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So just what is 16:9 SD video anyway?

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Nathan Tinsley
So just what is 16:9 SD video anyway?
on Dec 24, 2008 at 3:01:13 pm

Greetings,

I have a question (or assumption really) regarding the way 16:9 video is handled in the the Standard Def world, particularly in broadcast. First, my limited understanding in the edit world is that 16:9 or "widescreen" video for standard def is really anamorphic video with a raster of 720x480 pixels but with a pixel aspect ratio of 1.2. Therefore the each pixel gets stretched by 1.2 times along the horizontal and the 720 pixels fills a viewable frame size that would be 864x480 (720x1.2=864) if the pixels were square. This concept comes from the cinemascope days of film where the projecting lens had to have the same anamorphic qualities as the taking lens.

My assumption is that the standard def broadcast world is currently operating this way when it sends 16:9 standard def video to my TV set. My tv senses the aspect ratio and switches itself accordingly. I have a 16:9 TV. In other words there is NO BROADCAST standard def format that is 864x480 native with SQUARE PIXELS. Or to put it another way, all broadcast standard def wide screen video is by it's nature ANAMORPHIC. I know quicktime can do 864x480 square pixels but that's not my question.

So is my assumption correct or have I made an arse out of you and me!

Many happy returns.

Nate


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Gary Hazen
Re: So just what is 16:9 SD video anyway?
on Dec 24, 2008 at 9:45:05 pm

"all broadcast standard def wide screen video is by it's nature ANAMORPHIC" - Nate

Correct

"standard def is really anamorphic video with a raster of 720x480 pixels" - Nate

Correct for DV output. But... For broadcast the raster size is actually 720 x 486.



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David Coleman
Re: So just what is 16:9 SD video anyway?
on Jan 2, 2009 at 5:20:56 pm

My tv senses the aspect ratio and switches itself accordingly.

Your smart TV senses it only if the smart producer/broadcaster has embedded the correct anamorphic signal designator. Sometimes this isn't done, which is very frustrating.



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