[mythtv-users] Gentoo + VIA Binary driver

Wed Apr 14 15:29:15 EDT 2004

Well, you definitely have a stepping 3, so the EDX fix is required if
you're using software decode.  Double-checking that is probably a
good thing to do (you might even want to blow away the work
directory and the .tar from distfiles and start from scratch).

I'm running MythTV 0.14-r1 straight from the portage ebuild.  I've also
ran 0.13 on this box and had same performance.  It also looks
like your Epia setup (kernel version, XFree version) is very close
to the same as mine (and I haven't noticed any significant change
with the different -epia kernels or Xfree-epias).

What process is eating most of your CPU bandwidth?  If it's
mythfrontend, the EDX fix is suspect.  If it's something else then
I can't help out much - the incorrect MMX detection on the M10K
was the only CPU-hog issue I've had with MythTV.

Also, note that my ~50% CPU at 480x480 capture resolution is
with software decode.  With hardware decode, the CPU drops to
less than 20%.  Oh... and if you're using HW decode, the EDX
hack is not necessary (since the mpeg decoding doesn't even
touch the CPU).

Oh... and the 480x480 is the MythTV capture resolution.  Actually,
that's something to check.  In the recording profiles section of
MythTV, check to see what your capture resolution/bitrate is.
Mine is 480x480 with 4.5/6.0 Mbps.  Also, I believe MythTV
just uses the ivtv binaries to change the resolution/bitrate.  It's
possible that Myth cannot find the binaries and you're at the highest
setting (720x480, 8/16 Mbps) - that would cause poor performance
just because the M10K can't handle that much information.

A quick way to check the mpeg encoding is to run mythfrontend
from a terminal window and look at the output when you go to
watch live TV.  Myth should output the mpeg stream info (resolution,
bit rate, fps, etc.).

Mik

>From: "Paul W. Smith" <cvpsmith at ncche.olemiss.edu>
>Reply-To: cvpsmith at ncche.olemiss.edu,        Discussion about mythtv 
><mythtv-users at mythtv.org>
>To: Discussion about mythtv <mythtv-users at mythtv.org>
>Subject: Re: [mythtv-users] Gentoo + VIA Binary driver
>Date: Wed, 14 Apr 2004 12:21:32 -0500
>
>On Wednesday 14 April 2004 11:21 am, Mikhail D'Vane wrote:
> > Hmm... I'm running Gentoo on my M10K and playback at 480x480 resolution 
>is
> > smooth (CPU at ~50%).  I needed to apply the EDX hack to cputest.c, 
>though,
> > since I have a stepping 3 CPU.
> >
> > A few questions:
> >
> > 1.  What kernel are you running?  I'm on 2.4.24-epia1.  (I've also had
> > success
> >      with 2.4.25-epia1, but I didn't notice any difference in 
>performance).
>
>I'm running 2.4.24-epia1-r1and xfree-epia version 4.3.99.902-r3
>
> >
> > 2.  What's your CPU stepping?  (Look in /proc/cpuinfo.)
>
>CPUINFO:
>cpu family      : 6
>model           : 9
>model name      : VIA Nehemiah
>stepping        : 3
>cpu MHz         : 999.540
>cache size      : 64 KB
>
> >
> > 3.  Are you sure that the EDX patch has been applied?  Depending how you
> >      chose to install MythTV, it's possible that cputest.c got 
>overwritten.
> > To
> >      install on mine I have to use a slightly different approach than
> > normal emerge.  I have to:
> >
> >     - ebuild 
>/usr/portage/media-tv/mythtv/<mythtv-ebuild-filename>.ebuild
> > unpack
> >
> >     - go to the unpacked work directory and edit cputest.c
> >
> >     - ebuild 
>/usr/portage/media-tv/mythtv/<mythtv-ebuild-filename>.ebuild
> > merge
>
>I used the same approach, but I'm gonna try it again just to be sure...
>
> >
> > 4.  When you refer to binary drivers, do you mean the binary video 
>drivers
> > or the
> >      mpeg decoder driver (libddmpeg.so)?  I don't currently use the HW
> > decoder
> >      (can't apply any filters with it), but I have used it in the past 
>and
> > I found
> >      you can pretty much just replace the libddmpeg.so file in the 
>library
> > with
> >      whatever version you wish (Via's, Ivor's).  Performance/issues are
> > different
> >      between the various versions.
>
>Since you're getting decent performance with Ivor's mpeg decoder driver, 
>this
>leads me to think that it is a configuration issue and changing the driver
>won't help much.  What version of Myth are you running?  Also, where did 
>you
>set up your playback to be 480x480 resolution?  Is this an XF86Config
>setting?
>
>Thanks for the help, Mik!
>
> >
> > Mik
> >
> > From: "Paul W. Smith" <cvpsmith at ncche.olemiss.edu>
> >
> > >Reply-To: cvpsmith at ncche.olemiss.edu,        Discussion about mythtv
> > ><mythtv-users at mythtv.org>
> > >To: mythtv-users at mythtv.org
> > >Subject: [mythtv-users] Gentoo + VIA Binary driver
> > >Date: Wed, 14 Apr 2004 08:47:48 -0500
> > >
> > >
> > >I pretty much have my M10000+PVR250+Gentoo system set up now, except 
>for
> > >the
> > >fact that my CPU is hitting 100% when watching LiveTV, which causes
> > >occasional freezing.  I've tried adjusting all of the MythTV settings, 
>as
> > >well as the EDX field correction in cputest.c.  I've also gone through
> > > this post:
> > >
> > >http://www.gossamer-threads.com/perl/mailarc/
> > >gforum.cgi?post=110741;search_string=epia-m10k%20mpeg2%20decoder%
> > >20performance;guest=2880558&t=search_engine#110741
> > >
> > >
> > >I'm at the point now where I'm seriously considering attempting to go 
>with
> > >the
> > >VIA binary driver to see if this helps any.  A few quick questions:
> > >
> > >Does anyone know if there is a difference in the playback of live TV 
>when
> > >using the binary driver as opposed to Ivor's open source driver (does 
>live
> > >TV
> > >even use the hardware decoding of the M10000)?
> > >
> > >Is there a procedure on the net somewhere that will help me to get the 
>VIA
> > >binary driver working with Gentoo 1.4 (2.4 kernel)?  Is this even
> > > possible?
> > >
> > >Could my problem have more to do with my X configuration, rather than a
> > >driver
> > >issue?
> > >
> > >
> > >TIA
> > >
> > >Paul
> > >
> > >PS.  Thanks everybody for the excellent help that I received on 
>previous
> > >issues that I was having!
> > >
> > >
> > >_______________________________________________
> > >mythtv-users mailing list
> > >mythtv-users at mythtv.org
> > >http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> >
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>--
>Paul W. Smith
>Coordinator of Computing Facility Operations
>National Center for Computational Hydroscience and Engineering
>http://www.ncche.olemiss.edu
>
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