OpenCV  4.10.0-dev
Open Source Computer Vision
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samples/cpp/videowriter_basic.cpp

An example using VideoCapture and VideoWriter class

#include <opencv2/core.hpp>
#include <iostream>
#include <stdio.h>
using namespace cv;
using namespace std;
int main(int, char**)
{
Mat src;
// use default camera as video source
VideoCapture cap(0);
// check if we succeeded
if (!cap.isOpened()) {
cerr << "ERROR! Unable to open camera\n";
return -1;
}
// get one frame from camera to know frame size and type
cap >> src;
// check if we succeeded
if (src.empty()) {
cerr << "ERROR! blank frame grabbed\n";
return -1;
}
bool isColor = (src.type() == CV_8UC3);
//--- INITIALIZE VIDEOWRITER
VideoWriter writer;
int codec = VideoWriter::fourcc('M', 'J', 'P', 'G'); // select desired codec (must be available at runtime)
double fps = 25.0; // framerate of the created video stream
string filename = "./live.avi"; // name of the output video file
writer.open(filename, codec, fps, src.size(), isColor);
// check if we succeeded
if (!writer.isOpened()) {
cerr << "Could not open the output video file for write\n";
return -1;
}
//--- GRAB AND WRITE LOOP
cout << "Writing videofile: " << filename << endl
<< "Press any key to terminate" << endl;
for (;;)
{
// check if we succeeded
if (!cap.read(src)) {
cerr << "ERROR! blank frame grabbed\n";
break;
}
// encode the frame into the videofile stream
writer.write(src);
// show live and wait for a key with timeout long enough to show images
imshow("Live", src);
if (waitKey(5) >= 0)
break;
}
// the videofile will be closed and released automatically in VideoWriter destructor
return 0;
}
n-dimensional dense array class
Definition mat.hpp:812
MatSize size
Definition mat.hpp:2160
bool empty() const
Returns true if the array has no elements.
int type() const
Returns the type of a matrix element.
Class for video capturing from video files, image sequences or cameras.
Definition videoio.hpp:731
virtual bool read(OutputArray image)
Grabs, decodes and returns the next video frame.
virtual bool isOpened() const
Returns true if video capturing has been initialized already.
Video writer class.
Definition videoio.hpp:1009
virtual bool open(const String &filename, int fourcc, double fps, Size frameSize, bool isColor=true)
Initializes or reinitializes video writer.
virtual void write(InputArray image)
Writes the next video frame.
virtual bool isOpened() const
Returns true if video writer has been successfully initialized.
#define CV_8UC3
Definition interface.h:90
int main(int argc, char *argv[])
Definition highgui_qt.cpp:3
"black box" representation of the file storage associated with a file on disk.
Definition core.hpp:102
STL namespace.