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29th October 2002, 01:14 | #1 | Link |
teh 8bit fool
Join Date: Oct 2002
Posts: 266
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hybrid source with 2% NTSC / decomb questions
I've been trying to transcode(CCE) Fellini's 8 1/2 (Criterion edition) and since it's my first experience with a hybrid source I thought I'd ask the omniknowledgeable forum members a few questions.
1) When encoding a hybrid source with relatively low action, at what % of NTSC should I start considering decomb.dll? (in my example it was 98%film 2%ntsc for the actual movie) Since I thought the transfer was not perfect to begin with I frameserved it with DVD2AVI with "no field order" and ran it through Telecide(post=false) Decimate(mode=1,threshold=50) in my .avs script. 2) When do I want to use Telecide() vs. Telecide(post=false), I've been told that there is no rule of thumb but supposedly post=false works better on cleaner/more modern transfers. 3) Is it normal for the end result .mpv to come out with drop_frame flag set? I had to do a -nopulldown -drop_frame false to import chapters in Maestro as it does not like the drop for that. (later reverted back to dropped for subtitle sync) Sorry, if this belongs in a newbie forum and thank you for any feedback. |
29th October 2002, 02:46 | #2 | Link | |||
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Re: hybrid source with 2% NTSC / decomb questions
Quote:
Telecide(guide=1,post=false) Decimate(mode=2) or (mode=0) Neuron2, however, cautioned me against using mode=2, but his help file in decomb says this is better for IVTC of 3:2 pulldown material. Neuron2, care to clarify? Quote:
Quote:
Last edited by JohnMK; 29th October 2002 at 04:45. |
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29th October 2002, 06:55 | #3 | Link | |
teh 8bit fool
Join Date: Oct 2002
Posts: 266
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thanks!
Thanks for your reply, JohnMK!
Quote:
Would you say that mode=1 would be the most safe/almost loseless option for hybrid sources? Or am I just full of sh*t? Also, if you happen to know if there is a quick way to decide between "mode=0", "mode=2" and "mode=1, threshold=50" by stepping through the fragment in question in VDub with telecide(post=false) like it suggests in IVTC guide? I would really like to hear what Neuron2 has to say about it, after all if a certain way is better for hybrid than what's in Doom9's decomb.dll guide, might as well amend it or offer it as another option. |
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29th October 2002, 09:36 | #4 | Link |
developer wannabe
Join Date: Nov 2001
Location: Brooklyn, NY
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I don't do DVD rips so I can't make a direct comparison, but one of the TV shows I'm capping right now (Andromeda) has about the same ratio (5% video source / 95% film source). I decided to go with full-out Telecide(guide=1).Decimate(mode=2) -- terrific output on the film material, and while the CGI sections obviously get choppy they're no worse than any other method I tried short of going to 60fps.
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29th October 2002, 17:19 | #5 | Link |
teh 8bit fool
Join Date: Oct 2002
Posts: 266
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trying to avoid choppyness
hmm, that's what i'm trying to avoid at all costs, I want the copy to be as close to the original as possible without having to split to 2 DVD-Rs. So, I guess I'll play more with mode=0 or mode=1, threshold setting. Thanks for your input!
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29th October 2002, 18:05 | #6 | Link |
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Actually in my experience mode=1 on FILM material is a bad idea. Telecide spits out progressive frames + one duplicate in a series of 5. Mode=1 tries its best to make that duplicate a blend of the two surrounding progressive frames, but doesn't seem to ameliorate the problem altogether.
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29th October 2002, 19:42 | #10 | Link | |
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Quote:
Now, for something completely off-topic, what's the meaning of this contained within the DecombHelp.html file? About mode=2: "Note that for the most reliable IVTC of 3:2 pulldown material, you should use pattern guidance together with this mode of decimation." Exactly how necessary is this? From what I've seen, neuron2 is telling us to avoid mode=2 except for anime. |
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29th October 2002, 19:49 | #11 | Link | |
teh 8bit fool
Join Date: Oct 2002
Posts: 266
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modes
please share your wisdom on the:
Quote:
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29th October 2002, 20:32 | #12 | Link |
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If you notice some interlacing after the force film (the 2% that didn't have the pulldown flags) then you can use decomb to IVTC but if there is no visible interlacing then force film will encode a bit faster. I noticed some interlacing on some Sherlock Holmes DVD's when using force film when the % film was around 98%, while decomb gave me perfect progressive video (but I had post=true so it might have cleaned up a few interlaced frames, I didn't look through it that closely).
