Take a look at this screen grab. It shows two Web videos side by side, one from the BBC and the other from CNN. I paused them on very similar frames of President Obama giving his inaugural address. (It’s probably not the same moment in the speech, as I did not bother to listen to the sound.)
See the aspect ratio difference? According to my measurements, Obama’s head has a height/width ratio of 1.28 in the BBC video and 1.06 in the CNN video. To put it another way, his head looks about twenty percent wider (relative to its height) in the CNN video.
I have also compared CNN Web video images of two of their own anchors* to the portrait photos of the same anchors available on their site. The results were very similar to what I’ve shown you: the anchors’ heads appeared about nineteen percent wider in the videos.
It looks to me like CNN is horizontally stretching all their images. I find the effect pretty noticeable, especially when I play the videos and can see people’s faces and bodies seeming to change shape as they change orientation.
I suspect that this is not being caused by my browser. One reason I think that is that the CNN logo in these videos looks undistorted to my eye. (I presume that the red lines forming the logo are supposed to have the same thickness where they run vertically as where they run horizontally.) When I use an image editing program to correct the distortion of the picture, the logo looks horizontally squashed.
Why would they do this? Do they just want to make everybody look fat?
Is this only in their Web videos? (I don’t have access to the TV right now, but I’ll check that later.)
The hotel I’m staying in at the moment has a wide screen LCD TV, great! But it’s set to stretch the 4:3 feed, ok. Also a lot of the 4:3 feed is actually widescreen format so it has the black bars top and bottom. So what do I get to see on my TV? I get to see widescreen TV and movies with black bars top and bottom subsequently stretched to fit the widescreen TV. Bloody annoying, and the controls for the TV seem to be locked so I can’t change it.
The whole aspect ratio thing is a mess and it is made worse by the use of “rectangular pixels” rather than sticking with “square pixels”.
For instance, DVD does not use square pixels but rather the image has to be stretched or compressed horizontally to give the correct aspect ratio. If you do not stretch it or compress it horizontally as needed then you have a distorted image. NTSC uses 720 × 480 pixels which is 1.5 and has to be compressed horizontally by 12.5% to get the correct a/r. If you play it stright then it will be too wide.
Since the streams do not carry a/r information the player has to guess and sometimes guesses wrong. I often just wish there would be an easy way of manually selecting the a/r.
The video disc publishers should just start including a standard reference square image at the beginning of the disc (it could be just one frame) and let the video player manufacturers figure out how to program the player to make that square a square.
But that assumes the player can talk to an intelligent display which can in turn tell the player what shape it (and it’s pixels) are. Plenty of current displays are dumb as the 1950s.
