ios - 如何将 .caf 文件转换为 .mp3 文件？

Question

我已经使用以下方法将一些声音录制到文档文件夹中

 func record() {
    self.prepareToRecord()
    if let recorder = self.audioRecorder {
        recorder.record()
    }
}

    let recordSettings = [
    AVSampleRateKey : NSNumber(float: Float(44100.0)),
    AVFormatIDKey : NSNumber(int: Int32(kAudioFormatAppleLossless)),
    AVNumberOfChannelsKey : NSNumber(int: 2),
    AVEncoderAudioQualityKey : NSNumber(int: Int32(AVAudioQuality.Medium.rawValue)),
    AVEncoderBitRateKey : NSNumber(int: Int32(320000))
]

    func prepareToRecord() {

    let documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as NSString
    let soundFileURL: NSURL? = NSURL.fileURLWithPath("\(documentsPath)/recording.caf")
    print("\(soundFileURL)")

    self.audioRecorder = try! AVAudioRecorder(URL: soundFileURL!, settings: recordSettings)

    if let recorder = self.audioRecorder {
        recorder.prepareToRecord()
    }
}

此方法会将音频文件作为 recording.caf 保存到文档目录中，但我想将此 recording.caf 文件转换为 mp3 以便进一步操作。

如何快速将此 .caf 文件转换为 .mp3？

Answer 1

AVAudioRecorder 不支持 mp3 编解码器因为版税可用编解码器列表:

k音频格式MPEG4AAC
kAudioFormatAppleLossless
kAudioFormatAppleIMA4
kAudioFormatiLBC
kAudioFormatULaw
kAudioFormatLinearPCM

您可以在此处找到详细信息 How do I record audio on iPhone with AVAudioRecorder?