just my 2 cents |
30th October 2002, 00:23 | #13 | Link |
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Join Date: Feb 2002
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Try it
Try it, the ivtc filter that is. It doesn't work on all sources. It's strange. If decomb or tmpg work, then usually IT wont, whereas if decomb or tmpg don't ivtc the source well, then IT usually works. There is nothing to configure except whether the source is top or bottom field order. But I tried EVERYTHING on a few Region2 dvds I have and NOTHING worked to remove the interlacing on certain hybrid parts, BUT when I tried "IT" 95% of the interlaced frames were removed, NO blending! Give it a shot, it's definatly worth trying out. Search the threads for like IT and IVTC and ye shall find.
LB
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30th October 2002, 18:16 | #16 | Link |
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Hi-
by that logic i can just serve it as 'force FILM' in DVD2AVI though... Your's is faulty logic. A full strength IVTC will work on any material (more or less) that was telecined in the first place. Force Film will only work perfectly on telecined material where all the flags have been set properly. Of all the telecined material that I see, about 90% or so must be IVTC'd, and if only Force Filmed will leave behind at least some interlacing or jerkiness (and at percentages up to 99%). The only time that Force Film is guaranteed to work is when it shows as Film (100% Film). The guides say to Force Film when the Film percentage is equal to or greater than 95%. That may work, but isn't guaranteed. ...quick way to decide between "mode=0", "mode=2" and "mode=1, threshold=50" For the purposes of your movie, you can forget Mode=2, as it's mainly for anime. Make your .d2v with no Field Operation, open it in GKnot, and go to the places that show in DVD2AVI as interlaced or NTSC. Step through it frame by frame and if you see interlacing in every frame, then it's interlaced and Mode=1 may be the answer if you can't live with the jerkiness resulting from bringing it down to 23.976fps. If it shows the usual 2 interlaced frames in every 5, then IVTC it. Or doing it your way, make the .avs with Telecide(Post=False) and no Decimate(5). Go to those same places, and then you're looking for no interlacing and one duplicate frame in every 5. |
30th October 2002, 18:49 | #18 | Link |
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Hi wfn1-
You're fast on the reply-you must want to get this (great) movie finished. Ordinarily, when speaking of IVTC, we are referring to the "full strength" solutions such as Decomb, GreedyHMA, IVTC2.2, or IT. Force Film in DVD2AVI is a somewhat "weaker" solution that only follows the flags, and doesn't use the "brute force" methods of field matching or pattern detecting. But to answer the question-to be absolutely safe, I'd use Decomb if I were you. Force Film may work, but I've been burned too many times by using Force Film and then finding interlaced frames afterwards. Force Film is faster (particularly if the deinterlacer is turned on in Telecide()), but Decomb is surer. |
30th October 2002, 20:26 | #19 | Link |
teh 8bit fool
Join Date: Oct 2002
Posts: 266
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confirmation.
so in other words if i want to IVTC it I would be better off with
Telecide(guide=1,post=false) Decimate(mode=0) rather than DVD2AVI's force film. btw, I made 2 copies of the movie, one with Telecide(post=false) Decimate(mode=1,threshold=50) lost some bandwidth on the encoding part since it's 29.97 fps. and one with just force FILM in DVD2AVI, I'll watch both tonight and let you know which one turned out better. I will also try to use decomb to IVTC and see if the end result is better then DVD2AVI's force FILM. Cheers! |
30th October 2002, 21:17 | #20 | Link |
Guest
Join Date: Jan 2002
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@JohnMK
Mode 0 vs 2: If in a cycle you have multiple different strings of duplicates, e.g., n d d n d, where n is a new frame and d is a duplicate, mode 0 will take the frame that is most similar to its predecessor and not the one that is part of the longest string of duplicates. For normal films, these sequences are rare and it won't matter; use mode=0. For animations that are animated by duplicating or triplicating (or worse) each frame, you need to decimate from the longest duplicate sequence to avoid causing jerkiness; use mode=2. I need to correct the statement in my help file that you referred to. Thank you for pointing it out. @wfn1 You might also consider using Forced Film but passing the result through FieldDeinterlace(full=false). I know my hero manono is holding his hands over his ears and grimacing, but you may find it satisfactory for your purposes. Last edited by Guest; 30th October 2002 at 21:19. |
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