Interlaced or Progressive

I'm working with 1920x1080 25fps Progressive footage and need to master the final edit back to a PAL Mini DV TAPE or to a PAL Standard Def DVD.

So far I've taken this approach:

1. From the FC timeline I exported my sequence as a self contained file
2. In compressor selected the DV-PAL Anamorphic preset and set frame control ON
3. Adjusted the frame control settings as such



and submitted the render.

I also tried setting the Rate Conversion set to BETTER and BEST to see what the difference would be, but can't say I'm 100% happy with the results.

The other option I've been given was to try use FieldsKit by RE:Vision. I downloaded the trial version and tried giving it a shot, but felt like I was watching paint dry or grass grow during the render.

Is there anyone that can share a light on a faster/better solution?

Huh? You highlighted the rate conversion algorithm ? but you're not actually doing any rate conversion. I'm not at all clear on just what you're trying to solve, here.

When you remember that 25p isn't progressive, but rather progressive-segmented-frame, you'll see that you don't actually have a problem. Just scale the footage down to 720x576 PAL rez and lay off to tape as usual.

Sorry Jeff I got my wires crossed.

The original rushes are from the canon 5D 1920x1080 30P H.264, then converted to ProRes 422 1920x1080 30P (29.97) and edited.

Final edit was then exported from FCP as a self contained MOV file, and thrown into compressor to be down converted to SD PAL DVD with the settings mentioned in my previous post.

Does that make sense?

Oh. Then yeah, you're boned. It's not possible to go from 30psf to 25psf without motion estimation. This usually produces unacceptable artifacts that have to be hand-painted out, or short of that, ignored by sheer force of will. There are no great motion estimation solutions. Kronos, Twixtor and Compressor are all equally good or equally terrible, depending on your point of view.

If you want to be methodical about it, run the rushes through shot by shot, then conform them to your original edit. (Motion estimation sometimes has issues across edits.) Hand-paint the most objectionable artifacts out, and ignore the rest.

Turn "rate conversion" to "better" (you could try "best", but I'm not sure if it will affect areas with motion blur), output fields "same as source" (this toggles off the deinterlacer, which you don't want).

Motion estimation will happen if you need to create new frames. It's either motion estimation or frame blending. Motion estimation will produce sharper results, and in your case, it may not be so bad, as you're not trying to slow it down by that much.

You can try turning off "adaptive details". Although adaptive details help in resizing, it also explodes your encoding time.



www.strypesinpost.com

What if the rushes were shot at 1920x1080 25P, is it then possible to make a SD PAL DVD but in an interlaced mode?

25p is an interlaced format. The terminology is deeply misleading here. What people refer to as "25p" and "30p" actually mean "25psf" and "29.97psf." Each frame is made up of two fields, played back at fractionally different instants of time. The only difference between 25p and 50i, or 30p and 60i, is that both fields are recorded in one read of the sensor, rather than in separate reads.

In other words, 25p is totally compatible in every way with 50i, and 30p with 60i. Except in how they look. Which is bad. But that's subjective, so I won't rant about it any further.

So yes, if you shoot in 1080p25, you can deliver in 576p25 just by down-scaling, without having to do any frame-rate conversion. Whether how such a delivery look on a television is acceptable to you or not is between you and your eyeballs.

Stu Maschwitz likes to tell a story about this filmmaker who was shooting a documentary piece ? I don't think he's ever identified who she was. This was not all that long ago, before 24p recording was possible on video, and because she knew with absolute certainty that her film was never going to have a theatrical run, ever, she decided to save money and shoot on an inexpensive 30p video camera, instead of on film.

Except one day she got a call. She had to deliver a film print of her doco for Academy Award consideration. So she had to go through a nightmarish hell-march of conversion, sending her film out to be run through the best motion-estimation algorithms of the day at great expense, in order to get it printed to film for the Academy screening. The effort was ultimately unsuccessful; whether that was because her film didn't make the cut on its own merits, or because the film print looked awful is something we can only speculate about. But it's safe to say that the poor film print didn't help.

