using System;
using System.Configuration;

public class PublicMethod:System.Web.UI.Page
{
    public PublicMethod()
    {
       
    }
    //文件路径
    public static string ffmpegtool = "ffmpeg/ffmpeg.exe";         
    public static string mencodertool = "mencoder/mencoder.exe";
    public static string flvtool = "flvtool/flvtool2.exe";          //flv标记工具

    public static string upFile = "UpFiles" + "/";                        //上传文件夹
    public static string imgFile = "ImgFile" + "/";                       //图片文件夹
    public static string playFile = "PlayFiles" + "/";                    //flv文件夹
    public static string xmlFile = "xmlFiles" + "/";                      //xml文件夹

    public static string sizeOfImg = "240x180";                     //图片的宽与高
    public static string widthOfFile = "400";                       //flv文件的宽度
    public static string heightOfFile = "350";                      //flv文件的高度

    //public static string ffmpegtool = ConfigurationManager.AppSettings["ffmpeg"];
    //public static string mencodertool = ConfigurationManager.AppSettings["mencoder"];
    //public static string upFile = ConfigurationManager.AppSettings["upfile"] + "/";
    //public static string imgFile = ConfigurationManager.AppSettings["imgfile"] + "/";
    //public static string playFile = ConfigurationManager.AppSettings["playfile"] + "/";
    //文件图片大小
    //public static string sizeOfImg = ConfigurationManager.AppSettings["CatchFlvImgSize"];
    //文件大小
    //public static string widthOfFile = ConfigurationManager.AppSettings["widthSize"];
    //public static string heightOfFile = ConfigurationManager.AppSettings["heightSize"];

    //   // //获取文件的名字
    private System.Timers.Timer myTimer = new System.Timers.Timer(3000);//记时器
    public static string flvName = "";
    public static string imgName = "";
    public static string flvXml = "";
    public static int pId = 0;
   

    public static string GetFileName(string fileName)
    {
        int i = fileName.LastIndexOf("\\") + 1;
        string Name = fileName.Substring(i);
        return Name;
    }
    //获取文件扩展名
    public static string GetExtension(string fileName)
    {
        int i = fileName.LastIndexOf(".")+1;
        string Name = fileName.Substring(i);
        return Name;
    }
    //
    #region //运行FFMpeg的视频解码，(这里是绝对路径)
    /// <summary>
    /// 转换文件并保存在指定文件夹下面(这里是绝对路径)
    /// </summary>
    /// <param name="fileName">上传视频文件的路径（原文件）</param>
    /// <param name="playFile">转换后的文件的路径（网络播放文件）</param>
    /// <param name="imgFile">从视频文件中抓取的图片路径</param>
    /// <returns>成功:返回图片虚拟地址;   失败:返回空字符串</returns>
    public void ChangeFilePhy(string fileName, string playFile, string imgFile)
    {
        //取得ffmpeg.exe的路径,路径配置在Web.Config中,如:<add   key="ffmpeg"   value="E:\aspx1\ffmpeg.exe"   />  
        string ffmpeg = Server.MapPath(PublicMethod.ffmpegtool);
        if ((!System.IO.File.Exists(ffmpeg)) || (!System.IO.File.Exists(fileName)))
        {
            return;
        }

        //获得图片和(.flv)文件相对路径/最后存储到数据库的路径,如:/Web/User1/00001.jpg  
      
        string flv_file = System.IO.Path.ChangeExtension(playFile, ".flv");


        //截图的尺寸大小,配置在Web.Config中,如:<add   key="CatchFlvImgSize"   value="240x180"   />  
        string FlvImgSize = PublicMethod.sizeOfImg;

        System.Diagnostics.ProcessStartInfo FilestartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg);

        FilestartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;

