Convert HD to SD

I have a quicktime I need to convert.

What's the best way to convert 23.98 HD 1920x1080
to SD 29.97. It's a 12 min short film.
Inside FCP, Compressor, AE?

Thanks,

Gualex

Need more info than that, brother.

Do you want it letterboxed? Anamorphic? I would export it right from Quicktime with those settings (Preserve Aspect Ratio Using: Letterbox).

When life gives you dilemmas...make dilemmanade.

Compressor SD uncompressed anamorphic would be my choice.

Same as Tom. I'd use Compressor, although I'm quite curious about whether it interpolates frames or adds a pulldown. But naturally it depends on where you're going. If you're going out to DVD, you can keep it at 24p. If you're going out to deck, the card can add a pulldown.



www.strypesinpost.com

It's letterboxed. I am going to DVD.

How could I keep it at 24?
Doesn't it need to be 29.97 to play in any ordinary DVD player and TV Set?

Thanks,

Gualex

Nope. The DVD player can add a pulldown on playback (unless you need burnt in timecode at 29.97). You can have it anamorphic and the DVD player will letterbox if it's playing out to a 4:3 TV.



www.strypesinpost.com

Strypes is right; DVDs should not be 60i.

But just for future reference, if you ever do want to do this, it's a two-step process. The first step is to scale the footage down to the NTSC resolution of your choice without changing the frame rate. Pretty much any tool that scales footage can do an acceptable job of this, because it's just not that hard. You're dealing with frames, not fields, which means it's easy. Heck, you could do it all with Photoshop if you felt like doing each frame one by one.

The next step is to add the pulldown. There are, unfortunately, precious few good software tools for doing this on a Mac. Which is confusing, because it's such an easy thing to do.

My workflow of choice, when I have just my laptop and no access to other, better methods, is to use After Effects. You can take the material into After Effects, drop it on a timeline and render it out at 29.97 with 3:2 pulldown. It works well, though you have to keep an eye on the dynamic range and gamma. After Effects will sometimes change them behind the scenes, in ways I've never tried to fully understand. Just keep an eye on it.

A better option is to run the footage out to Digibeta through a Kona board, then re-capture. If you lay it off with pulldown (which the Kona will insert automatically), you can re-capture it as 60 and the pulldown will still be there. Or you can pass it through Smoke, if you have one handy. Smoke literally has an "Add 3:2 pulldown" button, and it processes it out at, at worst, about real time. So that's roughly twice as fast as laying off and re-capturing, if you happen to have a Smoke handy.

There are some other tools that others have recommended in the past. I know Graeme has an "add pulldown" filter in his Standards Conversion package, but I've never used it personally. If I remember right, it involves conforming your 24 material to 29.97, so it plays back too fast in your timeline, then applying the filter to add pulldown. Never tried it myself, because I've always had After Effects, a Digibeta deck or a Smoke nearby, but it'd be worth a look-see.

Since you guys are on the subject. I have a QT movie that the format reads in the QT Inspector; Apple ProRes 422, 1920 x 1080 (1888 x 1062). FPS: 29.97 Normal Size: 1920 x 1080 pixels.

I want to make a DVD that will play on a HDTV and a 4:3 TV. It looks great when I play it on my 1080 HDTV. I see the whole frame except for a little trim. I would like it to letterbox on a 4:3 TV. Everything I've tried using Compressor or DVD SP doesn't seem to work as far as having it letterbox on a 4:3 TV.

Where am I going wrong?

That's not a compressor issue, Russ. That's a DVD issue. When you plug in your DVD player you tell it what aspect ratio your TV is. Individual tracks on your DVD can be set to either pan-and-scan or to letterbox when played on a 4x3 television, though I think the player can override those on-disc settings.

Basically if you want to force the track to letterbox, you have to (a) set the track to force letterbox in DVD Studio Pro, and (b) embrace the fact that you really don't have the final vote on the issue, since the player itself can change the way the track plays.

At least ? I'm pretty sure that's correct. It's been a long time since I looked into that, and I may remember the details wrong.

