On Tue, 20 Nov 2007, Tom Metro wrote: > Simon Hyde wrote: >> The MVP can and does output widescreen signals (they're electronically >> identicle to 4:3 signals). There is no difference between a 4:3 PAL/NTSC >> signal and a 16:9 signal. The analogue signal describing a line lasts 52 >> microseconds for both. > > Wasn't this a technique originally developed for DVDs?
Not really, no. I'm talking about a PAL/NTSC signal here, ie the analogue Composite signal (although it applys just as much to a S-Video/RGB/YPrPb signal) that comes out of the back of the MVP. The amount of time it takes to scan a 16:9 line has to be the same as the amount of time it takes to scan a 4:3 line, since you've still got to squeeze in 625*50 (or 525*59.something if using NTSC) lines every minute. Your telly/camera just scans accross a longer area if it's a 4:3 picture than if it was a 16:9 picture. There is no difference whatsoever between a 16:9 and a 4:3 signal. > Doesn't go by the name anamorphic widescreen or something like that? It can be described as 16:9 FHA (Full Height Anamorphic), but basically it's a 16:9 signal. It's the format used by all broadcasters internally, on analogue and digital (SDI) video signals. It's also the format used for widescreen DVB broadcasts. Whilst I can't speak too much for ATSC (since America is the only place that ignore an international standard and just re-implement the same thing slightly differently, and I don't live in America), I'd be amazed if it did anything different. > Essentially, the pixel aspect ratio is no longer square. Well, almost, except it wasn't square before, neither 720x480 or 704x480 or 720x576 or 702x576 provide square pixels for either 4:3 or 16:9 video. > >> Even in an MPEG the actual picture is the same size >> (720x576 for PAL or 720x480 for NTSC) for both... > > That may be true in some cases, but it depends on where you source your > MPEG from. There are lots floating around that use square pixels and > different resolutions depending on whether they are 4:3 or 16:9. I'm talking about broadcast MPEGs here, or DVD ones. > Roger Heflin wrote: >> ...were both talking about zoom on the widescreen >> TV itself to make a 4:3 letterbox display go full screen... > ... >> Currently I take a HDTV 16:9 convert it, crop it to just the signal >> and then center it back to in the center of the 4:3 display >> (resulting in 4:3 letterbox) and then use the TV's zoom function to >> make this appear to be full screen widescreen. > > That process obviously throws away resolution. Does your TV support > anamorphic video? If it's a widescreen TV then it will support it. > If so, and you're going to bother switching modes on > your TV anyway, then you should be encoding your video so the 16:9 > picture completely fills the screen of a 4:3 TV and appears vertically > strteched. One of the modes on your 16:9 TV ought to be able to stretch > that back, while avoiding the loss of resolution. Yup, and if your telly supports WSS then it should do this automatically when instructed to do so by mvpmc (Sadly however I doubt the NTSC WSS works). Cheers, Simon ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Mvpmc-users mailing list Mvpmc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mvpmc-users mvpmc wiki: http://mvpmc.wikispaces.com/
