中文语音识别技术在c#中的应用(一)

 在.net中,对英文语音有较好的支持，但是对中文语音的支持还没有加入进来，我们要想实现中文发音或中文语音识别，必需先安装微软的Speech Application SDK（SASDK），它的最新版本是 SAPI 5.1 他能够识别中、日、英三种语言，你可以在这里下载：http://www.microsoft.com/speech/download/sdk51/,需要安装这两个文件Speech SDK 5.1和5.1 Language Pack，其中5.1 Language Pack可以选择安装支持的语言。

  安装好以后，我们就可以开始进行语音程序的开发了，当然，在这之前我们需要把SAPI.dll通过如下图所示添加到引用中

  下面我们设计一个能够朗读中英文混合语言的类：

  我们将用单例模式实现该类，类的代码如下，我们将详细解释：

 public class Speach

     {

          private static Speach _Instance = null ;

          private SpeechLib.SpVoiceClass voice =null;

          private Speach()

         {

              BuildSpeach() ;

         }

         public static Speach instance()

         {

              if (_Instance == null)

                   _Instance = new Speach() ;

              return _Instance ;

         }

          private void SetChinaVoice()

         {

              voice.Voice = voice.GetVoices(string.Empty,string.Empty).Item(0) ;

         }

          private void SetEnglishVoice()

         {

              voice.Voice = voice.GetVoices(string.Empty,string.Empty).Item(1) ;

          }

          private void SpeakChina(string strSpeak)

         {

              SetChinaVoice() ;

              Speak(strSpeak) ;

         }

          private void SpeakEnglishi(string strSpeak)

         {

              SetEnglishVoice() ;

              Speak(strSpeak) ;

         }

         public void AnalyseSpeak(string strSpeak)

         {

              int iCbeg = 0 ;

              int iEbeg = 0 ;

              bool IsChina = true ;

              for(int i=0;i<strSpeak.Length;i++)

              {

                   char chr = strSpeak[i] ;

                   if (IsChina)

                   {

                       if (chr<=122&&chr>=65)

                       {

                            int iLen = i - iCbeg ;

 

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                             string strValue = strSpeak.Substring(iCbeg,iLen) ;

                            SpeakChina(strValue) ;

                            iEbeg = i ;

                            IsChina = false ;

                       }

                   }

                   else

                   {

                       if (chr>122||chr<65)

                       {

                            int iLen = i - iEbeg ;

                            string strValue = strSpeak.Substring(iEbeg,iLen) ;

                            this.SpeakEnglishi(strValue) ;

                            iCbeg = i ;

                            IsChina = true ;

                       }

                   }

              }//end for

              if (IsChina)

              {

                   int iLen = strSpeak.Length - iCbeg ;

                   string strValue = strSpeak.Substring(iCbeg,iLen) ;

                   SpeakChina(strValue) ;

              }

               else

              {

                   int iLen = strSpeak.Length - iEbeg ;

                   string strValue = strSpeak.Substring(iEbeg,iLen) ;

                   SpeakEnglishi(strValue) ;

              }

         }

          private void BuildSpeach()

         {

              if (voice == null)

                   voice = new SpVoiceClass() ;             

         }

         public int Volume

         {

              get

              {

                   return voice.Volume ;

              }

              set

              {

                   voice.SetVolume((ushort)(value)) ;

              }

         }

 

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          public int Rate

         {

              get

              {

                   return voice.Rate ;

              }

              set

              {

                   voice.SetRate(value) ;

              }

         }

          private void Speak(string strSpeack)

         {

              try

              {

                   voice.Speak(strSpeack,SpeechVoiceSpeakFlags.SVSFlagsAsync) ;

              }

              catch(Exception err)

              {

                   throw(new Exception("发生一个错误："+err.Message)) ;

              }

         }

         public void Stop()

          {

              voice.Speak(string.Empty,SpeechLib.SpeechVoiceSpeakFlags.SVSFPurgeBeforeSpeak) ;

         }

         public void Pause()

         {

              voice.Pause() ;

         }

         public void Continue()

         {

              voice.Resume() ;

         }

     }//end class
 
  在 private SpeechLib.SpVoiceClass voice =null;这里，我们定义个一个用来发音的类，并且在第一次调用该类时，对它用BuildSpeach方法进行了初始化。

  我们还定义了两个属性Volume和Rate，能够设置音量和语速。

  我们知道，SpVoiceClass 有一个Speak方法，我们发音主要就是给他传递一个字符串，它负责读出该字符串，如下所示。

 

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private void Speak(string strSpeack)    
   {

              try

              {

                   voice.Speak(strSpeack,SpeechVoiceSpeakFlags.SVSFlagsAsync) ;

              }

              catch(Exception err)

              {

                   throw(new Exception("发生一个错误："+err.Message)) ;

              }

         }
 
  其中SpeechVoiceSpeakFlags.SVSFlagsAsync表示异步发音。