Weird frame blending question

[ReveriePass]

Hi! I have a DVD with a frame order like this:

1 - A
2 - B
3 - C
4 - D
5 - D
6 - E
7 - F
8 - G
9 - H
10 - H

What is this style referred to as? I was able to get a clean 24 frames using IVTC, using the frame blend option (whatever it was called) using Virtual Dub 2.

[davexnet]

Is it NTSC frame rate?
If so you can set the IVTC filter to
reduce frame rate/auto detect/adaptive
to recover the film underlying film frames

[ReveriePass]

Is it NTSC frame rate?
If so you can set the IVTC filter to
reduce frame rate/auto detect/adaptive
to recover the film underlying film frames

Thanks! It is an NTSC frame rate. When searching through this site, IVTC doubles the frame rate to around 60, correct?

[davexnet]

Thanks! It is an NTSC frame rate. When searching through this site, IVTC doubles the frame rate to around 60, correct?

NO. IVTC (Inverse telecine) undoes the telecine from the DVD, to leave 4 unique frames followed by a duplicate.

To remove the duplicate yielding the original 24 (23.976) unique frames use "reduce frame rate" as mentioned above.

If you're not sure it's right, provide a 30 second sample showing some movement

[ReveriePass]

Thanks! It is an NTSC frame rate. When searching through this site, IVTC doubles the frame rate to around 60, correct?

NO. IVTC (Inverse telecine) undoes the telecine from the DVD, to leave 4 unique frames followed by a duplicate.

To remove the duplicate yielding the original 24 (23.976) unique frames use "reduce frame rate" as mentioned above.

If you're not sure it's right, provide a 30 second sample showing some movement

So, the file I ripped from my DVD has 4 unique frames followed by a duplicate. What does this mean? That it was already inverse telecined?
Sorry, just trying to learn!

[poisondeathray]

So, the file I ripped from my DVD has 4 unique frames followed by a duplicate. What does this mean? That it was already inverse telecined?
Sorry, just trying to learn!

It depends on how you are viewing it, and how it's being processed. Some hardware or software might be deinterlacing it , for example

What hardware, what software, what configuration, what decoder, what renderer, what settings are being used to view the "ripped" DVD ? Is it a 1:1 rip , or a "copy " of the DVD, or is it not really a "rip", but a re-encode ?

[davexnet]

On typical NTSC DVD's produced from film stock (old Hollywood movies, etc),
without any vdub filters being active you would normally see
3 "clean" frames + 2 with combing. This is the 3/2 pulldown pattern,
4 source film frames become 5 video frames (because of the 29.97 fps NTSC requirement),.

if you enable the IVTC filter but not "reduce frames" you'll see 4 "clean" frames + 1 dup if you step through frame by frame
(The IVTC filter extracts the missing clean frame from the 2 combed frames)

https://en.wikipedia.org/wiki/Three-two_pull_down

EDIT - if your DVD file really has 4 good frames and one dup straight off, then maybe all it needs
is to decimate out the dup frame

[ReveriePass]

On typical NTSC DVD's produced from film stock (old Hollywood movies, etc),
without any vdub filters being active you would normally see
3 "clean" frames + 2 with combing. This is the 3/2 pulldown pattern,
4 source film frames become 5 video frames (because of the 29.97 fps NTSC requirement),.

if you enable the IVTC filter but not "reduce frames" you'll see 4 "clean" frames + 1 dup if you step through frame by frame
(The IVTC filter extracts the missing clean frame from the 2 combed frames)

https://en.wikipedia.org/wiki/Three-two_pull_down

EDIT - if your DVD file really has 4 good frames and one dup straight off, then maybe all it needs
is to decimate out the dup frame

Thanks so much for all of this information! Super helpful. To double check, I bought the DVD on eBay so I can rip it myself.