Now that 23.976p recording is practically ubiquitous on video, there's no excuse. You should always, always shoot 23.976p. That's the one format that can be easily and inexpensively ? and at high-quality ? converted to any other delivery format. To go 23.976p -> 50i for PAL television, conform to a 4%-and-a-bit speed-up and deliver 25psf. To go 23.976p -> 60i for NTSC television, add 3:2 pulldown. Or if you're going to NTSC DVD, don't even bother; just print your 23.976p material to disc, because that's the native DVD frame rate. Going from 23.976p -> 24p for film-out or DCP is also trivially easy, because whatever facility does the printing or digital conversion for you is already set up to handle 23.976p. All they'll have to do is conform your audio to the slightly faster frame rate, and poof, done.

All frame-rate conversion problems in post are really standards problems in production that got ignored until it was too late.

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So yes, if you shoot in 1080p25, you can deliver in 576p25 just by down-scaling, without having to do any frame-rate conversion. Whether how such a delivery look on a television is acceptable to you or not is between you and your eyeballs.

So I believe that slight flicker or strobe look on playback is what's "acceptable to you or not is between you and your eyeballs"? That's what I was hoping could be eliminated.

Digging around the forums, I came across this article which explains how to convert progressive to interlaced and decided to give it a shot. I purchased twixtor and used it as my choice to do the motion estimating. I found twixtor to be a tad better than After Effects pixel motion or even compressor's Rate Conversion set BEST. Having said that, the render time have been painful...!

Do I really need to go through all this to get an interlaced DVD! Had I known, I would have shot this in interlaced to begin with.

>You should always, always shoot 23.976p.

Eh. Jeff. I think Mr Blimpmedia is in a PAL country. He probably shot 30p (full integer frame rate) because his footage was shot on a Canon 5D (talk about designing a camera that shoots to a frame rate nobody works in).

Anyway, if Blimpmedia is shooting a film for international distribution, he would do better to shoot at 25p, and then conform it for distribution in NTSC countries. If he is shooting for TV (sports, events, reality, etc..), then he should shoot 50i to conform with broadcast specs, and for distribution, run it through a Teranex or an Alchemist for hardware based conversion.



www.strypesinpost.com

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So I believe that slight flicker or strobe look on playback is what's "acceptable to you or not is between you and your eyeballs"? That's what I was hoping could be eliminated.

Short answer: That's just how 25p looks.

Slightly longer answer: That's just how progressive segmented frame looks, regardless of your scan rate.

Even longer answer: Because both fields were recorded at the same time, but are being played back offset in time, you're inevitably going to get a slight stutter on moving objects. This is just a natural consequence of how progressive-segmented-frame playback works.

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Do I really need to go through all this to get an interlaced DVD! Had I known, I would have shot this in interlaced to begin with.

Well, that's how things go in this business. You never know what horribly dumb thing you're doing until after it's done and it's too late to fix it. If I had a nickel for every time that's happened to me, I could retire. And also buy Fiji.

The trick is to make sure, when something bad happens, that you take a minute to figure out exactly what happened and why, so you don't end up making the same mistake twice. Or rather, that would be the trick. Me, I usually have to make the same mistake three or four times before it sinks in. Hopefully you can do better.

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He probably shot 30p (full integer frame rate) because his footage was shot on a Canon 5D

Yes, that's true. Fortunately that's not a problem any more, now that 2.0.4 is out. I hear this one lets you shoot 24p and record audio at the same time. Bonus!

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Anyway, if Blimpmedia is shooting a film for international distribution, he would do better to shoot at 25p, and then conform it for distribution in NTSC countries.

That's one way to look at it, yeah. Which way you go is really a personal choice. If you shoot 23.976p, you're one step away from 25psf, 60i and 24-for-theaters. If you shoot 25psf, you're obviously zero steps away from 25psf, and one step away from 24, but two steps away from 60i (you have to conform to 23.976p, then add pulldown). The magic happens when you realize you can go from 23.976psf to 25psf with only a lossless conform, so you can go either direction with equal ease.

