Hi Scott, I've been doingh the same analysis on HD playback . I've been doing XvMC with an FX5200 AGP card. When it's working well, it's very good. But, I get the "prebuffering pause" issues, which causes choppy playback.
I'm surprised that you were able to do HD playback via the PCI bus. I didn't think the bandwidth was sufficient for [EMAIL PROTECTED] Maybe XvMC changes the equation a bit.. Can you still get decent HD playback without XvMC? Another thing I'm interested in is the 'Unichrome' display adapters. This S3/VIA video chips do full MPEG decoding, not just the iDCT+MC done with XvMC. I don't know if it is any more/less capable with things like de-interlacing. Also, the 'Unichrome' version is integrated into the motherboard, I don't know if they have the same capabilities in their add-in cards. Prior to moving to MythTV, I used a 'MyHD' card in Windows. It had a hardware MPEG decoder, which did a nice job of scaling and de-interlacing, which almost no CPU requirements. I would love to find something similar for MythTV. On 7/31/05, Scott <[EMAIL PROTECTED]> wrote: > Having been on the list for some time I was familiar with nvidia + > xvmc combination and wanted to try it out. I picked up an evga > GeForce FX 5200 PCI adapter and stuck it into my SIS based P4 > Northwood 2.4GHz Pundit system. (Note: not the Pundit-R) Setup was > done under Gentoo 2005.0 using all stable packages with kernel 2.6.12- > r4. I wanted to put down some notes for others who might be > considering the same. > > My goal was to evaluate the xvmc + nvidia playback quality for future > HDTV use. For playback I used xine-lib 1.1.0 and xine-ui 0.99.4 along > with a few 1920x1080i and 1280x720p clips. I also used some standard > DVD video to compare xv with xvmc processing. My viewing was focused > around deinterlacing and artifacts that might be seen from post > processing. For a display I used DVI out at 1280 x 720 to my > Panasonic PT-L500U projector. > > Setup of nvidia + xvmc on Gentoo is well documented and went off > without a hitch using nvidia-kernel 1.0.7667. Over all I was > impressed with the results. Using xvmc I was able to easily playback > 1080i clips with about 35% cpu use. Considering the low end PCI bus > on the Pundit system board and the low end GPU on the FX 5200. > > I had two issues that for me are critical. > > When using xvmc with Xine none of the OSD overlays would work. This > meant no on screen information, subtitles, or closed captions during > playback. I didn't investigate this to much however I think it could > be worked around. One possibility seems to be with the Xine xxmc > support. > > XvMC appears to do very simple one-field deinterlacing in hardware. > Xine 1.1.0 has experimental XvMC bob deinterlace support which I > enabled and saw some improvements. I compared various DVD (480i > content) scenes played via Xv with Xine deinterlace post processing > and XvMC with hardware deinterlace. It was pretty clear to me that Xv > with deinterlace post processing was producing a much better picture > than XvMC using hardware deinterlacing. > > Based on my testing I think using nvidia + xvmc could be acceptable > when dealing with HDTV streams but should be avoided for standard > NTSC 480i content or where ever else it isn't absolutely needed. The > best solution, from an image quality standpoint, would be to avoid > XvMC and use a powerful system to handle the HDTV content decoding > and playback. Obviously that solution brings with a host of other > problems dealing with heat and noise. > > Right now I'm unsure of which direction I'll go in. I know I will be > scraping my pundit and setting up a full FE/BE in a nice HTPC case > like the ones Silverstone makes. The cheap solution, for me, is to > get a socket 478 ATX board that supports my existing P4, memory, and > other hardware then add in a quality Nvidia AGP based adapter. > Considering the prices of nice looking HTPC cases and silent power > supplies this might be the way to go as an interim step. > > -- > Scott <[EMAIL PROTECTED]> > AIM: BlueCame1 > > > > _______________________________________________ > mythtv-users mailing list > [email protected] > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users > > > _______________________________________________ mythtv-users mailing list [email protected] http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
