linux 采集摄像头数据

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <linux/videodev2.h>

#define CLEAR(x) memset(&(x), 0, sizeof(x))

int main(int argc, char *argv[]) {
    int fd;
    struct v4l2_format fmt;
    struct v4l2_requestbuffers req;
    struct v4l2_buffer buf;
    char *buffer;
    int ret;

    fd = open("/dev/video0", O_RDWR);
    if (fd < 0) {
        perror("Failed to open device");
        return -1;
    }

    CLEAR(fmt);
    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    fmt.fmt.pix.width = 640;
    fmt.fmt.pix.height = 480;
    fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV;
    fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;

    ret = ioctl(fd, VIDIOC_S_FMT, &fmt);
    if (ret < 0) {
        perror("Failed to set format");
        close(fd);
        return -1;
    }

    CLEAR(req);
    req.count = 4;
    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    req.memory = V4L2_MEMORY_MMAP;

    ret = ioctl(fd, VIDIOC_REQBUFS, &req);
    if (ret < 0) {
        perror("Failed to request buffers");
        close(fd);
        return -1;
    }

    buffer = malloc(req.count * fmt.fmt.pix.sizeimage);
    if (!buffer) {
        perror("Failed to allocate memory");
        close(fd);
        return -1;
    }

    // MMAP and other operations would go here...

    free(buffer);
    close(fd);
    return 0;
}