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If he is shooting for TV (sports, events, reality, etc..), then he should shoot 50i to conform with broadcast specs, and for distribution, run it through a Teranex or an Alchemist for hardware based conversion.

Now that I'll take issue with. Obviously there are special cases where you want to shoot "the local video format," whether that be 60i or 50i. But they're special cases, not universal laws of nature. For example, at least in the States, much reality television and virtually all documentary is shot at 23.976p these days, in addition to obviously all drama and nearly all comedy. There are exceptions, but they're exceptions. News is still nearly always shot at 60i, but that's not universally true of sports. NFL Films shot NFL games on ? as the name would imply ? film for years, at 24 frames per second. The footage looks incredible, and there've been some whole games that've been transferred from the archival footage, edited and broadcast as special events. You'd be blown away how great it looks.

I guess I could sum up my point of view as: Shoot 23.976 unless you have some reason not to. And "my camera only does 30" is not a reason, in my book.

>That's one way to look at it, yeah. Which way you go is really a personal choice. If you shoot
>23.976p, you're one step away from 25psf, 60i and 24-for-theaters

Man... No... If anyone came to me in a PAL country, and they shot a TV program in 23.98, thinking it's the next best thing, I'd shoot coffee through my nose. It's not hard to conform, but it's one lunch break to duplicate the file and conform it to get something out for TV in that country.

If i wanted to send out a film specifically for distribution in an NTSC country on top of local distribution, it always happens during mastering- on the way out to tape/file master, either conform it or send it through a hardware converter.

>Do I really need to go through all this to get an interlaced DVD! Had I known, I would have shot
>this in interlaced to begin with.

Yes, if you wanted interlace, you shoot interlace. You don't shoot at half the temporal resolution and then spend days running your stuff through motion estimation to artificially double your temporal resolution. The difference between 25p and 50i, is that at 25p, you sample at 25Hz. At 50i, you sample at 50Hz. That's double the temporal resolution.



www.strypesinpost.com

hey, tony.

your best bet is to take your 29.97 file to a tape house and get them to run it though a Teranex or Alchemist converter.

this hardware will do a lot better job than the software, and should be real time,
although they may need to play it out to tape first, then run it through the box.

i see you are in Aus.
if you are in Sydney, Video-8 would be your best / cheapest option.

i did a 25fps doco a while back, which you could say was 25p (shot as DV, then de-interlaced in post) which they then converted it to NTSC.
looked as good as it could.


oh, ok, now i see you want a DVD.
well why don't you just make an NTSC DVD?
almost everyone in Aus will be able to play that.


nick

Strypes, your right on the money... I've been using the 5D to shoot corporate productions which revolve around motor-sports.

It's very important I transcode the progressive field back to interlaced because the final goes back to DVD. I't wouldn't be safe for me to encode a progressive DVD because I don't know if the end purchaser will have a progressive panels.

I've spent the past 4 weeks cutting this job and it's now draining me physically and mentally.

To give you an idea, the job entailed shooting a 2min interview with a driver followed by some overlay shots of the car racing around a circuit and some static detailed shots of his car, all in all approximately 5mins per person/car.

To eliminate this progressive flicker, I've found by drop twixtor on all the clips and add a 99% speed change, my progressive video turns to interlaced. However waiting for a 5min video with twixtor added can tack approximately 2hrs to render.

You mention Teranex and Alchemist for hardware based conversion. I've never heard of these! am I right to say either product can do what I'm trying to do with twixtor, convert progressive to interlaced?

among other things, Teranex and Alchemist will convert from NTSC to PAL, or vice-versa.

once you get it onto standard def tape it will be interlaced no matter what.

you will have 2 fields per frame, but both will be the same image.
(just as if you had shot on film and telecined to tape)

are you trying to actually get a different image on each field?
you really wouldn't want that.
people love the progressive look.


nick

Funny you mention that Nick. As an experiment I decided to make a NTSC DVD and played it back on my "old" TV set and found the results to be amazing.....

