[mythtv-users] Switch FC3 to Kubuntu Feisty, now HD is very jerky

Joseph Caputo jcaputo1 at gmail.com
Mon Jun 4 00:46:44 UTC 2007


On 6/3/07, Brad Templeton <brad+myth at templetons.com> wrote:
>
> I have been moving my systems to ubuntu (kubuntu) and am now working
> on the systems running Myth.   (I have 6 linux boxes in my house,
> don't you?)
>
> So I upgraded my main frontend from ancient FC3 to Kubuntu Feisty.
> That install was smooth and pleasant generally, and I recompiled
> Myth from a recent SVN checkout.  I have the lastest nvidia
> drivers installed by automatix2, as well as the many multimedia
> players (xine, mplayer etc.) which work fine and can play HD.
>
> However, Myth now produces very jerky video on HD.   The apparent
> cause is video getting ahead of audio.   I became an expert on getting
> Myth working on the old system, but none of the tricks are working here.
>
> Log entries look like this:
>     2007-06-03 15:08:41.441 NVP: Video is 14.5947 frames ahead of audio,
>                         doubling video frame interval to slow down.
>     2007-06-03 15:08:41.446 AO: Broadcasting free space avail
>     2007-06-03 15:08:41.447 AO: audio waiting for space on soundcard: have 104 need 4096
>     2007-06-03 15:08:41.458 AO: audio waiting for space on soundcard: have 2360 need 4096
>     2007-06-03 15:08:41.470 AO: Broadcasting free space avail
>     2007-06-03 15:08:41.471 AO: audio waiting for space on soundcard: have 612 need 4096
>     2007-06-03 15:08:41.477 NVP: Video is 16.6105 frames ahead of audio,
>                             doubling video frame interval to slow down.
>     2007-06-03 15:08:41.482 AO: audio waiting for space on soundcard: have 2860 need 4096
>     2007-06-03 15:08:41.494 AO: Broadcasting free space avail
>     2007-06-03 15:08:41.495 AO: audio waiting for space on soundcard: have 1132 need 4096
>     2007-06-03 15:08:41.506 AO: audio waiting for space on soundcard: have 3380 need 4096
>     2007-06-03 15:08:41.509 NVP: Video is 17.8376 frames ahead of audio,
>
> CPU is fine, running about 30-40% idle -- this is a 720p video on a
> P4-3ghz, and never had any problems with 720p or 1080i before.  As noted
> xine and mplayer are able to play the videos fine.
>
> I tried various tweaks:
>             OpenGL video sync on or off
>             Extra audio buffering on or off
>             Use video as timebase on or off
>             Deinterlace on or off (should not matter on 720p)
>             libmpeg2 decoder instead of ffmpeg (in spite of what it
>                 says, libmpeg2 seems to have better idle times so I
>                 am sticking with it even though it's a P4)
>             realtime priority on or off
>
>
>
> Other changes:
>         I added some more memory.  It's PC2700 instead of PC3200 but
>         this mobo handles that, clocking each bank independently.
>
>         I recompiled Myth, removing restrictions on architecture
>         that were there so I could move the binary to my Athlon.
>
>         Video driver is of course new, card is still Nvidia 5200.
>         Removed modelines (newer X now figures out the DPMS)
>
>         Changes to UI size and overscan due to new X config. (odd,
>             that this happened, but not hard to fix)
>
>         I turned on NvAGP in xorg.conf as getting suspend working
>             is one of my big goals.
>
>
> Other issue:
>         When the system boots up, or comes out of screensaver
>         (which I thought I disabled) there is wiggling to elements
>         on the screen for about 20 minutes that was not there before.
>
>
> In all cases myth is still using oss /dev/dsp, should I switch it to something else?
> It works OK on my desktop machine like this with the same settings, though
> that machine is much faster (Core 2 DUO 6600, nvidia 7600)
>
> Should I put an nvidia 7600 into the Myth machine?  It just generates
> more heat, I don't need its extra abilities.
>
> Any other thoughts?

Brad-

I'm very interested to hear how this works out for you, because I now
have all my other boxen running Kubuntu Feisty & am considering
changing my FE/BE over from FC3.

As to your problem, maybe this thread will help:

http://www.gossamer-threads.com/lists/mythtv/users/272362

Apparently new versions of X.org enable the Composite extension by
default, which causes the Xvideo overlay to be disabled on with some
Nvidia drivers/cards.  Don't know if that's your problem, but it's
worth a shot.

Cheers,
JAC


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