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#include <errno.h> | |
#include <fcntl.h> | |
#include <linux/videodev2.h> | |
#include <stdint.h> | |
#include <stdio.h> | |
#include <string.h> | |
#include <sys/ioctl.h> | |
#include <sys/mman.h> | |
#include <unistd.h> | |
#include <opencv2/core/core.hpp> | |
#include <opencv2/highgui/highgui.hpp> | |
uint8_t *buffer; | |
static int xioctl(int fd, int request, void *arg) | |
{ | |
int r; | |
do r = ioctl (fd, request, arg); | |
while (-1 == r && EINTR == errno); | |
return r; | |
} | |
int print_caps(int fd) | |
{ | |
struct v4l2_capability caps = {}; | |
if (-1 == xioctl(fd, VIDIOC_QUERYCAP, &caps)) | |
{ | |
perror("Querying Capabilities"); | |
return 1; | |
} | |
printf( "Driver Caps:\n" | |
" Driver: \"%s\"\n" | |
" Card: \"%s\"\n" | |
" Bus: \"%s\"\n" | |
" Version: %d.%d\n" | |
" Capabilities: %08x\n", | |
caps.driver, | |
caps.card, | |
caps.bus_info, | |
(caps.version>>16)&&0xff, | |
(caps.version>>24)&&0xff, | |
caps.capabilities); | |
struct v4l2_cropcap cropcap = {0}; | |
cropcap.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; | |
if (-1 == xioctl (fd, VIDIOC_CROPCAP, &cropcap)) | |
{ | |
perror("Querying Cropping Capabilities"); | |
return 1; | |
} | |
printf( "Camera Cropping:\n" | |
" Bounds: %dx%d+%d+%d\n" | |
" Default: %dx%d+%d+%d\n" | |
" Aspect: %d/%d\n", | |
cropcap.bounds.width, cropcap.bounds.height, cropcap.bounds.left, cropcap.bounds.top, | |
cropcap.defrect.width, cropcap.defrect.height, cropcap.defrect.left, cropcap.defrect.top, | |
cropcap.pixelaspect.numerator, cropcap.pixelaspect.denominator); | |
int support_grbg10 = 0; | |
struct v4l2_fmtdesc fmtdesc = {0}; | |
fmtdesc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; | |
char fourcc[5] = {0}; | |
char c, e; | |
printf(" FMT : CE Desc\n--------------------\n"); | |
while (0 == xioctl(fd, VIDIOC_ENUM_FMT, &fmtdesc)) | |
{ | |
strncpy(fourcc, (char *)&fmtdesc.pixelformat, 4); | |
if (fmtdesc.pixelformat == V4L2_PIX_FMT_SGRBG10) | |
support_grbg10 = 1; | |
c = fmtdesc.flags & 1? 'C' : ' '; | |
e = fmtdesc.flags & 2? 'E' : ' '; | |
printf(" %s: %c%c %s\n", fourcc, c, e, fmtdesc.description); | |
fmtdesc.index++; | |
} | |
/* | |
if (!support_grbg10) | |
{ | |
printf("Doesn't support GRBG10.\n"); | |
return 1; | |
}*/ | |
struct v4l2_format fmt = {0}; | |
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; | |
fmt.fmt.pix.width = 640; | |
fmt.fmt.pix.height = 480; | |
//fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_BGR24; | |
//fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_GREY; | |
fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_MJPEG; | |
fmt.fmt.pix.field = V4L2_FIELD_NONE; | |
if (-1 == xioctl(fd, VIDIOC_S_FMT, &fmt)) | |
{ | |
perror("Setting Pixel Format"); | |
return 1; | |
} | |
strncpy(fourcc, (char *)&fmt.fmt.pix.pixelformat, 4); | |
printf( "Selected Camera Mode:\n" | |
" Width: %d\n" | |
" Height: %d\n" | |
" PixFmt: %s\n" | |
" Field: %d\n", | |
fmt.fmt.pix.width, | |
fmt.fmt.pix.height, | |
fourcc, | |
fmt.fmt.pix.field); | |
return 0; | |
} | |
int init_mmap(int fd) | |
{ | |
struct v4l2_requestbuffers req = {0}; | |
req.count = 1; | |
req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; | |
req.memory = V4L2_MEMORY_MMAP; | |
if (-1 == xioctl(fd, VIDIOC_REQBUFS, &req)) | |
{ | |
perror("Requesting Buffer"); | |
return 1; | |
} | |
struct v4l2_buffer buf = {0}; | |
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; | |
buf.memory = V4L2_MEMORY_MMAP; | |
