[mythtv-users] Live TV - Prebuffering Pause

[Brian Wood]

On Feb 1, 2006, at 7:17 AM, Dave Pearson wrote:

> On Wednesday 01 Feb 2006 13:26, Brian Wood wrote:
>> On Feb 1, 2006, at 6:01 AM, Dave Pearson wrote:
>>> My problem is that when I try and watch Live TV from the PVR-250
>>> (Composite
>>> and Tuner input) or from the Avermedia Composite input, I get  
>>> constant
>>> prebuffering pauses. Live TV from the DVB Cards plays back OK and
>>> recorded TV
>>> from any source is OK. If I watch from my Dell Inspiron 6000 (via
>>> wireless
>>> network) I don't have any pauses. If I reconfigure X to use the nv
>>> driver (on
>>> a single monitor) playback is perfect. I have tried all sorts of
>>> combinations
>>> of the various playback settings, but nothing seems to help (most
>>> of the time
>>> I end up with the frontend crashing). I have also tried swapping
>>> the card for
>>> an ATI Radeon 9200SE, but this has the same problem with the
>>> manufacturers
>>> drivers and dual head (it works fine with the ati driver and single
>>> head).
>>>
>>> Any help will be gratefully received, I have attached the twinview
>>> xorg.conf
>>
>> Looks like it might be the infamous "High CPU load with nVidia
>> drivers" problem, although it usually doesn't strike with the 7676
>> drivers.
>>
>> I'd check what the CPU load while watching (top or vmstat) and, if it
>> is higher than it should be, try and figure out why.
>>
>> You might try commenting out "load glx" in your X config. Re-
>> compiling MythTV without OpenGL support is a possible solution, but
>> since you've installed from RPMs that might be difficult.
>>
>> The newer versions of MythTV  have an option to disable VSync, but I
>> don't think you have that option with 0.18.1.
>>
>> You say playback is "perfect" with the nv driver, is there some
>> reason you need the nVidia ones? or, like me, does it just "bother"
>> you that you can't use them?
>>
>>
>
> I have tried compiling myth myself on this box, but there is  
> something missing
> that causes the compile to fail - perhaps I should start another  
> thread to
> try and solve that problem.

Well that's another issue, as you said. I wouldn't spend much time  
trying to compile 0.18 what with 0.19 coming out soon, though you're  
likely to have the same problem if it's a missing dependency.
>
> I want to use the nvidia driver because I haven't been able to  
> successfully
> configure the nv driver to work with xinerama.

No, I don't think the "nv" drivers will ever do that.
>
> The CPU Load is running at between 5-10%, so I don't think that is  
> very high
> (it seems to be the same when I watch Live DVB TV.

Seems about right.
>
> I have tried removing "Load glx", but it hasn't made any difference.
>

I didn't really think it was the "high CPU load" problem, because  
your using 7676. It does seem to be related to the nVidia drivers  
though. You might try some of the config options in "nvidia- 
settings", V-Sync, flicker filter etc. Remember that these setting  
are specific for each screen, so be sure you have selected the  
correct output device before changing settings.

You might even try the 8178 drivers, although I suspect they may  
cause as many problems as they might solve.