在做一個視訊網站專案時，要求視訊能夠任意拖動播放，即使是沒有緩衝完也需要

網上查了下資料，主要需要3點

1. 播放器要支援
2. flv視訊要有關鍵幀和meta資訊
3. 伺服器端要支援

   <script>
      flowplayer("player", "../flowplayer-3.2.7.swf", {
          // configure clip to use "lighthttpd" plugin for providing video data
          clip: {
           url: 'http://pseudo01.hddn.com/vod/demo.flowplayervod/Extremists.flv',
        autoPlay:false , url: 't4.flv',
              provider: 'lighttpd'
          },
          // streaming plugins are configured normally under the plugins node
          plugins: {
              lighttpd: {
                  url: '../flowplayer.pseudostreaming-3.2.7.swf'
              }
          }
      });
     
        </script>
 

2、給flv視訊加入關鍵幀和meta資訊
上面提到，flv需要有meta資訊才能正確地被分析並根據時間獲取偏移量。有兩個工具可以補全meta資訊：

flvtool2：ruby寫的一個著名工具，地址：https://rubyforge.org/projects/flvtool2/
jamdi：另外一個補全meta資訊的工具，地址：http://yamdi.sourceforge.net/
兩者都是命令列工具，也都有windows版本，下載了直接用就好。這裡簡單介紹一下用法：

flvtool2：

flvtool2 –U <input file> <output file>

/// <summary>  
       /// 處理flv實現新增matedata資訊  
       /// </summary>  
       /// <param name="toolpath">toolpath="/FilesList/Exe/VideoTools/flvtool2.exe"</param>  
       /// <param name="filepath">視訊地址</param>  
       public void flvtodrog(string toolpath, string filepath)  
       {  
           System.Diagnostics.ProcessStartInfo startInfo = new System.Diagnostics.ProcessStartInfo(toolpath);  
           startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;  
           startInfo.UseShellExecute = false;  
           startInfo.CreateNoWindow = false;  
           startInfo.Arguments = " -U " + filepath;  
           try  
           {  
               System.Diagnostics.Process.Start(startInfo);  
           }  
           catch (Exception e)  
           {  
               //  
           }  
       }  
 

3.在視訊網站下新建一個handler，程式碼如下，使flv檔案流輸出

using System;
using System.IO;
using System.Web;
public class FLVStreaming : IHttpHandler
{
    private static readonly byte[] _flvheader = HexToByte("464C5601010000000900000009");
    public FLVStreaming()
    {
    }
    public void ProcessRequest(HttpContext context)
    {
        try
        {
            int pos;
            int length;
            // Check start parameter if present
            string filename = Path.GetFileName(context.Request.FilePath);
            using (FileStream fs = new FileStream(context.Server.MapPath(filename), FileMode.Open, FileAccess.Read, FileShare.Read))
            {
                string qs = context.Request.Params["start"];
                if (string.IsNullOrEmpty(qs))
                {
                    pos = 0;
                    length = Convert.ToInt32(fs.Length);
                }
                else
                {
                    pos = Convert.ToInt32(qs);
                    length = Convert.ToInt32(fs.Length - pos) + _flvheader.Length;
                }
                // Add HTTP header stuff: cache, content type and length       
                context.Response.Cache.SetCacheability(HttpCacheability.Public);
                context.Response.Cache.SetLastModified(DateTime.Now);
                context.Response.AppendHeader("Content-Type", "video/x-flv");
                context.Response.AppendHeader("Content-Length", length.ToString());
                // Append FLV header when sending partial file
                if (pos > 0)
                {
                    context.Response.OutputStream.Write(_flvheader, 0, _flvheader.Length);
                    fs.Position = pos;
                }
                // Read buffer and write stream to the response stream
                const int buffersize = 16384;
                byte[] buffer = new byte[buffersize];
               
                int count = fs.Read(buffer, 0, buffersize);
                while (count > 0)
                {
                    if (context.Response.IsClientConnected)
                    {
                        context.Response.OutputStream.Write(buffer, 0, count);
      
      //Starts sending to client right away
      context.Response.Flush();
   
                        count = fs.Read(buffer, 0, buffersize);
                    }
                    else
                    {
                        count = -1;
                    }
                }
            }
        }
        catch (Exception ex)
        {
            System.Diagnostics.Debug.WriteLine(ex.ToString());
        }
    }
    public bool IsReusable
    {
        get { return true; }
    }
    private static byte[] HexToByte(string hexString)
    {
        byte[] returnBytes = new byte[hexString.Length / 2];
        for (int i = 0; i < returnBytes.Length; i++)
            returnBytes[i] = Convert.ToByte(hexString.Substring(i * 2, 2), 16);
        return returnBytes;
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <handlers>
            <add name="FLVStreaming" path="*.flv" verb="*" type="FLVStreaming" resourceType="Unspecified" preCondition="integratedMode" />
        </handlers>
    </system.webServer>
</configuration>

執行IIS服務管理器，右鍵點選預設Web站點，選擇屬性，移動到主目錄選項頁，並點選配置按鈕。應用程式配置對話方塊彈出來了。點選新增按鈕並在可執行欄位輸入aspnet_isapi.dll檔案路徑，在擴充套件欄位輸入.flv
ps:如果你的作業系統是XP SP2的話，在輸入aspnet_isapi.dll路徑時需要手工輸入，不能用複製貼上的形式，否則儲存按鈕變灰。瀏覽時去掉check file exit選項。

至此就大功告成了，現在，播放flv視訊就可以任意拖動了