void Function::deviceInit(void)
{
struct v4l2_capability cap;
struct v4l2_cropcap cropcap;
struct v4l2_crop crop;
struct v4l2_format fmt;
unsigned int min;
if (-1 == xioctl(fd, VIDIOC_QUERYCAP, &cap))
{
if (EINVAL == errno)
{
QMessageBox::about(NULL,"Information"," no V4L2 device");
exit(EXIT_FAILURE);
}
else
{
errno_exit("VIDIOC_QUERYCAP");
}
}
// else
// {
// /// 2016/2/22 add
// printf("Driver Name:%s\nCard Name:%s\nBus info:%s\nDriver Version:%u.%u.%u\n", cap.driver, cap.card, cap.bus_info, (cap.version>>16)&0XFF, (cap.version>>8)&0XFF, cap.version&0XFF);
// }
if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE))
{
QMessageBox::about(NULL,"Information"," no video capture device");
exit(EXIT_FAILURE);
}
struct v4l2_input input;
input.index = 0;
if ( ioctl(fd, VIDIOC_ENUMINPUT, &input) != 0)
{
QMessageBox::about(NULL,"Information","set input error");
exit(0);
}
if ((ioctl(fd, VIDIOC_S_INPUT, &input)) < 0)
{
QMessageBox::about(NULL,"Information","set s_input error");
exit(0);
}
CLEAR(cropcap);
cropcap.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (0 == xioctl(fd, VIDIOC_CROPCAP, &cropcap))
{
crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
crop.c = cropcap.defrect; /* reset to default */
if (-1 == xioctl(fd, VIDIOC_S_CROP, &crop))
{
switch (errno)
{
case EINVAL:
break;
default:
break;
}
}
}
CLEAR (fmt);
// v4l2_format
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
fmt.fmt.pix.width = width;
fmt.fmt.pix.height = height;
// RGB32 and MJPEG can use
fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_RGB32;
// fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_MJPEG;
// fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV;
fmt.fmt.pix.field = V4L2_FIELD_ANY;
if (-1 == xioctl(fd, VIDIOC_S_FMT, &fmt))
errno_exit("VIDIOC_S_FMT");
/* Note VIDIOC_S_FMT may change width and height.*/
if (width != fmt.fmt.pix.width)
{
width = fmt.fmt.pix.width;
//fprintf(stderr,"Image width set to %i by device %s.\n",width,deviceName);
}
if (height != fmt.fmt.pix.height)
{
height = fmt.fmt.pix.height;
//fprintf(stderr,"Image height set to %i by device %s.\n",height,deviceName);
}
/*Buggy driver paranoia. */
min = fmt.fmt.pix.width * 2;
if (fmt.fmt.pix.bytesperline < min)
fmt.fmt.pix.bytesperline = min;
min = fmt.fmt.pix.bytesperline * fmt.fmt.pix.height;
if (fmt.fmt.pix.sizeimage < min)
fmt.fmt.pix.sizeimage = min;
/***** 2016/2/22 add *****************************
ioctl(fd, VIDIOC_G_FMT, &fmt);
printf("Current data format information:\n\twidth:%d\n\theight:%d\n", fmt.fmt.pix.width,fmt.fmt.pix.height);
struct v4l2_fmtdesc fmtdesc;
fmtdesc.index=0;
fmtdesc.type=V4L2_BUF_TYPE_VIDEO_CAPTURE;
while(ioctl(fd,VIDIOC_ENUM_FMT,&fmtdesc)!=-1)
{
if(fmtdesc.pixelformat & fmt.fmt.pix.pixelformat)
{
printf("\tformat:%s\n",fmtdesc.description);
// break;
}
fmtdesc.index++;
}
*****************************/
mmapInit();
}
/**
initialize device
*/
static void deviceInit(void)
{
struct v4l2_capability cap;
struct v4l2_cropcap cropcap;
struct v4l2_crop crop;
struct v4l2_format fmt;
