问题描述：

如题

问题原因：

其实就是保存的帧如果处理成灰度图（单通道）的话，保存为新视频，则新视频读取不了

解决办法：

处理成三通道，保存的新视频即可被读取

代码：

    VideoCapture inputVideo("/home/jason/work/01-img/红外/test.mp4");int width = static_cast<int>(inputVideo.get(CAP_PROP_FRAME_WIDTH));int height =  static_cast<int>(inputVideo.get(CAP_PROP_FRAME_HEIGHT));double fps = inputVideo.get(cv::CAP_PROP_FPS);VideoWriter outputVideo("/home/jason/work/01-img/红外/test_DDE.mp4",VideoWriter::fourcc('m', 'p', '4', 'v'),double(1000/fps),cv::Size(width, height));Mat frame, result;while (true){inputVideo >> frame;if (frame.empty())break;cv::cvtColor(frame, frame, cv::COLOR_BGR2GRAY);DDE(frame, result);cv::cvtColor(result, result, cv::COLOR_GRAY2BGR);// 必须转为3通道，否则保存的新视频读取不了outputVideo.write(result);imshow("input", frame);imshow("output", result);if (waitKey(30) == 'q')break;}inputVideo.release();outputVideo.release();