4:3 conversion to 16:9 anamorphic

[Jeff Pulera]

Hi Bill,

I will start by sharing my definition of what “anamorphic” means, as I understand it. For example, DV video is 720×480 pixels for 4:3, but the SAME dimensions are also used for 16:9 recording. The 16:9 recording uses rectangular pixels with a Pixel Aspect Ratio of 1.2 (standard for DV is 0.9).

You CAN view the 16:9 video on a 4:3 display, and it will fill the screen and people will look “stretched” vertically, while it will look correct on a 16:9 display. Square pixels are really the “standard”, so getting the 16:9 look with the stretched pixels makes this kind of 16:9 “anamorphic”, or stretched.

Moving to HD, standard 1080i video is 1920×1080 pixels (1.0 PAR), but 1080i HDV uses 1440×1080 with a 1.333 PAR, so this type of 1080 is “anamorphic”. A little math shows that 1440×1.33=1920, and that is how the display comes out correct on the monitor, but the key is that the monitor needs to know the PAR to display the video correctly.

Video monitors handle this just fine automatically, but for computer and internet playback, the players assume a PAR of 1.0, so if you export a 16:9 720×480 DV clip to a web format, it will come out looking like 4:3 video!

So to make along story longer…if you don’t want any black bars on the video, Import the 4:3 DV clip into a 16:9 DV project, the use Scale to enlarge the video until it fills the screen and “looks like 16:9”. You can also use the X-Y Position controls to then move the video up or down, for instance to not cut off tops of heads.

The next step is that when you export for the web, you must change the image size to account for square pixels, so a 720×480 image needs to be exported at 864×480, then it will have the proper 16:9 aspect when viewed. If you want a smaller image, reduce size accordingly, like 432×240 for instance.

Hope this makes sense, long answer to a short question

Jeff Pulera
Safe Harbor Computers

[William Mcqueen]

Thanks you so much, Jeff, for your reply. I’ve been experimenting.

I am having the following problem in moving forward.

In terms of playing out – exporting to 864×480:

In the export movie settings, the frame size is grayed out and the Pixel Aspect Ratio selected is “D1/DV NTSC Widescreen 16:9 (1:9); when I select “Square Pixels” I get the same frame size: 720×480 (grayed out).

I’m trying “square pixels”, but the client wants “flash” for her website. So, I wonder what will happen if converted to Flash, in terms of current standards and expectations. The video itself in the expanded to “16:9” looks fine.

A couple of the supers are cut off at the bottom of the screen. I wonder how it would look with black slight bars below (looking like Letterbox. Is it just a matter of aesthetics, or is there an expectation or standard?

Thanks so much, again: getting there.

Cheers,
Bill in Toronto