我可以让 AudioKit appendAsynchronously 创建一个名称不是“.caf”的文件，并以 .mp4 格式输出吗？

Question

我在iOS下有如下AudioKit使用场景：

我用麦克风录音。
我将声音异步保存到 tmp 目录作为 .mp4 文件。
我从麦克风录制第二个声音。
我尝试 (a) 检索以前保存的 .mp4 文件，以及 (b) 异步附加第二个麦克风声音。

我的问题是，虽然此过程确实成功，但附加文件以文件名“.caf”保存（字面意思就是这样，扩展名前没有任何内容）。

理想情况下，我希望通过某种方式强制附加文件具有更易于管理的名称。如果附加文件可以是.mp4格式也很好。

以下代码足以重现问题：

导入 SwiftUI 导入 AudioKit

构造 ContentView：视图 {

@State private var mic: AKMicrophone!
@State private var micBooster: AKBooster!
@State private var micRecorder: AKNodeRecorder! 

var body: some View {
    Button(action: {
        self.recordFirstSound()
    }) {
        Text("Start")
    }
}


func recordFirstSound() {
    
    AKAudioFile.cleanTempDirectory()
    AKSettings.audioInputEnabled = true
    AKSettings.defaultToSpeaker = true
    do {
        try AKSettings.setSession(category: .multiRoute)
    } catch {
        print("Failed to set session category to .playAndRecord");
    }
    AKSettings.bufferLength = .medium
    mic = AKMicrophone()
    micBooster = AKBooster()
    mic >>> micBooster
    micBooster.gain = 0.0
    
    do {
        micRecorder = try AKNodeRecorder(node: mic)
    } catch {
        print("Failed to initialise micRecorder")
    }
    
    AudioKit.output = micBooster
    do {
        try AudioKit.start()
    } catch {
        print("Failed to start AudioKit")
    }
    
    do {
        try micRecorder.record()
    } catch {
        print("Failed to start micRecorder")
    }
    
    DispatchQueue.main.asyncAfter(deadline: .now() + 5 , execute: {
        self.writeRecordingToTmpDir()
    })
}

func writeRecordingToTmpDir() {
    
    micRecorder.stop()
    if let recorderAudioFile = micRecorder.audioFile {
        recorderAudioFile.exportAsynchronously(name: "recording",
                                               baseDir: .temp,
                                               exportFormat: .mp4, callback: callbackAfterInitialExport)
    } else {
        print("Problem accessing micRecorder audioFile")
    }
    
    DispatchQueue.main.asyncAfter(deadline: .now() + 5 , execute: {
        self.recordSecondSound()
    })
}

func recordSecondSound() {
    do {
        try micRecorder.reset()
    } catch {
        print("Failed to reset micRecorder")
    }

    do {
        try micRecorder.record()
    } catch {
        print("Failed to re-start micRecorder")
    }
    
    DispatchQueue.main.asyncAfter(deadline: .now() + 5 , execute: {
        self.appendSecondSoundFileToFirstAsynchronously()
    })
}


func appendSecondSoundFileToFirstAsynchronously() {
    micRecorder.stop()
    do {
        let existingMp4File = try AKAudioFile(readFileName: "recording.mp4", baseDir: .temp)
        if let micRecorderAudioFile = micRecorder.audioFile {
            existingMp4File.appendAsynchronously(file: micRecorderAudioFile, completionHandler: callbackAfterAsynchronousAppend)
        }
    } catch {
        print("Failed to read or append recording.mp4")
    }
}


func callbackAfterInitialExport(processedFile: AKAudioFile?, error: NSError?) {
    if let file = processedFile {
        print("Asynchronous export of \(file.fileNamePlusExtension) succeeded")
        print("Exported file duration: \(file.duration) seconds")
    } else {
        print("Asynchronous export failed")
    }
}

func callbackAfterAsynchronousAppend(processedFile: AKAudioFile?, error: NSError?) {
    
    if let file = processedFile {
        print("Asynchronous append succeeded. New file is \(file.fileNamePlusExtension)")
        print("Duration of new file: \(file.duration) seconds")
    } else {
        print("Asynchronous append failed")
    }
}

}

Answer 1

没有为 appendAsynchronously 调用填充适当的参数。调用应该是：

如果让 micRecorderAudioFile = micRecorder.audioFile { existingMp4File.appendAsynchronously（文件：micRecorderAudioFile，baseDir：.temp，名称：“录音”，completionHandler：callbackAfterAsynchronousAppend） }

我可以让 AudioKit appendAsynchronously 创建一个名称不是“.caf”的文件，并以 .mp4 格式输出吗？

Can I get AudioKit appendAsynchronously to create a file with name other than '.caf', and to output in .mp4 format?

audiokit