Question

我使用设备麦克风录制音频，其中AVAssetExportSession以 .caf 格式返回文件，该格式仅可在Apple设备上播放，但不能在Android设备上播放。由于Apple不支持 .mp3 文件，因此我希望在上传到服务器之前将其转换为 .mp4 格式。 .mp4 仅适用于音频吗？我可以使用func setupAudioRecorder () { let fileMgr = FileManager.default let dirPaths = fileMgr.urls(for:.documentDirectory, in:.userDomainMask) let soundFileURL = dirPaths[0].appendingPathComponent("myaudio.caf") let recordSettings = [AVEncoderAudioQualityKey: AVAudioQuality.min.rawValue, AVEncoderBitRateKey: 16, AVNumberOfChannelsKey: 2, AVSampleRateKey: 44100.0] as [String : Any] do { try audioSession.setCategory( AVAudioSessionCategoryPlayAndRecord) } catch let error as NSError { print("audioSession error: \(error.localizedDescription)") } do { try audioRecorder = AVAudioRecorder(url: soundFileURL, settings: recordSettings as [String : AnyObject]) audioRecorder?.prepareToRecord() } catch let error as NSError { print("audioSession error: \(error.localizedDescription)") } }转换它吗？

以下是录音机代码：

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Answer 1

经过大量搜索，我可以使用这段代码将 .caf 转换为 .mp4

    let audioURL = ".caf audio file url"

    let fileMgr = FileManager.default

    let dirPaths = fileMgr.urls(for: .documentDirectory,
                                in: .userDomainMask)

    let outputUrl = dirPaths[0].appendingPathComponent("audiosound.mp4")

    let asset = AVAsset.init(url: audioURL)

    let exportSession = AVAssetExportSession.init(asset: asset, presetName: AVAssetExportPresetHighestQuality)

    // remove file if already exits
    let fileManager = FileManager.default
    do{
        try? fileManager.removeItem(at: outputUrl)

    }catch{
        print("can't")
    }


    exportSession?.outputFileType = AVFileTypeMPEG4

    exportSession?.outputURL = outputUrl

    exportSession?.metadata = asset.metadata

    exportSession?.exportAsynchronously(completionHandler: {
        if (exportSession?.status == .completed)
        {
            print("AV export succeeded.")

           // outputUrl to post Audio on server

        }
        else if (exportSession?.status == .cancelled)
        {
            print("AV export cancelled.")
        }
        else
        {
            print ("Error is \(String(describing: exportSession?.error))")

        }
    })

Answer 2

您可以直接在MPEG4 AAC中录制而无需添加步骤进行转换。将AVFormatIDKey与kAudioFormatMPEG4AAC值一起使用，并将采样率降至8000或16000。

如何将.caf音频文件转换为swift中的.mp4文件

2 个答案: