Revisiting PAL > NTSC for DVD... 30p? Or even 24p?

NickHope wrote on 10/18/2009, 9:20 PM
I have a project of standard definition interlaced PAL 4:3 DV footage from which I need to make a DVD for general sale that will play on players/TVs in the USA, Japan etc..

I've done this many times before by converting to NTSC (29.97fps) interlaced MPEG2 using Procoder or just Vegas. The result is OK but of course there is quality loss compared to the original PAL.

Before I just carry on and do the same old thing with this project, I'm wondering about 2 other options:

1. Might the DVDs look better if I convert to progressive 29.97fps NTSC? (i.e. Not re-interlace after the conversion). I'm particularly wondering this because of the higher proportion of panels compared to CRTs these days.

2. Might it be even better to just slow the project down 4%, deinterlace, and produce 24p DVDs? Would these be as compatible? i.e. Do the majority of DVDs/TVs in the USA play 24p DVDs (and I don't just mean newer ones)?

Nick

(p.s. I know about the hardware solutions (S&W Alchemist etc.) being better but the sales of this project don't justify that outlay)

Comments

farss wrote on 10/18/2009, 11:57 PM
My advice, do what you've done in the past.
Having to de-interlace to get 25p is going to be one issue, then you've got the 4% speed change as well to cope with. For those who have panels the de-interlacers in them can handle the issue for you. After all this is what your clients will be used to seeing and seems the best way to avoid having any unforseen funky problems arise.

Converting from 25fps to 29.97 fps seems very problematic to me, worse than going the other way as new data has to be invented completely compared to simply created by interpolation.

Bob.
NickHope wrote on 10/19/2009, 12:35 AM
Thanks Bob.

In my case I don't see much of a problem with the 4% speed decrease if I were to make 24p. There is no dialogue on this project so audio is not really a problem. The speed decrease certainly won't harm the video, which is nearly all underwater stuff. A lot of underwater video on TV is shown much slower than this.

As for deinterlacing, my results going from 50i to 25p for the net have been pretty good. I was using TDeint in AVIsynth but recently I've used the Smart Deinterlacer inside Vegas on my original video track so that titles and graphics on higher tracks don't get fuzzy by being interlaced then deinterlaced.

My understanding is that the players will generally output a 24p DVD at either 25i or at 30i (3:2 pulldown), but that an increasing proportion of playback scenarios will output and display 24p as is, without conversion.

>> Converting from 25fps to 29.97 fps seems very problematic to me, worse than going the other way as new data has to be invented completely compared to simply created by interpolation. <<

Indeed, which is why I'm considering 24p and letting playback hardware do the conversion if it has to.

I would absolutely LOVE to find a formula that can let me sell just one acceptable format of DVD worldwide. Offering 2 formats is an absolute pain in the backside for stocking, accounting, and even simply making shopkeepers and customers understand the difference. A number of online customers also order the wrong format despite my best efforts to explain on my website.

I think I'll have a go at a 24p DVD and see how it looks.

By the way Bob, did you have a chance to try élastique Pro in Sound Forge 10 yet (particularly with regard to maintaining audio pitch after a 4% change in speed)?
farss wrote on 10/19/2009, 1:46 AM
"By the way Bob, did you have a chance to try élastique Pro in Sound Forge 10 yet"

Sheesh, thank you for reminding to buy the upgrade before the discount period runs out. I've been keeping a weather eye on how the AUD is going (all UP so far) as I'm thinking to buy a Sachtler tripod and plumb forgot about SF.

Bob.
NickHope wrote on 11/7/2009, 7:44 AM
So I made a 24p DVD by slowing down my 50i 4:3 PAL DV footage to 48i in Vegas, frameserving to VirtualDub where I deinterlaced with Smart Deinterlacer 2.8 beta 1 (edge-directed interpolate method) and did a Lanczos3 resize to 720x480, then encoded to MPEG2 with CCE.

I tried it here in PAL-land (Thailand) on 3 different DVD players and my multi-system CRT TV.

It's certainly not as nice to watch as the original PAL 50i DVD, which is no surprise.

The comparison with an NTSC DVD that I made by converting PAL to 60i NTSC in Procoder 2 (or Vegas) is more interesting. The 24p version is much sharper, which may largely be a result of using an interpolate deinterlace method as opposed to a blend method. However the motion is just not smooth. I guess mainly because of the 3:2 pulldown. Just not comfortable to watch.

I think I'll try another one with a blend deinterlace instead of interpolate.
NickHope wrote on 11/9/2009, 3:30 AM
Apologies for talking to myself. Just reporting back in case anyone goes through the same process as me.

I made another 24p NTSC DVD using footage slowed down from 50i PAL footage, but this time used blend deinterlace and resize inside Vegas. The result is better. The interpolated one was too sharp. But the motion on my equipment still doesn't look quite right.

I then did a regular 29.97 fps interlaced NTSC DVD. All the adjustments were made in Vegas (blend deinterlace, resize, resample framerate). The result on my multi-system gear is MUCH better. No competition in fact, compared to the inferior 24p version. And I would even go as far as to say the result is better than PAL > NTSC conversions I did in Procoder 2, for which I paid more than Vegas purely for this purpose. I might even drop the PAL versions of my DVDs and sell just this NTSC one.
MPM wrote on 11/9/2009, 11:15 AM
Solely playing Devil's Advocate, have you tried the various AviSynth methods Nick?

I know multi-versioning HD I've liked the results opening the original & modding it using AviSynth, then feeding the results to Vegas time line through VFAPI or rendering intermediates. For re-size & deinterlace each there are several options/methods.