        FilestartInfo.Arguments = " -i " + fileName + " -ab 56 -ar 22050 -b 500 -r 15 -s " + widthOfFile + "x" + heightOfFile + " " + flv_file;
        //ImgstartInfo.Arguments = "   -i   " + fileName + "   -y   -f   image2   -t   0.05   -s   " + FlvImgSize + "   " + flv_img;

        try
        {
            //转换
            System.Diagnostics.Process.Start(FilestartInfo);
            //截图
            CatchImg(fileName, imgFile);
            //System.Diagnostics.Process.Start(ImgstartInfo);
        }
        catch
        {
        }
    }
    #endregion

    #region 截图
    public string CatchImg(string fileName,string imgFile)
    {
        //
        string ffmpeg = Server.MapPath(PublicMethod.ffmpegtool);
        //
        string flv_img =imgFile+".jpg";
        //
        string FlvImgSize = PublicMethod.sizeOfImg;
        //
        System.Diagnostics.ProcessStartInfo ImgstartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg);
        ImgstartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        //
        ImgstartInfo.Arguments = "   -i   " + fileName + "  -y  -f  image2   -ss 2 -vframes 1  -s   " + FlvImgSize + "   " + flv_img;
        try
        {
            System.Diagnostics.Process.Start(ImgstartInfo);
        }
        catch
        {
            return "";
        }
        //
        catchFlvTool(fileName);
        if (System.IO.File.Exists(flv_img))
        {
            return flv_img;
        }

        return "";
    }
    #endregion
 #region //运行FFMpeg的视频解码，(这里是(虚拟)相对路径)
    /// <summary>
    /// 转换文件并保存在指定文件夹下面(这里是相对路径)
    /// </summary>
    /// <param name="fileName">上传视频文件的路径（原文件）</param>
    /// <param name="playFile">转换后的文件的路径（网络播放文件）</param>
    /// <param name="imgFile">从视频文件中抓取的图片路径</param>
    /// <returns>成功:返回图片虚拟地址;   失败:返回空字符串</returns>
    public void ChangeFileVir(string fileName, string playFile, string imgFile)
    {
        //取得ffmpeg.exe的路径,路径配置在Web.Config中,如:<add   key="ffmpeg"   value="E:\aspx1\ffmpeg.exe"   />  
        string ffmpeg = Server.MapPath(PublicMethod.ffmpegtool);
        if ((!System.IO.File.Exists(ffmpeg)) || (!System.IO.File.Exists(fileName)))
        {
            return;
        }

        //获得图片和(.flv)文件相对路径/最后存储到数据库的路径,如:/Web/User1/00001.jpg  
        string flv_img = System.IO.Path.ChangeExtension(Server.MapPath(imgFile), ".jpg");
        string flv_file = System.IO.Path.ChangeExtension(Server.MapPath(playFile), ".flv");


        //截图的尺寸大小,配置在Web.Config中,如:<add   key="CatchFlvImgSize"   value="240x180"   />  
        string FlvImgSize = PublicMethod.sizeOfImg;

        System.Diagnostics.ProcessStartInfo FilestartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg);

        FilestartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        //此处组合成ffmpeg.exe文件需要的参数即可,此处命令在ffmpeg   0.4.9调试通过
        //ffmpeg -i F:\01.wmv -ab 56 -ar 22050 -b 500 -r 15 -s 320x240 f:\test.flv
        FilestartInfo.Arguments = " -i " + fileName + " -ab 56 -ar 22050 -b 500 -r 15 -s " + widthOfFile + "x" + heightOfFile + " " + flv_file;

        try
        {
            System.Diagnostics.Process ps = new System.Diagnostics.Process();
            ps.StartInfo = FilestartInfo;
            ps.Start();
            Session.Add("ProcessID", ps.Id);
            Session.Add("flv", flv_file);
            Session.Add("img", imgFile);
            myTimer.Elapsed += new System.Timers.ElapsedEventHandler(myTimer_Test);
            myTimer.Enabled = true;
        }
        catch
        {
        }
    }
    #endregion

