编写一个智芯猎鹰基于API接口的c语言摄像头拍照程序

以下是基于智芯猎鹰的API接口，使用C语言编写的摄像头拍照程序：

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <time.h>
#include <sys/ioctl.h>
#include <linux/videodev2.h>

#define CAMERA_DEVICE "/dev/video0"
#define IMAGE_FILE "image.jpg"

int main(int argc, char *argv[])
{
    int fd;
    struct v4l2_capability cap;
    struct v4l2_format fmt;
    struct v4l2_requestbuffers req;
    struct v4l2_buffer buf;
    void *buffer_start;
    unsigned int i;
    time_t timer;
    struct tm* tm_info;
    char buffer[80];

    // 打开摄像头设备
    fd = open(CAMERA_DEVICE, O_RDWR, 0);
    if (fd < 0) {
        perror("Cannot open camera device");
        return 1;
    }

    // 查询设备属性
    if (ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0) {
        perror("Cannot get camera capabilities");
        return 1;
    }

    // 设置视频格式
    memset(&fmt, 0, sizeof(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_MJPEG;
    fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
    if (ioctl(fd, VIDIOC_S_FMT, &fmt) < 0) {
        perror("Cannot set video format");
        return 1;
    }

    // 请求缓冲区
    memset(&req, 0, sizeof(req));
    req.count = 1;
    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    req.memory = V4L2_MEMORY_MMAP;
    if (ioctl(fd, VIDIOC_REQBUFS, &req) < 0) {
        perror("Cannot request buffers");
        return 1;
    }

    // 映射缓冲区
    buffer_start = malloc(fmt.fmt.pix.sizeimage);
    if (!buffer_start) {
        perror("Cannot allocate memory for buffer");
        return 1;
    }
    memset(buffer_start, 0, fmt.fmt.pix.sizeimage);

    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    buf.memory = V4L2_MEMORY_MMAP;
    buf.index = 0;
    if (ioctl(fd, VIDIOC_QUERYBUF, &buf) < 0) {
        perror("Cannot query buffer");
        return 1;
    }

    if (ioctl(fd, VIDIOC_STREAMON, &buf.type) < 0) {
        perror("Cannot start streaming");
        return 1;
    }

    // 捕获图像数据
    memset(buffer_start, 0, fmt.fmt.pix.sizeimage);
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    buf.memory = V4L2_MEMORY_MMAP;
    buf.index = 0;
    if (ioctl(fd, VIDIOC_QBUF, &buf) < 0) {
        perror("Cannot queue buffer");
        return 1;
    }

    if (ioctl(fd, VIDIOC_DQBUF, &buf) < 0) {
        perror("Cannot dequeue buffer");
        return 1;
    }

    // 保存图像数据
    time(&timer);
    tm_info = localtime(&timer);
    strftime(buffer, 80, "%Y%m%d%H%M%S.jpg", tm_info);
    FILE *fp = fopen(IMAGE_FILE, "wb");
    if (!fp) {
        perror("Cannot open image file");
        return 1;
    }
    fwrite(buffer_start, buf.bytesused, 1, fp);
    fclose(fp);

    if (ioctl(fd, VIDIOC_STREAMOFF, &buf.type) < 0) {
        perror("Cannot stop streaming");
        return 1;
    }

    free(buffer_start);
    close(fd);

    return 0;
}

运行程序后，将会在当前目录下生成名为 `image.jpg` 的图片文件，其中的内容是从摄像头捕获的图像数据。