Reinterlacing for output to DVD

[JIM E]

I downloaded a Xvid clip. It is 640x480 res, 29.97 fps, progressive frame. I want to burn it onto a DVD so that I can watch it on TV. Before I can do that, I need to convert it to a format that is TV friendly. It is obvious to me that this clip was shot in video, and as such, somebody must have deinterlaced it when they converted it to Xvid. I understand that TVs need interlaced footage to play properly, so I guess that I have to find some way to reinterlace this clip before I convert it to DVD. I have searched around and haven't been able to find any sites on this topic. Could someone just verify that this is the right way to go, and if so, how do I reinterlace it?

[guns1inger]

Simplest conversion would to DivxtoDVD or ConvertXtoDVD, then see how it looks. Otherwise it becomes a larger job involving avisynth scripts and other tricks.

[manono]

I understand that TVs need interlaced footage to play properly

You understand wrong. Although it probably played a bit more smoothly when interlaced, there's nothing wrong with encoding it the way it is, and there's no way to regain the lost smoothness. Most progressive 29.97fps footage is encoded as interlaced, but that's a bit different than it actually being interlaced.

[JIM E]

So you're saying I should just encode it as is. So if I were to use CCE to encode it, should I select zigzag scan order and non-progressive frames, or alternate scan and progressive frames, or what?

[edDV]

So you're saying I should just encode it as is. So if I were to use CCE to encode it, should I select zigzag scan order and non-progressive frames, or alternate scan and progressive frames, or what?

There are two ways to encode MPeg2 for standard NTSC DVD playback, 29.97fps interlace or 23.976fps progressive (I'll skip the details see https://www.videohelp.com/dvd ).

You need to convert to one or the other. Progressive video is reinterlaced in the DVD player (e.g. converted from 23.976 progressive to 29.97fps interlace) when played from the composite or S-Video outputs. YPbPr outputs can be set to play 29.97fps interlace 480i or 59.94fps 480p in the progressive DVD player menus.

[JIM E]

OK, so then I guess my question is how do I convert my 29.97 progressive to 29.97 interlaced?

[guns1inger]

If you have CCE, go with CCE. If you set the fps to 29.970 (which it will probably do itself anyway) you will get interlaced output.

[JIM E]

OK, so I encoded it using CCE. I selected progressive frames, and zigzag scanning order. It was a little bit jerky on my TV. Did I pick the wrong settings, or is this as good as I am going to get?

[guns1inger]

Chances are the original was 23.976 and has been very badly converted to 29.976 progressive by someone who didn't know what they were doing. This would have entailed the creation of duplicate frames and other issues that cause jerkiness. Not much you can do unless you want to try and undo the damage.

[manono]

In your first post you said it had obviously come from a video source. I figured you knew what you're talking about, and didn't pursue it. However, now you say it plays jerky after encoding, and it makes guns1inger's theory a real possibliity. So, what made you think it was from a video source originally? Just the 29.97fps framerate? There are so many people out there that don't know what they're doing, and turn 23.976fps into 29.97fps unknowingly, thus making them play jerky. Does the source AVI play jerky? Open it in VDub(Mod) and scroll to a place with motion, or open it in a player, such as MPC, that can advance a frame at a time. When stepping through it one frame at a time, do you see anything peculiar, or is it all clean, unique frames?

For what it's worth, when I have a 29.97fps progressive source, I also usually encode it using zig-zag scanning with the progressive box checked. And it doesn't play jerky.

[lordsmurf]

For the record, Procoder 2 does a really nice job of turning 23.976 progressive into 29.97 interlaced. It creates interlaced intermediate frames. This can be helpful if you are using authoring software that is noth friendly to NTSCfilm sources.

Most other encoders butcher it, adding duplicate frames or blurring frames together.

[JIM E]

The reason I believe it is video is because it has that "video look" to it. Also the clip itself is just a news broadcast from CNN, and I doubt CNN uses film cameras. Perhaps I overreacted when I said it was jerky on TV. It is not really jerky, just not quite as smooth as I'm used to seeing from regular video sources. I assume that that little bit of jerkyness comes from the fact that it has been deinterlaced, which is why I asked if there was any way to reinterlace it. I guess not. Oh, and manono, I opened it up the origonal clip in Vdub and went frame-by-frame and found no scanlines, or any other peculiar things. The origonal clip looks perfect on the computer.

[dphirschler]

Video looks so smooth because it is actually ~60 fields per second. But if what you have has been deinterlaced, then it is now ~30 (29.97) frames per second. I always find that progressive ~30 fps looks a bit jerky. But I doubt there is anything you can do about it. Maybe Procoder can fix you up.


Darryl

[manono]

Yeah, I agree with dphirschler. By having been deinterlaced, it went from 59.94 fields per second to 29.97 frames per second. It shouldn't be any less smooth as a DVD, though, than is the AVI.

[JIM E]

Alright, well then I guess there's nothing I can do then except encode it as is. Thanks anyway guys.