1 = RT_LumaDifference(Bobbed,Bobbed,n=bn1,n2=bn1+2) # next frame same (odd) field
            Type=(c0<n0||n1<n0)?2:3
            (Show)?RT_Subtitle("c0=%-7.3f n0=%-7.3f\n    x      n1=%-7.3f",c0,n0,n1,align=5):NOP
        } else {
            current_frame=current_frame+1 nxt=IsCombed(Threshold=Th)
            Type=(nxt)?1:0
        }
        if(Show) {
            TypeS=Select(Type,"Progressive","Hybrid:Progessive, Next Interlaced","Interlaced","Perverse Telecine")
            RT_Subtitle("Type=%d (%s)",Type,TYpeS)
        }
        return (Show) ? Last : Type
    }
""")

VideoFileName   ="D:\BAB-59\VIDEO_TS\bab59.d2v"
MPEG2Source(VideoFileName)
AssumeTFF
Bobbed=Bob
SSS="""
    IsCombedStatus(current_frame,Bobbed,Th=16,Show=true)
"""
return ScriptClip(SSS)

EDIT: Target is to MC double rate progressive and deinterlace interlaced, and to try to avoid letting QTGMC blend scene changes.
EDIT: There is loads of Perverse Telecine in there (esp prior to credits, several minutes in).
Quite a bit of the CGI has blended fields.

EDIT: "huge toilet seat". By the way, Not sure if in Babylon 5 (but think so), where someone is undergoing some kind of surgery,
I spotted a 'Solder Sucker' taped to his leg, I got one just like it only mines blue and the one in question was red
(guess they thought it looked kind of futuristic)
http://www.ebay.co.uk/itm/like/12155...0865095&crdt=0

[hello_hello]

Originally Posted by StainlessS

Could do. I only liked the Shadow Wars middle bit, the rest was a bit too much like "lets all get along nicely with each other" instead of "there's an alien, lets kill him".
(much like the earlier parts [at least] of Voyager, got a bit more interesting when 7 of 9 got un-assimilated).

I've never seen Voyager (I probably should one day) but that's why I'd take Blake's 7 over Star Trek any day. It's a pity Blake's 7 was never re-made. I know everybody "getting along" was part of Gene Roddenberry's grand design, but it never quite sat with me. I'd probably like Voyager more.

Originally Posted by StainlessS

EDIT: "huge toilet seat". By the way, Not sure if in Babylon 5 (but think so), where someone is undergoing some kind of surgery,
I spotted a 'Solder Sucker' taped to his leg, I got one just like it only mines blue and the one in question was red
(guess they thought it looked kind of futuristic)
http://www.ebay.co.uk/itm/like/12155...0865095&crdt=0

I think I remember something like that, except someone was holding it (and I'm pretty sure it was Babylon 5), but I couldn't put my finger on what it was. I thought it might have been some sort of caulking gun but I don't think it had a handle for squeezing so my brain never put it in the "case closed" department which is probably why I remember it. A solder sucker could very well have been what it was, but I probably have no hope of finding the scene, short of watching the entire series.

The zig zag shape of all the doors in Bablyon 5 always bothered me, now I think about it. Made for tripping over because their shape meant the doorway width decreased towards the bottom, and not that I'm an engineer, but I couldn't get my head around why those doors would make better airlocks or withstand blasts better than a doorway not made to trip you up.

(sorry for the short sidetrack)
I was watching some old Doctor Who the other day and after admiring the fact they use reel to reel tape on space stations in the future,


I wondered.....
The door opening mechanism is a transistor on a heatsink isn't it?


I take hope from the fact I've never seen a Sci-Fi show set in the future where computers run Windows. I don't know what OS they use, but wouldn't it be nice if they got that right?

[StainlessS]

I'd probably like Voyager more.

But probably not the first series (I'm guessin' that it had a woman writer, and when they had bad viewing figures brought in a guy or squad of guys and
7 of 9, and figures got better [EDIT: Janeway was a little less 'girly']).

