Help me fix a screwup....please!!!

[Mike Harrington]

I made a boo-boo
shot a couple of hours of a live switch in progressive format (30P dvcpro50)
using interlaced camera's

this was shot into a Video Toaster 4, and i wanted to use DVCPro 50, over DV for quality reasons, but it seems the codec overrided my recording settings and encoded everything as progressive.......ugh

so i got an interlaced signal encoded as progressive....

I need to get this back to interlaced, and smooth out the motion...

The best way i could think of, is some optical flow retiming, say 2:1 slowdown...and then re-encode it to interlaced DV, so basically the Optical flow would double the existing framerate, and create full frames, and then the DV encoding could use each frame as a field.

If anybody has any suggestions, it would be appreciated.

Please note, i am on a windows machine, so I do not have access to Shake 4's kick ass retimer.
Thanks

[Mike Harrington]

sony dsr-570
3 of em

[Mike Harrington]

just to clarify....
this was analogue into the switcher then encoded in DVCPro50
so the signal from the camera was interlaced.

Worst of both worlds...... interlaced fields, with only 30 of em per second

[Cail Young]

This is all hindsight now, but why didn't you just use a DVCPRO deck to record this thing?

That said, yes, you're pretty much limited to using o-flow analysis to interpolate the motion to get it back. Sorry.

[Mike Harrington]

cause I'm going into a Video Toaster http://www.newtek.com/vt/
the inputs are analogue.

you can use any codec you want, or uncompressed...
i thought DVCPro50 would be good, somehow though it only recorded as progressive

so you think the O-Flow option is the only real one out there?

[Cail Young]

cause I'm going into a Video Toaster http://www.newtek.com/vt/
the inputs are analogue.

you can use any codec you want, or uncompressed...
i thought DVCPro50 would be good, somehow though it only recorded as progressive

so you think the O-Flow option is the only real one out there?

The VT doesn't have any outputs? You may have been better off renting some analogue switching gear, unless you already owned the VT, I guess.

But yeah, o-flow is the more accurate way to do it if you really need that smoother motion.

[GlennChan]

1- Your footage/picture is either:
a- Interlaced (both fields captured at different points in time)
b- Progressive (both "fields" captured at the same point in time)
c- Interlaced converted into progressive (this would suck, but is unlikely)

2- You footage can be flagged as interlaced or progressive. If the interlaced/progressive flag is inappropriate, then in some cases you can have problems. But the fix for this is easy: just make sure the footage is interpreted correctly.

3- So unless your problem is 1c, then I don't think you really have much to worry about. It sounds like you have interlaced footage incorrectly interpreted as progressive?? In which case, the solution is easy.

[Bruce Allen]

Yep. If you're recording full raster, you probably recorded the interlaced signal but are just screwing something else up later, like GlennChan says. The chance of the Video Toaster actually deinterlacing on the fly is slim.

By the way... the 30P motion shouldn't be THAT jumpy! I have done dozens of nationally-broadcast TV spots where for various reasons (usually deadline ;) we have stripped the fields and just gone 30P. Haven't had a complaint so far...

If you really hate the motion signature, maybe try adding some motion blur using the Reelsmart Motion Blur plugin (I think you can get a demo at www.revisionfx.com)? But it seems like a total pain to have to do that for tons of footage. Optical flow sounds like even more of a pain.

Bruce Allen
www.boacinema.com

[Cail Young]

If you really hate the motion signature, maybe try adding some motion blur using the Reelsmart Motion Blur plugin (I think you can get a demo at www.revisionfx.com)? But it seems like a total pain to have to do that for tons of footage. Optical flow sounds like even more of a pain.

Reelsmart Motion Blur uses o-flow to determine the blur ;)

[Bruce Allen]

Reelsmart Motion Blur uses o-flow to determine the blur ;)

Yes, I know. And I'm only suggesting that as a last resort. But if I were trying to make motion smooth from a 30P source, I'd look into trying to add motion blur (via optical flow with Reelsmart Motion Blur) rather than trying to create whole new frames (via optical flow with Twixtor).

Bruce Allen
www.boacinema.com

[Mike Harrington]

GlennChan,

That makes a lot of sense, it may very well be a flag in the codec....
any idea how to manually overide that flag?
Is this something done in a text editor?

Bruce Allen..
I see what your saying, and a bit of motion blur would smooth it out a bit.

