iOS中 语音识别功能／语音转文字教程详解

 

iOS中 语音识别功能／语音转文字教程详解 

前言：最近研究了一下语音识别，从百度语音识别到讯飞语音识别；首先说一下个人针对两者的看法，讯飞毫无疑问比较专业，识别率也很高真对语音识别是比较精准的，但是很多开发者和我一样期望离线识别，而讯飞离线是收费的；请求次数来讲，两者都可以申请高配额，真对用户较多的几乎都一样。基于免费并且支持离线我选择了百度离线语音识别。比较简单，UI设计多一点，下面写一下教程：

1.首先：需要的库

2.我是自定义的UI所以以功能实现为主（头文件）

 // 头文件
 #import "BDVRCustomRecognitonViewController.h"
 #import "BDVRClientUIManager.h"
 #import "WBVoiceRecordHUD.h"
 #import "BDVRViewController.h"
 #import "MyViewController.h"
 #import "BDVRSConfig.h"

3.需要知道的功能：能用到的如下：

 //－－－－－－－－－－－－－－－－－－－类方法－－－－－－－－－－－－－－－－－－－－－－－－
 // 创建语音识别客户对像，该对像是个单例
 + (BDVoiceRecognitionClient *)sharedInstance;

 // 释放语音识别客户端对像
 + (void)releaseInstance;


 //－－－－－－－－－－－－－－－－－－－识别方法－－－－－－－－－－－－－－－－－－－－－－－
 // 判断是否可以录音
 - (BOOL)isCanRecorder;

 // 开始语音识别，需要实现MVoiceRecognitionClientDelegate代理方法，并传入实现对像监听事件
 // 返回值参考 TVoiceRecognitionStartWorkResult
 - (int)startVoiceRecognition:(id)aDelegate;

 // 说完了，用户主动完成录音时调用
 - (void)speakFinish;

 // 结束本次语音识别
 - (void)stopVoiceRecognition;

 /**
  * @brief 获取当前识别的采样率
  *
  * @return 采样率(16000/8000)
  */
 - (int)getCurrentSampleRate;

 /**
  * @brief 得到当前识别模式(deprecated)
  *
  * @return 当前识别模式
  */
 - (int)getCurrentVoiceRecognitionMode __attribute__((deprecated));

 /**
  * @brief 设置当前识别模式(deprecated)，请使用-(void)setProperty:(TBDVoiceRecognitionProperty)property;
  *
  * @param 识别模式
  *
  * @return 是否设置成功
  */
 - (void)setCurrentVoiceRecognitionMode:(int)aMode __attribute__((deprecated));

 // 设置识别类型
 - (void)setProperty:(TBDVoiceRecognitionProperty)property __attribute__((deprecated));

 // 获取当前识别类型
 - (int)getRecognitionProperty __attribute__((deprecated));

 // 设置识别类型列表, 除EVoiceRecognitionPropertyInput和EVoiceRecognitionPropertySong外
 // 可以识别类型复合
 - (void)setPropertyList: (NSArray*)prop_list;

 // cityID仅对EVoiceRecognitionPropertyMap识别类型有效
 - (void)setCityID: (NSInteger)cityID;

 // 获取当前识别类型列表
 - (NSArray*)getRecognitionPropertyList;

 //－－－－－－－－－－－－－－－－－－－提示音－－－－－－－－－－－－－－－－－－－－－－－
 // 播放提示音，默认为播放,录音开始，录音结束提示音
 // BDVoiceRecognitionClientResources/Tone
 // record_start.caf   录音开始声音文件
 // record_end.caf     录音结束声音文件
 // 声音资源需要加到项目工程里，用户可替换资源文件，文件名不可以变，建音提示音不宜过长，0。5秒左右。
 // aTone 取值参考 TVoiceRecognitionPlayTones，如没有找到文件，则返回ＮＯ
 - (BOOL)setPlayTone:(int)aTone isPlay:(BOOL)aIsPlay;

4.录音按钮相关动画（我自定义的，大家可以借鉴）

每日更新关注:http://weibo.com/hanjunqiang  新浪微博

 // 录音按钮相关
 @property (nonatomic, weak, readonly) UIButton *holdDownButton;// 说话按钮
 /**
  *  是否取消錄音
  */
 @property (nonatomic, assign, readwrite) BOOL isCancelled;

