Progressive DVCAM in FCP

[E_Tedeschi]

Hello all,

I have some tapes coming my way this week that have been shot 25 frame progressive. Not having done progressive scan material before, these may seem like silly questions:

Do I need a deck capable of progressive playback, or will a garden-variety DVCAM deck suffice?

Are there any specific progressive capture settings in FCP other than switching the field setting to "None"

Any tips on working with Progressive Scan material appreciated.

e.

[JWRL]

DVcam progressive is only progressive in the way the data is clocked out of the CCD in the camera. In all other respects it is a standard definition interlaced PAL signal. So, yes, you can use a standard DVcam deck to play the material into FCP.

If you wish to have your transitions and effects rendered as progressive you can set up your project that way, but it will still ultimately play out an interlaced PAL television signal on to tape.

[E_Tedeschi]

Thanks JWRL,

As per usual, a veritable font of knowledge.

Will the transitions look any different if rendered in progressive? I would imagine that if the footage is captured interlaced anyway that rendering transitions in progressive is kinda pointless.

e.

[JWRL]

The difference SHOULD be that the two fields of the transitions have the same motion content, and so should look more "filmic". I say "should" because I haven't yet tried this in FCP, but I have in Avid. If I get the time I might have a look tomorrow. You've whetted my curiosity.

In practice, on Avid, subjectively I've found very little visible difference though. But if you step through your transition in FCP you should see there's no interlace jitter on wipes and DVE transitions in progressive.

And to clarify the previous posting: Progressive output from a camera is clocked out of the imaging device in the camera at 25 frames per second, but each frame is fully interlaced. As with 25i, the two fields that make up each frame are different, but unlike 25i, the motion content of each field pair that makes up that frame is the same.

[E_Tedeschi]

Of course. That makes sense.

I get my rushes tomorrow, so if you don't get around to it, I'll let you know the results from my testing in FCP.

Thanks again, JWRL.

e.

[JWRL]

Sorry, E. It wasn't possible to make time on FCP to do that test today. But I would appreciate hearing how you get on.

[E_Tedeschi]

I got the rushes late today, so I haven't yet digitised. I've had a look through the tapes, though, and it has an interesting look. Although on some of the fine details (eg fine diagonals, or even silhouetted diagonals) it really looks blocky, as if it's missing a field rather than having double the information. There's also a weird strobe-like effect on everything. Obviously this is because of the progressive scan acquisition, but it's quite distracting. It actually looks as though there is something wrong with the footage in certain shots.

Is this what I should be seeing on an interlaced monitor from 25p footage? It certainly has a "filmic" quality, but it often looks like it has an interlacing problem.

When I've got it in FCP, I'll try de-interlacing it using my Nattress plugin and see if that helps any...

JWRL, You wrote: "As with 25i, the two fields that make up each frame are different, but unlike 25i, the motion content of each field pair that makes up that frame is the same."

Perhaps dropping a field will result in easier to look at images? We shall see...

[JWRL]

I'm a bit surprised about the blockiness of diagonals. I suspect that the problem lies with the camera used because I've done 25p projects without that being an issue. I haven't used the Natress plug-ins but if you do an interpolated de-interlace it may help the blockiness on diagonals. You'll probably achieve a measure of anti-aliasing that way, albeit at the expense of image resolution.

But motion strobing will always be an issue on fast action. I wouldn't have thought that the effect would be as visible as you find it though. Is it possible that the camera operator has switched the camera to some sort of pseudo 24 frame mode? The give away if that's the case is to check for a visible half-second hiccup in the action because every 12th frame is made up of three fields.

You could try this. Once you've digitised your material select a frame that exhibits diagonal blockiness and export it. Open it in Photoshop. Zoom in on a diagonal line until you can see the individual pixels and check that the pixels aren't duplicated in line pairs. If they are the camera isn't doing what it needs to do to produce true 25p, it's simply dropping the second field and duplicating the first.

Next in FCP find a section with fast horizontal movement and step through it to check that each frame moves with respect to the previous. I encountered a problem with a Panasonic camera set up to give a 25 frame image strobe that was intended by the cinematographer to give the film look. When we tested it we found that it was actually giving us 12.5 discrete frames per second, NOT 25. If every second frame is the identical to the previous you have the same problem.

(In my case and in fairness to Panasonic the strobe mode was intended as a special effect and could be set to a range of values. I don't believe it was ever intended by Panasonic to be used for 25p operation.)

I can't think of anything else that might help. As I said earlier, I'll be really interested to hear how you get on.

