Progressive vs Interlaced

[six13]

Is there any advantage to taking a source file that is interlaced and converting it to progressive. I have a mpg file satellite capture that I demuxed then authored the DVD files so I can run it through DVD-RB with Hcenc 21. HCenc sees it as ALTERNATE since it is interlaced. Is there any advantage to converting to progressive and is it possible? If so when is it done in the process?

Thanks in advance.

[Sharktooth]

If you're going to watch it on a progressive scan dislpay (like PC monitors, LCD TVs, etc) then yes. But be sure to use a good deinterlacer or you'll loose details or get artifacts.

[six13]

My TV is HD progressive scan and so is my DVD player with component cables.

(1) You believe the quality would be better, what would it look like if it was viewed on a conventional TV that isn't HD?

(2)Can you recomend a FREE good deinterlacer, when do you run the deinterlacer in the process.

I author with .m2v and the .ac3 files with DVDAuthorGUI and then run the folder with DVD-RB HCenc 21. The movie is King Kong and I have it over 2 DVD5's so I can get 6mbps.
thanks

[Manao]

Which King Kong ? If it's Peter Jackson's, the movie isn't interlaced, but telecined. And that definitely shouldn't be deinterlaced

[six13]

@Manao

it is Peter Jacksons 3 hr movie but it isn't a DVD rip. I recorded it with Media Center from a Satellite rec. with SVIDEO then demuxed the mpg and authored the files. I was going to use DVD-RB and HCenc but the compression was at 53% so I used Vobblanker to spread it over 2 DVD5's with no compression so I just used Imgburn in build mode for the DVD files. I have 6 mb p/s as a bitrate so it does look pretty good.

[Manao]

it is Peter Jacksons 3 hr movie but it isn't a DVD ripEven so, it's not interlaced. I don't think there's a video engineer dumb enough to interlace something that is progressive, since it would be more complicated than keeping it either progressive or telecined.

[Blue_MiSfit]

Right. You should use AviSynth to perform IVTC to recover the original 24p, and encode at 24p. Then use dgpulldown to apply soft pulldown, and author on the DVD.

~MiSfit

[six13]

@Manao,

I thought standard NTSC TV was interlaced, am I to assume that my media center would capture it as telecined (don't know what that means) So you are saying it is telecined and not interlaced. Is telecined refered to as progressive?

@Blue_MiSfit,

I don't follow, still learning. I see with DVD Rebuilder I can with Avisyth deinterlace with decombe or disable interlaced would this do the trick with DVD-RB then burn the output folder to DVD?

[Tack]

I thought standard NTSC TV was interlaced, am I to assume that my media center would capture it as telecined (don't know what that means) So you are saying it is telecined and not interlaced. Is telecined refered to as progressive?
Yes, NTSC is 60ish fields per second, interlaced. In an NTSC context, content that is telecined or "pulled down" refers to adapting 24 frames per second into 60 fields per second. A quick google will yield plenty of hits describing this process. The important thing to note about this is that given the telecined 60 field per second content, you can typically recover the 24 frame per second content losslessly.

Another way of saying this is that 480p24 content adapted to a 480i30 carrier using 3:2 pulldown can be losslessly restored to 480p24.

Deinterlacing this content is going to destroy the quality and, more significantly, cadence of the video. Panning scenes will be hopelessly jerky. You don't want to deinterlace telecined material but rather apply an inverse telecine or "pullup" filter to it, to restore the original 480p24 (or 720/1080p24 in the case of high def).

As an aside, the terminology can be a bit confusing sometimes, because I've found A/V enthusiasts (for example those on avsforum.com) will use the term "film deinterlacing" to mean inverse telecine (ivtc for short), and "video deinterlacing" or "deinterlacing" to mean, for example, 480i30 interpolated to 480p60 or 480p30. In contrast, I find those in the encoding and digital video scene (for example those on doom9 forum) tend to say deinterlacing only when they mean "video deinterlacing," and when they are referring to inverse telecine or pullup, they will say inverse telecine or pullup. :)

Progressive, telecined, and interlaced each mean different things, and sometimes it depends on context. Both progressive and interlaced can refer to either the underlying content, the carrier, or the display. Telecine refers more to the process, or rather the manner in which content is represented within the carrier. So suppose I am watching a film on satellite, and my satellite receiver is connected to my standard definition TV via svideo. In this case, the actual content is progressive (it is a 24fps film), the carrier is interlaced (480i NTSC), meaning 3:2 pulldown (telecine) was used, and my display is interlaced.

[Tack]

Even so, it's not interlaced. I don't think there's a video engineer dumb enough to interlace something that is progressive, since it would be more complicated than keeping it either progressive or telecined.But there seems to be no end of video engineers who edit film content in video mode, and when the resulting mess is converted back to film mode, you're left with several sequences of completely wrecked telecine patterns that even the smartest, stateless pullup filters can't make sense of.

[Blue_MiSfit]

That's more a side effect of poorly designed workflow, mostly in the NLE department. If the NLE actually performed IVTC on the fly, and presented the editors with 24p material, and outputted true 24p, then we would have no problems. But people want tape and (HD)SDI compatibility, which requires pulldown to conform with standards (usually).

Now if the NLE could edit in 24p natively, and output 24p, then apply pulldown before writing to tape, we would have no problems :)

~MiSfit

[manono]

I see with DVD Rebuilder I can with Avisyth deinterlace with decombe or disable interlaced would this do the trick with DVD-RB then burn the output folder to DVD?

You can't run that stuff through DVD-RB. You don't want to deinterlace it, and there's no way to get it to perform the needed IVTC. You'll have to reencode it manually, with the IVTC in the AviSynth script. Then you can put the whole movie on a single DVD5. It compresses pretty well. The DVD does, anyway. I don't know how noisey your cap is.