1 #include <iostream> // for standard I/O 2 #include <string> // for strings 3 4 #include <opencv2/core/core.hpp> // Basic OpenCV structures (cv::Mat) 5 #include <opencv2/videoio/videoio.hpp> // Video write 6 7 using namespace std; 8 using namespace cv; 9 10 static void help() 11 { 12 cout 13 << "------------------------------------------------------------------------------" << endl 14 << "This program shows how to write video files." << endl 15 << "You can extract the R or G or B color channel of the input video." << endl 16 << "Usage:" << endl 17 << "./video-write inputvideoName [ R | G | B] [Y | N]" << endl 18 << "------------------------------------------------------------------------------" << endl 19 << endl; 20 } 21 22 int main(int argc, char *argv[]) 23 { 24 help(); 25 26 if (argc != 4) 27 { 28 cout << "Not enough parameters" << endl; 29 return -1; 30 } 31 32 const string source = argv[1]; // the source file name 33 const bool askOutputType = argv[3][0] =='Y'; // If false it will use the inputs codec type 34 35 VideoCapture inputVideo(source); // Open input 36 if (!inputVideo.isOpened()) 37 { 38 cout << "Could not open the input video: " << source << endl; 39 return -1; 40 } 41 42 string::size_type pAt = source.find_last_of('.'); // Find extension point 43 const string NAME = source.substr(0, pAt) + argv[2][0] + ".avi"; // Form the new name with container 44 int ex = static_cast<int>(inputVideo.get(CAP_PROP_FOURCC)); // Get Codec Type- Int form 45 46 // Transform from int to char via Bitwise operators 47 char EXT[] = {(char)(ex & 0XFF) , (char)((ex & 0XFF00) >> 8),(char)((ex & 0XFF0000) >> 16),(char)((ex & 0XFF000000) >> 24), 0}; 48 49 Size S = Size((int) inputVideo.get(CAP_PROP_FRAME_WIDTH), // Acquire input size 50 (int) inputVideo.get(CAP_PROP_FRAME_HEIGHT)); 51 52 VideoWriter outputVideo; // Open the output 53 if (askOutputType) 54 outputVideo.open(NAME, ex=-1, inputVideo.get(CAP_PROP_FPS), S, true); 55 else 56 outputVideo.open(NAME, ex, inputVideo.get(CAP_PROP_FPS), S, true); 57 58 if (!outputVideo.isOpened()) 59 { 60 cout << "Could not open the output video for write: " << source << endl; 61 return -1; 62 } 63 64 cout << "Input frame resolution: Width=" << S.width << " Height=" << S.height 65 << " of nr#: " << inputVideo.get(CAP_PROP_FRAME_COUNT) << endl; 66 cout << "Input codec type: " << EXT << endl; 67 68 int channel = 2; // Select the channel to save 69 switch(argv[2][0]) 70 { 71 case 'R' : channel = 2; break; 72 case 'G' : channel = 1; break; 73 case 'B' : channel = 0; break; 74 } 75 Mat src, res; 76 vector<Mat> spl; 77 78 for(;;) //Show the image captured in the window and repeat 79 { 80 inputVideo >> src; // read 81 if (src.empty()) break; // check if at end 82 83 split(src, spl); // process - extract only the correct channel 84 for (int i =0; i < 3; ++i) 85 if (i != channel) 86 spl[i] = Mat::zeros(S, spl[0].type()); 87 merge(spl, res); 88 89 //outputVideo.write(res); //save or 90 outputVideo << res; 91 } 92 93 cout << "Finished writing" << endl; 94 return 0; 95 } 96