Blake 7, a bit like Doctor Who, what with its shaky scenery etc, not terribly well done, but some people seemed to like it.

The doors in Bab5, were obviously that way by design, what with all them there weird shaped aliens with bog seats adorning their upper parts,
doors were a nicety for their benefit (alien and actor).

transistor on a heatsink isn't it?

Sure looks like a power transistor or similar.

"Windows", nah, in the future Windows is long gone, also tape decks and vinyl surely are coming back in fashion (I hear something ridiculous about an
original boxed Sinclair ZX Spectrum coming in at about £1,500, who would have believed it).

Met a guy about 2 nights ago (in pub), about 6'4", wearing suede leather fedora, long wooly trench coat, brown brogues, and an 18 foot stripey woolen scarf, apparently a Dr Who (Tom Baker) fan who was a poet by profession (would you believe).

Solder Sucker, started looking for it (then thought, maybe Google would do it faster), here tis:- http://www.imdb.com/title/tt0517692/...ef_=tt_trv_trv

EDIT: Ep002 : S01E02. Soul hunter. (about 31:48 PAL time)


EDIT: Solder Sucker, you press the pluger and it locks fully depressed, then press button when solder liquid, and spring loaded
plunger flies out creating vacuum sucking solder inside. Unscrew metal and heat resistant silicone plastic tip assembly, and empty out solder fragments.

EDIT: By the way, Michael O'Hare (Commander Sinclair) came back in later episodes, also Claudia Christian (Ivanova) got the boot,
after some kind of spat with her ex (the writer or producer or someone like that), but also came back to do the final one or two episodes,
strange since she was dead (I think, cant remember how they worked that one).

[hello_hello]

Edit: You hadn't posted the pic when I read your post, hence me posting it too.
I encoded the series a long time ago so I can't remember, but I appear not to have gone ITU whereas you did. I wonder who's right.

How can you be a professional poet? Can you really get paid for that?

The effects for Blake's 7 were pretty average, although typical BBC for the time.
I liked the fact Blake's 7 was pretty much the opposite of Star Trek. The crew were the enemy of The Federation and they didn't always get along or trust each other. It's quite slow paced by today's standards, but so was a lot of TV at the time.

I couldn't find a scene where someone was holding it, although the Soul Hunter did put his hand on it, so maybe that's what I'm remembering, or maybe not.



I probably should finish watching Babylon 5. I watched at least two seasons (maybe three) about a year ago before deciding to have a break, but I never got around to going back to it.

[StainlessS]

I appear not to have gone ITU whereas you did.

I dont give a damn about ITU nor square pixels, and that particular frame was resized anyway to 640x360 just for the post (original recode was 720x576 @ 16.0/9.0).
Also, after primary processing, I put it though current version (not on-line) of DBSC, to remove all of the changing borders (me hates dat, I find myself watching for the next change instead of watching the movie. That is the reason that I dont like QTGMC nor blended scene changes,
cannot detect and remove dynamically changing borders).

EDIT: I dont get what all the fuss is about as far as AR is concerned, if its about right, I'm happy.

[hello_hello]

DBSC? Some sort of auto-cropping?

I crop the borders too, but maybe not the same way. Unless the borders change dramatically I just use whatever cropping removes them at their widest, and if I also crop a little picture elsewhere, so be it. My logic being... in the good old days you'd lose the borders due to overscanning, and the TV would be overscanning by the same amount throughout. Plus it's easier.
I don't understand the connection to QTGMC there.

Unfortunately I find myself being way too fussy about aspect ratio. Maybe it's a mild case of OCD. Thinking about it mine were taken from NTSC DVDs, so the PAL versions might be different.

I found this by accident. It's from episode 2, but it's a shot used in the opening sequences with the voice-over saying "It's a dangerous place" as Commander Stunned Bunny peers around the corner. For some reason I always found that especially funny, then I had to try to take the episode seriously.



