Charlie Brown specials - conversion problems from ABC HD.

[Tiernan]

As everyone is probably aware, the holiday season brings the annual airing of several Charlie Brown animated specials (and a couple of movies this year). In past years, I've capture (first in SD, then the HD TS stream) then converted and authored to DVD without any attempt to do anything to process it back to the orignal 24fps. I'd been using a semi-standard 720p 59.94fps script:

DGDecode_mpeg2source("C:\charlie brown.d2v", info=3)
ColorMatrix(hints=true, interlaced=true, threads=0)
TDecimate(cycleR=3)

in past, but, between the animation, and ABC's well-known inconsistant telecine pattern, I'm not getting a very good result. The Decimate function seems to work well (as there are no repeating frames), but I'm still getting stuttering in playback, which appears to be caused by the remaining half-frames that have not been removed (that is, points where, when single framing through the file, 2 consecutive frames are showing up merged together, as 1 frame)

Has anyone else been attempting to process these particular specials, and have you been successful? Do you have suggestions, or an example of the script you've been using.

Thanks for any suggestions you can offer.

[edDV]

720p should not have half frames. It is progressive 59.94 fps with frames repeating 3 then 2.

AAABBCCCDD and so on.

To convert to ABCD you would find the initial 3 frame, then decimate 2 then 1 and so on.

If ABC is mucking with the sequence, you would need a smart decimater like the one inside your HDTV. These monitor the sequence, then reset if the sequence goes whack. There are errors while the cadence resyncs so for a pure conversion, you would resort to manual decimation.

[Tiernan]

Thanks for chiming in Ed...

SO... I've taken the time to step through the original source again, before applying any decimation, etc. What I'm seeing is:

For portions of panning sequences (characters walking, usually with camera moving left or right), the sequence appears to be AAABCCC (with the B frame being the mix of A and C), but this particular cadence only continues for a few repetitions, because...

for most (all?) other sequences, it's AAAAABBBBBCCCCC

For those who've dealt with ABC before, maybe this is normal, but it doesnt make any sense to me, and I really don't know enough about AVS to be able to script something for (or tell MeGUI how to fix) such a thing.

Is this making sense?

[manono]

for most (all?) other sequences, it's AAAAABBBBBCCCCC

Simple animations aren't always drawn at 24fps, but more often at 8, 12, or 16fps. It varies with the amount of movement. If I were you I'd decimate it to 23.976fps, perhaps by using something like:

SelectEven()
Tdecimate(Mode=0,Cycle=5,CycleR=1)

Don't worry about there being remaining duplicate frames and don't worry about those blended ones, or even the fact that they have those weird patterns. The fact that it's animation works in your favor and makes it easier to decimate without dropping unique frames. You might have to fool with the settings, but you get the idea. Simple animations don't play completely smoothly anyway, because of the often low 'actual' framerate.

If you want to try and get rid of the blended frames, add a:

CDeblend()

to the script before the SelectEven. The blends should be replaced by 'good' frames on either side. CDeblend is part of the SRestore package.

Also, since the whole thing is progressive, you don't need the Interlaced=True in the ColorMatrix filter. And unless you're downsizing to standard definition you don't need the ColorMatrix filter at all. But you're making a DVD from this cap, I guess?

[Tiernan]

Thanks again manono. You always seem to be on top of these things.

So, I tried:

DGDecode_mpeg2source("D:\01 - Charlie Brown Christmas - 2009-12-15 - HD.d2v")

SelectEven() 
Tdecimate(Mode=0,Cycle=5,CycleR=1)

# CROPPING & RESIZING 
LanczosResize(720,480)

which seems to give pretty good results. The merged frames are, unfortunately, just a bit too visible, so I think I'd like to remove them. The problem I'm having now is that:

Import("C:\Program Files\AviSynth 2.5\plugins\SRestore.avsi")
DGDecode_mpeg2source("D:\01 - Charlie Brown Christmas - 2009-12-15 - HD.d2v")

CDeblend()

SelectEven() 
Tdecimate(Mode=0,Cycle=5,CycleR=1)

# CROPPING & RESIZING 
LanczosResize(720,480)

doesnt work. I get an error saying that the DeBlend function doesnt exist.. I have a feeling that I'm not loading it properly, or dont have all the necessary scripts, etc., but the documentation (what exists anyway), isnt very helpful.

[manono]

The problem I'm having now is that:

Import("C:\Program Files\AviSynth 2.5\plugins\SRestore.avsi")
DGDecode_mpeg2source("D:\01 - Charlie Brown Christmas - 2009-12-15 - HD.d2v")

CDeblend()

SelectEven() 
Tdecimate(Mode=0,Cycle=5,CycleR=1)

# CROPPING & RESIZING 
LanczosResize(720,480)

doesnt work. I get an error saying that the DeBlend function doesnt exist.

It's part of the SRestore package (the R_Pack):

http://forum.doom9.org/showthread.php?p=673243#post673243

It's in the "Old" folder. I rename CDeblend.avs as CDeblend.avsi, stick it in my AviSynth Plugins folder, and it loads automatically. Or you can import it from whereever you put it.

[Tiernan]

Thanks again for the suggestions and patience Manono..

Ok, got the script working, but, ... well, it doesnt appear to be working. Not only does it not remove the blended frames, but the script (at least when running the exact script you suggested) appears to be allowing at least 1 duplicate frame per each cycle. I have a feeling that it means that I will need to change the script slightly (per what you'd suggested), but I'm not sure I understand what it's doing well enough to make the needed change. Basically:

SelectEven()

(only selecting every other frame, so the pattern which means there are 5 frames to start with should only leave... 3?)

Tdecimate(Mode=0,Cycle=5,CycleR=1)

These settings should mean that, as it's using Mode 0, it's a straight decimation leaving 1 out of every 5 frames. If this is the case, shouldnt that logically mean that I don't want to remove every other frame BEFORE that process?

Yes, I'm beginning to wonder if this is worth the effort...

[manono]

First, isn't your ABC cap 59.94fps? SelectEven brings it down to 29.97fps and then removing one frame in five brings it down to 23.976fps.

Maybe do the SelectEven before the CDeblend. Doing it that way may remove some of the blends even before hitting the unblender. If you want to put up a small 10 second sample somewhere, we could have a look.

...but the script ... appears to be allowing at least 1 duplicate frame per each cycle.

Like I said, animation is usually drawn at much lower framerates than 23.976fps. You're supposed to have duplicate frames remaining.

[Tiernan]

Thanks again for your reply manono..

That seemed to do the trick.

It appears that one of, if not THE biggest issue in attempting to reauthor HD material is the complication of the source material itself. Just when you think that you get familiar with what you're working with, you have reason to tackle a new project, and the material seems to have all kinds of new challenges. So, in this case, the nature of animated material (even if we know what it's like in standard telecined film material now (23.975, supposedly),) this has changed any number of times over the years, so the actual number of frames being animated (and what we need to be aware of) has changed over time too.

Anyway, I've learned just that much more about AVS scripting, and I'll now be better prepared for the next project (which looks to be "how best to create MKV's from true 720p 59.94 material"...)