Film 95-99% / NTSC 15-25% All around the movie problem

[DJSatane]

Hello,

I am trying to rip Angel Heart dvd and I have ran into a little of a trouble. DVD2AVI 1.86 during preview shows that initial screens with logos and credits in black background are NTSC ~15-25% Progressive.

Once the movie starts its *mostly* FILM and FILM(Progressive) does reach 95-99% after previewing the whole movie. However, every here and there within the movie there are NTSC 5%-15%(Progressive) frames and so on. That is all at 29.970fps. I havent run into situation like this before.

I have attempted to do a quick IVTC with Video>Field Operation>Force Film and down to 23.976fps. Then used IVTC Reader to convert to pseudo avi, however when watching it there are small artifacts around the intro and ending credits, and in places where NTSC frames popped out within the movie. It does not look interlaced however, but I am not sure. Within the movie often in a all dark area there will be area of black divided by unequal brither area from another odd shaped are of blackness. Its not horribly apparent but its there.

Next I have tried doing Inverce Telecine with TMPG but that didnt clear those problems. I have looked over these forums and noticed that maybe the movie should be kept at 29.970 fps and used Decomb
Telecide()
Decimate(mode=1,threshold=50)
or something like this on it instead?

If anyone can help me or have any ideas on what I should do, I would appreciate it.

[DSPguru]

'angel heart' - what a strong film !!

[Antimon]

Yup, gotta love those mixed mode , ok heres the deal, DONT force film, leave it at 29.97 out of dvd2avi then sue decomb liek youthought, with deinterlace and ivtc set liek you said, thatshould generate a 23.967 fps progressive file all the way through,

[manono]

Hi-

I'm with Antimon. But Decimate(mode=1,threshold=50) will keep it at 29.97fps. I think I'd just use the standard Telecide()-Decimate(5) on it to bring it down to 23.976fps. If some of those problem parts really are pure interlace (which I doubt), then a few small parts may wind up a bit jerky. But, for me, that's still better than paying the price of a larger file size or lower quality.

[Nic]

Decimate(mode=1,threshold=50) will keep it at 29.97fps...so perhaps use: Decimate(cycle=5,mode=1,threshold=50) which will decimate to 23.976fps but will also allow for the hybrid bits....hopefully :)

-Nic

[manono]

Hi-

Nope-Decimate(cycle=5)=Decimate(5)=Decimate(). That is, knocking out one duplicate out of every 5 frames is default in Decimate. Therefore, Decimate(cycle=5,mode=1,threshold=50) is the same as Decimate(mode=1,threshold=50) and keeps it at 29.97fps.

To see if the problem parts really are pure interlaced (and therefore might be kept at 29.97fps), load your 29.97fps .d2v into GKnot, or make an .avs without IVTC and load it into VDub or NanDub, scroll to the problem parts and check to see if every frame is interlaced. My guess is they aren't and can be conventionally IVTC'd.

Hi Nic-I'm using your current 4-18 version of XviD for my encodes. Damn-I love that codec-keep up the good work!

[Antimon]

Nic is on the xvid team...? Or did i misunderstand something?

Man, this forum has like the be all end all of dvd->divx authers and programers :-)

No wonder the mods are so protective of it.


Hey Nic.....what version of decomb are you using in your dvd2avi compile, looks like 3.8?

I'm on graphs site trying to make heads or tails out of the decomb filter as i have no idea what the settings mean or how to use them.

I also get confused between ivtc and telecine, as to which is which, looking inthe help file in the 3.8 distro so you guys wont have to school me.....but feel free to offer any info you might have :-)

I knwo it's basicaly a 23.967<->25<->29.97 conversion with smart deinterlacing ideal for mix mode streams etc. But i'm not sure which term referse to 24-->29.97 conversion and what refers to 29.97 to 23.967 recover...thats ivtc right, and telcine is going from 24-->29.97?

How can you tell what a stream is....dvd2avi kept switching from progresive to interlaced, and was at 29.97 fps, so does that make it a canidate for ivtc processing? and i should not use teleced on that yes?

Am i correct in asuming that if set telecine you do not need to check the deinterlace boxes in the field deinterlacing section of the plugin?

i thought i had to, so looks like i was doing double processing...or is the interface smart enough to realise that and disable my checks?