buf.index = 0; | |
if(-1 == xioctl(fd, VIDIOC_QUERYBUF, &buf)) | |
{ | |
perror("Querying Buffer"); | |
return 1; | |
} | |
buffer = mmap (NULL, buf.length, PROT_READ | PROT_WRITE, MAP_SHARED, fd, buf.m.offset); | |
printf("Length: %d\nAddress: %p\n", buf.length, buffer); | |
printf("Image Length: %d\n", buf.bytesused); | |
return 0; | |
} | |
int capture_image(int fd) | |
{ | |
struct v4l2_buffer buf = {0}; | |
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; | |
buf.memory = V4L2_MEMORY_MMAP; | |
buf.index = 0; | |
if(-1 == xioctl(fd, VIDIOC_QBUF, &buf)) | |
{ | |
perror("Query Buffer"); | |
return 1; | |
} | |
if(-1 == xioctl(fd, VIDIOC_STREAMON, &buf.type)) | |
{ | |
perror("Start Capture"); | |
return 1; | |
} | |
fd_set fds; | |
FD_ZERO(&fds); | |
FD_SET(fd, &fds); | |
struct timeval tv = {0}; | |
tv.tv_sec = 2; | |
int r = select(fd+1, &fds, NULL, NULL, &tv); | |
if(-1 == r) | |
{ | |
perror("Waiting for Frame"); | |
return 1; | |
} | |
if(-1 == xioctl(fd, VIDIOC_DQBUF, &buf)) | |
{ | |
perror("Retrieving Frame"); | |
return 1; | |
} | |
printf ("saving image\n"); | |
IplImage* frame; | |
CvMat cvmat = cvMat(480, 640, CV_8UC3, (void*)buffer); | |
frame = cvDecodeImage(&cvmat, 1); | |
cvNamedWindow("window",CV_WINDOW_AUTOSIZE); | |
cvShowImage("window", frame); | |
cvWaitKey(0); | |
cvSaveImage("image.jpg", frame, 0); | |
return 0; | |
} | |
int main() | |
{ | |
int fd; | |
fd = open("/dev/video0", O_RDWR); | |
if (fd == -1) | |
{ | |
perror("Opening video device"); | |
return 1; | |
} | |
if(print_caps(fd)) | |
return 1; | |
if(init_mmap(fd)) | |
return 1; | |
int i; | |
for(i=0; i<5; i++) | |
{ | |
if(capture_image(fd)) | |
return 1; | |
} | |
close(fd); | |
return 0; | |
} |
Hi I need an urgent help. I am trying to install Video4Linux 2 driver so that I can run this code. Can you give me the commands for installing this driver in Ubuntu 16.04? I need it very urgently
Is there a newer version of this code that would work with OpenCV 4.2.0? The lines 183 to 189 use older named functions and I can't for the life of me find out what the newer function names are called. Any pointers would be great, thanks!!
Dan
Is there a newer version of this code that would work with OpenCV 4.2.0? The lines 183 to 189 use older named functions and I can't for the life of me find out what the newer function names are called. Any pointers would be great, thanks!!
Dan
Lines 183 to 189 change to:
cv::_InputArray pic_arr(buffer, IMAGEWIDTH * IMAGEHEIGHT * 3);
cv::Mat out_img = cv::imdecode(pic_arr, cv::IMREAD_UNCHANGED);
imshow("view", out_img);
imwrite("output.jpg",out_img);
waitKey(0);
Hi, I created a repo that supports OpenCV4:
how to handle this code for multiple device profiles while the camera is same. i.e different configurations of the snapshot requested from client side. I am sending a HTTP GET request from the client side to retrieve the image from server side for multiple device profiles while the camera is single. On first request I am getting the output but on second request my server is throwing "device or resource busy error." How can I make this thread safe. Please provide your suggestions. I am ready to provide more input if someone can help.
Sorry im late, im come from y2023.
Now the weather good, openCV ver 4.7.
Just want say thank all above.
Please advise how to check error if the program output "Start Capture: Input/output error"
if(-1 == xioctl(fd, VIDIOC_STREAMON, &buf.type))
{
perror("Start Capture");
return 1;
}