同时录制音频和播放声音 - C# - Windows Phone 8.1

Question

我正在尝试录制音频并直接播放（我想在耳机中听到我的声音而不保存它）但是 MediaElement 和 MediaCapture 似乎无法同时工作。我这样初始化我的 MediaCapture：

    _mediaCaptureManager = new MediaCapture();
    var settings = new MediaCaptureInitializationSettings();
    settings.StreamingCaptureMode = StreamingCaptureMode.Audio;
    settings.MediaCategory = MediaCategory.Other;
    settings.AudioProcessing = AudioProcessing.Default;
    await _mediaCaptureManager.InitializeAsync(settings);

但是我真的不知道如何进行；我想知道这些方法中的一种是否可行（我尝试实施它们但没有成功，而且我还没有找到示例）：

有没有办法使用 StartPreviewAsync() 录制音频，或者它只适用于视频？我注意到在设置我的 CaptureElement 源时出现以下错误："The specified object or value does not exist"；只有当我写 "settings.StreamingCaptureMode = StreamingCaptureMode.Audio;" 而 everyting 为 .Video.
如何使用 StartRecordToStreamAsync() 录制到流中；我的意思是，我如何初始化 IRandomAccessStream 并从中读取？我可以在流中写入的同时保持读取吗？

我读到将 MediaElement 的 AudioCathegory 和 MediaCapture 的 MediaCathegory 更改为 Communication 有可能会起作用。然而，虽然我的代码可以使用之前的设置工作（它只需要记录并保存在一个文件中），但如果我写 "settings.MediaCategory = MediaCategory.Communication;" 而不是 "settings.MediaCategory = MediaCategory.Other;"，它就不会工作。你能告诉我为什么吗？这是我当前的程序，只记录、保存和播放：

private async void CaptureAudio()
{
    try
    {
       _recordStorageFile = await KnownFolders.VideosLibrary.CreateFileAsync(fileName, CreationCollisionOption.GenerateUniqueName);                      
      MediaEncodingProfile recordProfile = MediaEncodingProfile.CreateWav(AudioEncodingQuality.Auto);
      await _mediaCaptureManager.StartRecordToStorageFileAsync(recordProfile, this._recordStorageFile);
      _recording = true;
     }
     catch (Exception e)
     {
        Debug.WriteLine("Failed to capture audio:"+e.Message);
     }
}

private async void StopCapture()
{
   if (_recording)
   {
      await _mediaCaptureManager.StopRecordAsync();
      _recording = false;
   }
}

private async void PlayRecordedCapture()
{
   if (!_recording)
   {
      var stream = await   _recordStorageFile.OpenAsync(FileAccessMode.Read);
      playbackElement1.AutoPlay = true;
      playbackElement1.SetSource(stream, _recordStorageFile.FileType);
      playbackElement1.Play();
   }
}

如果您有任何建议，我将不胜感激。祝你有个美好的一天。

Answer 1

您会考虑改为定位 Windows 10 吗？新的 AudioGraph API 允许您做到这一点，并且 Scenario 2 (Device Capture) in the SDK sample 很好地演示了它。

首先，示例将所有输出设备填充到一个列表中：

private async Task PopulateDeviceList()
{
    outputDevicesListBox.Items.Clear();
    outputDevices = await DeviceInformation.FindAllAsync(MediaDevice.GetAudioRenderSelector());
    outputDevicesListBox.Items.Add("-- Pick output device --");
    foreach (var device in outputDevices)
    {
        outputDevicesListBox.Items.Add(device.Name);
    }
}

然后开始构建 AudioGraph：

AudioGraphSettings settings = new AudioGraphSettings(AudioRenderCategory.Media);
settings.QuantumSizeSelectionMode = QuantumSizeSelectionMode.LowestLatency;

// Use the selected device from the outputDevicesListBox to preview the recording
settings.PrimaryRenderDevice = outputDevices[outputDevicesListBox.SelectedIndex - 1];

CreateAudioGraphResult result = await AudioGraph.CreateAsync(settings);

if (result.Status != AudioGraphCreationStatus.Success)
{
    // TODO: Cannot create graph, propagate error message
    return;
}

AudioGraph graph = result.Graph;

// Create a device output node
CreateAudioDeviceOutputNodeResult deviceOutputNodeResult = await graph.CreateDeviceOutputNodeAsync();
if (deviceOutputNodeResult.Status != AudioDeviceNodeCreationStatus.Success)
{
    // TODO: Cannot create device output node, propagate error message
    return;
}

deviceOutputNode = deviceOutputNodeResult.DeviceOutputNode;

// Create a device input node using the default audio input device
CreateAudioDeviceInputNodeResult deviceInputNodeResult = await graph.CreateDeviceInputNodeAsync(MediaCategory.Other);

if (deviceInputNodeResult.Status != AudioDeviceNodeCreationStatus.Success)
{
    // TODO: Cannot create device input node, propagate error message
    return;
}

deviceInputNode = deviceInputNodeResult.DeviceInputNode;

// Because we are using lowest latency setting, we need to handle device disconnection errors
graph.UnrecoverableErrorOccurred += Graph_UnrecoverableErrorOccurred;

// Start setting up the output file
FileSavePicker saveFilePicker = new FileSavePicker();
saveFilePicker.FileTypeChoices.Add("Pulse Code Modulation", new List<string>() { ".wav" });
saveFilePicker.FileTypeChoices.Add("Windows Media Audio", new List<string>() { ".wma" });
saveFilePicker.FileTypeChoices.Add("MPEG Audio Layer-3", new List<string>() { ".mp3" });
saveFilePicker.SuggestedFileName = "New Audio Track";
StorageFile file = await saveFilePicker.PickSaveFileAsync();

// File can be null if cancel is hit in the file picker
if (file == null)
{
    return;
}

MediaEncodingProfile fileProfile = CreateMediaEncodingProfile(file);

// Operate node at the graph format, but save file at the specified format
CreateAudioFileOutputNodeResult fileOutputNodeResult = await graph.CreateFileOutputNodeAsync(file, fileProfile);

if (fileOutputNodeResult.Status != AudioFileNodeCreationStatus.Success)
{
    // TODO: FileOutputNode creation failed, propagate error message
    return;
}

fileOutputNode = fileOutputNodeResult.FileOutputNode;

// Connect the input node to both output nodes
deviceInputNode.AddOutgoingConnection(fileOutputNode);
deviceInputNode.AddOutgoingConnection(deviceOutputNode);

完成所有这些后，您可以录制到文件，同时播放录制的音频，如下所示：

private async Task ToggleRecordStop()
{
    if (recordStopButton.Content.Equals("Record"))
    {
        graph.Start();
        recordStopButton.Content = "Stop";
    }
    else if (recordStopButton.Content.Equals("Stop"))
    {
        // Good idea to stop the graph to avoid data loss
        graph.Stop();
        TranscodeFailureReason finalizeResult = await fileOutputNode.FinalizeAsync();
        if (finalizeResult != TranscodeFailureReason.None)
        {
            // TODO: Finalization of file failed. Check result code to see why, propagate error message
            return;
        }

        recordStopButton.Content = "Record";
    }
}

同时录制音频和播放声音 - C# - Windows Phone 8.1

Recording Audio and Playing sound at the same time - C# - Windows Phone 8.1

c#

windows-phone-8.1

windows-applications