I was always told it sometimes a DVD player issue. I went in and set the aspect ratio of the TV and still it won't letterbox. This is after I set the track in DVD SP to letterbox. Why is when someone hands me a DVD, it letterbox on my 4:3 TV? or when you rent a movie from blockbusters...


Jeff Harrell Wrote:
-------------------------------------------------------
> That's not a compressor issue, Russ. That's a DVD
> issue. When you plug in your DVD player you tell
> it what aspect ratio your TV is. Individual tracks
> on your DVD can be set to either pan-and-scan or
> to letterbox when played on a 4x3 television,
> though I think the player can override those
> on-disc settings.
>
> Basically if you want to force the track to
> letterbox, you have to (a) set the track to force
> letterbox in DVD Studio Pro, and (b) embrace the
> fact that you really don't have the final vote on
> the issue, since the player itself can change the
> way the track plays.
>
> At least ? I'm pretty sure that's correct. It's
> been a long time since I looked into that, and I
> may remember the details wrong.

Jeff, you ever tried adding a pulldown via Compressor? I'm quite curious as to whether you can add a pulldown with Compressor. The only issue with AE is that you can't batch convert. Quite a pity actually.

For pulldowns, i'd use JES Deinterlacer. Free and really zippy at adding pulldowns, but it seems that you have no luck with it, Jeff.

Not sure what's going on, but I generally have no issues with getting DVDs to letterbox. You may need to go into the settings on the player.



www.strypesinpost.com

Quote

It's letterboxed. I am going to DVD.

As they said - no need to Letterbox - FHA or Full Height Anamorphic if flagged correctly on a DVD with play out letterbox on a 4:3 TV and full screen 16:9 on a 16:9 TV/Screen

Quote

How could I keep it at 24?

You simply leave it at 23.98 or put in another 23.98 timeline.

Quote

Doesn't it need to be 29.97 to play in any ordinary DVD player and TV Set?

No. As Strypes said; there is no need to add pull-down for DVDs.

The DVD player will add the pulldown on old NTSC 4:3 SD CRT TVs

and all new ATSC 16:9 HD Digital TVs should be able to display (at least an approximation of) all the SD and HD formats up to and including 1920x1080 in all frame rates.



This is my route - you can use 23.98


Steps to take:

? Put it on a ProRes 422 Timeline - NTSC 720x480 Anamorphic @ 23.98fps 720x480 (NOT 720x486!!!)

? Export Movie to a Self Contained Quicktime Movie

? Convert to MPEG-2 and AC-3 in Compressor

? Import into DVDSP and make a 16:9 NTSC DVD with a single "play first" track (delete the menu unless you want to use one)

? Drop your MPEG-2 & AC-3 tracks onto the DVD Track

? Master the DVD

The great thing about this route is the 6(ish) extra frames of video don't need to be compressed and therefore don't take up any extra space in the video stream.

