Apple Final Cut Pro Legacy Forum
FCP 7 & Aspect Ratio (where do the #s come from and how to calculate?)
FCP 7 & Aspect Ratio (where do the #s come from and how to calculate?)
by Bryce Hoover on Jan 31, 2014 at 5:18:50 pm

A lot of the work I've been doing lately has been taking SD footage and scaling it up to fit the 1920x1080 raster. Dropping an SD 4x3 clip (720x486) into an HD 1920x1080 timeline makes the SD clip 226 scaled and 12.5 distort/aspect ratio. Where does that number (12.5) come from and how can I "do the math" or know what distortion value to use when there's anamorphic SD footage I need to "up rez"?

I've seen -33.33 and -12.5 (and probably others I can't remember). Sometimes 12.5 doesn't look right but then 10 doesn't really either. I'm not really comfortable eyeballing everything. I've searched google (and the cow) for answers and haven't found anything. Maybe there's not an answer other than eyeballing everything. It's maddening! Any ideas?

-bh



Re: FCP 7 & Aspect Ratio (where do the #s come from and how to calculate?)
by Bret Williams on Feb 1, 2014 at 5:28:40 am

Best I can tell is that number comes from dividing the pixel horizontal count (720) by the square pixel equivalent (640). 720/640=1.125 the .125 equating -12.5 somehow. The same hold for a 1440x1080 16:9 format. We know that the 1440 is presented/expanded to fill a 1920x1080 space. 1920/1440=1.3333333333 giving that -33.3 number.

But FCP adds this distortion for you. When you place a 1440x1080 clip in a 1920x1080 timeline, it adds the appropriate distortion.


Re: FCP 7 & Aspect Ratio (where do the #s come from and how to calculate?)
by Bryce Hoover on Feb 1, 2014 at 7:03:44 am

thank you.

-bh



Re: FCP 7 & Aspect Ratio (where do the #s come from and how to calculate?)
by James Wages on Nov 19, 2014 at 12:50:00 am

I myself ignored the math and did it by sight. Here's how.

I had an SD 4:3 video in FCP7 that I wanted to convert to 720p HD (1280x720). Why? Because putting SD videos on YouTube looks absolutely horrible -- you only get decent quality with 720p or (or higher). So within FCP7, I right-clicked on "Sequence 1" and chose "Settings..." I set FRAME SIZE to "HDTV 720p (16:9)." I then set the PIXEL ASPECT RATIO to SQUARE, which will widened my SD clips. To fix the clips, I manually double-clicked each clip and in the MOTION tab I set the SCALE to 150% (which made the top and bottom go to the 720 pixel height), and then I chose an ASPECT RATIO of 7, which fixed the width perfectly (to my eye, anyway).

Yes, there are black bars on the left and right, but since SD isn't a 16x9 wide format, such is to be expected and I have zero problem with that. I just wanted the top and bottom to fit perfectly in 720p and at the same time make sure the width of each converted SD clip was proportionally the same as what I started with.

I hope this helps.





© CreativeCOW.net