开启VI视频输入设备 范例

文档示例：

/*********************************
*函数功能：开启VI设备
*输出参数：
*返回值：成功为0 失败非0
*********************************/
HI_S32 enable_VI()
{
    HI_S32 s32Ret;         //返回值
    VI_DEV ViDev = 0;     //VI设备号
    VI_CHN ViChn = 0;     //VI通道号
    VI_DEV_ATTR_S stDevAttr; //视频输入设备的属性
    VI_CHN_ATTR_S stChnAttr; 

    /*配置视频输入设备的属性*/
    stDevAttr.enIntfMode =VI_MODE_BT1120_STANDARD;         //接口模式
    stDevAttr.enWorkMode = VI_WORK_MODE_1Multiplex;     //124路复合工作模式
    stDevAttr.au32CompMask[0] = 0xFF000000;             //分量掩码
    stDevAttr.au32CompMask[1] = 0xFF0000; 
    stDevAttr. enClkEdge = VI_CLK_EDGE_SINGLE_UP;         //时钟边沿采样模式
    stDevAttr.s32AdChnId[0] = -1;                         //取值范围
    stDevAttr.s32AdChnId[1] = -1; 
    stDevAttr.s32AdChnId[2] = -1;
    stDevAttr.s32AdChnId[3] = -1; 
    s32Ret = HI_MPI_VI_SetDevAttr(ViDev, &stDevAttr);     //设置VI设备属性
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Set dev attributes failed with error code %#x!
", s32Ret); 
        return HI_FAILURE; 
    } 

    s32Ret = HI_MPI_VI_EnableDev(ViDev);         //使能VI设备
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Enable dev failed with error code %#x!
", s32Ret); 
        return HI_FAILURE; 
    } 

    /*配置VI通道属性*/
    stChnAttr.stCapRest.s32X = 0;         //捕获区域起始坐标
    stChnAttr.stCapRect.s32Y = 0; 
    stChnAttr.stCapRect.u32Width = 1920;     //捕获区域宽高
    stChnAttr.stCapRect.u32Height = 1080; 
    stChnAttr.stDestSize.u32Width = 1920;     //目标图像大小
    stChnAttr.stDestSize.u32Height = 1080; 
    stChnAttr.enCapSel = VI_CAPSEL_BOTH;         //帧场选择
    stChnAttr.enScanMode = VI_SCAN_PROGRESSIVE;     //输入扫描模式 隔行or逐行
    stChnAttr.enPixFormat = PIXEL_FORMAT_YUV_SEMIPLANAR_422;     //像素储存格式
    stChnAttr.bMirror = HI_FALSE;         //是否水平翻转
    stChnAttr.bFlip = HI_FALSE;         //是否垂直翻转
    stChnAttr.s32SrcFrameRate = -1;     //原始帧率
    stChnAttr.s32DstFrameRate = -1;     //目标帧率
    s32Ret = HI_MPI_VI_SetChnAttr(ViChn,&stChnAttr); 
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Set chn attributes failed with error code %#x!
", s32Ret); 
        return HI_FAILURE; 
    } 

    s32Ret = HI_MPI_VI_EnableChn(ViChn);     //使能VI通道
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Enable chn failed with error code %#x!
", s32Ret); 
        return HI_FAILURE; 
    } 

/* now, vi is capturing images, you can do something else ... */ 

    s32Ret = HI_MPI_VI_DisableChn(ViChn);         //关闭通道
    if (s32Ret != HI_SUCCESS)
    { 
        printf("Disable chn failed with error code %#x!
", s32Ret); 
        return HI_FAILURE; 
    } 

    s32Ret = HI_MPI_VI_DisableDev(ViDev);         //关闭设备
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Disable dev failed with error code %#x!
", s32Ret); 
        return HI_FAILURE; 
    }
}