[pvrusb2] Poor analog picture on HVR-1950 after upgrade to 2.6.28 kernel

[Mike Isely]

On Fri, 12 Jun 2009, Scott Doty wrote:

   [...]

> 
> Thanks for the post...at least now I know it _can_ work! :)
> 
> What software did you use to do the capture, and did you use v4l2-ctl to set
> anything beforehand?
> 
> Thanks...personally, I did that capture with MythTV, which is maybe where I
> should go talk to next...or maybe the rpmfusion guys...

All good questions.  And in fact MythTV might be playing a part here 
since it can set the video standard!

The testing I generally do is very very simple:

1. Plug in the device, note correct initialization.

2. Use sysfs to set up my test (e.g. change the input to composite).

3. Run mplayer on /dev/video0 if testing analog.  Or use azap to start 
the DVB side and mplayer on /dev/dvb/adapterX/dvr0 to stream digital.

Generally the digital side "just works"; most of the ongoing problems 
have to do with the analog side so that's where I tend to focus my 
attention.  This should come as no surprise because actually the analog 
side is significantly more complex to operate.

If I suspect mplayer is contributing to a problem (e.g. stuttering, 
audio foul-ups) then instead I'll just do "cat /dev/video0 > 
/tmp/foo.mpg" and then copy foo.mpg somewhere else and use any old media 
app to play it.

I tend not to touch v4l2-ctl unless I'm chasing a problem where I 
suspect involvement of the V4L API itself (which is a pretty rare 
situation).

I hadn't considered in your case if MythTV is doing something bad here 
because you said that you used sysfs to set the video standard.  However 
MythTV might have set it again after that point (though in that case you 
should be able to see the changed value again via sysfs).  Generally 
it's a good idea to do the testing in as simple a means as possible in 
order to avoid additional factors caused by whatever app you are using - 
and MythTV is the grandaddy of apps that can cause unintended problems!

Can you test in the above manner (with the mythtv back end shut off 
during the test) and verify that the problem is still happening?  I'd 
love to hear a success report then - because right now including your 
issue I'm simultaneously examining 3 different problems :-(

  -Mike


-- 

Mike Isely
isely @ isely (dot) net
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