[E_Tedeschi]

I will do those tests, and might even post some screen shots if there's anything worth looking at.

I doubt it's 24p, as the Sony PD170 does 24p, although, there's this from the PD170 brochure:

"These CCDs are capable of interlace scan to acquire moving images and progressive* scan to capture still images."

With the footnote reading:

"* Moving images cannot be acquired in the progressive scan mode."

That could explain it.... ! It seems that the DOP might have stuffed up and used a mode meant for stills, not for video. Looks like I'm gonna have to do something to "fix" it.

Watch this space....

[JWRL]

Very few people shooting a movie on film would NOT build camera tests into the budget, especially if shooting with untried equipment. Very few shooting tape do though.

And who has to fix any problems? You guessed it. No, You ARE it.

Good luck!

[JWRL]

So how have you got on, E? Problems solved? Or have they gone back to the drawing board?

[E_Tedeschi]

Not yet JWRL. I have had to give my time over to more pressing projects since I had the tapes delivered. At this stage it looks like I won't be looking closely at those rushes until Wednesday.

It won't be back to the drawing board, though, as it is a low-budget short film, so it's "press-forward" regardless.

But don't worry, I shall keep you posted!

[E_Tedeschi]

Hey JWRL, Better late than never!

I have finally been working with that dodgy 25P stuff. Most of the jerkiness and jagged edging I initially complained about are obviously related to the fact that it was shot 25P on a camera that doesn't shoot 25P.

Adding to my woes, on closer inspection, it would seem that the footage has gone to tape at 12.5 fps rather than 25. No wonder things seemed jumpy!

Anyhow, I decided not to worry too much about progressive scan settings etc, as the whole thing is a shemozzle and I am just going to have to live with / deal with / fix it.... bugger....

Thanks for all your help, all the same!

[JWRL]

Yeah, that sounds like the situation that we had with the test that I referred to earlier. It would have been nice if they'd spoken to you before they went out and shot it, though!

[annac]

25p on Avid

Working on new Avid Media Composer at UTS we can set up 25i and 25p projects, but we're finding that DVcam footage telecined from 25fps film only syncs up in 25i projects. Obviously the footage is still "progressive" as there are only 25 fps not 50 - is it a frame dominance issue or is the 25p project setting for other video formats? Alternatively perhaps it's editor error.

[E_Tedeschi]

As JWRL mentioned earlier in the thread:

"DVcam progressive is only progressive in the way the data is clocked out of the CCD in the camera. In all other respects it is a standard definition interlaced PAL signal. So, yes, you can use a standard DVcam deck to play the material into FCP."

The same would apply for telecined footage at 25fps. You may only have 1 film frame per frame of PAL tape, but the PAL tape still runs an interlaced signal. You may find if you step through the footage field by field that both will be displaying the same frame? You won't notice it on the computer monitor, though, as those screens are not interlaced. You'll need to look at it on a broadcast monitor to see it.

Enzo.

[JWRL]

Or if you use the field step function on the Avid you will notice that the action only changes every second field.

But I'm surprised that you're having trouble with a 25p project on the Media Composer. On Avid one of the things that 25p projects are designed to do is ensure that your transitions are rendered progressively rather than interlaced, thus matching the action and making the end result more filmic.

It's also useful if you intend sending the final cut to film, but nowadays standard def PAL and NTSC is largely being superceded by HDV and similar formats for low budget electronic cinematography.

If you're problems persist, Anna, you might like to try posting on the Avid user forums at http://www.avid.com/exchange/forums/ and see if someone there can help you. By and large they're a pretty helpful and knowledgeable bunch.

[Neil Ryan]

My question was going to be 'why was it shot this way' but you may have answered that:
Originally posted by E_Tedeschi
It seems that the DOP might have stuffed up and used a mode meant for stills, not for video. Looks like I'm gonna have to do something to "fix" it.

So if its a fault, and YOU have to find the solution, who will pay for it? Seems you're going light years beyond the roll of editor.
Or is just standard fare for an editor these days; 'Yes, please fix our production problems ... and oh yes, if you've got time, can you do some creative editing on it, too?'
Ahhh seems an all-too-familiar tale, these days...

Make sure you look right down the track to see what's required to use this footage, what the end result will be, and the costs involved BEFORE you commit to that path.

Keep us informed, Enzo.

Neil.

[E_Tedeschi]

Neil,

It's a little bit of all of that!

It was an error on the DOPs behalf, essentially. As it's presently a no-budget independant production (read: Tropfest film), I've made the director aware of the issues, and he understands that there may not be much that can be done under the circumstances.

