flipping between 5:4 and 4:3

Am I flipping or is it flipping?

The project which I've inherited was shot in PAL mini-DV with 720x576 pixels. I'm pretty sure the camera format was 4:3. If so the camera pixels weren't square.

I don't know how the camera tapes were captured into FCP, but now when I go to play a captured tape QT shows a 5:4 image which is obviously distorted. Spherical objects look taller than wide. I can measure them and it's like 4:3 has been squeezed into 5:4. But all the pixels are there.

In the FCP project everything is 4:3. The canvas measures 4:3 and the shots which look distorted when viewed from their scratch file with QT look correct on the canvas. Nothing has been cropped, it is just correctly 4:3 in FCP.

In FCP the sequence settings are:
Frame Size: 720x576 CCIR 601 / DV PAL (5:4)
Pixel Aspect Ratio: PAL - CCIR 601 (720x576)

The sequence presets show 720x576 PAL CCIR 601. The capture presets show 720x576 PAL

I don't see any mention of 4:3 in any FCP setting (though I might not know where to look) and yet there is a 4:3 undistorted image on the canvas.

When I now try to make a PAL QT export I get a one that QT plays at 5:4 looking distorted.
Then when I used Compressor on that PAL QT to make an NTSC QT it came out as 720x480 DV/DVCPRO-NTSC alright, but QT plays it with 3:2 format so it has the opposite distortion.

Are the QT movies I've made actually OK and is just the player at fauth? Are QT movies formatless, and the QT player ASSUMES they have square pixels so it plays the 720x576 as 5:4 and plays the 720x480 as 3:2? Is there a way to play these QT movies as 4:3 so they look right? If I burn a DVD from these QT movies will it play as 4:3 and look right?

Thanks.

Dennis Couzin
Berlin, Germany

Its not the display aspect ratio which isn't necessarily measured in pixels but simply a ratio of
width compared to height.

5:4 is the D1 pixel ratio for PAL eg 720(5)x576(4) it still displays as Non-square pixel 4:3 or 16:9 Anamorphic.


4:3 Square Pixel for PAL is 768x576 and the 720x576 (if 4:3) stretches to this.

16:9 Square Pixel for PAL is 1024x576 and the 720x576 (if 16:9 FHA/anamorphic) stretches to this.

QT movies from FCP will be displayed as Square Pixels in QT Player but pixel for pixel so you don't get a 16:9 or 4:3 image you simply get a 5:4 720x576 image.

If you want to compress the 5:4 movie to square pixels:

Simply convert the QT movie by stretching it to the correct aspect ratio for square pixels. eg: 1024x576 for 16:9 widescreen (from an anamorphic source) or 768x576 for 4:3 (from a 720x576 5:4 D1 source)

or any other ratio of 4:3 or 16:9 depending on the application it needs to be displayed in.



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BK, I don't want square pixels. I want people to play it as 4:3 so it doesn't look ridiculous. Now if I hand people the QT .mov file and they use a QT player they'll see it as 5:4 and wrong. But when I simply Toast it onto a DVD, either Toast or the DVD player must know (from its being PAL or NTSC) to show it as 4:3. (I'm surprised QT doesn't know this, or have a facility for adjusting it.)
So should I have chosen square pixels when I made the PAL .mov file in the first place. It would have made the 720 columns into 768 in an unlossy a way as any subsequent scaler?

Now that I have the 720x480 NTSC .mov file (which took 80 hours to make), is there a quick way to convert it to a 720x540 NTSC .mov file?

Thanks.

Dennis Couzin
Berlin, Germany

Open the file in quicktime. Hit CMD+J to open the movie properties and select the Visual Settings for the Video Track. Turn off Preserve Aspect Ratio and type 540 in the Scaled Size box in place of 480. Save.

Andy

Wow, CMD+J opens all that. Now QT does play the PAL and NTSC .mov files as 4:3. It makes sense. Thanks much.

Dennis Couzin
Berlin, Germany

or if PAL then use the 768x576 instead of 720x576...



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