On 10 Apr 2002, Gerd Knorr wrote:
> Trent Piepho wrote:
> > On 10 Apr 2002, Gerd Knorr wrote:
> > > video_tuner->signal = (BT848_DSTATUS & BT848_DSTATUS_HLOC) ? 0xFFFF : 0;
> >
> > Not very useful. You can't query the tuner unless you have it
> > selected as the input. So if your card doesn't have a tuner, or you
> > are using the composite or s-video input, this won't work.
>
> Wrong at least for bttv. bttv doesn't check that the current selected
> input _really_ is the tuner, thus it works for other inputs to.
I didn't check every version from bttv released in the last 5 years, but this
is from linux-2.2.20 kernel driver:
case VIDIOCGTUNER:
{
struct video_tuner v;
if(copy_from_user(&v,arg,sizeof(v))!=0)
return -EFAULT;
if(v.tuner||btv->channel) /* Only tuner 0 */
return -EINVAL;
See that if(v.tuner||btv->channel)? You can only query the tuner if you
have channel 0 selected as input. So in this case, you're the one who's
wrong.
