[Openchrome-users] Question about new CX700M2

[Bert Haverkamp]

Hi Christiaan,

Thanks for your pointer!!. I I am compiling mythtv at the moment. let
you know the
result as soon as the votes are in;-)


Regards,

Bert

2007/5/29, Christiaan van Dijk <dvbmail at xs4all.nl>:
> perevera wrote:
> > Re: Question about new CX700M2
> >
> >> Hello Perevera,
> >>
> >>
> >> 2007/5/18, perevera :
> >>
> >>> Re: Question about new CX700M2
> >>> I performed a test by connecting both PCs through a cross-over link and I saw the same image/sound artifacts and CPU occuppacy as with the Wi-Fi connection through the router.
> >>>
> >>> So, I'm now possitive: or my mythfrontend is not correctly compiled for XvmC support (I don't think so, because the configurator let me check this option) or the OpenChrome drivers (experimental branch) are not ready for this video card.
> >>>
> >>> I believe this latter is the case. Moreover, I upgraded from revision 319 to the latest, 331, and DVD play with Totem or VLC was worst than before, with some colour stripes on the screen.
> >>>
> >> I am stuck in the same spot. mytthv doesn't play smoothly. However,
> >> playing the same recording via xine or mplayer works fine overhere.
> >> Could you confirm if this is the same on your side. This means that xv
> >> is fast enough for playing mpeg2, but mythtv is doing something odd.
> >>
> >> What happens here is:
> >> - livetv mythtv stutters, image and sound freeze about very second
> >> -  recording mythtv, image and sound play too fast.
> >> - recording xine, plays smoothly.
> >>
> >> Regards,
> >>
> >> Bert
> >>
> >> -----------------------------------------------
> >> Bert en Selena
> >> www.bertenselena.net
> >> -----------------------------------------------
> >> Only two things are infinite:
> >> human stupidity and the universe,
> >> and I'm not sure about the latter.
> >>    Albert Einstein
> >> -----------------------------------------------
> >>
> >
> > Hi, Bert.
> >
> > Yes indeed, I have the same symptoms, though I'm using Totem and VLC instead, but yes, I can view normally XivD and MPEG2 recordings through NFS and those tools, while mythfrontend is as bad as you explained.
> >
> >
> >
> Hi,
>
> this problem could be caused by the way MythTV determines the refresh
> rate of the monitor which is used as a reference in the playback part.
> MythTV uses the modeline information from Xorg to determine the refresh
> rate (/libs/libmythtv/videoout_xv.cpp), in my case (CN700) Openchrome
> returns zeros when using VBE modes. The calculation in Myth does a
> divide by zero and uses NaN as playback reference :-( . This results in
> stuttering playback
> I patched the file to use my real refresh rate when Openchrome returns
> zeros (patch attached). Normally MythTV reverts to 60Hz, I did not test
> what a difference in real/myth refresh rate does.
>
> I could call this an Openchrome bug since it returns zeros in the
> modeline, MythTV is also at fault by doing the divide by zero. Best
> solution for MythTV would be a more reliable way to determine the
> refresh rate, any ideas???
>
> Hope this helps,
> Christiaan van Dijk
>
>
> diff -u -r -x .svn ./a/mythtv/libs/libmythtv/videoout_xv.cpp ./b/mythtv/libs/libmythtv/videoout_xv.cpp
> --- ./a/mythtv/libs/libmythtv/videoout_xv.cpp   2007-05-27 13:05:40.000000000 +0200
> +++ ./b/mythtv/libs/libmythtv/videoout_xv.cpp   2007-05-27 13:44:28.000000000 +0200
> @@ -278,6 +278,8 @@
>
>  int VideoOutputXv::GetRefreshRate(void)
>  {
> +    double rate;
> +
>      if (!XJ_started)
>          return -1;
>
> @@ -294,8 +296,12 @@
>          return -1;
>      }
>
> -    double rate = (double)((double)(dot_clock * 1000.0) /
> -                           (double)(mode_line.htotal * mode_line.vtotal));
> +    // See if there's valid data to prevent a divide by zero.
> +    if (mode_line.htotal * mode_line.vtotal > 0)
> +        rate = (double)((double)(dot_clock * 1000.0) /
> +                        (double)(mode_line.htotal * mode_line.vtotal));
> +    else
> +        rate = 60.09; // or zero...
>
>      // Assume 60Hz if we can't otherwise determine it.
>      if (rate == 0)
> @@ -308,6 +314,8 @@
>          rate = 60;
>      }
>
> +    VERBOSE(VB_PLAYBACK, LOC + QString("Refresh rate set to %1Hz ").arg(rate));
> +
>      rate = 1000000.0 / rate;
>
>      return (int)rate;
>
> _______________________________________________
> openchrome-users mailing list
> openchrome-users at openchrome.org
> http://wiki.openchrome.org/mailman/listinfo/openchrome-users
> Main page:
> http://www.openchrome.org
> Wiki:
> http://wiki.openchrome.org
> User Forum:
> http://wiki.openchrome.org/tikiwiki/tiki-view_forum.php?forumId=1
>


-- 

-----------------------------------------------
Bert en Selena
www.bertenselena.net
-----------------------------------------------
Only two things are infinite:
human stupidity and the universe,
and I'm not sure about the latter.
   Albert Einstein
-----------------------------------------------