Completely progressive?

[girotour]

I read the interesting thread http://forum.doom9.org/showthread.php?threadid=38351 and I finally understood the difference between an interlaced movie and a progressive movie with shifted fields.
I just have one more doubt: could a movie be interlaced (or have shifted fields) only partially?
I mean: when DVD2AVI says that a movie is interlaced, but I can't see any black line playing, for example, the first two minutes, may I be sure that the movie is completely progressive? Or it could be interlaced (or have shifted fields) somewhere?

Thx.

[jggimi]

If you have not yet seen it, please review www.doom9.org/ivtc-tut.htm for helpful information.

[girotour]

Hi Jggimi and thank you for your answer.
Yes, I read the whole document, but I couldn't find the answer to my question (or, perhaps, I missed it).
In the thread I was talking about in my previous post, N_F asks: "Does "Swap Field Order" in DVD2AVI have any place in all this?". And manono replies: "Yes, very definitely. But *only* if they have all been shifted."
This seems to indicate that you can have a movie which is half "real progressive" and half "progressive with shifted frames".
If this is true, is there any way to discover it without looking at every single frame (this could be a little bit long :))?
Perhaps, every time DVD2AVI says that my movie is interlaced I should use the "Telecide()" technique even if I can't see any black horizontal line, but I'm not sure this is the right thing to do...

Bye.

[N_F]

Two things:

1. Yes, a movie can appear both progressive and interlaced (or shifted fields), but this is quite unusual. First you have the hybrids you can read about in the ivtc-tut (and decomb manual), but that's for NTSC. For PAL I can only remember seeing it once in all the movies I've made, at that time I used Fielddeinterlace(full=false).

All in all, just glance through the movie to see whether it's interlaced or not. If in doubt, it may be a good idea using Telecide() just as you suggests, however, I wouldn't suggest that you use it in every movie "just in case". This whole case is an extreme scenario that you're very unlikely to end up in (at least IMHO, maybe hakko or anyone else think differently?).


2. I'm not 100% sure I understand manono correctly, but I'm sure he'll correct me if I'm wrong. First, a movie can be (1) progressive, (2) interlaced or (3) have it fields misarranged.

Point (3) can be further divided up. It can simply have it's fields swapped (top field becomes bottom field, etc...) through the whole movie in a regular pattern, in this case "Swap Field Order" would most likely be your best choice. But the fields can also be misarranged in many other ways, where "Swap Field Order" wouldn't help you, in this case Telecide() would be your choice.

Oh, well, hope I make some sense (I always feel like I'm kinda loosing control of the post whenever I write something longer (for me) like this)

[manono]

Hi-

I assume this is PAL material. If so, DVD2AVI is just plain wrong a lot of the time when it says it's interlaced. A quick scroll through it should tell you if it's really progressive. DVDs where there are periods of progressive frames followed by periods of interlaced frames are, as N_F says, extremely rare (although I did read the other day that the R2 Conan is like that).

If this is NTSC, then a completely different answer is required.

[girotour]

Guys, thank you for your answers.
Yes, I mainly encode PAL movies so, from now on, I'll avoid to trust DVD2AVI infos.
Another little question: can DVD2AVI be wrong also when it indicates that a movie is progressive? Or it just make some mistakes when it says that the movie is interlaced.

Bye.

[manono]

Hi-

I've never seen any examples where it said progressive but it really wasn't. You can trust DVD2AVI when it says progressive. If it says Interlaced, and it is NTSC, then you have to look at the frames to determine if it's really Interlaced, or if it can be IVTC'd to return the Progressive frames. If it's PAL and says Interlaced, then it might not be interlaced at all, or if it appears interlaced, then usually it can be fixed by swapping the field order or putting on Telecide() in the .avs.

The document jggimi referred you to, especially the PAL portion, has more information on that.

[N_F]

Originally posted by manono
If it's PAL and says Interlaced, then it might not be interlaced at all, or if it appears interlaced, then usually it can be fixed by swapping the field order or putting on Telecide() in the .avs.


I have to disagree on that. The PAL movies/series I have seen have always been progressive or truly interlaced, I have yet to see a clip where Telecide(post=false) would actually help you.

[hakko504]

Originally posted by N_F
I have to disagree on that. The PAL movies/series I have seen have always been progressive or truly interlaced, I have yet to see a clip where Telecide(post=false) would help you. I've done 5 or 6 DVD's that looked like that over the last months, most notable E.T. as it was a quite high quality DVD and still had that kind of mastering error, but Telecide(guide=2,post=false) fixed it.

[N_F]

Originally posted by hakko504
I've done 5 or 6 DVD's that looked like that over the last months

I'm surprised to hear that. But at least it has to be among ~70-100 DVD's?

[hakko504]

...out of 40~50 PAL originating on FILM. Total rips of all kinds is much higher, 150~200.

[N_F]

Is it weird that I'm tempted to get E.T. just to see how a movie with disorganized fields would really look and behave?

Just like I bought Euphoria (X-rated movie) a while ago just to see how an X-rated movie would "look" like (from a DVD --> DivX perspective, nothing else :)).