struct v4l2_streamparm frameint;
unsigned int min;
if (-1 == xioctl(fd, VIDIOC_QUERYCAP, &cap)) {
if (EINVAL == errno) {
fprintf(stderr, "%s is no V4L2 device\n",deviceName);
exit(EXIT_FAILURE);
} else {
errno_exit("VIDIOC_QUERYCAP");
}
}
if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
fprintf(stderr, "%s is no video capture device\n",deviceName);
exit(EXIT_FAILURE);
}
switch (io) {
#ifdef IO_READ
case IO_METHOD_READ:
if (!(cap.capabilities & V4L2_CAP_READWRITE)) {
fprintf(stderr, "%s does not support read i/o\n",deviceName);
exit(EXIT_FAILURE);
}
break;
#endif
#ifdef IO_MMAP
case IO_METHOD_MMAP:
#endif
#ifdef IO_USERPTR
case IO_METHOD_USERPTR:
#endif
#if defined(IO_MMAP) || defined(IO_USERPTR)
if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
fprintf(stderr, "%s does not support streaming i/o\n",deviceName);
exit(EXIT_FAILURE);
}
break;
#endif
}
/* Select video input, video standard and tune here. */
CLEAR(cropcap);
cropcap.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (0 == xioctl(fd, VIDIOC_CROPCAP, &cropcap)) {
crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
crop.c = cropcap.defrect; /* reset to default */
if (-1 == xioctl(fd, VIDIOC_S_CROP, &crop)) {
switch (errno) {
case EINVAL:
/* Cropping not supported. */
break;
default:
/* Errors ignored. */
break;
}
}
} else {
/* Errors ignored. */
}
CLEAR(fmt);
// v4l2_format
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
fmt.fmt.pix.width = width;
fmt.fmt.pix.height = height;
fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUV420;
if (-1 == xioctl(fd, VIDIOC_S_FMT, &fmt))
errno_exit("VIDIOC_S_FMT");
if (fmt.fmt.pix.pixelformat != V4L2_PIX_FMT_YUV420) {
fprintf(stderr,"Libv4l didn't accept YUV420 format. Can't proceed.\n");
exit(EXIT_FAILURE);
}
/* Note VIDIOC_S_FMT may change width and height. */
if (width != fmt.fmt.pix.width) {
width = fmt.fmt.pix.width;
fprintf(stderr,"Image width set to %i by device %s.\n", width, deviceName);
}
if (height != fmt.fmt.pix.height) {
height = fmt.fmt.pix.height;
fprintf(stderr,"Image height set to %i by device %s.\n", height, deviceName);
}
/* If the user has set the fps to -1, don't try to set the frame interval */
if (fps != -1)
{
CLEAR(frameint);
/* Attempt to set the frame interval. */
frameint.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
frameint.parm.capture.timeperframe.numerator = 1;
frameint.parm.capture.timeperframe.denominator = fps;
if (-1 == xioctl(fd, VIDIOC_S_PARM, &frameint))
fprintf(stderr,"Unable to set frame interval.\n");
}
/* Buggy driver paranoia. */
min = fmt.fmt.pix.width * 2;
if (fmt.fmt.pix.bytesperline < min)
fmt.fmt.pix.bytesperline = min;
min = fmt.fmt.pix.bytesperline * fmt.fmt.pix.height;
if (fmt.fmt.pix.sizeimage < min)
fmt.fmt.pix.sizeimage = min;
switch (io) {
#ifdef IO_READ
case IO_METHOD_READ:
readInit(fmt.fmt.pix.sizeimage);
break;
#endif
#ifdef IO_MMAP
case IO_METHOD_MMAP:
mmapInit();
break;
#endif
#ifdef IO_USERPTR
case IO_METHOD_USERPTR:
userptrInit(fmt.fmt.pix.sizeimage);
break;
#endif
}
}
