iOS中 语音识别功能／语音转文字教程具体解释 韩俊强的博客

原文地址：http://blog.****.net/qq_31810357/article/details/51111702

前言：近期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，讯飞毫无疑问比較专业。识别率也非常高真对语音识别是比較精准的，可是非常多开发人员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。两者都能够申请高配额，针对用户较多的差点儿都一样。

基于免费而且支持离线我选择了百度离线语音识别。比較简单，UI设计多一点，以下写一下教程：

1.首先：须要的库

2.我是自己定义的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.须要知道的功能：能用到的例如以下：

//－－－－－－－－－－－－－－－－－－－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－－－－－－－－－－－－－－－－－－－－－－－
// 推断能否够录音
- (BOOL)isCanRecorder;

// 開始语音识别，须要实现MVoiceRecognitionClientDelegate代理方法。并传入实现对像监听事件
// 返回值參考 TVoiceRecognitionStartWorkResult
- (int)startVoiceRecognition:(id<MVoiceRecognitionClientDelegate>)aDelegate;

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

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

/**
 * @brief 获取当前识别的採样率
 *
 * @return 採样率(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
// 能够识别类型复合
- (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。默觉得播放,录音開始，录音结束提示音
// BDVoiceRecognitionClientResources/Tone
// record_start.caf   录音開始声音文件
// record_end.caf     录音结束声音文件
// 声音资源须要加到项目project里。用户可替换资源文件，文件名称不能够变，建音提示音不宜过长，0。5秒左右。
// aTone 取值參考 TVoiceRecognitionPlayTones，如没有找到文件。则返回ＮＯ
- (BOOL)setPlayTone:(int)aTone isPlay:(BOOL)aIsPlay;

4.录音button相关动画（我自己定义的，大家能够借鉴）

// 录音button相关
@property (nonatomic, weak, readonly) UIButton *holdDownButton;// 说话button
/**
 *  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button被按下所触发的事件，这时候是開始录音
 */
- (void)holdDownButtonTouchDown;

/**
 *  当手指在录音button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button范围之内离开屏幕所触发的事件，这时候是完毕录音
 */
- (void)holdDownButtonTouchUpInside;

/**
 *  当手指滑动到录音button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

/**
 *  依据正常显示和高亮状态创建一个button对象
 *
 *  @param image   正常显示图
 *  @param hlImage 高亮显示图
 *
 *  @return 返回button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中显示具体错误信息
- (void)createRunLogWithStatus:(int)aStatus; // 在状态view中显示具体状态信息

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

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

6.最重要的部分

// 录音完毕
 [[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: // 识别正常完毕并获得结果
        {
			[self createRunLogWithStatus:aStatus];

            if ([[BDVoiceRecognitionClient sharedInstance] getRecognitionProperty] != EVoiceRecognitionPropertyInput)
            {
                //  搜索模式下的结果为数组，演示样例为
                // ["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:
        {
            // 此状态仅仅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，示比例如以下：
            //  [
            //      [
            //         {
            //             "百度" = "0.6055192947387695";
            //         },
            //         {
            //             "摆渡" = "0.3625582158565521";
            //         },
            //      ]
            //      [
            //         {
            //             "一下" = "0.7665404081344604";
            //         }
            //      ],
            //   ]
//临时关掉 -- 否则影响跳转结果
//            NSString *tmpString = [[BDVRSConfig sharedInstance] composeInputModeResult:aObj];
//            [clientSampleViewController logOutToContinusManualResut:tmpString];

            break;
        }
        case EVoiceRecognitionClientWorkStatusEnd: // 用户说话完毕，等待server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: // 识别库開始识别工作，用户能够说话
        {
            if ([BDVRSConfig sharedInstance].playStartMusicSwitch) // 假设播放了提示音。此时再给用户提示能够说话
            {
                [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button的一些操作

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

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

 // 開始语音识别功能，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 {

    //假设已經開始錄音了, 才须要做拖曳出去的動作, 否則仅仅要切換 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];
}

完毕以上操作，就大功告成了！

温馨提示：

1.因为是语音识别，须要用到麦克风相关权限。模拟器会爆12个错误。使用真机能够解决；

2.涉及到授权文件相关并不复杂，projectBundle Identifier仅仅须要设置百度的离线授权一致就可以。例如以下图：

终于效果例如以下：

有不懂或不明确的地方能够微博联系我：

iOS开发人员交流群：446310206