Meaning if you encoded at 7Mbps 23.98 vs 29.97 there are more bits per second available to keep the quality of the original picture.

~~~~~~~~~

NOTE: make sure you add about 3 to 5 seconds of black at the start of the movie as some DVD players can miss the AV as the disc spins up - more usually my old DVD player misses the sound start.

By putting a lead in you will make sure that your audience won't miss anything - better still - add a clock and title board.



For instant answers to more than one hundred common FCP questions, check out the LAFCPUG FAQ Wiki here : [www.lafcpug.org]

Alternatively, if you've an extremely long break, you could simply export a QT movie (switch timeline to ProRes if you're working with a long GOP format), keep the frame size the same. Then bring that QT movie into Compressor and drag a DVD best 90 min preset, turn on frame controls, set resizing to "better" or "best". Then go home for the day. The next day, burn with the M2v and ac3 file.



www.strypesinpost.com

Quote

I was always told it sometimes a DVD player issue. I went in and set the aspect ratio of the TV and still it won't letterbox.

Russ - this is because your DVD setup also has output settings for the video outputs too!

Check that the settings are for 16:9 Widescreen (or Fullscreen / Anamorphic / FHA / etc) and not set to letterbox.

Also that if you use a SCART connection (use RGB or Component settings on the DVD setup if available and supported by your TV!) you will see a vast improvement in the picture as well as seeing it 16:9.

This also applies to Cable and Satellite boxes too!



For instant answers to more than one hundred common FCP questions, check out the LAFCPUG FAQ Wiki here : [www.lafcpug.org]

<Ben King Wrote: Russ - this is because your DVD setup also has output settings for the video outputs too! Check that the settings are for 16:9 Widescreen (or Fullscreen / Anamorphic / FHA / etc) and not set to letterbox.>

I'll go through it again, thanks.

Just to be sure I made sense - I mean your hardware DVD Player setup!



For instant answers to more than one hundred common FCP questions, check out the LAFCPUG FAQ Wiki here : [www.lafcpug.org]

I started over and I got it to letterbox on a 4:3 TV. I don't know what I did different but I'll take it.

Thanks guys,

We read this thread with great interest since we're experiencing something of the same problem -- with a couple of interesting variations.

It makes my teeth hurt when people toss off words like "24p." We folks with the sprocket holes are the only ones actually working in 24.000p. All you other interlopers are really running at 23.976p, and yes, there's a world of difference, not just one frame a minute or so.

So the first step is to get the film people to export the work in carefully numbered 1080 Targa frames. We pull them into QuickTime Pro and export an uncompressed QuickTime Movie at 23.976 -- and don't change anything else. We know we succeeded then the QuickTime Movie has a file size very close to the size of the folder holding the numbered stills.

This gets us over the 24/23.98 barrier with no damage except speed. It has another benefit that neither FCP nor DVDSP applies gamma correction when we import a movie. Stills are a completely different story.

Our FCP and DVDSP are old enough not to have gamma controls.

Then, near as I can tell. The operator dumps the QuickTime movie into Compressor, tells it letterbox and it does everything else.

Movie DVDs do not support 24 or 23.98, so the DVD authoring software has to create the 59.94i with a flag that the original was 23.98.

If you play the movie on a DVD player, the movie plays straight. No conversion. If you play it on a computer, the display gets the de-3:2, 23.98 version. Neither version has motion artifacts or interlace damage. You know you succeeded when the computer version will still-frame and step in even frames through the whole movie. If you have one of the other oddball pulldowns, theatrical motion is compromised and still frame playback turns into 4:5 -- every fourth frame is duplicated.

---Is there any technical reason not to do this? Why is it assumed that you need to be in a program outside of Compressor to get all this to work? This produces disks that are far and away better looking than anything we've been able to produce using any other method.

There is one shortcoming. If someone has the bad form to plug a DVD player into a 72-million inch flat panel display in a conference room, they appear slightly soft. We assume that's the downrezzing (or that may just be normal NTSC which was designed around a 21 inch glass monitor). This is seen as a grand improvement over the alternative error which is frying details.

Koz

Quote

It makes my teeth hurt when people toss off words like "24p." We folks with the sprocket holes are the only ones actually working in 24.000p.

The term "60i" must make you want to jump off a bridge then. Kidding aside, yes, it's an abbreviation. And it can be a confusing one, in the wrong situation. Whenever it's not utterly obvious from context whether you're talking about 24 frames per second or 23.976 frames per second, it pays to specify.

Quote

So the first step is to get the film people to export the work in carefully numbered 1080 Targa frames.

