Question

我想使用iOS Speech框架在Objective-C应用程序中进行语音识别。

我找到了一些Swift示例但是还没有能够在Objective-C中找到任何东西。

是否可以从Objective-C访问此框架？如果是这样，怎么样？

Answer 1

花了足够的时间寻找Objective-C样本 - 即使在Apple文档中 - 我也找不到任何体面的东西，所以我自己想出来了。

头文件（.h）

/*!
 * Import the Speech framework, assign the Delegate and declare variables
 */

#import <Speech/Speech.h>

@interface ViewController : UIViewController <SFSpeechRecognizerDelegate> {
    SFSpeechRecognizer *speechRecognizer;
    SFSpeechAudioBufferRecognitionRequest *recognitionRequest;
    SFSpeechRecognitionTask *recognitionTask;
    AVAudioEngine *audioEngine;
}

方法文件（.m）

- (void)viewDidLoad {
    [super viewDidLoad];

    // Initialize the Speech Recognizer with the locale, couldn't find a list of locales
    // but I assume it's standard UTF-8 https://wiki.archlinux.org/index.php/locale
    speechRecognizer = [[SFSpeechRecognizer alloc] initWithLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US"]];

    // Set speech recognizer delegate
    speechRecognizer.delegate = self;

    // Request the authorization to make sure the user is asked for permission so you can
    // get an authorized response, also remember to change the .plist file, check the repo's
    // readme file or this project's info.plist
    [SFSpeechRecognizer requestAuthorization:^(SFSpeechRecognizerAuthorizationStatus status) {
        switch (status) {
            case SFSpeechRecognizerAuthorizationStatusAuthorized:
                NSLog(@"Authorized");
                break;
            case SFSpeechRecognizerAuthorizationStatusDenied:
                NSLog(@"Denied");
                break;
            case SFSpeechRecognizerAuthorizationStatusNotDetermined:
                NSLog(@"Not Determined");
                break;
            case SFSpeechRecognizerAuthorizationStatusRestricted:
                NSLog(@"Restricted");
                break;
            default:
                break;
        }
    }];

}

/*!
 * @brief Starts listening and recognizing user input through the 
 * phone's microphone
 */

- (void)startListening {

    // Initialize the AVAudioEngine
    audioEngine = [[AVAudioEngine alloc] init];

    // Make sure there's not a recognition task already running
    if (recognitionTask) {
        [recognitionTask cancel];
        recognitionTask = nil;
    }

    // Starts an AVAudio Session
    NSError *error;
    AVAudioSession *audioSession = [AVAudioSession sharedInstance];
    [audioSession setCategory:AVAudioSessionCategoryRecord error:&error];
    [audioSession setActive:YES withOptions:AVAudioSessionSetActiveOptionNotifyOthersOnDeactivation error:&error];

    // Starts a recognition process, in the block it logs the input or stops the audio
    // process if there's an error.
    recognitionRequest = [[SFSpeechAudioBufferRecognitionRequest alloc] init];
    AVAudioInputNode *inputNode = audioEngine.inputNode;
    recognitionRequest.shouldReportPartialResults = YES;
    recognitionTask = [speechRecognizer recognitionTaskWithRequest:recognitionRequest resultHandler:^(SFSpeechRecognitionResult * _Nullable result, NSError * _Nullable error) {
        BOOL isFinal = NO;
        if (result) {
            // Whatever you say in the microphone after pressing the button should be being logged
            // in the console.
            NSLog(@"RESULT:%@",result.bestTranscription.formattedString);
            isFinal = !result.isFinal;
        }
        if (error) {
            [audioEngine stop];
            [inputNode removeTapOnBus:0];
            recognitionRequest = nil;
            recognitionTask = nil;
        }
    }];

    // Sets the recording format
    AVAudioFormat *recordingFormat = [inputNode outputFormatForBus:0];
    [inputNode installTapOnBus:0 bufferSize:1024 format:recordingFormat block:^(AVAudioPCMBuffer * _Nonnull buffer, AVAudioTime * _Nonnull when) {
        [recognitionRequest appendAudioPCMBuffer:buffer];
    }];

    // Starts the audio engine, i.e. it starts listening.
    [audioEngine prepare];
    [audioEngine startAndReturnError:&error];
    NSLog(@"Say Something, I'm listening"); 
}

- (IBAction)microPhoneTapped:(id)sender {
    if (audioEngine.isRunning) {
        [audioEngine stop];
        [recognitionRequest endAudio];
    } else {
        [self startListening];
    }
}

现在，添加代理SFSpeechRecognizerDelegate以检查语音识别器是否可用。

#pragma mark - SFSpeechRecognizerDelegate Delegate Methods

- (void)speechRecognizer:(SFSpeechRecognizer *)speechRecognizer availabilityDidChange:(BOOL)available {
    NSLog(@"Availability:%d",available);
}

说明＆amp;备注

请记住修改.plist文件以获取用户对语音识别的授权并使用麦克风，当然<String>值必须根据您的需要进行自定义，您可以通过创建和修改Property List中的值或右键单击.plist文件和Open As - ＆gt; Source Code并在</dict>代码前粘贴以下行。

<key>NSMicrophoneUsageDescription</key>  <string>This app uses your microphone to record what you say, so watch what you say!</string>

<key>NSSpeechRecognitionUsageDescription</key>  <string>This app uses Speech recognition to transform your spoken words into text and then analyze the, so watch what you say!.</string>

还要记住，为了能够将Speech框架导入到项目中，您需要拥有iOS 10.0 +。

要让它运行并进行测试，你只需要一个非常基本的用户界面，只需创建一个UIButton并为其分配microPhoneTapped动作，按下该应用程序应该开始监听并记录它通过麦克风听到的所有内容到控制台（在示例代码中NSLog是唯一接收文本的东西）。它应该在再次按下时停止录制。

我创建了一个带有示例项目的Github repo，享受！

如何通过语音框架实现语音到文本

1 个答案:

头文件（.h）

方法文件（.m）

说明＆amp;备注