video for linux 2, v4l. v4l2 demo code.

vid-ctrl.c

#include <linux/videodev2.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>

int main(int argc, char **argv)
{
    int i, ctrl, fd = open(argc > 1 ? argv[1] : "/dev/video0", O_RDWR);
    if(fd < 0) {
        perror("open failed");
        return 1;
    }

    struct v4l2_queryctrl qc;
    for(ctrl=V4L2_CID_BASE; /**/; ctrl = qc.id) {
        memset(&qc, 0, sizeof(qc));
        qc.id = ctrl | V4L2_CTRL_FLAG_NEXT_CTRL;

        if(ioctl(fd, VIDIOC_QUERYCTRL, &qc))
            break;

        printf("ctrl %0xx \"%s\" [%d,%d]@%d def %d flags 0x%x\n",
               qc.id, qc.name, qc.minimum, qc.maximum, qc.step,
               qc.default_value, qc.flags);
    }

    return 0;
}
~