If you must. The Targa file format is 8-bit only, which isn't enough for film. I've more commonly seen DPX, 16-bit TIFF or 16-bit half-float or 32-bit float OpenEXR. But the principle is the same, yeah.

Quote

It has another benefit that neither FCP nor DVDSP applies gamma correction when we import a movie.

Whoops, that's not actually correct. Final Cut doesn't do any additional gamma correction for YUV media only. RGB media always gets gamma-corrected by Final Cut.

Quote

Movie DVDs do not support 24 or 23.98, so the DVD authoring software has to create the 59.94i with a flag that the original was 23.98.

I hate to sound nitpicky, but that's not correct either. The DVD spec allows 23.976 tracks in all regions, PAL or NTSC. The player itself inserts 3:2 pulldown in real time during playback.

Quote

If you play the movie on a DVD player, the movie plays straight. No conversion. If you play it on a computer, the display gets the de-3:2, 23.98 version.

Backwards. Or, well, actually that's probably accurate in the scenario you're describing, where you convert to 60i before authoring the DVD. If your DVD playback software in your computer supports deinterlacing (and I believe Apple's does, though I'm not sure of that), then an interlaced track will be software-deinterlaced. But that's not how it's supposed to work. What's supposed to happen is that 23.976 source material is authored to the disc as a 23.976 track, so a player in a computer will simply decode the data stream at that frame rate, without inserting pulldown in the first place. This is not universally true, however.

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You know you succeeded when the computer version will still-frame and step in even frames through the whole movie.

A DVD player, either hardware- or software-based, will always freeze-frame on a single field, by scan-line doubling. So that's not a good way to judge, unfortunately. You can't see the jitter frames on a DVD.

Quote

If you have one of the other oddball pulldowns, theatrical motion is compromised and still frame playback turns into 4:5 -- every fourth frame is duplicated.

Right. This is called 2:2:2:4 where I'm from, and it's the default pulldown Final Cut uses when editing 24p material in a 60i timeline, and it's an abomination and it sucks and yes I am bitter thanks for asking.

Quote

Is there any technical reason not to do this?

Well, there are many things about your pipeline that I would change, if it were me. It's not me, and I'm not trying to tell you how to do your business. But since you asked,

1. Get your animators to work in a consistent gamma space. What space this should be depends entirely on your destination format. If you're going out to television, it should be gamma 2.2, and your monitors should be calibrated to the Rec. 709 specification. If you're going out to film, that gets into print LUTs and all this complicated stuff; others are far more qualified to give advice on that than I am.

2. Targa is not good enough any more. Switch your render pipeline to 16-bit TIFF if you're not doing render passes; if you are, look into 16-bit multichannel OpenEXR, because it stores all the separate passes in a single file.

3. When you get into editorial for video out, convert your image sequences to ProRes 4444 Quicktime movies at (as you said) 23.976. You'll want to keep an eye on this to make sure everything goes correctly when you're settling the workflow. In particular, you want to be sure that your black and white points are coming in where they should be during the RGB-YUV conversion. But once you get those settings dialed in, you should be fine. If you don't need the extra chroma resolution and the alpha channel, ProRes 422 or ProRes 422 HQ should be fine.

4. Stay in 23.976 all the way through DVD authoring. Let the player insert pulldown for you, because that's one of its jobs.

But again, and I really can't emphasize this enough: I'm not you, and I'm not trying to tell you what to do. Those are just the changes I'd make if I were in your situation, nothing more.

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If someone has the bad form to plug a DVD player into a 72-million inch flat panel display in a conference room, they appear slightly soft.

Flat panel displays are typically LCDs, sometimes plasmas. They all work differently from CRTs, in that they're made up of discrete picture elements. If you're lucky, the raster is exactly 1920x1080 elements ? which is great for HD, but stinks for SD because the display has to approximate the SD raster. If you're unlucky, the array of picture elements on your screen matches neither the HD nor the SD rasters, and it's always going to look a bit crappy no matter what you do.

This is, unfortunately, an unavoidable fact of life these days. The era of the analog scanning cathode-ray tube is over. Fixed projection and display rasters are where it's at, and we all just have to get used to it. I'm going to go sob into my beer now, weeping for all that we've lost. No, seriously. CRTs were better. Stay off my lawn.

We may be running into Image Enhancement problems. You can't really go between HiDef and Standard Def. A straight conversion always looks funny because SD has edge enhancement missing in HD. In the earlier cameras, this was a setup knob and you could tune the "sharpness" for the show. If the newscaster bought you enough chocolate, you could make it so he didn't look like he was on death's door.

