如何实现C#和Python之间实时视频数据交互

我们在做RTSP|RTMP播放的时候，遇到好多开发者，他们的视觉算法大多运行在python下，需要高效率的实现C#和Python的视频数据交互，常用的方法如下：

方法一：通过HTTP请求传输视频数据

服务器端（Python）

使用Flask或Django等Web框架创建一个HTTP服务器，通过API接口提供视频数据。

from flask import Flask, send_file, request, jsonify  
import cv2  
import io  
import base64  app = Flask(__name__)  def get_video_frame():  # 读取视频帧  cap = cv2.VideoCapture('your_video.mp4')  ret, frame = cap.read()  cap.release()  if not ret:  return None, "No more frames"  # 转换为RGB格式  frame_rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)  # 转换为字节流  ret, buffer = cv2.imencode('.jpg', frame_rgb)  if not ret:  return None, "Could not encode frame"  # 将字节流转换为base64字符串  img_str = base64.b64encode(buffer).decode('utf-8')  return img_str, 200  @app.route('/video_frame', methods=['GET'])  
def video_frame():  img_str, status_code = get_video_frame()  if img_str is None:  return jsonify({"error": status_code}), status_code  return jsonify({"image": img_str})  if __name__ == '__main__':  app.run(debug=True)

客户端（C#）

使用HttpClient从Python服务器获取视频帧，并将其显示在PictureBox中。

using System;  
using System.Drawing;  
using System.Drawing.Imaging;  
using System.IO;  
using System.Net.Http;  
using System.Windows.Forms;  public class VideoForm : Form  
{  private PictureBox pictureBox;  private HttpClient httpClient;  public VideoForm()  {  pictureBox = new PictureBox  {  Dock = DockStyle.Fill,  SizeMode = PictureBoxSizeMode.StretchImage  };  this.Controls.Add(pictureBox);  httpClient = new HttpClient();  Timer timer = new Timer();  timer.Interval = 100; // Adjust the interval as needed  timer.Tick += Timer_Tick;  timer.Start();  }  private async void Timer_Tick(object sender, EventArgs e)  {  try  {  HttpResponseMessage response = await httpClient.GetAsync("http://localhost:5000/video_frame");  response.EnsureSuccessStatusCode();  string jsonResponse = await response.Content.ReadAsStringAsync();  dynamic jsonData = Newtonsoft.Json.JsonConvert.DeserializeObject(jsonResponse);  string base64String = jsonData.image;  byte[] imageBytes = Convert.FromBase64String(base64String);  using (MemoryStream ms = new MemoryStream(imageBytes))  {  Image image = Image.FromStream(ms);  pictureBox.Image = image;  }  }  catch (Exception ex)  {  MessageBox.Show($"Error: {ex.Message}");  }  }  [STAThread]  public static void Main()  {  Application.EnableVisualStyles();  Application.Run(new VideoForm());  }  
}

方法二：通过ZeroMQ传输视频数据

ZeroMQ是一种高性能的异步消息库，适用于需要低延迟和高吞吐量的应用。

服务器端（Python）

使用pyzmq库发送视频帧。

import zmq  
import cv2  
import numpy as np  context = zmq.Context()  
socket = context.socket(zmq.PUB)  
socket.bind("tcp://*:5555")  cap = cv2.VideoCapture('your_video.mp4')  while True:  ret, frame = cap.read()  if not ret:  break  frame_rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)  frame_bytes = frame_rgb.tobytes()  socket.send_string("FRAME", zmq.SNDMORE)  socket.send(frame_bytes, flags=0, copy=False)

客户端（C#）

使用NetMQ库接收视频帧。

using System;  
using System.Drawing;  
using System.Drawing.Imaging;  
using System.Runtime.InteropServices;  
using System.Threading.Tasks;  
using System.Windows.Forms;  
using NetMQ;  
using NetMQ.Sockets;  public class VideoForm : Form  
{  private PictureBox pictureBox;  private SubscriberSocket subscriber;  public VideoForm()  {  pictureBox = new PictureBox  {  Dock = DockStyle.Fill,  SizeMode = PictureBoxSizeMode.StretchImage  };  this.Controls.Add(pictureBox);  var address = "tcp://localhost:5555";  using (var context = NetMQContext.Create())  {  subscriber = context.CreateSubscriberSocket();  subscriber.Connect(address);  subscriber.Subscribe("FRAME");  Task.Run(() => ReceiveFramesAsync(subscriber));  }  }  private async Task ReceiveFramesAsync(SubscriberSocket subscriber)  {  while (true)  {  var topic = await subscriber.ReceiveFrameStringAsync();  var frameBytes = await subscriber.ReceiveFrameBytesAsync();  if (topic == "FRAME")  {  int width = 640; // Adjust based on your video resolution  int height = 480; // Adjust based on your video resolution  int stride = width * 3;  Bitmap bitmap = new Bitmap(width, height, PixelFormat.Format24bppRgb);  BitmapData bitmapData = bitmap.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.WriteOnly, bitmap.PixelFormat);  Marshal.Copy(frameBytes, 0, bitmapData.Scan0, frameBytes.Length);  bitmap.UnlockBits(bitmapData);  pictureBox.Image = bitmap;  }  }  }  [STAThread]  public static void Main()  {  Application.EnableVisualStyles();  Application.Run(new VideoForm());  }  
}