camera应用

说明:

1 v4l2.c 参考 v4l2uvc.c 内核参考uvc_v4l2.c yuv2rgb.c 参考 utils.c
2 yuv/rgb565 2字节/像素 rgb24 3字节/像素 rgb32 4字节/像素
3 取得LCD屏的分辨率 GetDispResolvtion(int width,int height，int* iLcdapp);
4 摄像头格式为RGB

1 video_manager.h (构造3个结构体)     - struct VideoDevice {            width、height、format...            struct *videoOPr ptOPr;    }    - typedef struct VideoBuf {        T_PixelDatas tPixelDatas;        int iPixelFormat;    }    - struct VideoOpr {        char *name;        int (*InitDevice)(char *strDevName, PT_VideoDevice ptVideoDevice);        int (*ExitDevice)(PT_VideoDevice ptVideoDevice);        int (*GetFrame)(PT_VideoDevice ptVideoDevice, PT_VideoBuf ptVideoBuf);        int (*GetFormat)(PT_VideoDevice ptVideoDevice);        int (*PutFrame)(PT_VideoDevice ptVideoDevice, PT_VideoBuf ptVideoBuf);        int (*StartDevice)(PT_VideoDevice ptVideoDevice);        int (*StopDevice)(PT_VideoDevice ptVideoDevice);        struct VideoOpr *ptNext;    }

2 v4l2.c (实现videoOPr的函数)    struct v4l2_capability tV4l2Cap;    struct v4l2_fmtdesc tFmtDesc;    struct v4l2_format  tV4l2Fmt;    struct v4l2_requestbuffers tV4l2ReqBuffs;    struct v4l2_buffer tV4l2Buf;    /* 构造一个VideoOpr结构体 */    static T_VideoOpr g_tV4l2VideoOpr = {        .name        = "v4l2",        .InitDevice  = V4l2InitDevice,        .ExitDevice  = V4l2ExitDevice,        .GetFormat   = V4l2GetFormat,        .GetFrame    = V4l2GetFrameForStreaming,        .PutFrame    = V4l2PutFrameForStreaming,        .StartDevice = V4l2StartDevice,        .StopDevice  = V4l2StopDevice,    };    static int V4l2InitDevice(char *strDevName, PT_VideoDevice ptVideoDevice)    {        /* open */        /* VIDIOC_QUERYCAP 确定它是否视频捕捉设备,支持哪种接口(streaming/read,write) */        iError = ioctl(iFd, VIDIOC_QUERYCAP, &tV4l2Cap);        /* VIDIOC_ENUM_FMT 查询支持哪种格式 */        iError = ioctl(iFd, VIDIOC_ENUM_FMT, &tFmtDesc)        /* VIDIOC_S_FMT    设置摄像头使用哪种格式 */        iError = ioctl(iFd, VIDIOC_S_FMT, &tV4l2Fmt);         /* VIDIOC_REQBUFS  申请buffer */        iError = ioctl(iFd, VIDIOC_REQBUFS, &tV4l2ReqBuffs);        /* VIDIOC_QUERYBUF 确定每一个buffer的信息 并且 mmap */        iError = ioctl(iFd, VIDIOC_QUERYBUF, &tV4l2Buf);    }    static int V4l2GetFrameForStreaming(PT_VideoDevice ptVideoDevice, PT_VideoBuf ptVideoBuf)    {        /* poll            等待有数据  */        /* VIDIOC_DQBUF    从队列中取出  */        //并把struct videodeivce 的数据赋给 struct VideoBuf.tPixelDatas;        iRet = ioctl(ptVideoDevice->iFd, VIDIOC_DQBUF, &tV4l2Buf);    }    static int V4l2PutFrameForStreaming(PT_VideoDevice ptVideoDevice, PT_VideoBuf ptVideoBuf)    {        /* VIDIOC_QBUF     放入队列 */        iError = ioctl(ptVideoDevice->iFd, VIDIOC_QBUF, &tV4l2Buf);    }

3 yuv2rgb.c/rgb2rgb.c/mjpeg2rgb.c   //实现这3个函数    typedef struct VideoConvert {        char *name;        int (*isSupport)(int iPixelFormatIn, int iPixelFormatOut);        int (*Convert)(PT_VideoBuf ptVideoBufIn, PT_VideoBuf ptVideoBufOut);        int (*ConvertExit)(PT_VideoBuf ptVideoBufOut);        struct VideoConvert *ptNext;    }T_VideoConvert, *PT_VideoConvert;    static int isSupportYuv2Rgb(int iPixelFormatIn, int iPixelFormatOut)    {        if (iPixelFormatIn != V4L2_PIX_FMT_YUYV)            return 0;        if ((iPixelFormatOut != V4L2_PIX_FMT_RGB565) && (iPixelFormatOut != V4L2_PIX_FMT_RGB32))        {            return 0;        }        return 1;    }    /* 参考luvcview */    static int Yuv2RgbConvert(PT_VideoBuf ptVideoBufIn, PT_VideoBuf ptVideoBufOut)    {        Pyuv422torgb565(ptPixelDatasIn->aucPixelDatas, ptPixelDatasOut->aucPixelDatas, ptPixelDatasOut->iWidth, ptPixelDatasOut->iHeight);        Pyuv422torgb32(ptPixelDatasIn->aucPixelDatas, ptPixelDatasOut->aucPixelDatas, ptPixelDatasOut->iWidth, ptPixelDatasOut->iHeight);    }