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 PGP: 03 54 43 4D 75 E5 CC 92 71 16 01 E2 B5 F5 C1 E8 _______________________________________________ pvrusb2 mailing list [email protected] http://www.isely.net/cgi-bin/mailman/listinfo/pvrusb2
