Trying to understand/resolve interlacing

[FoolsFollowing]

I'm currently having various interlacing problems. It first occured last week when some footage from a different ripped DVD appeared to be extremely skewed. I managed to resolve this by following an online guide and using PGPulldown. However, I have since noticed that my other footage also contains an interlacing problem, it's just far more subtle.

The problem that I have is that I do not understand interlacing. I have no idea what using PGpulldown actually did or why it helped. I have tried many online guides, but they virtually all refer to interlacing problems as being a result of editing camcorder footage, not editing official DVDs. I think interlacing relates to issues regarding the fps, which I also have trouble understanding. I am currently converting all my footage to 23.976 fps but I do not know why and when I have enquired about this on this forum I have not yet recieved an explanation. Finally, I think my problem may be conected to the role of NTSC/PAL in the conversion process. Once again I have followed Boon's guide and Captain Khajiit's guide's to the letter, and while these have been very useful and helped me overcome certain problems when they arise, they have not helped me understand what those problems were or why they arose in the first place.

I have read through a great many online guides on these subjects, but to date none have really helped me understand what these settings do, and very few directly relate to fanediting as opposed to home-movie editing. I have read all the guides on this site, but am still lost. Naturally, the Sony Vegas tutorial was even less helpful! Thus I come here asking if anybody knows of any guides that helped them with the following two issues:

1. Interlacing. Why is my footage interlacing. What is the cause of it. What is the best way to deal with it. How does this relate to: fps, NTSC/PAL, region, and/or screen resolution. Why don't the de-interlacing settings on Sony Vegas have any effect (blend or interpolate fields) and what is the difference between them.

2. Why am I converting all my fps to 23.976, as suggested in Boon's guide. Why not 25 or 30 as are the standard settings.

Any advice or help would be wonderful

[geminigod]

Oh boy. Very very long response required. No snarkiness intended in the following comment. A book might be super helpful. Library or book store probably has some great stuff that do a much better job of covering conceptual stuff than endless web browsing of forums will accomplish.

That said, your source video probably wasn't deinterlaced properly. Be wary of messing with FPS. Very tricky.

Download mediainfo http://mediainfo.sourceforge.net/en. Post the results for the main source video VOB that you are trying to work with. I.e. the one that was just a straight rip from DVD with no conversions or changes made.

[FoolsFollowing]

Oh boy. Very very long response required. No snarkiness intended in the following comment. A book might be super helpful. Library or book store probably has some great stuff that do a much better job of covering conceptual stuff than endless web browsing of forums will accomplish.

That said, your source video probably wasn't deinterlaced properly. Be wary of messing with FPS. Very tricky.

Download mediainfo http://mediainfo.sourceforge.net/en. Post the results for the main source video VOB that you are trying to work with. I.e. the one that was just a straight rip from DVD with no conversions or changes made.

Thanks Geminigod.

Here are the results for the Video_TS VOB (thats the only file I used MediaInfo on, lemme know if I should scan the other vob files):

General
Format : MPEG-PS
File size : 358 KiB
Duration : 480ms
Overall bit rate : 6 110 Kbps

Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings, BVOP : Yes
Format settings, Matrix : Custom
Duration : 480ms
Maximum bit rate : 6 000 Kbps
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Scan order : Top Field First
Compression mode : Lossy

[TV's Frink]

Compression mode : Lossy

I don't know much, but that doesn't sound good.

[njvc]

I had this issue with my silent consecution edit. My footage was PAL (25 fps) and I needed to convert it to NTSC (23.97 fps). There are many programs that claim to be able to convert frame rates, but not many that do it very well... It's a tricky one. TMBTM has experience in this area. Perhaps send him a PM?

[Captain Khajiit]

I don't know much, but that doesn't sound good.

It sounds exactly as it should sound. MPEG-2 is lossy compression, and all FoolsFollowing is doing is using a mediainfo to read a VOB from the disc that he ripped before any conversions have been done. If it said anything else, I would be concerned.

[TV's Frink]

Well, as I said, I don't know much.

[juice4z0]

I use xvid4psp to handle my frame rate issues. It seems to be able to convert them properly

[geminigod]

Damn, I was hoping CK would walk you through this.

Good news, the scan type is progressive so you are all set on the interlacing issue! Bad news. It is PAL video, which means your framerate and resolution are a bit different from the traditional NTSC.

I say you should bug njvc. Make him show you how he handled this conversion.

Alternatively search the forum for PAL conversion guides. CK wrote one up a while ago. I remember he and I debating about the best way to handle the framerate conversion. The consensus seemed to be that the best way is to just slow down the video and audio slightly.

[njvc]

I say you should bug njvc. Make him show you how he handled this conversion.

To be perfectly honest, I can't remember how I did it! I tried so many programs, I actually can't recall which one I settled on. The problem was, that in the end I wasn't very happy with the results anyway and concluded that either it can't be done well, or I don't have the patience to figure it out... Which is why I suggested TMBTM, as I think he knows how to do it...?