AVAudioRecorder从不记录

Question

我正在用AVAudioRecorder记录人类的声音。我的代码如下：

// Property of Class
var recorder:AVAudioRecorder?

func recordButtonTapped() {
    let audioSession = AVAudioSession.sharedInstance()
    do {
        try audioSession.setCategory(AVAudioSessionCategoryRecord)
        try audioSession.setActive(true)
        if audioSession.recordPermission() != .granted {
            audioSession.requestRecordPermission({ (success) in
                self.startRecording()
            })
        }
        else {
            self.startRecording()
        }

    } catch {
        print("Unable To Set Category")
    }
}

func startRecording() {
    // libraryPathWith(media) just gets the path to the documents directory
    // Like so: Documents/MediaLibrary/Audio/<mediaID>.<mediaExtension>
    if let path = MMFileManager.libraryPathWith(media: self.media) {
        isRecording = true
        do {
            let settings = [
                AVFormatIDKey: Int(kAudioFormatMPEG4AAC),
                AVSampleRateKey: 44100,
                AVNumberOfChannelsKey: 1,
                AVEncoderAudioQualityKey: AVAudioQuality.high.rawValue
            ]

            recorder = try AVAudioRecorder(url: path, settings: settings)

            recorder?.delegate = self

            if recorder!.prepareToRecord() {
                recorder?.record()
            }
        }
        catch {
            isRecording = false
        }
    }
}

func stopRecording() {
    self.recordingLabel.text = "Recording Complete"
    self.recordingLabel.textColor = UIColor.white
    if let rec = recorder {
        rec.stop()
        recorder = nil
    }
    isRecording = false
}

AVAudioRecorderDelegate

func audioRecorderDidFinishRecording(_ recorder: AVAudioRecorder, successfully flag: Bool) {
    print("RECORDED AUDIO SUCCESSFULLY \(flag)")
}
func audioRecorderEncodeErrorDidOccur(_ recorder: AVAudioRecorder, error: Error?) {
    print("AUDIO RECORDER ERROR \(error?.localizedDescription)")
}

在AVAudioRecorder上调用stop之后，audioRecorderEncodeErrorDidOccur函数永远不会被调用，但是audioRecorderDidFinishRecording函数会调用，但是flag总是false。它打印出"RECORDED AUDIO SUCCESSFULLY false"

问题

当我使用上面的代码进行记录时，我会将一个文件保存到指定位置的文档目录中。但这份文件不是我能播放的。它写入文本文件，而不是音频文件，因为我指定扩展名为.aac。

为什么AVAudioRecorder不记录音频？我怎样才能让它这么做？

Answer 1

问题在于stopRecording()函数中的行。在调用stop() (记录器)下面，我立即将AVAudioRecorder实例分配给nil。在完成后处理以创建真实的AVAudioRecorder文件之前，此文件将释放并结束该.aac。

Answer 2

我就是这么做的，第一次进口

AVFoundation

并将AVAudioRecorderDelegate添加到ViewController中：

class RecordViewController: UIViewController, AVAudioRecorderDelegate

然后创建AVAudioRecorder的全局实例：

var audioRecorder : AVAudioRecorder!

然后，我创建了一个开始录制的记录按钮：

@IBAction func playButton(_ sender: Any) {

    let dirPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as String
    let recordingName = "voiceRecording.wav"
    let pathArray = [dirPath, recordingName]
    let filePath = URL(string: pathArray.joined(separator: "/"))

    let session = AVAudioSession.sharedInstance()
    try! session.setCategory(AVAudioSessionCategoryPlayAndRecord, with: .defaultToSpeaker)

    try! audioRecorder = AVAudioRecorder(url: filePath!, settings: [:])
    audioRecorder.delegate = self
    audioRecorder.isMeteringEnabled = true
    audioRecorder.prepareToRecord()
    audioRecorder.record()
}

dirPath找到存储图像的目录。

recordingName将设置实际记录文件的名称。

filepath将目录和recordingName组合为最终位置

其余的几乎是不言自明的。

然后创建一个更简单的暂停按钮：

@IBAction func pauseButton(_ sender: Any) {

    audioRecorder.stop()
    let audioSession = AVAudioSession.sharedInstance()
    try! audioSession.setActive(false)
}

这应该可以解决你如何录制音频。

Answer 3

如果您已经验证了您的url有"aac“扩展，那么我怀疑您只是忘了在您的记录器上调用stop()。这将导致一个未最后定稿的文件。

还在catch块中打印错误。

do{
    try throwingFunc()
} catch {
    print(error)
}