视频输出 范例

开启VO设备

/*********************************
*函数功能：开启VO设备
*输出参数：
*返回值：成功为0 失败非0
*********************************/
HI_S32 enable_VO()
{
    HI_S32 s32Ret;        //返回值 
    VO_DEV VoDev = 0;         //输出设备号
    VO_PUB_ATTR_S stPubAttr;     //VO公共属性。


    s32Ret = HI_MPI_VO_GetPubAttr(VoDev, &stPubAttr);    //获取视频输出设备的公共属性。
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Get device attributes failed with error code %#x!
", s32Ret); 
        return HI_FAILURE; 
    } 

    /*配置VO公共属性*/
    stPubAttr.u32BgColor = 0xff;         //背景色 RGB格式
    stPubAttr.enIntfType = VO_INTF_VGA;     //VO接口类型
    stPubAttr.enIntfSync = VO_OUTPUT_1280x1024_60;         //VO时序类型
    s32Ret = HI_MPI_VO_SetPubAttr(VoDev, &stPubAttr);     //配置视频输出设备的公共属性
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Set device attributes failed with errno %#x!
", s32Ret); 
        return HI_FAILURE; 
    } 

    s32Ret = HI_MPI_VO_Enable(VoDev);     //启用视频输出设备
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Enable vo dev %d failed with errno %#x!
", VoDev, s32Ret); 
        return HI_FAILURE; 
    } 

    /*.....*/

    s32Ret = HI_MPI_VO_Disable(VoDev);     //关闭VO设备
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Enable vo dev %d failed with errno %#x!
", VoDev, s32Ret); 
        return HI_FAILURE; 
    } 

    s32Ret = HI_MPI_VO_CloseFd();     //关闭VO文件描述符
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Some device is not disable with errno %#x!
", VoDev, s32Ret); 
        return HI_FAILURE; 
    }
}

开启VO视频层

/*********************************
*函数功能：开启视频层
*输出参数：
*返回值：成功为0 失败非0
*********************************/
HI_S32 start_VO_Layer()
{
    HI_S32 s32Ret;         //返回值
    VO_LAYER VoLayer = 0;         //视频层号
    RECT_S stRect; 
    VO_VIDEO_LAYER_ATTR_S stLayerAttr;         //视频层属性

    s32Ret = HI_MPI_VO_GetVideoLayerAttr(VoLayer, &stLayerAttr);     //获取视频层属性
    if (s32Ret != HI_SUCCESS)
    { 
        printf("Get video layer attributes failed with errno %#x!
", s32Ret); 
        return HI_FAILURE; 
    } 

    /*定义视频层属性*/  //stDispRect——显示分辨率 stImageSize——图像分辨率
    stLayerAttr.stDispRect.s32X = 0;     //左上角顶点坐标
    stLayerAttr.stDispRect.s32Y = 0; 
    stLayerAttr.stDispRect.u32Width = 720;         //显示分辨率
    stLayerAttr.stDispRect.u32Height = 576; 
    stLayerAttr.stImageSize.u32Width = 720;     //画布大小(图像分辨率)
    stLayerAttr.stImageSize.u32Height = 576;     
    stLayerAttr.u32DispFrmRt = 25；                //帧率
    stLayerAttr.enPixFormat = PIXEL_FORMAT_YUV_SEMIPLANAR_422；        //像素格式
    stLayerAttr.bDoubleFrame = HI_TRUE;             //视频是否开启倍频
    stLayerAttr.bClusterMode = HI_FALSE;             //视频层是否采用聚集的方式
    s32Ret = HI_MPI_VO_SetVideoLayerAttr(VoLayer, &stLayerAttr); 
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Set video layer attributes failed with errno %#x!
", s32Ret); 
        return HI_FAILURE; 
    } 

    s32Ret = HI_MPI_VO_EnableVideoLayer(VoLayer);     //使能视频层
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Enable video layer failed with errno %#x!
", s32Ret); 
        return HI_FAILURE; 
    } 

    s32Ret = HI_MPI_VO_DisableVideoLayer(VoLayer);     //关闭视频层
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Disable video layer failed with errno %#x!
", s32Ret); 
        return HI_FAILURE; 
    }
}

使能VO通道

/*********************************
*函数功能：使能视频输出通道
*输出参数：
*返回值：成功为0 失败非0
*********************************/
HI_S32 start_VO_chn()
{

    VO_DEV VoDev = 0;         //VO设备
    VO_LAYER VoLayer = 0;     //VO视频输出视频层号
    VO_CHN VoChn = 0;         //VO视频输出通道
    VO_CHN_ATTR_S stChnAttr; 

    s32Ret = HI_MPI_VO_GetChnAttr(VoLayer, VoChn, &stChnAttr);         //获取VO chn属性
    if (s32Ret != HI_SUCCESS)     
    { 
        printf("Get channel attr failed with errno %#x!
", s32Ret); 
        return HI_FAILURE; 
    } 

    stChnAttr.u32Priority = 0;         //通道优先级
    stChnAttr.stRect.s32X = 0;         //通道显示区域 顶点(左上角)
    stChnAttr.stRect.s32Y = 0; 
    stChnAttr.stRect.u32Width = 720;     //通道显示区域大小
    stChnAttr.stRect.u32Height = 576; 
    s32Ret = HI_MPI_VO_SetChnAttr(VoLayer, VoChn, &stChnAttr);         //配置指定视频输出通道的属性
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Set channel attr failed with errno %#x!
", s32Ret); 
        return HI_FAILURE; 
    } 

    s32Ret = HI_MPI_VO_EnableChn(VoLayer, VoChn);     //开启指定的VO通道
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Enable channel failed with errno %#x!
", s32Ret);
        return HI_FAILURE; 
    } 

    s32Ret = HI_MPI_VO_DisableChn(VoLayer, VoChn);     //关闭通道
    if (s32Ret != HI_SUCCESS) 
    { 
        printf("Disable channel failed with errno %#x!
", s32Ret); 
        return HI_FAILURE; 
    }

}