DGIndex Force Film vs IVTC

[alcOre]

Ok, I've been reading quite a few articles/tutorials on telecine/interlacing/blah blah blah. I understand a lot more now which should help me understand how to handle my source material. But I have a question...Force Film in DGIndex is a IVTC process isn't it? What's the difference between using FORCE FILM when creating a .d2v project in DGIndex or using TIVTC or decomb IVTC in MeGUI's avisynth script creator? Aren't they both doing the exact same thing? (Reversing the telecine process.)

[manono]

What's the difference between using FORCE FILM when creating a .d2v project in DGIndex or using TIVTC or decomb IVTC in MeGUI's avisynth script creator?

You use Forced Film when the pulldown flags are present (soft telecine). When you run the Preview in DGIndex, you'll see both Progressive and Film in the information window. Forced Film reads the flags to pull out the original 23.976fps frames, giving you a 23.976fps D2V.

In the absence of pulldown flags (showing as Interlaced and NTSC in the Preview), if it's been hard telecined you create a 29.97fps D2V using "Honor Pulldown Flags" and IVTC it.

Whenever possible, you want to Force Film it rather than IVTCing it. The encoding will go much faster, and the results will be better, given the sometimes imperfect nature of an IVTC. Is Force Film an IVTC process? You might think of it as IVTC lite, but they're not really the same thing. A Force Film just reads the flags and drops the repeated fields, while a full-on IVTC first matches up the fields and then drops the duplicate frames.

[alcOre]

Great...I understand it now, at least I think I do.

From what I understand from your explanation, FORCE FILM is used on source material that is stored as 23.976p and flaged for 3:2 pulldown with flags, and the telecine is performed by the hardware player.

ITVC to get the original 23.976p fps is used when the original source video was telecined during the original encode and is already at 29.97 fps, and is not flagged with a 3:2 pulldown for the hardware player since the telecine is already done...is my understanding correct?

[manono]

What you said is correct. You might also have a look at a D2V sometime. Open it in Notepad. If it says:

900 5 0 125532160 0 11 1 70 71 d2 f3 f0 e1 f2 f3 e0 f1 f2 e3
900 5 0 125718528 0 11 1 70 71 d2 f3 f0 e1 f2 f3 e0 f1 f2 e3
900 5 0 125925376 0 11 1 70 71 d2 f3 f0 e1 f2 f3 e0 f1 f2 e3

Those 0123 0123 are evidence of the 3:2 pulldown. If it's hard telecine (or also really interlaced), you'll get either a series of 2s or 0s or both, something like this:

d00 5 0 2421672 0 0 0 b2 b2 92 b2 b2 a2 b2 b2 a2 b2 b2 a2
d00 5 0 2721784 0 0 0 b2 b2 92 b2 b2 a2 b2 b2 a2 b2 b2 a2
d00 5 0 3030848 0 0 0 b2 b2 92 b2 b2 a2 b2 b2 a2 b2 b2 a2

For more information on DGIndex, the D2V, and all the letters and numbers it contains, read the FAQ:

http://forum.doom9.org/showthread.php?t=87809

[alcOre]

thank you so much manono...you have been a great help. I really appreciate it.