请给我一个用c语言写的，通过v4l2读取usb摄像头图片，通过udp传输到pc端的代码

以下是一个用C语言编写的通过v4l2读取USB摄像头图片并通过UDP传输到PC端的代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <linux/videodev2.h>

#define WIDTH 640
#define HEIGHT 480
#define BUFSIZE (WIDTH * HEIGHT * 3)

int main(int argc, char **argv)
{
    int fd, sockfd, ret;
    struct v4l2_capability cap;
    struct v4l2_format fmt;
    struct v4l2_requestbuffers req;
    struct v4l2_buffer buf;
    void *buffer;
    struct sockaddr_in servaddr;
    char *ipaddr;
    int port;

    if (argc != 3) {
        fprintf(stderr, "Usage: %s <ipaddr> <port>\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    ipaddr = argv[1];
    port = atoi(argv[2]);

    fd = open("/dev/video0", O_RDWR);
    if (fd < 0) {
        perror("open");
        exit(EXIT_FAILURE);
    }

    ret = ioctl(fd, VIDIOC_QUERYCAP, &cap);
    if (ret < 0) {
        perror("ioctl VIDIOC_QUERYCAP");
        exit(EXIT_FAILURE);
    }

    if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
        fprintf(stderr, "Device does not support video capture\n");
        exit(EXIT_FAILURE);
    }

    memset(&fmt, 0, sizeof(fmt));
    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    fmt.fmt.pix.width = WIDTH;
    fmt.fmt.pix.height = HEIGHT;
    fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_RGB24;
    fmt.fmt.pix.field = V4L2_FIELD_NONE;

    ret = ioctl(fd, VIDIOC_S_FMT, &fmt);
    if (ret < 0) {
        perror("ioctl VIDIOC_S_FMT");
        exit(EXIT_FAILURE);
    }

    memset(&req, 0, sizeof(req));
    req.count = 1;
    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    req.memory = V4L2_MEMORY_MMAP;

    ret = ioctl(fd, VIDIOC_REQBUFS, &req);
    if (ret < 0) {
        perror("ioctl VIDIOC_REQBUFS");
        exit(EXIT_FAILURE);
    }

    memset(&buf, 0, sizeof(buf));
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    buf.memory = V4L2_MEMORY_MMAP;
    buf.index = 0;

    ret = ioctl(fd, VIDIOC_QUERYBUF, &buf);
    if (ret < 0) {
        perror("ioctl VIDIOC_QUERYBUF");
        exit(EXIT_FAILURE);
    }

    buffer = mmap(NULL, buf.length, PROT_READ | PROT_WRITE, MAP_SHARED, fd, buf.m.offset);
    if (buffer == MAP_FAILED) {
        perror("mmap");
        exit(EXIT_FAILURE);
    }

    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    memset(&servaddr, 0, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = inet_addr(ipaddr);
    servaddr.sin_port = htons(port);

    while (1) {
        ret = ioctl(fd, VIDIOC_QBUF, &buf);
        if (ret < 0) {
            perror("ioctl VIDIOC_QBUF");
            exit(EXIT_FAILURE);
        }

        ret = ioctl(fd, VIDIOC_STREAMON, &buf.type);
        if (ret < 0) {
            perror("ioctl VIDIOC_STREAMON");
            exit(EXIT_FAILURE);
        }

        ret = recvfrom(sockfd, NULL, 0, MSG_PEEK, NULL, NULL);
        if (ret < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
            perror("recvfrom");
            exit(EXIT_FAILURE);
        }

        ret = sendto(sockfd, buffer, BUFSIZE, 0, (struct sockaddr *)&servaddr, sizeof(servaddr));
        if (ret < 0) {
            perror("sendto");
            exit(EXIT_FAILURE);
        }

        ret = ioctl(fd, VIDIOC_STREAMOFF, &buf.type);
        if (ret < 0) {
            perror("ioctl VIDIOC_STREAMOFF");
            exit(EXIT_FAILURE);
        }
    }

    return 0;
}

请注意，此代码仅供参考，可能需要根据您的具体情况进行修改。