Texas Instruments OMAP35 Series User Manual page 185

Ioctl: VIDIOC_QUERYSTD
It takes a pointer to v4l2_std_id instance as an output argument. Driver will
call the current decoder's function internally (which has been initialized) to
detect the current standard set in hardware. Support of this IOCTL depends on
decoder device, whether it can detect a standard or not.
Note: This IOCTL should be called by the application so that the camera driver
can configure ISP properly with the detected decoder standard.
Standard IDs are defined in the V4L2 header files
Example:
v4l2_std_id std;
struct v4l2_standard standard;
ret = ioctl(fd, VIDIOC_QUERYSTD, &std);
if (ret < 0) {
}
while(1) {
}
9.3.2.9. Set Standard
This IOCTL is used to set the standard in the decoder.
Ioctl: VIDIOC_S_STD
It takes a pointer to v4l2_std_id instance as an input argument. If the standard
is not supported by the decoder, the driver will return an error
Standard IDs are defined in the V4L2 header files (few new standards are
included in respective decoder header files, which were not available in standard
V4L2 header files).
Note: Application need not call this IOCTL as the decoder can auto detect the
current standard. This is required only when the application needs to set a
Version 02.01.01.08
perror("VIDIOC_QUERYSTD\n");
close(fd);
return -1;
standard.index = i;
ret = ioctl(fd, VIDIOC_ENUMSTD, &standard);
if (ret < 0)
break;
if (standard.std & std) {
printf("%s standard detected\n",
standard.name);
break;
}
i++;
Platform Support Products
Capture Driver
Software Design Interfaces
163