And the voice-over saying "The name of the place, is Babylon 5".... I dunno.... it just sounds wrong to me.

[StainlessS]

DBSC, http://forum.doom9.org/showthread.ph...highlight=dbsc
(My current version is somewhat better than posted one, Need RT_Stats 2.0 Beta 3, not really ready for release)

I don't understand the connection to QTGMC there.

DBSC, first splits into scenes, and detects border on each scene separately, then can apply user selected operations (via a user function),
on each scene, eg AutoContrast, or select operation by cropped DAR eg (4:3, 16/9). Final scenes are resized to some user selected size.
QTGMC, creates blended scene changes and so prevents DBSC from doing its job (cannot detect blended scene change, reliably or at all).

Bab5 can have as much as about 12 pixels left and right changing borders, about up to 7 top and bottom, I'de rather keep what I can.
Of course cropping changing borders changes (slightly) the aspect ratio, but I dont give a Monkeys Chuff bout dat.
Some of us have OCD, some dont give a monkeys.

It did not really get going until Bruce Boxleitner took over command.

[hello_hello]

You made me paranoid, thinking I've been missing something, so I checked.
The only QTGMC de-interlaced video I had on the hard drive that happened to be connected to the PC was co-incidentally Blake's 7.

Frame 51048:


Frame 51049:


I couldn't find any blended frames at scene changes. There was a little bit of chroma "bleeding" at some scene changes but without looking I'd be guessing that's in the source and not QTGMC's fault.

I'm not sure I've ever seen QTGMC produce blended frames at scene changes. I don't know how it works on scene changes though, because admittedly I've not really thought about it before.

PS I'll check out DBSC, although I might wait for the new release before trying it. I'm not working on anything I could test it on properly at the moment. Cheers.

[StainlessS]

Hmm. Yours is 50 fps double rate, perhaps only blends if single rate, don't really use qtgmc, much, bit slow on my crap m/c.
Guessing your source was also progressive.
Mobile.

[hello_hello]

It's an episode of Blake's 7. Old, interlaced PAL video. QTGMC de-interlaces exactly the same way in single/original fame rate mode. It has a single or double frame rate output parameter but I'm pretty sure single frame rate mode is exactly the same as this:

QTGMC()
SelectEven()

It's slow on my old PC too. Fortunately I don't work with interlaced sources much, but I still use QTGMC in progressive mode as a noise filter quite a bit. Fortunately it's not as slow that way.

QTGMC(InputType=1, Preset="Medium", EzDenoise=1)

I've been promising myself I'll build a new PC for so long I'm quite keen. I'm only not building one now because Kaby Lake isn't far away, and apparently it'll have 10 bit HEVC hardware decoding (only 8 bit AVC though), so I thought I'd wait till the New Year. Hopefully the i7 7700k will be out in January. Then that'll probably have to do me for another 8-9 years.

[StainlessS]

Thanks, Ill try your settings, guess I musta screwed up somewhere and blamed QTGMC, still though a bit slow on my m/c.
(Core Duo 2.4 GHz, cost me a tenner at Wimbledon Stadium [dog track not tennis] car boot sale about 3 years ago, [me loves a deal,
also like to collect abandoned machines and give them a good home, guess I dont really care too much if I'm using garbage machine,
gives me incentive to make stuff run a bit faster in code], also, I dont actually do any processing on my number 1 m/c [2.4GHz],
tis delegated to 1 of 4 [currently only 2 in-one-piece for some time] machines for encoding, and I dont give a monkeys about how long they take).
Strangely, I dont get any Out-Of-Memory type errors on an old P4 with 768MB RAM that I sometimes do on No 1, 4GB machine, go figure.
Guess I need to re-visit the car boot with a nice new sparkly twenty in the poke, see what I can get
EDIT: Last time I was at the car boot [bout 14 months ago] saw an enormous Xeon m/c, (~£10-£20, at least 8 drive bays) but did not have any clue as to
what era [HP, could have been from as early as 1995 <they re-use the same name>], so I gave it a miss [despite having about 16GB->32GB of server memory (registered/Buffered/ECC, but only DDR-1) and no where to put it].

