Five different source types - should I IVTC for each?

[yoshikunai]

Hey, everyone. I've followed threads in this forum for months, but this is my first post. I hope that I'm not being overly ignorant by asking this, or repeating someone else's question. I've read a lot about IVTC, 3:2 Pulldown and interlacing but I confess I still don't understand all of it.

Here's my question: How should I deal with telecine, interlace, and decimate issues when encoding these five DVDs to one CD DivX 5.0.1 files? The last encode I did, I used these AviSynth settings with decomb:

Telecide(guide=1,gthresh=50,chroma=true,threshold=30)
#Decimate(mode=1,threshold=50)

When decimate was on, I'd get choppy pans (the 'camera' wouldn't move smoothly), so I turned it off and kept a 29.97 FPS. I'd like to get that to the ~23.97 FPS if I could, but I'm not sure where it's safe.
(on a side note -- when I use vobsub and decomb's decimate together in the same .avs file, virtualdub 'crashes' before encoding)

If something has a tricky frame order changes partway through the video, I don't need to try TMPG, right? Will decomb's telecide(gthresh=x) and decimate(threshold=x) handle pattern changes just as well (and what specific settings are recommended)? Should I forget decimate for anything that has a long stretch of pure interlaced video? I have read doom9's decomb guide and the decomb manual, but am still shakey on some of these issues.

Here are the videos and their pertinent information. I hope I've left nothing out.


THE BIG O
About ten seconds of interlaced, then mixed at FILM: 70. NTSC: 30.
29.97, 4:3
Repeating frame pattern appears to be 3 non-interlaced, then 2 interlaced.

GRAVE OF THE FIREFLIES
Completely progressive. FILM: 80. NTSC: 20. Goes for long stretches without switching between FILM and NTSC.
29.97 4:3

SAILOR MOON R
Periods of interlaced interrupted by mixed. FILM: 15. NTSC: 85.
29.97 4:3

MACROSS 3 - 4
Completely interlaced, completely NTSC.
29.97 4:3

WINGS OF HONNEAMISE
Completely progressive, completely NTSC.
29.97 16:9


If I understand right, Macross 3-4 should get FieldDeinterlace(), Wings of Honneamise should get Telecide(post=false) ?; Decimate(cycle=5), and I'm really not sure about the rest. I think some people always recommend decimating to put the %20 saved space to the quality of the other frames, regardless of actual frame order. Is this generally an acceptable practice?


Looks I managed to fit a lot of questions into one post. Thanks very much for advice on any of them.

yoshi-kun
yoshikunai@hotmail.com




The full AVS file I used:


LoadPlugin("C:\Video\GORDIA~1\mpeg2dec.dll")

LoadPlugin("C:\WINDOWS\System32\vobsub.dll")
LoadPlugin("C:\Video\GORDIA~1\decomb.dll")

mpeg2source("C:\Anime\angel sanctuary.d2v")

Telecide(guide=1,gthresh=50,chroma=true,threshold=30)
#Decimate(mode=1,threshold=50)


crop(8,0,704,480)

VobSub("C:\Anime\angel sanctuary_0")

BicubicResize(640,480,0,0.5)


System Specs:

Athlon XP 1800
ECS K7S5A Motherboard (SIS 735 Chipset)
Windows XP HE
Virtualdub 1.4.10
DVD2AVI 1.85
Decomb 3.8

[Kyo]

if you don't wanna loose the smooth on panings put
Decimate(mode=1,threshold=50), maybe that the order field in your last encode was reversed and decomb go crazy(?)
But i Really Really recomend decimate, 23.967 make the difference on anime content :D

THE BIG O
Telecide(Post=false or Guide=1,gthresh=50-30,chroma=true,threshold=30-25)
Decimate(Cycle=5)

GRAVE OF THE FIREFLIES
Telecide(Post=false or Guide=1,gthresh=50-30,chroma=true,threshold=30-25)
Decimate(Cycle=5)

SAILOR MOON R
Telecide(Post=true,chroma=true,threshold=30-25,dthreshold=30-25)
Decimate(Cycle=5)

MACROSS 3 - 4
FieldDeinterlace()

WINGS OF HONNEAMISE
Progressive!! it is your day of luck
aka. nothing to do ;)

put crop before Telecide
try simpleresize

and excuse me the evil :devil: English

[Hanty]

I personally know a great looking encode of "Big O" (demo material Quality) that's at 23.937 with no choppiness, so most likely decimate is dropping the wrong frames for you.

[yoshikunai]

Thank you so much!

And you're right, Hanty, I did the rip of Big O with the guide=1 settings and is looks as good, if not better, as anything I've ever ripped.

It's at 23 FPS without any problems whatsoever.

Thanks again Kyo! On to the rest of them now...

[ssjbrolly]

yoshikunai: sorry to ask, but how did u checked if the movies are purely interlaced or not? Did u ran then through DVD2AVI and had a look at the info window? Or did u used another method?

[manono]

Hi-

Just make your .d2v with no Field Operation (30fps), and then open it up in GKnot and start scrolling through it frame by frame in a few different places. Don't pay any attention to what DVD2AVI tells you about it. You have to look at the frames. Alternatively, make a 30fps .avs from the .d2v and open it in VDub-Nandub and scroll.

[ssjbrolly]

so and if I see 2 repeated fields on 2 frames then the source is telecined is that it?
And how do I detect if it's pure interlaced? I never got to understand this very well I think :(
I think on doom9's guide he says to use what DVD2AVI says for the video type... and that was how I was doing it.

[manono]

Hi-

This is for NTSC material-not PAL. Find a place where there's movement. Scroll frame by frame. If you see the interlacing in every frame, then it's pure interlace, and cannot be IVTC'd. If, in a pattern of 5 frames, you see 3 progressive frames (non-interlaced) and 2 interlaced frames, then it has been telecined, and you can perform an IVTC and bring it back down to its original 23.976fps. Do this in several places to be sure you don't have hybrid material which opens up a whole other can of worms.

[yoshikunai]

Sorry, ssjbrolly, I didn't get any email notification that someone was replying here until just now. :)

I opened the .vob files in DVD2AVI and hit 'F5' to preview. Then I watched what the info said in the statistics window that appears. Doom9 talks about that here: http://www.doom9.org/mpg/dvd2avi.htm. It's easier than trying to figure it out yourself--but if you don't watch the statistics info as it previews you might miss whether or not it's hybrid (I think).

[ssjbrolly]

yoshikunai: yeah that's usually what I do, but many ppl says not to rely on what DVD2AVI tells, so is this reliable or what?

Also manono: how can I see by just looking at a frame if it is progressive or interlaced? If I see artifacts can I say it's interlaced and if not it's progressive? Or should I just look at the sequence of frames to find the matching fields?

tkz