VIDIOCCAPTURE and Invalid argument

[Adam Grossman <aglist@xxxxxxxxxxxxxx>]

I have been looking all over for an answer to this, but i can't...

i am trying to just create a simple TV viewer using an overlay.  but
everytime:


if (-1 == ioctl(fd, VIDIOCCAPTURE, (int *)&b))
        { perror("capture"); close(fd); exit(1);}

is called i get:

"capture: Invalid argument"

but if i run "xawtv" first, i do not get the error, so i obviously not
setting something right.

without all the extra code, here is what i am doing:

vidName="/dev/video";
fd=open(vidName,O_RDWR)
ioctl(fd,VIDIOCGCAP,&capability)

vc.channel=0;
strcpy(vc.name,"NTSC");
vc.tuners=0;
vc.flags=VIDEO_VC_AUDIO ;
vc.type = VIDEO_TYPE_TV;
vc.norm=VIDEO_MODE_NTSC;
ioctl(fd, VIDIOCSCHAN, &vc);

vw.x=0; vw.y=0;
vw.width=640; vw.height=480;
vw.chromakey=1;
vcl[0].x=0; vcl[0].y=0;
vcl[0].width=640; vcl[0].height=480;
vw.clips=vcl;
vw.clipcount=0;
ioctl(fd,VIDIOCSWIN,&vw);

vt.tuner=0;
strcpy(vt.name,"tuner");
vt.rangelow=55250;
vt.rangehigh=799250;
vt.flags=VIDEO_TUNER_NTSC;
vt.mode=VIDEO_MODE_NTSC;
vt.signal=32678;
ioctl(fd, VIDIOCSTUNER, &vt);

unsigned long longfreq=(freq*16)/1000;
ioctl(fd, VIDIOCSFREQ, &longfreq);

int b=1;
ioctl(fd, VIDIOCCAPTURE, &b);

thanks for any help,
-- adam grossman
   aglist (at) metashadow.com