Quote:
Originally Posted by turbojet
Are you guys sure 702 is actually the correct width of dvd's? I've always heard (mostly from an electronics engineer) 703 PAL and 706 NTSC which is typically rounded to 704.
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Absolutely certain about 576/50i (aka "PAL") being 702 samples wide. Comes directly from 13.5MHz sampling of a 52us active line.
I don't know about NTSC - as there were all sorts of issues with 480 vs 486 lines. (Modern digital "NTSC" is based on 480 active lines, but analogue NTSC and digital broadcast video originally worked on the basis of 486 active lines)
(NB PAL changed from analogue 575 to digital 576 active lines - but didn't change picture height. How? Originally analogue "PAL" was deemed to be 575/50i active lines - with each 575 line frame made up from two fiels each of 287.5 lines - one had a half-line at the top, one had a half-line at the bottom. In digital "PAL" these half-lines are padded to full lines creating 2 x 288 line fields or a 576 line frame. You often still see the half-lines at the top and bottom of frame when viewing 576/50i content scaled to 1920x1080 and viewed with no overscan)