Opencv写摄像头输出到avi文件

opencv write webcam output to avi file

本文关键字：avi 文件 输出 摄像头 Opencv      更新时间：2023-10-16

我正在尝试使用opencv从我的网络摄像头输出创建一个avi视频。没有抛出异常，但是它创建的avi文件大小为414字节，并且不会增长。

也不能在任何媒体播放器上播放。我怀疑写入文件部分有问题。

代码如下:

  CvCapture *capture = cvCaptureFromCAM( 0 );
  int width = ( int )cvGetCaptureProperty( capture, 
  CV_CAP_PROP_FRAME_WIDTH );
  int height = ( int )cvGetCaptureProperty( capture,
  CV_CAP_PROP_FRAME_HEIGHT );
  CvVideoWriter *writer = cvCreateVideoWriter("CamCapture.avi",                                                     
  -1,30, cvSize(  width, height ) );
  cvNamedWindow("capWindow", CV_WINDOW_AUTOSIZE);
  IplImage *frame = 0;
  // this returns 0 not sure why ??
  //double fps = cvGetCaptureProperty(capture, CV_CAP_PROP_FPS);
  double fps = 30;
  while( 1 )
  {
      frame = cvQueryFrame( capture );
      cvShowImage("capWindow",frame);
      cvWriteFrame( writer, frame );
      char c = cvWaitKey(1000/fps);
      if( c == 27 ) break;
  }
   cvReleaseCapture( &capture );
   cvReleaseVideoWriter( &writer );
   cvDestroyWindow( "capWindow" );

我参考并尝试了以下示例，但没有运气:

  • http://gipetrou.com/scc/2010/12/12/save-video-from-webcam-with-opencv-2-1/
  • http://answers.oreilly.com/topic/1366-how-to-write-to-an-avi-file-with-opencv/
  • https://www.cs.utexas.edu/teammco/misc/udp_video/

不要使用过时的C语言，使用c++ api，使用方便简单，例如上面的代码可以用c++重写，如

#include "opencv2/opencv.hpp"
#include <iostream>
using namespace std;
using namespace cv;
int main(){
    VideoCapture vcap(0); 
      if(!vcap.isOpened()){
             cout << "Error opening video stream or file" << endl;
             return -1;
      }
   int frame_width=   vcap.get(CV_CAP_PROP_FRAME_WIDTH);
   int frame_height=   vcap.get(CV_CAP_PROP_FRAME_HEIGHT);
   VideoWriter video("out.avi",CV_FOURCC('M','J','P','G'),10, Size(frame_width,frame_height),true);
   for(;;){
       Mat frame;
       vcap >> frame;
       video.write(frame);
       imshow( "Frame", frame );
       char c = (char)waitKey(33);
       if( c == 27 ) break;
    }
  return 0;
}

使用下面的代码从捕获相机输入写入AVI格式。

#include "opencv2/highgui/highgui.hpp"
#include <iostream>
using namespace cv;
using namespace std;
int main(int argc, char* argv[])
{
    VideoCapture cap(0); // open the video camera no. 0
    if (!cap.isOpened())  // if not success, exit program
    {
        cout << "ERROR: Cannot open the video file" << endl;
        return -1;
    }
 namedWindow("MyVideo",CV_WINDOW_AUTOSIZE); //create a window called "MyVideo"
   double dWidth = cap.get(CV_CAP_PROP_FRAME_WIDTH); //get the width of frames of the video
   double dHeight = cap.get(CV_CAP_PROP_FRAME_HEIGHT); //get the height of frames of the video
   cout << "Frame Size = " << dWidth << "x" << dHeight << endl;
   Size frameSize(static_cast<int>(dWidth), static_cast<int>(dHeight));
 VideoWriter oVideoWriter ("D:/MyVideo.avi", CV_FOURCC('P','I','M','1'), 20, frameSize, true); //initialize the VideoWriter object 
   if ( !oVideoWriter.isOpened() ) //if not initialize the VideoWriter successfully, exit the program
   {
        cout << "ERROR: Failed to write the video" << endl;
        return -1;
   }
    while (1)
    {
        Mat frame;
        bool bSuccess = cap.read(frame); // read a new frame from video
        if (!bSuccess) //if not success, break loop
       {
             cout << "ERROR: Cannot read a frame from video file" << endl;
             break;
        }
         oVideoWriter.write(frame); //writer the frame into the file
        imshow("MyVideo", frame); //show the frame in "MyVideo" window
        if (waitKey(10) == 27) //wait for 'esc' key press for 30ms. If 'esc' key is pressed, break loop
       {
            cout << "esc key is pressed by user" << endl;
            break; 
       }
    }
    return 0;
}
相关文章：