> > > card without signal support should return a 0 as maximun > signal and digital > > signal card (noise or signal) should return 1. > > > > Sounds sensible - some other cards basically do this, or even > abuse stereo > detect bits to guess signal present > Yes but seem no method to tell program the signal range. I think best (and compatible method) is add an V4L2_CID_TUNER_SIGNAL (or something else) to VIDIOC_QUERYCTRL ioctl. freddy77
