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Pixel Aspect question that has been driving me nuts
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[Kevin Monahan] “One would never edit a 720 x 540 graphic directly into the timeline, if you do that, you’ll get small black bars at the top and bottom of the screen.”
Which end up getting cropped off anyways when someone actually sees it. See my earlier post. Name one instance where a consumer will view 720×486. It doesn’t happen.
You’re not looking at this in a practical sense or in a sense that’s relative to 2008. That Apple doc is very old. Those 6 extra lines are trivial, and they get cropped off during delivery anyways. 480 is new size standard for Standard Definition, as defined by the ATSC. D1 486 doesn’t fit into the digital/HDTV world. The proper handling of it is to crop 6 lines or add 6 lines of black. Look at this for example: 1080i and 720p are both based on multiples of 540 lines (square pixel equivalent of 480) for a reason (1080 is 2x, 720 is 1.5x).
Long explanations aside, 480 video should never, ever be scaled to 486, and vice-versa. Apple agrees with this 100% as evident by the behavior of FCP. If you don’t believe me, place 480 video in a 486 sequence (or vice-versa) and see how FCP handles it.
As for stills, again it’s trivial. You can design stills to fill those 6 extra lines if you want, but they’re going to get cropped off anyways when the consumer sees it. All digital SD is 480, not 486. Sonic hardware DVD MPEG encoders with SDI input crop 4 lines from the top, 2 from the bottom to create 720×480 MPEGs. So does Apple Compressor.
Long story short, if someone sends you 720×540 graphics, leave it that way. Don’t scale it.
Sean
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[Dave LaRonde] “Jeez, Chris, it sounds like you’re suggesting that Apple ought to FIX ITS SOFTWARE so it plays nice with just about every other application on the planet! What a concept!
Logical, too…..
I know….How Dare Me! 😉
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There is another reason not to switch 480 to 486 and vice versa.
in some applications that will introduce tearing in the image.
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sorry, wrong thread
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