On Fri, 9 Nov 2007, MVallevand wrote: > That's for video, which as mentioned works. Simon's great WSS code > often helps too even when that is not set.
Hello! Someone mentioned widescreen. I know a bit too much about that! The way that widescreen telly is implemented is a rather confusing matter, so I'll try to clear up some of the innacuracies in this thread: Pre-letterboxed menus ===================== To answer the original question, mvpmc does not offer any kind of OSD using a reduced area of the screen, and i don't think it would be very easy to implement. "I don't have a "Full" button" ============================== The "Prev. Ch." on the larger remotes button does the same thing as the "Full" button would on the smaller ones. The MVP can output "true widescreen" ==================================== 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. Even in an MPEG the actual picture is the same size (720x576 for PAL or 720x480 for NTSC) for both, there's just a flag in the headers specifying whether those 720 pixels show the length of a 4:3 line or a 16:9 line. The real problem you have here is that your cable provider isn't broadcasting "true widescreen" pictures in an analogue form, because they don't want to upset their 4:3 viewers. Instead they're taking the 16:9 picture and letterboxing it into the middle of a 4:3 picture. Sadly we're not aware of any way to cut out and zoom this section of the picture using the MVP's hardware, this would be the cleanest way to handle your question. What does the "-a" flag do? =========================== The -a flag affects what shape MVPMC thinks your TV is. In reality at the moment this only affects what the MVP/MVPMC does with an MPEG which has a 16:9 flag in it's header (*): 16x9: The video is shown as-is, occupying all the picture area of the output signal. 4x3: The video is letterboxed in the middle of the picture, with large black bars top and bottom. 4x3cco: The middle bit of the video is chopped out and drawn occupying the full area of the output. Roger Heflin wrote: > Also note that if you put a widescreen without letterbox the video > shows at the top of the screen the the zoom function works badly. Nope, I fixed that almost 2 years ago (the commit was made by jon on 18th of December 2005 by the looks of it). It should only go into this mode if you've told mvpmc that you have a 4:3 display anyway. What is WSS? ============ If you're using a mix of 4:3 and 16:9 signals then a TV has to be told which type of signal it is receiving to know what area of the TV to draw this picture over. This can be (and often is) done by the user pressing buttons on the remote control. In PAL countries we use something called WSS to do this, which is a data signal stuck on the first half of the first line of picture that is visible(**). It describes various details about the signal, like which parts of the signal actually contain picture information (in the case of a letterboxed signal), and what shape the overall picture is. The MVPMC implements this, to allow a sensible PAL TV to switch back and forth and around as the picture switches. A similar signal with less features is available for use in NTSC, I tried to implement this on the MVPMC, but I had to use some maths and guess work to try to get the timing/line number right. I'd be very suprised if this worked. To get the NTSC equivalent working I'd need to check the output with a decent NTSC waveform monitor, but at the moment i don't think it works. The Smallprint ============== * This isn't actually true, it also affects how a particular type of video flagged with a specific AFD (a UK specific extension carrying more information about aspect ratio/active areas than is possible in the MPEG headers) code ** This is actually a bit of a lie. Only the second half of line that it's on (line 23) is supposed to contain visible picture, so the WSS is in the invisible bit. ------------------------------------------------------------------------- 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/
