How do I IVTC a hard telecined AVI?

[MYoung]

I'm desperately trying to figure out how to take a 29.970fps AVI of film based content back into 23.976fps progressive video. It looks like the way to do it is to use Telecine() in AVISynth. I tried this script...

LoadPlugin("C:\stuff\AviTools\decomb\Decomb510.dll ")
clip1 = AVISource("C:\656_dvd\movement\test.avi")
Telecide()
return clip1

but AVISynth gives me this error...

"Invalid arguments to function Telecide"

Anyone know what I'm doing wrong?

[pijetro]

LoadPlugin("C:\stuff\AviTools\decomb\Decomb510.dll ")
clip1 = AVISource("C:\656_dvd\movement\test.avi")
Telecide()
return clip1

Try:

LoadPlugin("C:\stuff\AviTools\decomb\Decomb510.dll ")
AVISource("C:\656_dvd\movement\test.avi")
Telecide()
Decimate()#I believe Decimate(cycle=5) is default...

Drop the .AVS into Vdub, and check to see that you've got the correct Framerate.
Good luck!!!

[Cunhambebe]

How about the inverse? - 23,976 to NTSC DV 29,970????? Is that possible?

[MYoung]

pijetro,

Your code worked! Well, kinda. It accepted it but something still isn't right. I took a 60 frame sample of my video and ran your code on it and it did take it to 48 frames, all of which were progressive. However, for some odd reason, within those 48 frames, 3 are duplicates of other frames! They should be all unique frames! I am baffled! Any ideas? Telecide seems to want to take every 60 frames to 45 frames instead of 48.

The pattern of the telecined video is (P=progressive, I=interlaced)...

...PPIPPPIPPPIPPPIPPPIPPPI...

Any ideas?

Cunhambebe,

Yeah, that can be done. I have some AVISynth code that will do that. Let me see if I can find it. Then again, why would you want to do that? An MPEG2 encoder would do that automatically.

[adam]

That is not a conventional telecine pattern. The classic hard telecined video will have 3 progressive frames for every 2 interlaced ones. The default decomb settings will work flawlessly on these sources everytime.

For sources that don't follow such patterns you may have to manually set the pattern, or you could use decomb's pattern guidance. If that pattern is constant throughout then it should work well I think. Just read the documentation that comes with decomb for the syntax.

The only possible reasons I can think of when you would ever want to telecine 23.976fps material to 29.97fps material would be if you need to convert an NTSCfilm VCD to a compliant DVD (and even this is highly questionable- just go mpeg2 instead) or if you need analogue output. Storing video internally at 23.976fps and allowing the decoder to play it back at 29.97fps is by far the preferred method of storing NTSC footage.

[MYoung]

Hmm. In looking at my video some more I see that the pattern is also for some shots...

PPIIPPIIPPII

Also, when stepping through the clip, there are interlacing lines in areas where in adjacent frames, there are no corresponding lines in the other field, which seems to indicate that in the telecine process that frame information was lost. Maybe that would explain why 3 out of every 48 from 60 video frames are being duplicated. I guess I have no choice but to just encode my film as hard telecined 29.970fps. That really sucks.

Thanks for the help though!

[adam]

I'm wondering if this is anime or if maybe it could have originated from another region? These types of problems pop up all the time when people/studios do unconventional region conversions.

You can try using decomb's pattern guidance. It really does work wonders even on ridiculously screwed up sources, but of course like you said you will probably have to just keep it interlaced.

[MYoung]

It's actually a 16mm film that I shot in a film production class. It was telecined to DVCAM tape, imported into Final Cut Pro, and then exported as an uncompressed AVI so I could author it to DVD on my good ol' PC. I understand this because another film that I shot has the distinct 3:2 pulldown pattern and I just ran telecide on it and it performs perfectly. I guess my source is just messed up. Bummer!