Hopefully GlennChan is right and it is just a flag in the codec, cause O-Flowing hours of switched footage would suck...

Thanks for the input everybody..

[GlennChan]

1- I don't use video toaster so I can't say. To state the obvious: have you tried searching the manual for phrases like "field order" ?
The field order should likely be interpreted as lower (DV50 should be lower field first from what I remember), not progressive.

2- It is easy to check what your footage is. Interlaced footage will have the venetian blinds effect if you pause on a frame of high motion (look on an external monitor).

[Mike Harrington]

Glenn

I did have the settings correct in the toaster(this was a concern for days,and was double,triple and quadruple checked), somehow the progressive flag was put into the video file....

I was actually wondering if you knew how to manually edit the flag in the video file? I thought that's what you meant...

I have been google'n like mad on the subject for hours, and it mostly sounds like a hex editor job.

[Steve Tammi]

If you haven't done so already there are two forums for the Video Toaster. One at newtek.com and the other at yahoogroups.com called VTNT. There is a lot of expertise in those forums and the NewTek engineers answer many questions directly. Best of luck.

Steve

[JohnF]

If you're in real trouble try this:

Split the video file into a still image sequence (not compressed files try BMP or PSD) and put them in a specific folder.

Create an "action" in photoshop using the de-interlace filter - under video in filters. (it's very good and doesn't drop pic resolution much at all)

Then in automation (under File is PS) set the action to work on all your still images but create a new folder for them to sit in and make sure that within the automation window you have selected the function to save to folder (it's called something like that) mode. (and use the new folder as destination).

Then sit back and wait for the computer to do the business. (make sure you've got the storage space though)

But try the filter on a single frame grab image first, to see if it works, before you do the whole lot though.

Hopefully, if I've understood the problem you're having with your images, this will pull all those unwanted lines back into place. Though it well may look like a progresive video file I'm afraid.

JohnF

[Cail Young]

Hopefully, if I've understood the problem you're having with your images, this will pull all those unwanted lines back into place. Though it well may look like a progresive video file I'm afraid.

He has the inverse problem - he wants interlaced video but only seems to have deinterlaced video!

[Cail Young]

Yes, I know. And I'm only suggesting that as a last resort. But if I were trying to make motion smooth from a 30P source, I'd look into trying to add motion blur (via optical flow with Reelsmart Motion Blur) rather than trying to create whole new frames (via optical flow with Twixtor).

Good point; don't know if it would be much faster as the o-flow estimation is still performed on the entire frame with both twixtor and reelsmart motion blur, but certainly the blur operation would be quicker.

[GlennChan]

I have been google'n like mad on the subject for hours, and it mostly sounds like a hex editor job.
In FCP, the solution is pretty simple. You right click on the clip, go into properties, and tell FCP that the footage should be interpreted as lower field first. You don't need to edit the original file.

2- IMO, a lot of this is much ado about nothing.

Interpreting the file inappropriately only becomes an issue in certain situations. For example, if you apply a gaussian blur on interlaced footage, the gaussian blur should be applied on each field individually. If you apply the gaussian blur on the frame (the fields combined), then it's technically wrong... though it doesn't look that wrong. And some programs will process the frame by default, instead of each field individually.

For effects that work on individual pixels (like color correction), it doesn't matter if your NLE interprets the footage incorrectly.

If you make a DVD, you should however ensure that the DVD encoder knows the footage is interlaced. Doing this may be as simple as exporting your final timeline without a progressive flag (which would be the default if your timeline is interlaced... which would sometimes be under field order / lower field first).

3- Or, just watch your material on a CRT. If the motion looks fine, then you're fine.

4- I assume that your problem is interlaced footage being incorrectly interpreted as progressive. Is this the case?

[Mike Harrington]

Glenn,

I don't have the file in front of me, but I am fairly certain now that it is interlaced being interpreted as progressive.

The editors I use (avid Liquid, and VTedit) do not have the properties that you mentioned Final Cut having, it seems they read the flag and that is it.
I will look into some of my colleague's edit suite's and see if one of them has similar options.

[Cail Young]

The editors I use (avid Liquid, and VTedit) do not have the properties that you mentioned Final Cut having, it seems they read the flag and that is it.
I will look into some of my colleague's edit suite's and see if one of them has similar options.

After Effects can reinterpret footage, although it needs to render it out again.