It doesn't actually get sharper, but it appears like it does.

So somehow, we need to put that slight edge boosting back in in the downrez step.

Koz

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You can't really go between HiDef and Standard Def.

I think you typed that backwards. Going from a higher resolution format to a lower resolution format is not only trivial, it's optimal. Nyquist oversampling and all that.

Quote

In the earlier cameras, this was a setup knob and you could tune the "sharpness" for the show.

What the knob called "sharpness" was just ringing in the analog signal, and it was actually an artifact that broadcast engineers had to work hard to eliminate, or at least keep to a minimum. You can simulate it with an unsharp mask filter if you really wanted to; unsharp mask (despite the counterintuitive name) does a very good approximation in digital of what analog ringing does in analog.

0.3 to 0.6 Gaussian Blur over the whole image will take the detail down enough not to ring like a sabre sharp edge.

Useful for photos and graphics not pre-treated for SD too.



For instant answers to more than one hundred common FCP questions, check out the LAFCPUG FAQ Wiki here : [www.lafcpug.org]

I love it when two Unquestioned Great Authorities tell me two different things.

Your authority that DVDs natively support 23.98 is what? Links to documents are good.

Koz

You know, you've got me there. I don't actually have it written down anyplace. It's one of those things I just know from experience.

I spent a couple minutes in Google to find something for you, and I discovered that there's a lot of really bad information out there. I found a forum discussion about the minimum frame rate of DVD, and somebody wrote in that anything lower than 18-20 frames per second would cause players to lock up. Golly! That's some good Internet wisdom, right there. My guess is that this is due to a lot of amateurs having a vested interest in the technical details of the DVD format ? that is to say, pirates. But that's just a guess.

I did find this with a google search, though. Seems pretty clear to me.

[documentation.apple.com]

But you don't have to look it up. Just do it. Take a 23.976 fps Quicktime movie and run it through Compressor, using one of the DVD presets. Examine the resulting MPEG-2 elementary stream. See that it's 23.976 frames per second. Take that elementary stream into DVD Studio Pro and author a disc with it. Observe that DVD Studio Pro does not re-encode your elementary stream, nor modify it in any way. It just burns it to disc in VOB format. Heck, if you want, you can then open the subsequent VOB in MPEG Streamclip, and see that yup, it really is by gosh and by gum 23.976.

<<<It just burns it to disc in VOB format.>>>

I will.

I was afraid you were going to do the "everybody knows" thing. My engineering authority has all the SMPTE documents and other engineering standards and a Technical Academy Award for his visual effects design efforts. No small feat.

So here I am standing between the two with a coffee cup leaking on my pants.

And I'm not on your lawn.

Koz

Alas, the DVD specification is not, to my knowledge, a SMPTE standard. It's governed by the DVD Forum, and is available from them for a price. I tried finding it for you a few minutes ago when I first replied, but their frustrating Web site stymied me. You're welcome to give it a shot if you wanna:

[www.dvdforum.org]

And no, Koz, I wasn't gonna pull the "everybody knows" trick on you. I never use that one. If everybody knows this stuff, then how can I be special!?

Wikipedia says it can, but it's no authority on the subject.

[en.wikipedia.org]

Alas, I tried extracting a chapter from Cold Mountain to prove it, but it was a no go, and i now have 3 more changes left to the DVD region on my mac (VLC won't play past the copyright notice).



www.strypesinpost.com

Video Tracks:
224 MPEG-2, 720 ? 480, 16:9, 23.976 fps, 9.80 Mbps, lower field first

Audio Tracks:
128 AC3 3/2, 48 kHz, 448 kbps
129 AC3 3/2, 48 kHz, 384 kbps

Stream Files:
COLD_MOUNTAIN Title 1 (Ch27 - Ch27).VOB (164.21 MB)

Done. End of discussion.



www.strypesinpost.com

Actually, I still have a question on what Jeff mentioned...

>Going from a higher resolution format to a lower resolution format is not only trivial, it's optimal.
>Nyquist oversampling and all that.

For the Nyquist principle, it requires oversampling of 2F or more to accurately recreate an analog signal. That accounts for 44.1khz sampling rate on audio cds.

I've always assumed that when it comes to frame size, eg. oversampling for downconversion, mainly allows for a wider range of image manipulation, and more accuracy in noise reduction. Basically it aids signal processing to have more rather than less. Eg. you have more room to reposition a 4K shot for SD transmission than if you were working from an SD source. On the other hand, a 4K frame is more likely to alias on down conversion than if the image was sampled at the intended frame size or slightly larger (eg. SD for SD or 720p for SD).



www.strypesinpost.com