TTS(Text To Speech 文本转语音缩写)
简介
涉及到AVFoundatio框架中的AVSpeechSynthesizer、AVSpeechUtterance、AVSpeechSynthesisVoice三个类，这三个类的声明都在AVSpeechSynthesis.h里，这三个类比较简单。
需要用到的一些枚举与宏
-
播放暂停时是立即停止播放语音还是播放完当前词再暂停。
typedef NS_ENUM(NSInteger, AVSpeechBoundary) { AVSpeechBoundaryImmediate, AVSpeechBoundaryWord } -
语音质量
typedef NS_ENUM(NSInteger, AVSpeechSynthesisVoiceQuality) { AVSpeechSynthesisVoiceQualityDefault = 1, AVSpeechSynthesisVoiceQualityEnhanced } -
速率
AVF_EXPORT const float AVSpeechUtteranceMinimumSpeechRate NS_AVAILABLE_IOS(7_0); AVF_EXPORT const float AVSpeechUtteranceMaximumSpeechRate NS_AVAILABLE_IOS(7_0); AVF_EXPORT const float AVSpeechUtteranceDefaultSpeechRate NS_AVAILABLE_IOS(7_0); -
注意：设置属性字符串时，AVSpeechSynthesisIPANotationAttribute的正确使用，最后会有Demo传送门
AVF_EXPORT NSString *const AVSpeechSynthesisIPANotationAttribute;
AVSpeechUtterance
要开始说话，请指定AVSpeechSynthesisVoice和要说出的字符串，然后根据需要随意更改速率，音高或音量。
四种初始化方法
+ (instancetype)speechUtteranceWithString:(NSString *)string;
+ (instancetype)speechUtteranceWithAttributedString:(NSAttributedString *)string API_AVAILABLE(ios(10.0), watchos(3.0), tvos(10.0));
- (instancetype)initWithString:(NSString *)string;
- (instancetype)initWithAttributedString:(NSAttributedString *)string API_AVAILABLE(ios(10.0), watchos(3.0), tvos(10.0));
通过以上创建出来的实例，其语音、语速、音调、音量都是默认的，可以通过属性进行定制，但是在入队后设置这些值将不起作用。其中rate的值应该介于AVSpeechUtteranceMinimumSpeechRate和AVSpeechUtteranceMaximumSpeechRate之间
@property(nonatomic, retain, nullable) AVSpeechSynthesisVoice *voice;
@property(nonatomic) float rate;
@property(nonatomic) float pitchMultiplier; // [0.5 - 2] Default = 1
@property(nonatomic) float volume; // [0-1] Default = 1
@property(nonatomic) NSTimeInterval preUtteranceDelay; // Default is 0.0
@property(nonatomic) NSTimeInterval postUtteranceDelay; // Default is 0.0
有两个属性可以获得当前播放的字符串或属性字符串
@property(nonatomic, readonly) NSString *speechString;
@property(nonatomic, readonly) NSAttributedString *attributedSpeechString
AVSpeechSynthesisVoice
通过指定应该在其中说出文本的语言代码来检索语音，或者通过使用voiceWithIdentifier来获取已知语音标识符。
现支持的语音语言37种,可以用类方法speechVoices获取
+ (NSArray *)speechVoices;
| language | name | quality | identifier |
|---|---|---|---|
| ar-SA | Maged | Default | com.apple.ttsbundle.Maged-compact |
| cs-CZ | Zuzana | 同上 | com.apple.ttsbundle.Zuzana-compact |
| ar-SA | Maged | 同上 | com.apple.ttsbundle.Maged-compact |
| cs-CZ | Zuzana | 同上 | com.apple.ttsbundle.Zuzana-compact |
| da-DK | Sara | 同上 | com.apple.ttsbundle.Sara-compact |
| de-DE | Anna | 同上 | com.apple.ttsbundle.Anna-compact |
| el-GR | Melina | 同上 | com.apple.ttsbundle.Melina-compact |
| en-AU | Karen | 同上 | com.apple.ttsbundle.Karen-compact |
| en-GB | Daniel | 同上 | com.apple.ttsbundle.Daniel-compact |
| en-IE | Moira | 同上 | com.apple.ttsbundle.Moira-compact |
| en-US | Samantha | 同上 | com.apple.ttsbundle.Samantha-compact |
| en-ZA | Tessa | 同上 | com.apple.ttsbundle.Tessa-compact |
| es-ES | Monica | 同上 | com.apple.ttsbundle.Monica-compact |
| es-MX | Paulina | 同上 | com.apple.ttsbundle.Paulina-compact |
| fi-FI | Satu | 同上 | com.apple.ttsbundle.Satu-compact |
| fr-CA | Amelie | 同上 | com.apple.ttsbundle.Amelie-compact |
| fr-FR | Thomas | 同上 | com.apple.ttsbundle.Thomas-compact |
| he-IL | Carmit | 同上 | com.apple.ttsbundle.Carmit-compact |
| hi-IN | Lekha | 同上 | com.apple.ttsbundle.Lekha-compact |
| hu-HU | Mariska | 同上 | com.apple.ttsbundle.Mariska-compact |
| id-ID | Damayanti | 同上 | com.apple.ttsbundle.Damayanti-compact |
| it-IT | Alice | 同上 | com.apple.ttsbundle.Alice-compact |
| ja-JP | Kyoko | 同上 | com.apple.ttsbundle.Kyoko-compact |
| ko-KR | Yuna | 同上 | com.apple.ttsbundle.Yuna-compact |
| nl-BE | Ellen | 同上 | com.apple.ttsbundle.Ellen-compact |
| nl-NL | Xander | 同上 | com.apple.ttsbundle.Xander-compact |
| no-NO | Nora | 同上 | com.apple.ttsbundle.Nora-compact |
| pl-PL | Zosia | 同上 | com.apple.ttsbundle.Zosia-compact |
| pt-BR | Luciana | 同上 | com.apple.ttsbundle.Luciana-compact |