 /**
  *  是否正在錄音
  */
 @property (nonatomic, assign, readwrite) BOOL isRecording;
 /**
  *  当录音按钮被按下所触发的事件，这时候是开始录音
  */
 - (void)holdDownButtonTouchDown;

 /**
  *  当手指在录音按钮范围之外离开屏幕所触发的事件，这时候是取消录音
  */
 - (void)holdDownButtonTouchUpOutside;

 /**
  *  当手指在录音按钮范围之内离开屏幕所触发的事件，这时候是完成录音
  */
 - (void)holdDownButtonTouchUpInside;

 /**
  *  当手指滑动到录音按钮的范围之外所触发的事件
  */
 - (void)holdDownDragOutside;

5.初始化系统UI

 #pragma mark - layout subViews UI

 /**
  *  根据正常显示和高亮状态创建一个按钮对象
  *
  *  @param image   正常显示图
  *  @param hlImage 高亮显示图
  *
  *  @return 返回按钮对象
  */
 - (UIButton *)createButtonWithImage:(UIImage *)image HLImage:(UIImage *)hlImage ;
 - (void)holdDownDragInside;
 - (void)createInitView; // 创建初始化界面，播放提示音时会用到
 - (void)createRecordView;  // 创建录音界面
 - (void)createRecognitionView; // 创建识别界面
 - (void)createErrorViewWithErrorType:(int)aStatus; // 在识别view中显示详细错误信息
 - (void)createRunLogWithStatus:(int)aStatus; // 在状态view中显示详细状态信息

 - (void)finishRecord:(id)sender; // 用户点击完成动作
 - (void)cancel:(id)sender; // 用户点击取消动作

 - (void)startVoiceLevelMeterTimer;
 - (void)freeVoiceLevelMeterTimerTimer;

6.最重要的部分

 // 录音完成
  [[BDVoiceRecognitionClient sharedInstance] speakFinish];

 // 取消录音
 [[BDVoiceRecognitionClient sharedInstance] stopVoiceRecognition];

7.两个代理方法

 - (void)VoiceRecognitionClientWorkStatus:(int)aStatus obj:(id)aObj
 {
     switch (aStatus)
     {
         case EVoiceRecognitionClientWorkStatusFlushData: // 连续上屏中间结果
         {
             NSString *text = [aObj objectAtIndex:0];

             if ([text length] > 0)
             {
 //                [clientSampleViewController logOutToContinusManualResut:text];

                 UILabel *clientWorkStatusFlushLabel = [[UILabel alloc]initWithFrame:CGRectMake(kScreenWidth/2 - 100,64,200,60)];
                 clientWorkStatusFlushLabel.text = text;
                 clientWorkStatusFlushLabel.textAlignment = NSTextAlignmentCenter;
                 clientWorkStatusFlushLabel.font = [UIFont systemFontOfSize:18.0f];
                 clientWorkStatusFlushLabel.numberOfLines = 0;
                 clientWorkStatusFlushLabel.backgroundColor = [UIColor whiteColor];
                 [self.view addSubview:clientWorkStatusFlushLabel];

             }

             break;
         }
         case EVoiceRecognitionClientWorkStatusFinish: // 识别正常完成并获得结果
         {
             [self createRunLogWithStatus:aStatus];

             if ([[BDVoiceRecognitionClient sharedInstance] getRecognitionProperty] != EVoiceRecognitionPropertyInput)
             {
                 //  搜索模式下的结果为数组，示例为
                 // ["公园", "公元"]
                 NSMutableArray *audioResultData = (NSMutableArray *)aObj;
                 NSMutableString *tmpString = [[NSMutableString alloc] initWithString:@""];

                 for (int i=0; i < [audioResultData count]; i++)
                 {
                     [tmpString appendFormat:@"%@\r\n",[audioResultData objectAtIndex:i]];
                 }

                 clientSampleViewController.resultView.text = nil;
                 [clientSampleViewController logOutToManualResut:tmpString];

             }
             else
             {
                 NSString *tmpString = [[BDVRSConfig sharedInstance] composeInputModeResult:aObj];
                 [clientSampleViewController logOutToContinusManualResut:tmpString];

