ASP.net 視頻上傳轉換flv並且抓取第一幀產生圖片源碼

WEB.config配置節如下

    <appSettings>
        <!--工具檔案夾-->
        <add key="ffmpeg" value="ffmpeg/ffmpeg.exe"/>
        <add key="mencoder" value="mencoder/mencoder.exe"/>
        <add key="mplayer" value="mencoder/mplayer.exe"/>
        <!--上傳檔案的路徑-->
        <add key="upfile" value="UpFiles"/>
        <!--上專檔案圖片路徑-->
        <add key="imgfile" value="ImgFile"/>
        <!--上傳檔案圖片大小-->
        <add key="CatchFlvImgSize" value="240x180"/>
        <add key="widthSize" value="400"/>
        <add key="heightSize" value="350"/>
        <!--轉換後檔案路徑-->
        <add key="playfile" value="PlayFiles"/>
    </appSettings>
上傳類：
namespace VideoToFLV
{
    public class PublicMethod:System.Web.UI.Page
    {
          public PublicMethod()
    {
       
    }
    //檔案路徑
    public static string ffmpegtool = ConfigurationManager.AppSettings["ffmpeg"];
    public static string mencodertool = ConfigurationManager.AppSettings["mencoder"];
    public static string mplayertool = ConfigurationManager.AppSettings["mplayer"];
    public static string upFile = ConfigurationManager.AppSettings["upfile"] + "/";
    public static string imgFile = ConfigurationManager.AppSettings["imgfile"] + "/";
    public static string playFile = ConfigurationManager.AppSettings["playfile"] + "/";
    //檔案圖片大小
    public static string sizeOfImg = ConfigurationManager.AppSettings["CatchFlvImgSize"];
    //檔案大小
    public static string widthOfFile = ConfigurationManager.AppSettings["widthSize"];
    public static string heightOfFile = ConfigurationManager.AppSettings["heightSize"];
    //
    //
    //擷取檔案的名字
    public static string GetFileName(string fileName)
    {
        int i = fileName.LastIndexOf("\\") + 1;
        string Name = fileName.Substring(i);
        return Name;
    }
    //擷取副檔名
    public static string GetExtension(string fileName)
    {
        int i = fileName.LastIndexOf(".")+1;
        string Name = fileName.Substring(i);
        return Name;
    }
    //

     #region
     //運行FFMpeg的視頻解碼，(這裡是絕對路徑)
    /// <summary>
    /// 轉換檔並儲存在指定檔案夾下面(這裡是絕對路徑)
    /// </summary>
    /// <param name="fileName">上傳視頻檔案的路徑（原檔案）</param>
    /// <param name="playFile">轉換後的檔案的路徑（網路播放檔案）</param>
    /// <param name="imgFile">從視頻檔案中抓取的圖片路徑</param>
    /// <returns>成功:返回圖片虛擬位址;  失敗:返回Null 字元串</returns>
    public string ChangeFilePhy(string fileName, string playFile, string imgFile)
    {
        //取得ffmpeg.exe的路徑,路徑配置在Web.Config中,如:<add  key="ffmpeg"  value="E:\51aspx\ffmpeg.exe"  /> 
        string ffmpeg = Server.MapPath(PublicMethod.ffmpegtool);
        if ((!System.IO.File.Exists(ffmpeg)) || (!System.IO.File.Exists(fileName)))
        {
            return "";
        }

        //獲得圖片和(.flv)檔案相對路徑/最後儲存到資料庫的路徑,如:/Web/User1/00001.jpg 
     
        string flv_file = System.IO.Path.ChangeExtension(playFile, ".flv");

        //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
        {
            //轉換
            System.Diagnostics.Process.Start(FilestartInfo);
            //
            CatchImg(fileName, imgFile);
            //System.Diagnostics.Process.Start(ImgstartInfo);
        }
        catch
        {
            return "";
        }
        //
        return "";
    }
    //
    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 "";
        }
        //
        if (System.IO.File.Exists(flv_img))
        {
            return flv_img;
        }

        return "";
    }
    #endregion
    //
#region
    //運行FFMpeg的視頻解碼，(這裡是(虛擬)相對路徑)
    /// <summary>
    /// 轉換檔並儲存在指定檔案夾下面(這裡是相對路徑)
    /// </summary>
    /// <param name="fileName">上傳視頻檔案的路徑（原檔案）</param>
    /// <param name="playFile">轉換後的檔案的路徑（網路播放檔案）</param>
    /// <param name="imgFile">從視頻檔案中抓取的圖片路徑</param>
    /// <returns>成功:返回圖片虛擬位址;  失敗:返回Null 字元串</returns>
    public string ChangeFileVir(string fileName, string playFile, string imgFile)
    {
        //取得ffmpeg.exe的路徑,路徑配置在Web.Config中,如:<add  key="ffmpeg"  value="E:\51aspx\ffmpeg.exe"  /> 
        string ffmpeg = Server.MapPath(PublicMethod.ffmpegtool);
        if ((!System.IO.File.Exists(ffmpeg)) || (!System.IO.File.Exists(fileName)))
        {
            return "";
        }

        //獲得圖片和(.flv)檔案相對路徑/最後儲存到資料庫的路徑,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");

        //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);
        System.Diagnostics.ProcessStartInfo ImgstartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg);

        FilestartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        ImgstartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        //此處組合成ffmpeg.exe檔案需要的參數即可,此處命令在ffmpeg  0.4.9調試通過
        //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;
        ImgstartInfo.Arguments = "  -i  " + fileName + "  -y  -f  image2  -t  0.001  -s  " + FlvImgSize + " " + flv_img;

        try
        {
            System.Diagnostics.Process.Start(FilestartInfo);
            System.Diagnostics.Process.Start(ImgstartInfo);
        }
        catch
        {
            return "";
        }

        ///注意:圖片截取成功後,資料由記憶體緩衝寫到磁碟需要時間較長,大概在3,4秒甚至更長; 
        ///這兒需要延時後再檢測,我伺服器延時8秒,即如果超過8秒圖片仍不存在,認為失敗; 
        ///此處略去延時代碼.如有那位知道如何捕捉ffmpeg.exe失敗訊息,請告知,先謝過! 
        if (System.IO.File.Exists(flv_img))
        {
            return flv_img;
        }

        return "";
    }
    #endregion

    #region
    //運行mencoder的視頻解碼器轉換(這裡是(絕對路徑))
    public string 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");

        //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.Start(FilestartInfo);
            CatchImg(flv_file, imgFile);
        }
        catch
        {
            return "";
        }
        //
        return "";
    }
    #endregion

    }
}