/// <summary>
        /// 执行一条command命令
        /// </summary>
        /// <param name="command">需要执行的Command</param>
        /// <param name="output">输出</param>
        /// <param name="error">错误</param>
        public static void ExecuteCommand(string command,out string output,out string error)
        {
            try
            {
                //创建一个进程
                Process pc = new Process();
                pc.StartInfo.FileName = "cmd.exe";
                pc.StartInfo.UseShellExecute = false;
                pc.StartInfo.RedirectStandardInput = true;
                pc.StartInfo.RedirectStandardOutput = true;
                pc.StartInfo.RedirectStandardError = true;
                pc.StartInfo.CreateNoWindow = true;
 
                //启动进程
                pc.Start();
                //执行命令
                pc.StandardInput.WriteLine(command);
 
                //等待退出
                pc.StandardInput.WriteLine("exit");
 
                //获取所有输出
                output = pc.StandardOutput.ReadToEnd();
                error = pc.StandardError.ReadToEnd();
                //关闭进程
                pc.Close();
            }
            catch(Exception)
            {
                output = null;
                error = null;
            }
        }

/// <summary>
        /// 获取视频的帧宽度和帧高度
        /// </summary>
        /// <param name="videoFilePath">mov文件的路径</param>
        /// <returns>null表示获取宽度或高度失败</returns>
        public static void GetMovWidthAndHeight(string videoFilePath, out int? width, out int? height)
        {
            try
            {
                //判断文件是否存在
                if (!File.Exists(videoFilePath))
                {
                    width = null;
                    height = null;
                }
 
                //执行命令获取该文件的一些信息 
                string ffmpegPath = new FileInfo(Process.GetCurrentProcess().MainModule.FileName).DirectoryName + @"\ffmpeg.exe";
 
                string output;
                string error;
                Helpers.ExecuteCommand("\"" + ffmpegPath + "\"" + " -i " + "\"" + videoFilePath + "\"",out output,out error);
                if(string.IsNullOrEmpty(error))
                {
                    width = null;
                    height = null;
                }
 
                //通过正则表达式获取信息里面的宽度信息
                Regex regex = new Regex("(\\d{2,4})x(\\d{2,4})", RegexOptions.Compiled);
                Match m = regex.Match(error);
                if (m.Success)
                {
                    width = int.Parse(m.Groups[1].Value);
                    height = int.Parse(m.Groups[2].Value);
                }
                else
                {
                    width = null;
                    height = null;
                }
            }
            catch (Exception)
            {
                width = null;
                height = null;
            }
        }