             }

             if (self.view.superview)
             {
                 [self.view removeFromSuperview];
             }

             break;
         }
         case EVoiceRecognitionClientWorkStatusReceiveData:
         {
             // 此状态只有在输入模式下使用
             // 输入模式下的结果为带置信度的结果，示例如下：
             //  [
             //      [
             //         {
             //             "百度" = "0.6055192947387695";
             //         },
             //         {
             //             "摆渡" = "0.3625582158565521";
             //         },
             //      ]
             //      [
             //         {
             //             "一下" = "0.7665404081344604";
             //         }
             //      ],
             //   ]
 //暂时关掉 -- 否则影响跳转结果
 //            NSString *tmpString = [[BDVRSConfig sharedInstance] composeInputModeResult:aObj];
 //            [clientSampleViewController logOutToContinusManualResut:tmpString];

             break;
         }
         case EVoiceRecognitionClientWorkStatusEnd: // 用户说话完成，等待服务器返回识别结果
         {
             [self createRunLogWithStatus:aStatus];
             if ([BDVRSConfig sharedInstance].voiceLevelMeter)
             {
                 [self freeVoiceLevelMeterTimerTimer];
             }

             [self createRecognitionView];

             break;
         }
         case EVoiceRecognitionClientWorkStatusCancel:
         {
             if ([BDVRSConfig sharedInstance].voiceLevelMeter)
             {
                 [self freeVoiceLevelMeterTimerTimer];
             }

             [self createRunLogWithStatus:aStatus];

             if (self.view.superview)
             {
                 [self.view removeFromSuperview];
             }
             break;
         }
         case EVoiceRecognitionClientWorkStatusStartWorkIng: // 识别库开始识别工作，用户可以说话
         {
             if ([BDVRSConfig sharedInstance].playStartMusicSwitch) // 如果播放了提示音，此时再给用户提示可以说话
             {
                 [self createRecordView];
             }

             if ([BDVRSConfig sharedInstance].voiceLevelMeter)  // 开启语音音量监听
             {
                 [self startVoiceLevelMeterTimer];
             }

             [self createRunLogWithStatus:aStatus];

             break;
         }
         case EVoiceRecognitionClientWorkStatusNone:
         case EVoiceRecognitionClientWorkPlayStartTone:
         case EVoiceRecognitionClientWorkPlayStartToneFinish:
         case EVoiceRecognitionClientWorkStatusStart:
         case EVoiceRecognitionClientWorkPlayEndToneFinish:
         case EVoiceRecognitionClientWorkPlayEndTone:
         {
             [self createRunLogWithStatus:aStatus];
             break;
         }
         case EVoiceRecognitionClientWorkStatusNewRecordData:
         {
             break;
         }
         default:
         {
             [self createRunLogWithStatus:aStatus];
             if ([BDVRSConfig sharedInstance].voiceLevelMeter)
             {
                 [self freeVoiceLevelMeterTimerTimer];
             }
             if (self.view.superview)
             {
                 [self.view removeFromSuperview];
             }

             break;
         }
     }
 }

 - (void)VoiceRecognitionClientNetWorkStatus:(int) aStatus
 {
     switch (aStatus)
     {
         case EVoiceRecognitionClientNetWorkStatusStart:
         {
             [self createRunLogWithStatus:aStatus];
             [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
             break;
         }
         case EVoiceRecognitionClientNetWorkStatusEnd:
         {
             [self createRunLogWithStatus:aStatus];
             [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
             break;
         }
     }
 }

8.录音按钮的一些操作

 #pragma mark ------ 关于按钮操作的一些事情-------
 - (void)holdDownButtonTouchDown {
     // 开始动画
     _disPlayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(delayAnimation)];
     _disPlayLink.frameInterval = 40;
     [_disPlayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

     self.isCancelled = NO;
     self.isRecording = NO;

  // 开始语音识别功能，之前必须实现MVoiceRecognitionClientDelegate协议中的VoiceRecognitionClientWorkStatus:obj方法
     int startStatus = -1;
     startStatus = [[BDVoiceRecognitionClient sharedInstance] startVoiceRecognition:self];
     if (startStatus != EVoiceRecognitionStartWorking) // 创建失败则报告错误
     {
         NSString *statusString = [NSString stringWithFormat:@"%d",startStatus];
         [self performSelector:@selector(firstStartError:) withObject:statusString afterDelay:0.3];  // 延迟0.3秒，以便能在出错时正常删除view
         return;
     }
     // "按住说话－松开搜索"提示
     [voiceImageStr removeFromSuperview];
     voiceImageStr = [[UIImageView alloc]initWithFrame:CGRectMake(kScreenWidth/2 - 40, kScreenHeight - 153, 80, 33)];
     voiceImageStr.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"searchVoice"]];
     [self.view addSubview:voiceImageStr];

