Swift和音频录制

Question

我正在使用Swift构建iOS应用程序，客户返回了一个与音频录制有关的问题，基本上它没有记录任何东西。他在iPhone 5/5s上测试了iOS 9.x。检查了权限和手机空间是否足够，这些都不是问题。

我个人测试了iPhone 6s设备和iOS 10.x以及模拟器上的iPhone 5，录音正常工作。是否有人遇到过这样的问题，或者我做错了什么让我看不到错误。

添加注释到不同的函数说明应用程序的功能。

protocol RecordAndPlayManagerDelegate : class{
    func recorderDidStopRecording()
}

class RecordAndPlayManager: NSObject, AVAudioRecorderDelegate {
    var soundRecorder: AVAudioRecorder!
    let recordSettings = [
        AVFormatIDKey: Int(kAudioFormatMPEG4AAC),
        AVSampleRateKey: 12000,
        AVNumberOfChannelsKey: 1,
        AVEncoderAudioQualityKey: AVAudioQuality.high.rawValue
    ]
    class func directoryURL() -> URL? {
        let fileManager = FileManager.default
        let urls = fileManager.urls(for: .documentDirectory, in: .userDomainMask)
        let documentDirectory = urls[0] as URL
        let soundURL = documentDirectory.appendingPathComponent("recording.m4a")
        return soundURL
    }

    //calling this from outside to get the audio
    class func getLocalOrRemoteRecording(_ recordingID : String!) -> URL?{

        let fileManager = FileManager.default
        let urls = fileManager.urls(for: .documentDirectory, in: .userDomainMask)
        let documentDirectory = urls[0] as URL
        let soundURL = documentDirectory.appendingPathComponent(recordingID)

        if (fileManager.fileExists(atPath: soundURL.path)){
            return soundURL
        }

        let path = kBaseServerURLNOPORT + "data/" + recordingID
        let url = URL(string: path)

        return url

    }

    //called from outside, recordingID -> name of the file
    class func storeRecording(_ recordingID : String!) -> URL? {
        let fileManager = FileManager.default
        let urls = fileManager.urls(for: .documentDirectory, in: .userDomainMask)
        let documentDirectory = urls[0] as URL
        let soundURL = documentDirectory.appendingPathComponent("recording.m4a")

        let data = try? Data(contentsOf: soundURL)
        //data here has only 28bytes and from this I know it didn't record. In my tests, I always get at least 20000 bytes.

        let newSoundURL = documentDirectory.appendingPathComponent(recordingID)
        try? data?.write(to: newSoundURL, options: [.atomic])

        do {
            try  FileManager.default.removeItem(at: soundURL)
        } catch _ {
            print("failed to delete file")
            return newSoundURL
        }

        return newSoundURL
    }

    //called on viewDidLoad in another screen
    func setupRecorder() {
        let url = DRMessageRecordAndPlayManager.directoryURL()!
        do {
            try self.soundRecorder = AVAudioRecorder(url: url, settings: self.recordSettings)
        } catch _ {
            return
        }
        soundRecorder.delegate = self
        soundRecorder.prepareToRecord()
    }

    //calling this from outside to start recording
    func startRecording() {
        if !self.soundRecorder.isRecording {
            let audioSession = AVAudioSession.sharedInstance()
            do {
                try audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord)
                try audioSession.setActive(true)
                soundRecorder.record(forDuration: 15)
            } catch {
            }
        }
    }

    //called from outside when I hit stop
    func stopRecording() {

        self.soundRecorder.stop()
        let audioSession = AVAudioSession.sharedInstance()

        do {
            try audioSession.setActive(false)
        } catch {
        }
    }

    func audioRecorderDidFinishRecording(_ recorder: AVAudioRecorder, successfully flag: Bool) {
        self.delegate?.recorderDidStopRecording()
    }
}

- Adrian Coman

Answer 1

我猜测startRecording()中的catch按预期工作并防止崩溃，但您没有记录它。

我建议更改两个catch语句，像这样打印提供的错误对象：

catch {
    // or use an alert controller to display the error
    print("caught error: \(error)")
}

- Casey

Answer 2

这是一些关于在Objective C中进行音频录制的代码。

 NSMutableDictionary *recordSetting;

 NSString *recorderFilePath;

 AVAudioRecorder *recorder;

- (void) startRecording{


    AVAudioSession *audioSession = [AVAudioSession sharedInstance];

    NSError *err = nil;

    [audioSession setCategory :AVAudioSessionCategoryPlayAndRecord error:&err];

    if (err) {

        NSLog(@"audioSession: %@ %ld %@", [err domain], (long)[err code], [[err userInfo] description]);

        return;
    }

    [audioSession setActive:YES error:&err];

    err = nil;

    if (err) {

        NSLog(@"audioSession: %@ %ld %@", [err domain], (long)[err code], [[err userInfo] description]);

        return;
    }

    recordSetting = [[NSMutableDictionary alloc] init];

    [recordSetting setValue :[NSNumber numberWithInt:kAudioFormatLinearPCM] forKey:AVFormatIDKey];

    [recordSetting setValue:[NSNumber numberWithFloat:44100.0] forKey:AVSampleRateKey];

    [recordSetting setValue:[NSNumber numberWithInt: 2] forKey:AVNumberOfChannelsKey];

    [recordSetting setValue :[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];

    [recordSetting setValue :[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey];

    [recordSetting setValue :[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey];

    // Create a new dated file
    NSDate *now = [NSDate dateWithTimeIntervalSinceNow:0];

    NSString *caldate = [now description];

    recorderFilePath = [NSString stringWithFormat:@"%@/%@.caf", DOCUMENTS_FOLDER, caldate];

    NSURL *url = [NSURL fileURLWithPath:recorderFilePath];

    err = nil;

    recorder = [[ AVAudioRecorder alloc] initWithURL:url settings:recordSetting error:&err];

    if (!recorder) {

        NSLog(@"recorder: %@ %ld %@", [err domain], (long)[err code], [[err userInfo] description]);

        return;
    }

    //prepare to record
    [recorder setDelegate:self];

    [recorder prepareToRecord];

    recorder.meteringEnabled = YES;

    BOOL audioHWAvailable = audioSession.inputAvailable;

    if (!audioHWAvailable) {

        UIAlertController *alertController = [UIAlertController alertControllerWithTitle:NSLocalizedString(@"title_warning", nil) message:NSLocalizedString(@"recorder_warning_message", nil) preferredStyle:UIAlertControllerStyleAlert];

        UIAlertAction* ok = [UIAlertAction actionWithTitle:NSLocalizedString(@"ok_action", nil) style:UIAlertActionStyleDefault handler:nil];

        [alertController addAction:ok];

        [self presentViewController:alertController animated:YES completion:nil];

        return;

    } else {

        [recorder record];
    }
}

- Punit

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谢谢，但问题是关于Swift而不是Obj-C。 - Adrian Coman