[pvrusb2] PVR USB2 - how to check if it's dead? [SOLVED]

[Mike Isely]

On Thu, 20 Dec 2012, Helmut Jarausch wrote:

> On 12/19/2012 04:40:08 PM, Mike Isely wrote:
> 
> Hi Mike,
> 
> that was my testing all the time.
> 
> Now, I've traced xawtv step for step.
> The single control which is needed by my device to even produce a single byte
> of output on /dev/video0 is
> 
> v4l2-ctl -s "pal"
> 
> i.e. setting the video standard to PAL.

Oh, of course.  I'm getting slow.  The driver tries to pick a default 
video standard based on the hardware it has encountered but that is an 
imperfect process at best.  But it's also true that any app which uses a 
V4L2 device really has the responsibility to set the correct video 
standard to be used, which is what xawtv did for you there.

I tend to miss this because my area is NTSC and the driver tends to 
start in that mode automatically for me.

> 
> Is there any means to set this without v4l2-ctl ?

Yes, there is a sysfs way to do this...

> 
> Here, I do not have
> /sys/class/pvrusb2/sn-8039400/ctl_video_standard

I believe there was a change a while back which eliminated that 
particular control (because the underlying V4L feature I believe went 
away).  However you can achieve the same effect with another control.  
IIRC, it's ctl_video_standard_mask_active.  I can e-mail additional 
detail about that, if you haven't already figured it out.

  -Mike

-- 

Mike Isely
isely @ isely (dot) net
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