 }

 - (void)holdDownButtonTouchUpOutside {
     // 结束动画
     [self.view.layer removeAllAnimations];
     [_disPlayLink invalidate];
     _disPlayLink = nil;

     // 取消录音
     [[BDVoiceRecognitionClient sharedInstance] stopVoiceRecognition];

     if (self.view.superview)
     {
         [self.view removeFromSuperview];
     }
 }

 - (void)holdDownButtonTouchUpInside {
     // 结束动画
     [self.view.layer removeAllAnimations];
     [_disPlayLink invalidate];
     _disPlayLink = nil;

     [[BDVoiceRecognitionClient sharedInstance] speakFinish];
 }

 - (void)holdDownDragOutside {

     //如果已經開始錄音了, 才需要做拖曳出去的動作, 否則只要切換 isCancelled, 不讓錄音開始.
     if (self.isRecording) {
 //        if ([self.delegate respondsToSelector:@selector(didDragOutsideAction)]) {
 //            [self.delegate didDragOutsideAction];
 //        }
     } else {
         self.isCancelled = YES;
     }
 }


 #pragma mark - layout subViews UI

 - (UIButton *)createButtonWithImage:(UIImage *)image HLImage:(UIImage *)hlImage {
     UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(kScreenWidth/2 -36, kScreenHeight - 120, 72, 72)];

     if (image)
         [button setBackgroundImage:image forState:UIControlStateNormal];
     if (hlImage)
         [button setBackgroundImage:hlImage forState:UIControlStateHighlighted];

     return button;
 }

 #pragma mark ----------- 动画部分 -----------
 - (void)startAnimation
 {
     CALayer *layer = [[CALayer alloc] init];
     layer.cornerRadius = [UIScreen mainScreen].bounds.size.width/2;
     layer.frame = CGRectMake(0, 0, layer.cornerRadius * 2, layer.cornerRadius * 2);
     layer.position = CGPointMake([UIScreen mainScreen].bounds.size.width/2,[UIScreen mainScreen].bounds.size.height - 84);
     //    self.view.layer.position;
     UIColor *color = [UIColor colorWithRed:arc4random()%10*0.1 green:arc4random()%10*0.1 blue:arc4random()%10*0.1 alpha:1];
     layer.backgroundColor = color.CGColor;
     [self.view.layer addSublayer:layer];

     CAMediaTimingFunction *defaultCurve = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionDefault];

     _animaTionGroup = [CAAnimationGroup animation];
     _animaTionGroup.delegate = self;
     _animaTionGroup.duration = 2;
     _animaTionGroup.removedOnCompletion = YES;
     _animaTionGroup.timingFunction = defaultCurve;

     CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:@"transform.scale.xy"];
     scaleAnimation.fromValue = @0.0;
     scaleAnimation.toValue = @1.0;
     scaleAnimation.duration = 2;

     CAKeyframeAnimation *opencityAnimation = [CAKeyframeAnimation animationWithKeyPath:@"opacity"];
     opencityAnimation.duration = 2;
     opencityAnimation.values = @[@0.8,@0.4,@0];
     opencityAnimation.keyTimes = @[@0,@0.5,@1];
     opencityAnimation.removedOnCompletion = YES;

     NSArray *animations = @[scaleAnimation,opencityAnimation];
     _animaTionGroup.animations = animations;
     [layer addAnimation:_animaTionGroup forKey:nil];

     [self performSelector:@selector(removeLayer:) withObject:layer afterDelay:1.5];
 }

 - (void)removeLayer:(CALayer *)layer
 {
     [layer removeFromSuperlayer];
 }


 - (void)delayAnimation
 {
     [self startAnimation];
 }

完成以上操作，就大功告成了！

温馨提示：

1.由于是语音识别，需要用到麦克风相关权限，模拟器会爆12个错误，使用真机可以解决；

2.涉及到授权文件相关并不复杂，工程Bundle Identifier只需要设置百度的离线授权一致即可，如下图：

最终效果如下：