Thanks - great clarification! On Monday 31 December 2001 04:15 pm, you wrote: > joe briggs (jbriggs@xxxxxxxxxxxx): > > Isn't this standard conversion a hardware process? > > Being able to output a composite NTSC signal, a VGA signal, or a PAL > signal is a hardware process handled by the video card. However, > software still needs to provide the images to display. > > > For example, you have long been able to buy analog standard converters > > from RadioShack, and you have certainly been able to purchase digital > > standard convertser which frame grab in one standard, and clock out in > > another - these are used by tv stations and tape conversion houses. > > There are many poor methods of framerate conversion. See my repost > where I describe one way of using 50-50 image blurring to deal with > motion. Other converters screw motion. I see some really strange > artifacts sometimes when watching PAL-recorded material broadcast here, > and often the motion is just messed up. > > Do a search on 'pal ntsc conversion' for more discussion. There's > also a really great article on it that I found once and I'll try to find > again... > > > However, many "book pc's" - these small footprint PC's, usually a i810 > > chipset, have both VGA and composite/s-video output as well. In the > > bios setting for these, you have the option of selecting the TV video > > mode to PAL/NTSC/SECAM. Even if you are running Linux and set X to > > 640x480, it looks great on the TV out. > > Watching low-framerate material, like using your desktop or watching a > 24fps video, looks fine on displays at 50hz (PAL TV), 59.94hz (NTSC TV), > and a VGA monitor (50hz+). > > Watching 25fps or 29.97fps material on an NTSC TV is also pretty safe, > you'll likely only see a stutter every 30 seconds or so depending on how > different your clocks are. > > But watching true 50fps or 59.94fps material on any of these displays, > you start to get into trouble. > > Remember, when you watch a PAL TV, you're watching 50 images per > second, and with NTSC TVs, it's 59.94 images per second. Recording at > half rate like 25fps or 29.97fps you're already protecting yourself > against framerate judder.
