文字识别

今天发现了一个很好玩的功能,语音识别和文字识别,这一篇文章先记录下文字识别.

AV Foundation中提供了一个AVSpeechSynthesizer类来向app中添加朗诵文本的功能.这个类用来播放一个或者多个语音内容,每条语音内容都是一个AVSpeechUtterance对象.(快速记忆:一个语音合成器(SpeechSynthesizer)播放需要一段语音内容(SpeechUtterance))

//首先导入框架
#import 
//遵守协议

//创建实例变量
@property (strong, nonatomic) AVSpeechSynthesizer *speech;
@property (strong, nonatomic) UIBarButtonItem *readItem;

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    //停止类型:迅速停止(也可以是念完整个单词后停止)
    [self.speech stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];
}
#pragma mark -     监听朗读状态
- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didStartSpeechUtterance:(AVSpeechUtterance *)utterance {
    //已经开始
}
- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didFinishSpeechUtterance:(AVSpeechUtterance *)utterance {
    //已经结束
}
- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didCancelSpeechUtterance:(AVSpeechUtterance *)utterance {
    //已经取消
}
- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didPauseSpeechUtterance:(AVSpeechUtterance *)utterance{
    //已经暂停
}
- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didContinueSpeechUtterance:(AVSpeechUtterance *)utterance{
    //已经继续
}
- (void)viewDidLoad {
    [super viewDidLoad];

    self.view.backgroundColor = [UIColor whiteColor];
    
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:@"暂停" style:UIBarButtonItemStyleDone target:self action:@selector(readAction:)];;
    
    
    //初始化一个语音合成器
    _speech = [[AVSpeechSynthesizer alloc] init];
    //设置代理
    _speech.delegate = self;
    
    ////创建被播放对象   (有多少个播放语句,就有多少个被播放对象 )
    AVSpeechUtterance *utt = [AVSpeechUtterance speechUtteranceWithString:@"静夜思,李白,床前明月光,疑是地上霜,举头望明月,低头思故乡--AVSpeechSynthesizer"];
    //设置语言类型
    utt.voice = [AVSpeechSynthesisVoice voiceWithLanguage:@"zh-CN"];
    //指定播放语音时的速率
    //最小值和最大值分别是    AVSpeechUtteranceMinimumSpeechRate和AVSpeechUtteranceMaximumSpeechRate,
    utt.rate = 0.4;
    //设置声调,属性值介于0.5(低音调)~2.0(高音调)之间
    utt.pitchMultiplier = 0.8;
    //告诉synthesizer本句朗读结束后要延迟多少秒再接着朗读下一秒
    utt.postUtteranceDelay = 0.3;
    [self.speech speakUtterance:utt];
    
    /*
     Arabic (ar-SA)
     Chinese (zh-CN, zh-HK, zh-TW)
     Czech (cs-CZ)
     Danish (da-DK)
     Dutch (nl-BE, nl-NL)
     English (en-AU, en-GB, en-IE, en-US, en-ZA)
     Finnish (fi-FI)
     French (fr-CA, fr-FR)
     German (de-DE)
     Greek (el-GR)
     Hebrew (he-IL)
     Hindi (hi-IN)
     Hungarian (hu-HU)
     Indonesian (id-ID)
     Italian (it-IT)
     Japanese (ja-JP)
     Korean (ko-KR)
     Norwegian (no-NO)
     Polish (pl-PL)
     Portuguese (pt-BR, pt-PT)
     Romanian (ro-RO)
     Russian (ru-RU)
     Slovak (sk-SK)
     Spanish (es-ES, es-MX)
     Swedish (sv-SE)
     Thai (th-TH)
     Turkish (tr-TR)
     */
}
-(void)readAction:(UIBarButtonItem *)sender{
    
    if (self.speech.speaking) {
        [self.speech pauseSpeakingAtBoundary:AVSpeechBoundaryWord];
        sender.title = @"读笑话";
    }
    if(self.speech.paused){
        [self.speech continueSpeaking];
        sender.title = @"暂停";
        
    }
}

如果想在后台播放, 需要在background modes配置里设置

AVAudioSession *se = [AVAudioSession sharedInstance];
[se setCategory:AVAudioSessionCategoryPlayback error:nil];
[se setActive:true error:nil];