opencv视频读写

需要使用VideoCapture类

读取mp4文件

cv::VideoCapture vcapture("chouyan2.mp4");if (vcapture.isOpened()) {while (vcapture.grab()) {// 直接从视频文件或者设备捕获中抓取帧cv::Mat myFrame;//vcapture >> myFrame; // 将视频中的数据流向Matif (vcapture.read(myFrame)) {cv::imshow("读取mp4视频文件", myFrame);cv::waitKey(40);}}}vcapture.release();

读取rtsp流并且按下空格键保存图片

修改文件名即可

cv::VideoCapture vcapture("rtsp://admin:Admin123@192.168.101.234");int picNum{ 0 };if (vcapture.isOpened()) {while (vcapture.grab()) {// 直接从视频文件或者设备捕获中抓取帧cv::Mat myFrame;//vcapture >> myFrame; // 将视频中的数据流向Matif (vcapture.read(myFrame)) {cv::imshow("读取rtsp视频文件", myFrame);if (cv::waitKey(20) == 32) {std::string picName = std::to_string(picNum) + ".jpg";cv::imwrite(picName.c_str(), myFrame);picNum++;}}}}vcapture.release();

编码生成视频文件

cv::VideoCapture vcapture("rtsp://admin:Admin123@192.168.101.234");cv::VideoWriter vcwriter("test.mp4", cv::VideoWriter::fourcc('X', '2', '6', '4'), 25, cv::Size(vcapture.get(cv::CAP_PROP_FRAME_WIDTH), vcapture.get(cv::CAP_PROP_FRAME_HEIGHT)), true);int picNum{ 0 };if (vcapture.isOpened()) {while (vcapture.grab()) {// 直接从视频文件或者设备捕获中抓取帧cv::Mat myFrame;//vcapture >> myFrame; // 将视频中的数据流向Matif (vcapture.read(myFrame)) {drawrectangle(myFrame);cv::imshow("读取rtsp视频文件", myFrame);int key = cv::waitKey(20);if (key == 32) {std::string picName = std::to_string(picNum) + ".jpg";cv::imwrite(picName.c_str(), myFrame);picNum++;break;} else if (key == 'q') {break;}vcwriter.write(myFrame);}}}vcapture.release();vcwriter.release();