ardupilot/Tools/ArdupilotMegaPlanner/Utilities/CaptureMJPEG.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.IO;
using System.Drawing;
using System.Threading;
using log4net;

namespace ArdupilotMega.Utilities
{
    public class CaptureMJPEG
    {
        private static readonly ILog log =
    LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

        static Thread asyncthread;
        static bool running = false;
        public static string URL = @"http://127.0.0.1:56781/map.jpg";

        public static event EventHandler OnNewImage;

        static DateTime lastimage = DateTime.Now;
        static int fps = 0;

        public static void runAsync()
        {
            while (asyncthread != null && asyncthread.IsAlive)
            {
                running = false;
            }

            asyncthread = new Thread(new ThreadStart(getUrl))
            {
                IsBackground = true,
                Priority = ThreadPriority.BelowNormal,
                Name = "mjpg stream reader"
            }; 
            
            asyncthread.Start();
        }

        public static void Stop()
        {
            running = false;
        }

        public static string ReadLine(BinaryReader br)
        {
            StringBuilder sb = new StringBuilder();

            while (true) {
                byte by = br.ReadByte();
                sb.Append((char)by);
                if (by == '\n')
                    break;
            }

            sb = sb.Replace("\r\n", "");

            return sb.ToString();
        }

        static void getUrl()
        {

            running = true;

            Bitmap frame = new Bitmap(640, 480);

            try
            {

                // Create a request using a URL that can receive a post. 
                WebRequest request = HttpWebRequest.Create(URL);
                // Set the Method property of the request to POST.
                request.Method = "GET";

                ((HttpWebRequest)request).AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;

                request.Headers.Add("Accept-Encoding", "gzip,deflate");

                // Get the response.
                WebResponse response = request.GetResponse();
                // Display the status.
                log.Debug(((HttpWebResponse)response).StatusDescription);
                // Get the stream containing content returned by the server.
                Stream dataStream = response.GetResponseStream();

                BinaryReader br = new BinaryReader(dataStream);

                // get boundary header

                string mpheader = response.Headers["Content-Type"];
                if (mpheader.IndexOf("boundary=") == -1)
                {
                    ReadLine(br); // this is a blank line
                    string line = "proxyline";
                    do
                    {
                        line = ReadLine(br);
                        if (line.StartsWith("--"))
                        {
                            mpheader = line;
                            break;
                        }
                    } while (line.Length > 2);
                }
                else
                {
                    int startboundary = mpheader.IndexOf("boundary=") + 9;
                    int endboundary = mpheader.Length;

                    mpheader = mpheader.Substring(startboundary, endboundary - startboundary);
                }

                dataStream.ReadTimeout = 30000; // 30 seconds
                br.BaseStream.ReadTimeout = 30000;

                while (running)
                {
                    try
                    {
                        // get the multipart start header
                        int length = int.Parse(getHeader(br)["Content-Length"]);

                        // read boundary header
                        if (length > 0)
                        {
                            byte[] buf1 = new byte[length];

                            dataStream.ReadTimeout = 3000;

                            int offset = 0;
                            int len = 0;

                            while ((len = br.Read(buf1, offset, length)) > 0)
                            {
                                offset += len;
                                length -= len;

                            }
                            /*
                            BinaryWriter sw = new BinaryWriter(File.OpenWrite("test.jpg"));

                            sw.Write(buf1,0,buf1.Length);

                            sw.Close();
                            */
                            try
                            {

                                frame = new Bitmap(new MemoryStream(buf1));

                            }
                            catch { }

                            fps++;

                            if (lastimage.Second != DateTime.Now.Second)
                            {
                                Console.WriteLine("MJPEG " + fps);
                                fps = 0;
                                lastimage = DateTime.Now;
                            }

                            if (OnNewImage != null)
                                OnNewImage(frame, new EventArgs());
                        }

                        // blank line at end of data
                        ReadLine(br);
                    }
                    catch (Exception ex) { log.Info(ex); break; }
                }

                // clear last image
                if (OnNewImage != null)
                    OnNewImage(null, new EventArgs());

                dataStream.Close();
                response.Close();

            }
            catch (Exception ex) { log.Error(ex); }

            running = false;
        }

        static void getUrlRTSP()
        {

        
        }

        static Dictionary<string, string> getHeader(BinaryReader stream)
        {
            Dictionary<string, string> answer = new Dictionary<string, string>();

            string line;

            do
            {
                line = ReadLine(stream);

                string[] items = line.Split(new char[] { ':' }, StringSplitOptions.RemoveEmptyEntries);


                if (items.Length == 2)
                    answer.Add(items[0].Trim(), items[1].Trim());

            } while (line != "");

            return answer;
        }

    }
}