The help fiel says do not resize vertically before running, but by using the internal resizing of dvd2avi, is it following that rule...or do you have the decomb filter running pre resize?

[Milkman Dan]

Yeah, you have the IVTC/Telecining process correct.

You shouldn't resize or otherwise mess with the frames (temporalsmoother, spatialsmoother, crop) before Decomb does it's work.

Decomb has the facility to only deinterlace the portions of the video frame that it considers to be interlaced. This is set by one of those thresholds.

[Nic]

Hiya,

1) Many people are on the XviD team, the main people are the likes of gruel, isibaar, suxen_drol, etc. I just created a filter for it with post-processing (with a little help from trbarry of course :) )..I hope you like it :)

2) @Antimon: Erm, my interface isnt that inteligent, so it would have been adding FieldDeinterlace()....It should be more intelligent though...(but im lazy :) .. but ill try to add it :) )

Cheers,
-Nic

[Asmodian]

I hope I am not just restating what you already know Antimon but here goes
Basics of Decomb
Telecide reconstructs progressive video from (partially)interlaced video but leaves the frame rate alone, it also deinterlaces frames it detects as having interlacing artifacts (combing) if postprocess=true (the default)
Decimate with mode=0 (default) drops 1 in [cycle] (default cycle=5) frames which it picks using a reasonably sophisticated technique for detecting the frames generated by a telecining process (i.e. converting from 24fps film to 30fps for region 1 TV - not telecide, telecine), to go from 30 to 24fps.
Decimate with mode=1 does the same as mode=0 when the content is telecined except for instead of just dropping the detected frame it replaces it with a blend of the previous and next frame. If it detects the video as not having been telecined (native 30fps) it just leaves it alone. This is only useful for mixed content (some native 30fps video and some telecined (so now at 30fps) 24fps video - i.e. TV shows that were shot on film (24fps) but have special effect scenes generated at 30fps) that has interlacing problems after a telecide, with postprocess=false, (in the telecined sections) due to 'bad' telecining. If you don't notice any artifacts or combing after telecide I would not use decimate with mode=1
Hope this helps someone :)

ps I have yet to mention my respect of the incredible (and very active!) coders on this board... but when posting below Nic (though he/you ;) is/are but one of many deserving coders) I just have to say I do feel... a little humble :)

[JohnMK]

Originally posted by Asmodian
Decimate with mode=1 does the same as mode=0 when the content is telecined except for instead of just dropping the detected frame it replaces it with a blend of the previous and next frame. If it detects the video as not having been telecined (native 30fps) it just leaves it alone. This is only useful for mixed content (some native 30fps video and some telecined (so now at 30fps) 24fps video - i.e. TV shows that were shot on film (24fps) but have special effect scenes generated at 30fps) that has interlacing problems after a telecide, with postprocess=false, (in the telecined sections) due to 'bad' telecining. If you don't notice any artifacts or combing after telecide I would not use decimate with mode=1
Hope this helps someone :)


Is this probably what I should do with Star Trek The Next Generation NTSC DVDs? Mode = 1? I do notice credits and special effects scenes are reported as 'interlaced' by DVD2AVI, while the rest of the film is reported as 'progressive.' I guess this is why DVD2AVI's Force FILM actually works pretty well for Star Trek The Next Generation DVDs, except for the aforementioned types of scenes.

So. What's the correct procedure here? Should I continue to use DVD2AVI Force FILM, and add in decomb to the process? I've done a lot of reading today, and while I may find the answer in another 30 minutes of reading, if anyone here knows it and can give it to me in 10 seconds, well, please go ahead. :)

Thank you everyone,

John

[jggimi]

Should I continue to use DVD2AVI Force FILM, and add in decomb to the process?No!

Force FILM *is* an Inverse Telecine, done through reassembling mpeg2 fields from the VOB. Decomb is also an Inverse Telecine -- with default parameters for Telecide and Decimate -- done by frame analysis. If you do both, you'll end up with a framerate of 18.976. Ouch!

Here's a link that might help explain your options a little bit: http://forum.doom9.org/showthread.php?s=&threadid=32826

And here's one with good advice for hybrid content: http://forum.doom9.org/showthread.php?s=&postid=179901

[JohnMK]

Thank you ever so much.