29.97 to 23.976 - interlace dilemma

[TenementLady]

I've been asked to de-interlace a movie which was originally transfered from 16mm film to PAL digibeta, and was then converted to NTSC for its American DVD release. The original master is now lost, so I am working from a DVD rip. However, I can't seem to work out the correct way to de-interlace - it is showing up differently as either telecine, 23.976 interlace or 29.97 progressive in different software. I've tried various variations of QTGMC / TIVTC but I keep getting dupe frames. Can anyone help?

sample MKV file

[jagabo]

It's normal 3:2 pulldown. Inverse telecine to 23.976 fps.

Mpeg2Source("sample_from_DVD.d2v") 
Crop(6,0,-10,-0)
TFM() 
TDecimate()

[TenementLady]

Thanks - how would I do that in Hybrid?

[jagabo]

I don't use Hybrid but I believe it lets you modify the scripts it builds.

[Selur]

Hybrid does not support crop before deinterlacing/ivtc, but you can add a custom section and add the crop there.
Just make sure to (additionally) let Hybrid now via:

# width XXX
# height YYY

in that section that you changed the resolution.

TFM() 
TDecimate()

should be the same as normal TIVTC.

[Selur]

Just did a quick check and Vapourynth TIVTC does return different results, sou you would need to use Avisynt to reproduce this.
Correction: moving crop before Deinterlacing is supported, I just totally forgot I added that.

[jagabo]

I didn't notice this before but the MPEG 2 data is encoded at 23.976 fps progressive with pulldown flags. If the entire video is like that you can use DgIndex in Force Film mode and you won't need to TFM().TDecimate().

[Selur]

Okay, found the issue: the source filter.
Hybrid by default used DGDecNV, when using LWLibavSource normal TIVTC in Vapoursynth works too.

[TenementLady]

re: 2:3 pulldown

As the original master was PAL and 2:3 pulldown was added for NTSC, should I be taking the file back to 25fps or 23.976? Confusing.

[jagabo]

If you want 25p you'll have to speed up the audio too.