On Nov 7, 2007 10:32 PM, MythTV User <<a href="mailto:mythuser@mydean.com">mythuser@mydean.com</a>> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
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<div><font face="Arial" size="2"><span>I set my Xorg to
output at 1080p which my 46" LCD displays nicely, with 1:1 pixel mapping. Is
playing DVD discs using xine (or internal dvd player) with anamorphic
setting on equivalent to playing the DVD in an upconverting/upscaling player? If
not, is this possible?</span></font></div></div></blockquote><div><br>What exactly does the upconverting/upscaling player do? What a typical software player such as Xine, Mplayer, or MythTV does is to display images using the XVIDEO X11 extension. This allows the player to send frames of video in the same uncompressed format contained in the encoded video to the X11 server. The server then typically uses the video hardware to convert the images to an RGB colorspace and scale it to the desired size, which might be 1920x1080 or 1280x720. That certainly sounds like upscaling or upconverting to me, but I don't know how the marketroids use those terms.
<br><br>I've read that the scaling algorithms implemented in video hardware may not be the best quality ones. I know that mplayer has several scaling algorithms it can use internally that are supposed to give better quality results at the cost of more CPU time (since the video card isn't doing the scaling) and you can probably also use software scaling in MythTV with the right playback filter, though I haven't tried it. I haven't personally noticed the difference between the quality of the video card's scaler and a high quality software scaler, but someone with better vision and/or a better display might.
<br><br>Another commonly used conversion is deinterlacing, which MythTV, Xine and Mplayer can all do. Thankfully this is usually not needed to play DVD movies, since a properly encoded movie will be progressive frames with MPEG flags that also allow it to play well on an interlaced display. What I can't figure out is why the same technique isn't used to encode the vast majority of HD shows I see that are clearly from progressive sources.
<br></div></div><br>In any case, when I play DVD movies with any software player, the image quality looks great on my 26" 1366x768 LCD panel. Though there is noticeably less detail than a 720p or 1080i show, it looks much better than regular NTSC and most 480i ATSC shows.
<br><br>Jonathan Rogers<br>