    #region //运行mencoder的视频解码器转换(这里是(绝对路径))
    public void MChangeFilePhy(string vFileName, string playFile, string imgFile)
    {
        string tool = Server.MapPath(PublicMethod.mencodertool);
        //string mplaytool = Server.MapPath(PublicMethod.ffmpegtool);
       
        if ((!System.IO.File.Exists(tool)) || (!System.IO.File.Exists(vFileName)))
        {
            return;
        }

        string flv_file = System.IO.Path.ChangeExtension(playFile, ".flv");


        //截图的尺寸大小,配置在Web.Config中,如:<add   key="CatchFlvImgSize"   value="240x180"   />  
        string FlvImgSize = PublicMethod.sizeOfImg;

        System.Diagnostics.ProcessStartInfo FilestartInfo = new System.Diagnostics.ProcessStartInfo(tool);
      
        FilestartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        FilestartInfo.Arguments = " " + vFileName + " -o " + flv_file + " -of lavf -lavfopts i_certify_that_my_video_stream_does_not_use_b_frames -oac mp3lame -lameopts abr:br=56 -ovc lavc -lavcopts vcodec=flv:vbitrate=200:mbd=2:mv0:trell:v4mv:cbp:last_pred=1:dia=-1:cmp=0:vb_strategy=1 -vf scale=" + widthOfFile + ":" +heightOfFile + " -ofps 12 -srate 22050";
        try
        {
            System.Diagnostics.Process ps = new System.Diagnostics.Process();
            ps.StartInfo = FilestartInfo;
            ps.Start();
            Session.Add("ProcessID", ps.Id);
            Session.Add("flv", flv_file);
            Session.Add("img", imgFile);
            //pId = ps.Id;
            //flvName = flv_file;
            //imgName = imgFile;
            myTimer.Elapsed += new System.Timers.ElapsedEventHandler(myTimer_Test);
            myTimer.Enabled = true;
        }
        catch
        {
        }
    }


    /// <summary>
    /// 记时器功能，自动保存截图
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void myTimer_Test(object sender, System.Timers.ElapsedEventArgs e)
    {
        if (!object.Equals(null, Session["ProcessID"]))
        {
            try
            {
                System.Diagnostics.Process prs = System.Diagnostics.Process.GetProcessById(int.Parse(Session["ProcessID"].ToString()));
                if (prs.HasExited)
                {
                    CatchImg(Session["flv"].ToString(), Session["img"].ToString());
                    catchFlvTool(Session["flv"].ToString());
                    myTimer.Enabled = false;
                    myTimer.Close();
                    myTimer.Dispose();
                    Session.Abandon();
                }
            }
            catch
            {
                CatchImg(Session["flv"].ToString(), Session["img"].ToString());
                catchFlvTool(Session["flv"].ToString());
                myTimer.Enabled = false;
                myTimer.Close();
                myTimer.Dispose();
                Session.Abandon();
            }
        }
    }

    #endregion


    public string catchFlvTool(string fileName)
    {
        //
        string flvtools = Server.MapPath(PublicMethod.flvtool);
        //
        string flv_xml = fileName.Replace(".flv", ".xml").Replace(PublicMethod.upFile.Replace("/", ""), PublicMethod.xmlFile.Replace("/", ""));
        //
        System.Diagnostics.ProcessStartInfo ImgstartInfo = new System.Diagnostics.ProcessStartInfo(flvtools);
        ImgstartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        //
        ImgstartInfo.Arguments = "   " + fileName + "   -UPx   " + fileName + "  >  " + flv_xml;
        try
        {
            System.Diagnostics.Process.Start(ImgstartInfo);
        }
        catch
        {
            return "";
        }
        //
        if (System.IO.File.Exists(flv_xml))
        {
            return flv_xml;
        }

        return "";
    }
}

大文件上传,现在也有不少不错的控件,像slickupload等
http://www.cnblogs.com/bashan
写了一篇大文件上传总结,带状态和进度条.
里面有详细的原理,逐步实现的方法,1.1和2.0的原码都有
想学习的可以看看

http://topic.csdn.net/u/20080527/12/c03d32b6-36b8-4838-b706-cba1b91df4de.html