Is my source definitely Pure Interlaced if every frame has combing?

[Meeple]

I've checked and double checked my source by creating the d2v with no Field Operations, and opening it in GKnot, advancing one frame at a time through 10-20 frames from 3 or 4 different sections of the whole program.

Each time I find combing in every single frame.

This would lead me to believe that my source is pure interlaced material and can be deinterlaced when I encode it. However, what's confusing me is that in DGIndex, when I Preview, sometimes the content shows up as NTSC Progressive. :confused:

Is this just DGIndex (DVD2AVI) being inaccurate as usual? Or is it really an indication that my source is actually progressive in some sections?

BTW, this is a DVD of a TV series.

[CWR03]

It depends on the series - if it was originally videotaped, it should be None, if it was originally filmed, in most cases it should be Film. If in doubt, create a sample by scrolling to a point where the camera pans, set your in and out points to include only 30 seconds or so of the video, save it in both formats and run some trials.

[neuron2]

Is this just DGIndex (DVD2AVI) being inaccurate as usual? DGIndex is accurately reporting the flags that are present in the MPEG2 syntax.

>Is my source definitely Pure Interlaced if every frame has combing?

No. For example, one-field-shifted progressive PAL shows combing on all motion frames but is really progressive. For a definitive conclusion, you have to inspect the field pattern, ignoring frame boundaries.

[manono]

Hi-

Is this just DGIndex (DVD2AVI) being inaccurate as usual?

No, it's just you not understanding what DGIndex is telling you. It's possible that some sections you didn't examine really are Progressive. It's possible that portions of the DVD are incorrectly flagged as Progressive. It's uncommon, but not unheard of. It's possible that the Progressive portions aren't part of the TV show itself, but maybe some pre-show studio logo, or post-show credits or something similar. I've also read that some TV shows, such as the R1 Friends DVDs, are 30fps progressive, and could possibly become field shifted after bad edits. I don't know for sure though, as I've never had a look at the Friends DVDs.

To look for field shifts, check the fields. First, put on a Smart Bobber, such as KernelBob(Order=1), or TDeint(Mode=1). If, during a motion sequence, every one is different, then you'd be safe in concluding it's interlaced. If you see every field repeated or duplicated, then it's progressive and just field shifted.

If none of that helps, then maybe you can make available a piece of a vob, either here, or uploaded to neuron2's server, for us/him to have a look.

[Meeple]

Thanks for the replies. Okay, bad choice of wording in my original post. I didn't mean to say that DGIndex is inaccurate, but rather that the flags in the source could be inaccurate. (Hence the advice I've repeatedly seen here to not just trust what DGIndex says, and instead to actually inspect the frames)

To look for field shifts, check the fields. First, put on a Smart Bobber, such as KernelBob(Order=1), or TDeint(Mode=1). If, during a motion sequence, every one is different, then you'd be safe in concluding it's interlaced. If you see every field repeated or duplicated, then it's progressive and just field shifted.I'll go ahead and try this to inspect the fields. It's getting to be a little bit too advanced for my comfort though... so I'm not sure if I'm doing it right. I do intend to get into using other Avisynth filters, so now's as good a time to jump in as any. Heh.

So I'm still using GKnot, and I've put a copy of TDeint in the GKnot Avisynth plugin directory. I'm going to edit the avs file, add a line to load TDeint, and then add another line in the Deinterlacing section. Is it correct to just put "TDeint(mode=1)" and that's the exact syntax needed?

Also, to inspect the fields, do I need to just hit the Preview button? Or do I actually need to encode a portion of video?

Thanks for bearing w/ my newbie questions.

[manono]

Hi-

Up at the top of the script, you also have to LoadPlugin. TDeint(Mode=1) is good for examining the fields. Or you can also use KernelBob as it's a part of KernelDeint, which comes with GKnot. To use it, remove the "#" from in front of its LoadPlugin, and further down, where it says, "#KernelDeInt(order=1,sharp=true)", edit that to say, "KernelBob(Order=1)". Should work, I hope. In both cases, you're doubling the framerate from 29.97fps to 59.94fps by making each field into a full frame

I don't know that I'd use the Preview, though, as it's going to play it as if it were a movie. You want to be able to advance a frame at a time. So either open the saved .avs in GKnot, just the way you would the D2V, or open the .avs in VDubMod. No need to encode anything. You're just going to inspect it.

[Meeple]

Okay, I did as suggested using TDeint(mode=1), opened the avs file in GKnot (noted that the clip was now indeed double the # of frames) and advanced frame by frame. No repeated fields, every single one is different.

So, it looks like another case of the DVD's flag being incorrect (saying it's Progressive when it's actually Interlaced).