如何在Ubuntu 16.04虚拟机中通过Code::Blocks+OpenCV3访问IP摄像头？

Hey there! Since you already got the Edimax IC-3110P stream working in Visual Studio on Windows, let's get that same functionality up and running in your Ubuntu 16.04 VM with Code::Blocks and OpenCV 3. Here's a step-by-step breakdown:

First, make sure your VM has a working OpenCV 3 installation—this is often the root cause of cross-platform issues.

• Check your current OpenCV version with this terminal command:

  pkg-config --modversion opencv
  

  You should see a 3.x number (like 3.4.16, which is fully compatible with Ubuntu 16.04).
• If you need to install or upgrade OpenCV 3:
  1. Install required dependencies:

     sudo apt-get update && sudo apt-get install build-essential cmake git libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev
     

  2. Grab the stable OpenCV 3.4.x source branch:

     git clone https://github.com/opencv/opencv.git
     cd opencv && git checkout 3.4.16
     mkdir build && cd build
     

  3. Compile and install:

     cmake -D CMAKE_BUILD_TYPE=Release -D CMAKE_INSTALL_PREFIX=/usr/local ..
     make -j$(nproc)  # Uses all CPU cores for faster build
     sudo make install
     sudo ldconfig
     

Code::Blocks needs to know where to find OpenCV's headers and libraries to compile your project correctly:

• Open your project, go to Settings > Compiler > Linker settings
• In the Other linker options field, add:

  pkg-config --libs opencv
  

  This automatically pulls in all necessary OpenCV libraries without manual entry.
• Next, go to Search directories > Compiler and add these paths:
  • /usr/local/include/opencv
  • /usr/local/include/opencv2
• Then, in Search directories > Linker, add:
  • /usr/local/lib

Your existing code is almost ready—just tweak a few Linux-specific details:

• Network Setup: Set your VirtualBox network to Bridge Adapter (Settings > Network) so your Ubuntu VM can directly reach the camera's IP on your local network.
• RTSP URL: Edimax IC-3110P uses a standard RTSP stream URL. Replace the placeholder with your camera's credentials and IP:

  const std::string rtsp_url = "rtsp://your_username:your_password@camera_ip:554/h264";
  

  If /h264 doesn't work, try /mpeg4—some firmware versions use that alternative path.
• Full Working Code (completing your partial snippet):

  #include <stdio.h>
  #include <opencv2/opencv.hpp>
  #include <iostream>
  
  int main(int, char**) {
      cv::VideoCapture vcap;
      // Update this with your camera's actual RTSP URL
      const std::string rtsp_url = "rtsp://admin:12345@192.168.1.100:554/h264";
  
      // Open the RTSP stream
      if (!vcap.open(rtsp_url)) {
          std::cerr << "Error: Could not open video stream" << std::endl;
          return -1;
      }
  
      cv::Mat frame;
      while (true) {
          // Grab a frame from the stream
          if (!vcap.read(frame)) {
              std::cerr << "Error: No frame captured" << std::endl;
              break;
          }
          // Display the frame
          cv::imshow("Edimax IC-3110P Live Stream", frame);
          // Exit when 'q' is pressed
          if (cv::waitKey(1) == 'q') {
              break;
          }
      }
  
      // Clean up resources
      vcap.release();
      cv::destroyAllWindows();
      return 0;
  }
  

• Can't reach the camera: Ping the camera's IP from Ubuntu (ping camera_ip) to confirm connectivity. If it fails, double-check your VirtualBox network mode and router settings.
• OpenCV can't open the stream: Verify the RTSP URL is correct with ffplay (install with sudo apt-get install ffmpeg) to rule out OpenCV-specific issues:

  ffplay rtsp://your_username:your_password@camera_ip:554/h264
  

• Code::Blocks build errors: If the pkg-config line doesn't work, manually add the OpenCV libraries to linker options:

  -lopencv_core -lopencv_highgui -lopencv_videoio -lopencv_imgproc
  

• Laggy stream: Enable 3D acceleration in VirtualBox (Settings > Display) and lower the camera's resolution via its web interface to reduce VM resource usage.

内容的提问来源于stack exchange，提问作者Winbuntu