[Katie Boundary]

What is "Perverse Telecine"?

[StainlessS]

Originally Posted by Katie Boundary

What is "Perverse Telecine"?

Originally Posted by StainlessS

BabylonEp59 (S03DISK04-Ep03) PAL version has Perverse Telecine from about Frame 710->1073,
Sequence should be Progressive but every other field is from the wrong progressive frame, eg

    abcdefg
    bcdefgh

From scharfis_brain ExoticInterLacing, original in German
(Full text translated to English on MediaFire in sig below this post, in the DATA Folder)



EDIT: Found the original web page here:- http://home.arcor.de/scharfis_brain/...hesInterlacing
EDIT: Original link )German) no longer available.

[hello_hello]

I can't say I'd heard the term "Perverse Telecine" until now, but I knew what you were referring to. It's a phenomenon I only became aware of relatively recently. Maybe around a year ago. I think I was playing around with TFM at the time because I suspected Euro-pulldown, but it meant I had to go back and check some old encodes to see if I'd actually de-interlaced them unnecessarily (DVDs created from film sources rather than video). For a couple of them I had, but at least I worked how to check for "Perverse Telecine" easily.

Aside from TFM() fixing it, if double frame rate de-interlacing such as Yadif(mode=1) or QTGMC() is applied and you step through the output one frame at a time, each frame will be unique if the source is interlaced. If it's "Perverse Telecine", each frame will be repeated... almost.... there'll be slight differences due to the de-interlacing but it'll be obvious the output is not really 50fps progressive.

I'm not sure I've ever seen the same thing for NTSC but I don't work with a lot of NTSC. It might be a PAL phenomenon.

[StainlessS]

It might be a PAL phenomenon.

Dont know if there is a 29.97 fps (fully) progressive format, but assume there is, and there would have to be for this perversity to occur.
From what I've seen, mostly occurs in NTSC to PAL conversions, although I know of at least one PAL originated DVD with it
(Come Play With Me, a soft 1970's sex comedy that played at some cinema in London for about 25 years non-stop [EDIT: Was actually 4 years, thought it was a lot longer], no real idea why, it was garbage,
came as a freebie DVD with the Sunday Sport newspaper about 2005, EDIT: Starred the late Mary Millington).

EDIT:

PAL originated DVD

Well, presumably 24FPS film, but not via any NTSC route.

[hello_hello]

Here's an odd one. An old Australian mini series (Against The Wind). I assume it was shot on film and the DVD is progressive (in theory).
You've rekindled my interest in this one now I've ripped an episode again. Originally I couldn't work out how to fix it properly because field matching works on the luma, but the chroma looks as though it's still interlaced, and/or the chroma is out of phase in a different way to the luma, so I just gave it to QTGMC to play with when I encoded it a while back. Each frame either side of a scene change showed that chroma "bleed" with TFM() but after de-interlacing there was only the one "bad" frame before a scene change (or maybe just the one after the scene change).

I'll have a bit more of a play and if you're interested in looking at it, I'll upload a sample if I can't work it out myself. The chroma problem may have been inflicted on it before the field phase problem so the Pervese Telecine mightn't have anything to do with that. I thought for a while field matching the luma and de-interlacing the chroma would do the trick, but I don't think I could get them to line up properly. Maybe TFM for the luma and SRestore() for the chroma?

No filtering


TFM()
jpeg chroma subsampling enabled so you can't see the chroma combing


TFM()
jpeg chroma subsampling disabled so hopefully you can see the chroma combing


Yadif()


TFM().Greyscale()