Fortunately, the visuals are quite strong: fantastic use of light, and impeccably shot... other than the progressive issue... :) It may be enough to support the director's bid to raise a real budget for a re-shoot. The rough has been done, and it's feeling good.

As it wasn't me who broke it, I don't think anyone expects me to fix it, and the focus for me (and of the director) has always been getting the cut right, and then seeing if there's something we can do to minimise the weird flickering effect.

I'm pretty sure that if this were a project with any funding against it that heads would be rolling. Or at the very least a camera test would have been done initially...

Having said all of that regarding this particular project, I think you're on the money when you say the role of the editor is changing (or at least what is sometimes expected). In my case, getting ready to launch a small cutting room (already "soft" launched, but officially soon), I feel that any knowledge gained for me is potentially useful. When you're running your own gear the buck stops with you. You can't fix it, you're in a bit of trouble (or at least a potentially hefty consultant's bill!).

I might try and post a short segment of the rough cut so you can see what I'm dealing with....?

[Davade]

Hello all,

I have problem doing with the progressive issue and I think I have found the answer....

You can actually capture progressive scan materials as progressive.

Go to Final Cut Pro> Audio/Video Setting>

Using any of the presets that suits your materials most ie.(DV PAL 48Khz Anamorphic)>

Go to edit>

At Quicktime video settings, there is an "Advanced..." icon

Click there and you will find progressive scan at "Scan Mode"

Hope this will solve any progressive material from now on....

(PS. Arghhh... I have to re-capture my all materials now after I found this relevations....)

[JWRL]

While that's useful information, the problem that Enzo had wasn't really a progressive versus interlaced issue. It was that the DOP, through ignorance of the particular camera used, shot motion footage in a mode designed for stills.

And as stated earlier, in a standard definition PAL project the only thing that will change when you go to progressive mode is your transitions. There is no such thing as a progressive standard definition television image.

[Davade]

If that is the case, then what is the whole "whoa-ha" thing when a DOP insist on shoting it in progressive scan? After all it just gives you a little "filmic" feel.

Isn't it better to shot in normal interlaced then graded the material after that in post to have the filmic feels?

Isn't this a classic case of redundant technology?

[JWRL]

No, I think we're talking about two different issues here. There is no such thing as progressive scan PAL, because PAL is by definition an 8-field video sequence. Of those eight fields, successive field pairs are defined as interlaced television frames, so that the 8 field sequence consists of four television frames. The reasons for this complexity is that the combination of colour subcarrier phase and vertical sync sequence only return to where they started after the eighth field.

On the other hand, cameras that claim to produce a "progressive" SD output usually do it by clocking the signal out of the CCD chip in such a way that the motion content of pairs of fields is the same. The signal is still interlaced. So field one of such a frame consists of all the odd lines and field two of all the even in the case of an odd-field dominant frame.

I hope that isn't too complex to follow. The issue that Enzo had was faulty material, not progressive scan SD.

I haven't played with the FCP implementation of SD "progressive", but I have with Avid's. And there's really very little subjective difference. The only visible issue is that dissolves etc. tend to display the classic flickery film look. But you can definitely edit "progressive" material in an interlaced project.

[Davade]

Oh mine, where will anybody learn all this in school?
You are indeed a guru and I am glad that I am able to learn something here.

Thank you.

[Daz]

Damn fine effort for Christmas Day, that's all I can say. My eyes at that stage were so crossed up with, um, er, let's just say: "Christmas cheer" that I wouldn't be able to tell progressive scan from a zebra!

[E_Tedeschi]

I think zebras are interlaced, Daz.

e.

[JWRL]

For logistical reasons we celebrated our big family Christmas two days earlier, so on the 25th I was home alone and bored!

[Daz]

Zebras: natures own moire

[Robin]

Hey JWRL,

Firstly, thanks for always so generously sharing your knowledge.

How does "film dissolve" (as opposed to normal dissolve) work on Avid then? Why does it usually give a cleaner transition?

[JWRL]

Firstly, thanks for the nice comment, Robin. Much appreciated.

The film dissolve effect seems to be a non-linear dissolve as opposed to a "normal" dissolve. I suspect that there is a bit of a gamma tweak going on through the dissolve to simulate an optical printer effect. I'm only guessing, however.

You could get an answer at the Avid user forums at http://www.avid.com/exchange/forums/ - there are some pretty knowlegeable people there, and Avid personnel often browse also.