> IIRC TVs use pixels a bit taller than square. 320x240 fills a 4:3 screen on
> a computer, but it looks like 352x240 is required on a TV [1]. So TV pixels
> are 320/352 = 10/11 the width of a square pixel, or 11/10 the height of a
> square pixel, take your pick. So your 1280x800 screen should look 11/10 - 1
> = 10% too narrow, or 1 - 10/11 ~= 9% too tall on a TV. Is that about right?
>
> [1] http://www.videohelp.com/vcd#tech2
Video encoding and playback are totally different than standard
display. You encode an ntsc vcd at 352x240, but the 4:3 aspect ratio
is embedded in the mpeg stream so that it actually plays back at
352x264. (You'll notice this if you play a vcd using
mplayer/xine/vlc.) DVDs are the same way. You encode at 720x480
(NTSC), and the aspect ratio is embedded in the mpeg stream, so that
it plays back at 720x540(4:3), 854x480(16:9), or what have you.
Regardless of all that stuff, however, the picture on a(n old 4:3, I
have no experience with these newfangled widescreen ones) tv has a
little less (about 10/11, like you found) vertical resolution than a
square-pixel display does. Not sure how or if this applies to the
projector in question, but 1280x720 would appear on a tv to be
vertically stretched to the same aspect as 1280x768 on a square-pixel
display.
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