Problem is, this job I'm currently cutting was shot on 2x cameras, My 5D as 1920x1080 30P and the other guy shot on a Sony Z1 (1440x1080 50i) but mainly shot for audio.

Had I known better, I should have converted the Zi rush to equal the 5D rushes and cut the whole job in 29.97 and then created a NTSC DVD, I would have saved myself hour of render. Or even better yet, I should have hired an EX1 and shot the whole thing as 50i and be done with it.

Could have, should have DIDN'T HAVE..... I' paying the price now

>I't wouldn't be safe for me to encode a progressive DVD because I don't know if the end
>purchaser will have a progressive panels.

It's not a problem, because a DVD player can play out a 25p DVD even on an analog SD TV. Most people would probably have bought a progressive LCD HDTV if they bought a TV in the last 5 years.

As Nick also mentioned, you don't have to create a PAL DVD. Most DVD players in the PAL region can play back NTSC frame rates and watch it even on an old analog TV.

If you're running Twixtor in AE CS4, and you are on a Mac Pro, you should set it to render across all available cores in your machine. Same goes if you're running it through Compressor (you use Qmaster for this).

A hardware converter like the Teranex does it all in real time and in good quality. That's the beauty of it. However, it's pricier, and you may want to call up your local post facility to check the rates. I'm not sure if it will convert progressive to interlaced as usually we tend to preserve interlaced/progressive fields that it was shot in. You may want to quiz the house on it.

The bottom line now is, do you need an interlaced PAL DVD and why? If you are distributing the DVD in a PAL country, you don't need it in PAL. I have a bunch of DVDs in code 3 encoded in NTSC (23.98). No issues with them.



www.strypesinpost.com

The only issue denigrated here is frame blending to smooth out the jitters of PAL projection. The OP asks for a solution to the jitters also.

23.98 or 24p look is not always preferred by everyone. As you mentioned this other fellow cinematographer that likes the 30p look in digital shooting. Not trying to cause trouble, just asking for a difference of opinion.

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Jeff Harrell
Even longer answer: Because both fields were recorded at the same time, but are being played back offset in time, you're inevitably going to get a slight stutter on moving objects. This is just a natural consequence of how progressive-segmented-frame playback works.

Other experts in this forum have mentioned "frame blending" to create the more acceptable blur for smooth motion -- as you indicated in another thread regarding the blur in 35mm frames shot at 1/48 shutter speed.

woah.. so now there are two formats?

but you converted the Canon 30P footage to 29.97.
then what?
cut in a 25fps timeline?

i did a job recently where we had PAL digibeta (25fps interlaced)
and Cannon 30P

we converted both to 29.97, and will deliver as NTSC

the Cannon was converted ("conformed" using Cinema Tools, which is instantaneous, but changes the playback speed.

so our digibeta plays a little bit faster than it was shot.
it's all action to music, no sync sound, so the speed change doesn't really show up
(i was surprised how un-noticeable it was)

we could have gone ether way with CT,
but as we were delivering mainly to folks in the US decided on 29.97


i wonder if you could do something similar?


nick

vic, do you mind if we get to the bottom of the original problem first?
i think it will be a lot simpler for tony that way.

thanks,
nick

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Nick Meyers
vic, do you mind if we get to the bottom of the original problem first?
i think it will be a lot simpler for tony that way.

No, problem. I must admit having footage from a still digital camera, h 264, and pro-rez all in the same timeline and then having to end up as SD DVD -- well, personally, I'd be pulling all my hair out:-)

My question is inconsequential in comparison. We'll let it go.

thanks vic

"srtobey" flickering" blurry" are all terms that could mean different things to different people.
very hard to advise on those sorts of issues without seeing them.

Tony is going to be sending me some of his footage so i can check it out and se what i think might be the issue, and maybe we can come up with a solution.


nick