[mythtv-users] nVidia and XvMC

[William Lewis]

>I have gotten XvMC working on my Athlon 64 with an nVidia 6600LE.
>However, it wasn't easy, basically, I do a brute force hack to beat it
>into submission whenever I start up my X Session.
>
>First, when compiling Myth, force it to compile against libXVMCNVIDIA,
>I've had nothing but trouble with libXVMCW.  This requires modifying the
>"if" statement around line 1699 of configure (talking v0.18.1 here).
>You might need to do "ln
>-s /usr/X11R6/lib/libXvMCNVIDIA.so.1 /usr/lib/libXvMCNVIDIA.so" for this
>to work properly.
>
>Recompile MythTV, go into TV Options and select the option to use XVMC.
>Playback a video and prepare to be disappointed (at least I was).
>
>Why is this?  Because it couldn't open up the video properly.
>Apparently it gets some access denied issue (I'm at work so I can't get
>the exact output right now).  Here's what I did to fix it.
>
>Create a two frame mpeg movie using mencoder.  It's important that it
>have more than one frame.  Two seems to work quite well.  Then, I made
>sure that my version of mplayer had xvmc support with it.  I had to
>recompile it for that (using Ubuntu Breezy).  Then, I had my startup
>script for mythfrontend execute the following script:
>
>#!/bin/sh
># bang away on XVMC until it works
>ROUNDS=0
>for x in $(seq 1 100); do
>         LINE=$(~/bin/mplayer -vo xvmc -vc ffmpeg12mc ~/bin/fix.mpg -ao 
>none 2>&1 | grep "End of file")
>         if [ "x$LINE" == "xExiting... (End of file)" ]; then
>                 echo "Took ${ROUNDS} tries to succeed"
>                 exit
>         fi
>         ROUNDS=$x
>done
>echo "Unable to initialize xvmc"

I wonder why I didn't think of that...

>Where fix.mpg is the name my little two frame mpeg file.  This
>essentially tries to run Mplayer 100 times on the little file.  The
>first time it actually succeeds and plays it, it stops.  The reason is
>because I notice that once I actually had XVMC working, it would just
>keep working for that session.  Thus, by beating XVMC into submission
>when I first start, I'm good for XvMC on MythTV.  Usually it takes about
>3 or 4 tries.  Once it took 15, but that's the most.  This script
>automates all that, and makes it transparent.

If I have a DVD and want to extract the first couple of frames to generate a 
fix.mpg, what is a simple mencoder command line to do that?  That would make 
life a lot easier than trudging through the mplayer man page...

Thanks very much.  That's the most informative answer I've gotten all over 
the internet.