Toybrick TB-RK3399ProD《基于TB-RK3399ProD开发板实现camera采集、编码、显示》

本文链接：https://blog.youkuaiyun.com/qq_22633333/article/details/108646261

TB-RK3399ProD实现USBcamera通过V4L2图像采集+RKMPP编码成H264+OpenCV显示采集的图像

前期准备

需要以下设备：
1、Toybrick TB-RK3399ProD开发板
2、USB摄像头（Logitech Webcam C270）
3、HDMI显示器、USB鼠标/键盘、以太网线缆

一、操作系统

我用的TB-RK3399ProD开发板跑的操作系统是烧写的Toybrick官方提供的Debian10固件（Toybrick社区重点维护），下载地址：(http://t.rock-chips.com/wiki.php?mod=view&id=11)

二、开发环境搭建

1、软件升级

sudo apt update
sudo apt upgrade

2、drm、rga、mpp安装

参考：http://t.rock-chips.com/wiki.php?mod=view&id=115
sudo apt install rockchip-drm-dev libdrm-dev
sudo apt install rockchip-rga-dev
sudo apt install rockchip-mpp-dev

3、ISP安装

sudo apt install rockchip-isp

4、OpenCV安装：

sudo apt-get update
sudo apt install libopencv-dev

注：安装后的头文件目录：/usr/include/rockchip、库目录：/usr/lib/aarch64-linux-gnu、example目录：/usr/share/rockchip-xxx

三、功能实现

本功能的是基于上面几个库的example例程参考实现的
1、USB camera的V4L2图像采集参考：/usr/share/rockchip-isp/example/example.cpp
2、V4L2采集的图像调用RKMPP编码参考：/usr/share/rockchip-mpp/example/mpp_encode.cpp
3、OpenCV要播放V4L2获取的图像，需要先用RKRGA图像加速库把视频格式转换成V4L2_PIX_FMT_RGB24，参考：/usr/share/rockchip-rga/example/rga_convert.cpp

四、主体源码

源码编译：源码是放到板子进行编译的
源码增加了三个宏开关，如下：

#define RK_MPP_ENC 1 //使用RKMPP编码并存储到H264文件宏开关
#define RK_SAVE_YUYV 1 //V4L2采集到的原始图像存成YUYV文件宏开关
#define RK_OPENCV_SHOW 1 //使用RKRGA进行原始图像格式转换并送给OpenCV显示宏开关

功能源码主要部分如下：

int camera(char *dev, __u32 w, __u32 h, RgaRotate r, int V, int H, __u32 cx, __u32 cy, __u32 cw, __u32 ch, CameraType type, __u32 f)
{
    int ret = 0;
    int frames = PLAY_FRAMES;
    v4l2_camera camera;
    rockchip_rga rga;
    Mat mat;
    FILE *fp = NULL;
    FILE *fp_h264 = NULL;
    
#if RK_SAVE_YUYV
    /* Save to file */
    if(f == V4L2_PIX_FMT_YUYV)
    	fp = fopen("test.yuyv", "w+");
    else if(f == V4L2_PIX_FMT_YUV420)
    	fp = fopen("test.yuv420", "w+");
    else
    	fp = fopen("test.unknown", "w+");

    if (fp == NULL)
	    return -EIO;
#endif

#if RK_OPENCV_SHOW
    cv::namedWindow(winname);
    cv::moveWindow(winname, w, h);
    mat.create(cv::Size(RGA_ALIGN(w, 16), RGA_ALIGN(h, 16)), CV_8UC3);
	
	ret = rga.init();
    if(ret < 0)
	    goto exit;
#endif

    /* TODO: Init camera deivce */
    ret = camera.init(dev, type);
    if(ret < 0)
	    goto exit;

    /* TODO: Set picture format */
    ret = camera.setfmt(w, h, f);
    if(ret < 0)
	    goto exit;

    /* TODO: Request and mmap buffers */
    ret = camera.reqbufs_mmap(4);
    if(ret < 0)
	    goto exit;

    /* TODO: Start stream capture */
    ret = camera.start();
    if(ret < 0)
	    goto exit;
	    
#if RK_MPP_ENC
    fp_h264 = fopen("test.h264", "w+");
	ret = mpp_enc_init(fp_h264, f, w, h);
	if(ret < 0)
	    goto exit;
#endif

    while(frames--) {
    	int index;
    	size_t len = 0;
    	void *buf = NULL;
    	unsigned long long t1, t2, t3, t4;
#if RK_OPENCV_SHOW    	
        struct rga_format src_fmt, dst_fmt;
        struct rga_crop crop;

        src_fmt.width = w;
        src_fmt.height = h;
        src_fmt.format = f;

        dst_fmt.width = w;
        dst_fmt.height = h;
        dst_fmt.format = V4L2_PIX_FMT_RGB24;

        crop.x = cx;
        crop.y = cy;
        crop.h = ch;
        crop.w = cw;
#endif	
    	t1 = nanoTime();
    	/* TODO: Dequeue buffer */
    	buf = camera.dequeue(&index, &len);
#if RK_MPP_ENC
    	mpp_enc(fp_h264, buf, len);
#endif

#if RK_SAVE_YUYV
    	fwrite(buf, len, 1, fp);
#endif
    	t2 = nanoTime();
#if RK_OPENCV_SHOW
        ret = rga.convert(buf, mat.data, src_fmt, dst_fmt, crop, r);
    	if(ret < 0)
    	    goto exit;
#endif
    	/* TODO: Enqueue buffer */
    	camera.enqueue(index);

    	t3 = nanoTime();
#if RK_OPENCV_SHOW
        imshow(winname, mat);
        cv::waitKey(1);
#endif
    	t4 = nanoTime();

    	printf("Picture size %llu, dequeue time %llums, enqueue time: %llums, display time: %llums\n",
    	        len, (t2 - t1) / 1000000, (t3 - t2) / 1000000, (t4 - t3) / 1000000);

    }
	
exit:

#if RK_MPP_ENC
    mpp_enc_unit();
    if(fp_h264 != NULL)
        fclose(fp_h264);
#endif

#if RK_SAVE_YUYV
    if(fp != NULL)
        fclose(fp);
#endif

    return ret;
}