Question about Progressive/Interlace

[dazzle]

Question:
What happens when you encode a progressive movie as interlaced?

The reason I'm wondering is:
I used dvd2dvdr before (which also uses CCE), and if you encoded progressive material as interlaced in that program it didn't mess up the video (I only tried with PAL so far though).

However, if you encode interlaced as progressive it's a mess.

Another reason for asking this is, from time to time I've run into purely interlaced NTSC-movies or progressive movies with some interlaced content. Would it be possible to NOT choose Auto Select Ntsc Type, and just encode it as Interlaced, without screwing up the progressive parts?

Sorry if I'm being stupid, but I find these things interesting :D

[hendrix]

Originally posted by dazzle
Another reason for asking this is, from time to time I've run into purely interlaced NTSC-movies or progressive movies with some interlaced content. Would it be possible to NOT choose Auto Select Ntsc Type, and just encode it as Interlaced, without screwing up the progressive parts?

sounds to me that the DVD has been authored with progressive and interlaced intermixed. you'll want to demux per VobID and encode each parts as either interlaced or progressive. dont deinterlace your footage it'll only make it look worse IMO.

[dazzle]

Thanks for that hendrix.

Another question:
Could I still use the Auto Select Ntsc Type, and just not check Preogressive later on in DoCCE if the source is Interlaced?

[hendrix]

ya...use auto select NTSC type and demux per VOBID and DIF4U will determine whether or not each parts is interlaced or progressive and DO NOT correct audio delays when demuxing per VOBID...the delays are normal

[dazzle]

Thanks!
And for pure interlaced NTSC I do the same, exept the "demux by VobId"-part, right?
I do it the normal way, except I don't check Prog (use alt scan) in DoCCE?

[hendrix]

ya...just dont deinterlace

[dazzle]

Thanks!
I get it...I hope :)

[influenza]

AFAIK it won't matter if you encode progressive material as interlaced. It won't look any worse. Encoding speed just drops a bit.
With PAL material it's like this most of the time anyway. Material is progressive, but flagged as being interlaced.

Encoding interlaced as being progressive I never tried. I know Fmalibu did that and he says it didn't look worse and encoding was a bit faster. So maybe only correct field order is important when encoding interlaced material.

[dazzle]

Originally posted by influenza
AFAIK it won't matter if you encode progressive material as interlaced. It won't look any worse. Encoding speed just drops a bit.
With PAL material it's like this most of the time anyway. Material is progressive, but flagged as being interlaced.
Yes, that's what I thought. So basically if you're in doubt, you could always set it to interlaced.

An easy (and not scientifically correct) way of deciding between Prog/Interlaced on Main Movie material (PAL) is:
If the movie was shown in theatres, it's (almost) always progressive.

Encoding interlaced as being progressive I never tried. I know Fmalibu did that and he says it didn't look worse and encoding was a bit faster. So maybe only correct field order is important when encoding interlaced material. [/B]
Hmm, I'm not sure about this though...I just encoded some extras as progressive by mistake. And I could see the combing (you usually only see in dvd2avi) in WinDvd as well.
I'm re-encoding this extra right now (with same Field Order) as interlaced right now. So I guess I'll see in about 1 hour :)

[influenza]

An easy (and not scientifically correct) way of deciding between Prog/Interlaced on Main Movie material

yes there are more scientific ways ;)

[dazzle]

Hehe...I know :D

[SeeMoreDigital]

Hi dazzle

Why do you want to encode (or re-encode) progressive video as interlaced?

Cheers

[dazzle]

SeeMoreDigital: I don't. I was just curious what happens if you do. :)

[SeeMoreDigital]

Originally posted by dazzle
SeeMoreDigital: I don't. I was just curious what happens if you do. :) I see...

Well it's really a pretty pointless exercise because in order to make progressive video interlaced you obviously have to create fields. ie 2 fields for each frame.

This is not so difficult to do with PAL prog' sources. But with NTSC prog' sources it can look a right mess if not done properly!

Arguably you won't notice the difference too much when viewing via a PC monitor (because they handle video progressively) but via a CRT TV, your NTSC interlaced images may look pants!

Cheers

[dazzle]

SeeMoreDigital: Yes I know that. :)
As I said, I don't wanna make progressive material into interlaced. I just wanted to know what happens IF you encode a progressive source as Interlaced (by mistake for example).

[SeeMoreDigital]

Originally posted by dazzle
SeeMoreDigital: Yes I know that. :)
As I said, I don't wanna make progressive material into interlaced. I just wanted to know what happens IF you encode a progressive source as Interlaced (by mistake for example). I do have some 'bad' PAL examples on a disc somewhere.

If I find them I'll post a short clip. But in order to see the full 'pants' effect, they have to be viewed on an CRT TV!

Cheers

[coona]

I have the same experience like influenza
With PAL material it's like this most of the time anyway. Material is progressive, but flagged as being interlaced.

And there is no difference if you encode these materials as progressive or interlaced, results are the same in both ways. DoItFast4U handle these materials like interlaced but in my opinion in this case it doesn´t matter anyway.