| pt-PT | Joana | 同上 | com.apple.ttsbundle.Joana-compact |
| ro-RO | Ioana | 同上 | com.apple.ttsbundle.Ioana-compact |
| ru-RU | Milena | 同上 | com.apple.ttsbundle.Milena-compact |
| sk-SK | Laura | 同上 | com.apple.ttsbundle.Laura-compact |
| sv-SE | Alva | 同上 | com.apple.ttsbundle.Alva-compact |
| th-TH | Kanya | 同上 | com.apple.ttsbundle.Kanya-compact |
| tr-TR | Yelda | 同上 | com.apple.ttsbundle.Yelda-compact |
| zh-CN | Ting-Ting | 同上 | com.apple.ttsbundle.Ting-Ting-compact |
| zh-HK | Sin-Ji | 同上 | com.apple.ttsbundle.Sin-Ji-compact |
| zh-TW | Mei-Jia | 同上 | com.apple.ttsbundle.Mei-Jia-compact |
获取设备当前语言语音码
+ (NSString *)currentLanguageCode;
根据指定的语言语音码获取语音
+ (nullable AVSpeechSynthesisVoice *)voiceWithLanguage:(nullable NSString *)languageCode;
根据指定的语言语音标识码获取语音 iOS9.0之后可用
+ (nullable AVSpeechSynthesisVoice *)voiceWithIdentifier:(NSString *)identifier NS_AVAILABLE_IOS(9_0);
获取某个语音的信息，只读
@property(nonatomic, readonly) NSString *language;
@property(nonatomic, readonly) NSString *identifier NS_AVAILABLE_IOS(9_0);
@property(nonatomic, readonly) NSString *name NS_AVAILABLE_IOS(9_0);
@property(nonatomic, readonly) AVSpeechSynthesisVoiceQuality quality NS_AVAILABLE_IOS(9_0);
AVSpeechSynthesizer
合成器
是否正在播放、暂停
@property(nonatomic, readonly, getter=isSpeaking) BOOL speaking;
@property(nonatomic, readonly, getter=isPaused) BOOL paused;
将已加入或正在讲话的相同AVSpeechUtterance加入会引发异常。
- (void)speakUtterance:(AVSpeechUtterance *)utterance;
以下方法只对正在讲话的语音进行操作才有效。 如果成功则返回YES，失败则返回NO。
- (BOOL)stopSpeakingAtBoundary:(AVSpeechBoundary)boundary;
- (BOOL)pauseSpeakingAtBoundary:(AVSpeechBoundary)boundary;
- (BOOL)continueSpeaking;
指定要用于合成语音的音频通道，如AVAudioSession当前路径中的通道描述所述。
语音音频将复制到每个指定的频道。默认值为nil，表示系统默认值。
@property(nonatomic, retain, nullable) NSArray *outputChannels;
学习资源
#import "ViewController.h"
#import
@interface ViewController ()
@property(nonatomic, strong) AVSpeechSynthesizer *speechSynthesizer;
@property(nonatomic, strong) AVSpeechUtterance *utterance;
@property(nonatomic, strong) UILabel *label;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.speechSynthesizer = [[AVSpeechSynthesizer alloc] init];
[self commonInit];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)commonInit {
UISwitch *senderSwitch = [[UISwitch alloc] init];
senderSwitch.on = YES;
senderSwitch.frame = CGRectMake(0, 0, 100, 20);
senderSwitch.center = self.view.center;
[senderSwitch addTarget:self action:@selector(updateUtterance:) forControlEvents:UIControlEventValueChanged];
[self.view addSubview:senderSwitch];
self.label = [[UILabel alloc] initWithFrame:CGRectMake((self.view.bounds.size.width - 200)/2.0f, CGRectGetMaxY(senderSwitch.frame) - 80, 200, 20)];
self.label.textAlignment = NSTextAlignmentCenter;
[self.view addSubview:self.label];
UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
btn.frame = CGRectMake((self.view.bounds.size.width - 128)/2.0f, CGRectGetMaxY(senderSwitch.frame) + 20, 128, 128);
[btn setImage:[UIImage imageNamed:@"audio"] forState:UIControlStateNormal];
[btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn];
[self updateUtterance:senderSwitch];
}
- (void)updateUtterance:(UISwitch *)sender {
sender.on = !sender.isOn;
if (sender.on) {
NSMutableAttributedString *attString = [[NSMutableAttributedString alloc] initWithString:@"Tsutsumi"];
// 这里的国际音标可以随意修改 eg:"tən.tən.mə" "tən.mə" ... 可以多试试其他的情况
[attString addAttribute:AVSpeechSynthesisIPANotationAttribute value:@"tən.tən.mi" range:NSMakeRange(0, attString.length)];
self.utterance = [AVSpeechUtterance speechUtteranceWithAttributedString:attString];
self.label.text = @"Tsutsumi(Attributed)";
} else {
self.utterance = [AVSpeechUtterance speechUtteranceWithString:@"Tsutsumi"];
self.label.text = @"Tsutsumi";
}
}
- (void)btnClick:(UIButton *)sender {
if (self.speechSynthesizer.isSpeaking) {
NSLog(@"正在朗读中....");
return;
}
[self.speechSynthesizer speakUtterance:self.utterance];
}
@end
想看Demo的同学请移驾-->TTS