Opencv学习笔记（八）视频流2

    用类封装了下视频的读取（可以是视频文件也可以是图片序列），处理，以及写入文件（可以是视频文件也可以是图片序列）。

    代码如下：

#include "opencv2/opencv.hpp"#include <sstream>#include <iomanip>using namespace std;using namespace cv;class FrameProcessor;class FrameProcessor{    public:        virtual void process(Mat &input,Mat &ouput);};class VideoProcessor{private:    VideoCapture caputure;    //写视频流对象    VideoWriter writer;    //输出文件名    string Outputfile;    int currentIndex;    int digits;    string extension;    FrameProcessor *frameprocessor;    //图像处理函数指针    void (*process)(Mat &,Mat &);    bool callIt;    string WindowNameInput;    string WindowNameOutput;    //延时    int delay;    long fnumber;    //第frameToStop停止    long frameToStop;    //暂停标志    bool stop;    //图像序列作为输入视频流    vector<string> images;    //迭代器public:    VideoProcessor() : callIt(true),delay(0),fnumber(0),stop(false),digits(0),frameToStop(-1){}   //设置图像处理函数    void setFrameProcessor(void (*process)(Mat &,Mat &)){        frameprocessor = 0;        this->process = process;        CallProcess ();    }    //打开视频    bool setInput(string filename){        fnumber = 0;        //若已打开，释放重新打开        caputure.release ();        return caputure.open (filename);    }    //设置输入视频播放窗口    void displayInput(string wn){        WindowNameInput = wn;        namedWindow (WindowNameInput);    }    //设置输出视频播放窗口    void displayOutput(string wn){        WindowNameOutput = wn;        namedWindow (WindowNameOutput);    }    //销毁窗口    void dontDisplay(){        destroyWindow (WindowNameInput);        destroyWindow (WindowNameOutput);        WindowNameInput.clear ();        WindowNameOutput.clear ();    }    //启动    void run(){        Mat frame;        Mat output;        if(!isOpened())            return;        stop = false;        while(!isStopped()){            //读取下一帧            if(!readNextFrame(frame))                break;            if(WindowNameInput.length ()!=0)                imshow (WindowNameInput,frame);            //处理该帧            if(callIt){                if(process)                    process(frame,output);                else if(frameprocessor)                    frameprocessor->process (frame,output);            }            else{                output = frame;            }            if(Outputfile.length ()){                    cvtColor (output,output,CV_GRAY2RGB);                    writeNextFrame (output);              }            if(WindowNameOutput.length ()!=0)                imshow (WindowNameOutput,output);            //按键暂停，继续按键继续            if(delay>=0&&waitKey (delay)>=0)                waitKey(0);            //到达指定暂停键，退出            if(frameToStop>=0&&getFrameNumber()==frameToStop)                stopIt();        }    }    //暂停键置位    void stopIt(){        stop = true;    }    //查询暂停标志位    bool isStopped(){        return stop;    }    //返回视频打开标志    bool isOpened(){       return  caputure.isOpened ()||!images.empty ();    }    //设置延时    void setDelay(int d){        delay = d;    }    //读取下一帧    bool readNextFrame(Mat &frame){        if(images.size ()==0)            return caputure.read (frame);        else{            if(itImg!=images.end()){                frame = imread (*itImg);                itImg++;                return frame.data?1:0;            }            else                return false;        }    }    void CallProcess(){        callIt = true;    }    void  dontCallProcess(){        callIt = false;    }    //设置停止帧    void stopAtFrameNo(long frame){        frameToStop = frame;    }   // 获得当前帧的位置    long getFrameNumber(){        long fnumber = static_cast<long>(caputure.get ((CV_CAP_PROP_POS_FRAMES)));        return fnumber;    }     //获得帧大小       Size getFrameSize() {        if (images.size()==0) {            // 从视频流获得帧大小            int w= static_cast<int>(caputure.get(CV_CAP_PROP_FRAME_WIDTH));            int h= static_cast<int>(caputure.get(CV_CAP_PROP_FRAME_HEIGHT));            return Size(w,h);            }        else {                //从图像获得帧大小                cv::Mat tmp= cv::imread(images[0]);                return (tmp.data)?(tmp.size()):(Size(0,0));            }          }   //获取帧率    double getFrameRate(){        return caputure.get(CV_CAP_PROP_FPS);    }    vector<string>::const_iterator itImg;    bool setInput (const vector<string> &imgs){        fnumber = 0;        caputure.release ();        images = imgs;        itImg = images.begin ();        return true;    }    void  setFrameProcessor(FrameProcessor *frameprocessor){        process = 0;        this->frameprocessor = frameprocessor;        CallProcess ();    }    //获得编码类型    int getCodec(char codec[4]) {        if (images.size()!=0)            return -1;        union { // 数据结构4-char            int value;            char code[4];        } returned;        //获得编码值        returned.value= static_cast<int>(        caputure.get(CV_CAP_PROP_FOURCC));        // get the 4 characters        codec[0]= returned.code[0];        codec[1]= returned.code[1];        codec[2]= returned.code[2];        codec[3]= returned.code[3];        return returned.value;    }    bool setOutput(const string &filename,int codec = 0,double framerate = 0.0,bool isColor = true){        //设置文件名        Outputfile = filename;        //清空扩展名        extension.clear ();        //设置帧率        if(framerate ==0.0){            framerate = getFrameRate ();        }        //获取输入原视频的编码方式        char c[4];        if(codec==0){            codec = getCodec(c);        }        return writer.open(Outputfile,                           codec,                           framerate,                           getFrameSize(),                           isColor);    }    //输出视频帧到图片fileme+currentIndex.ext,如filename001.jpg    bool setOutput (const string &filename,//路径                    const string &ext,//扩展名                    int numberOfDigits=3,//数字位数                    int startIndex=0 ){//起始索引           if(numberOfDigits<0)               return false;           Outputfile = filename;           extension = ext;           digits = numberOfDigits;           currentIndex = startIndex;           return true;    }    //写下一帧    void writeNextFrame(Mat &frame){        //如果扩展名不为空，写到图片文件中        if(extension.length ()){            stringstream ss;            ss<<Outputfile<<setfill('0')<<setw(digits)<<currentIndex++<<extension;            imwrite (ss.str (),frame);        }        //反之，写到视频文件中        else{            writer.write (frame);        }    }};//帧处理函数：canny边缘检测void canny(cv::Mat& img, cv::Mat& out) {    //灰度变换    if (img.channels()==3)        cvtColor(img,out,CV_BGR2GRAY);    // canny算子求边缘    Canny(out,out,100,200);    //颜色反转，看起来更舒服些    threshold(out,out,128,255,cv::THRESH_BINARY_INV);}int main(int argc, char *argv[]){    VideoProcessor processor;    //打开输入视频    processor.setInput ("bike.avi");    processor.displayInput ("Current Frame");    processor.displayOutput ("Output Frame");    //设置每一帧的延时    processor.setDelay (1000./processor.getFrameRate ());    //设置帧处理函数，可以任意    processor.setFrameProcessor (canny );    processor.setOutput ("./bikeout.avi");//    processor.setOutput ("bikeout",".jpg");    processor.run ();    return 0;}