/// <summary>
/// 演示如何进行音频自采集和自渲染
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void StartEngineAndSelfAudioProcess()
{
    InitEngine();
    InitAudioCapture();
    this.engine.SetExternalAudioSource(true, m_audioCapture.AudioFormat.AudioEncodingProperties.SampleRate, (byte)m_audioCapture.AudioFormat.AudioEncodingProperties.ChannelCount);
}

private void InitAudioCapture()
{
    var sourceGroup = MediaFrameSourceGroup.FindAllAsync().AsTask().GetAwaiter().GetResult();
    if (sourceGroup.Count == 0) return;
    m_audioCapture = new GeneralMediaCapturer(sourceGroup[0], StreamingCaptureMode.Audio);
    m_audioCapture.OnAudioFrameArrived += AudioFrameArrivedEvent;
}

private void AudioFrameArrivedEvent(AudioMediaFrame frame)
{
    using (Windows.Media.AudioFrame rawAudioFrame = frame.GetAudioFrame())
        using (AudioBuffer audioBuffer = rawAudioFrame.LockBuffer(AudioBufferAccessMode.Read))
        using (AgoraWinRT.AudioFrame audioFrame = new AgoraWinRT.AudioFrame())
    {
        var buffer = Windows.Storage.Streams.Buffer.CreateCopyFromMemoryBuffer(audioBuffer);
        buffer.Length = audioBuffer.Length;
        using (var dataReader = DataReader.FromBuffer(buffer))
        {
            dataReader.ByteOrder = ByteOrder.LittleEndian;
            byte[] tmp = new byte[buffer.Length / 2];
            int pos = 0;
            while (dataReader.UnconsumedBufferLength > 0)
            {
                var int16Data = (Int16)(dataReader.ReadSingle() * Int16.MaxValue);
                byte[] chunck = BitConverter.GetBytes(int16Data);
                tmp[pos++] = chunck[0];
                tmp[pos++] = chunck[1];
            }
            var format = frame.AudioEncodingProperties;
            audioFrame.bytesPerSample = 2;
            audioFrame.channels = (byte)format.ChannelCount;
            audioFrame.samplesPerSec = format.SampleRate;
            audioFrame.samples = (uint)(tmp.Length / 4);
            audioFrame.type = AUDIO_FRAME_TYPE.FRAME_TYPE_PCM16;
            audioFrame.buffer = tmp;
            engine.PushAudioFrame(audioFrame);
        }
    }
}

private void StartEngineAndPullAudioProcess()
{
    InitEngine();
    InitAudioGraph();
    log("Set External Audio Sink", this.engine.SetExternalAudioSink(true, DEFAULT_SAMPLE_RATE, (byte)DEFAULT_CHANNEL_COUNT));
}

private void InitAudioGraph()
{
    var settings = new AudioGraphSettings(AudioRenderCategory.Media);
    var createGraphResult = AudioGraph.CreateAsync(settings).AsTask().GetAwaiter().GetResult();
    m_audioGraph = createGraphResult.Graph;
    var outputResult = m_audioGraph.CreateDeviceOutputNodeAsync().AsTask().GetAwaiter().GetResult();

    m_audioInput = m_audioGraph.CreateFrameInputNode(
        new AudioEncodingProperties
        {
            BitsPerSample = DEFAULT_BITS_PER_SAMPLE,
            ChannelCount = DEFAULT_CHANNEL_COUNT,
            SampleRate = DEFAULT_SAMPLE_RATE,
            Subtype = MediaEncodingSubtypes.Pcm,
        });
    m_audioInput.QuantumStarted += QuantumStartedEvent;
    m_audioInput.AddOutgoingConnection(outputResult.DeviceOutputNode);
    m_audioInput.Stop();
}

private void QuantumStartedEvent(AudioFrameInputNode sender, FrameInputNodeQuantumStartedEventArgs args)
{
    using (var frame = new AgoraWinRT.AudioFrame())
    {
        frame.bytesPerSample = 2;
        frame.channels = (byte)DEFAULT_CHANNEL_COUNT;
        frame.samplesPerSec = DEFAULT_SAMPLE_RATE;
        frame.type = AUDIO_FRAME_TYPE.FRAME_TYPE_PCM16;
        frame.renderTimeMs = 0;
        frame.samples = DEFAULT_SAMPLE_RATE / 100;
        var result = engine.PullAudioFrame(frame);
        if (result == 0) PlayAudioFrame(frame);
    }
}

 private unsafe void PlayAudioFrame(AgoraWinRT.AudioFrame frame)
 {
     using (var audioFrame = new Windows.Media.AudioFrame((uint)frame.buffer.Length))
     {
         using (var buffer = audioFrame.LockBuffer(AudioBufferAccessMode.Write))
             using (var reference = buffer.CreateReference())
         {
             byte* data;
             uint size;
             ((IMemoryBufferByteAccess)reference).GetBuffer(out data, out size);
             fixed (byte* raw = frame.buffer)
             {
                 System.Buffer.MemoryCopy(raw, data, size, size);
             }
         }
         m_audioInput?.AddFrame(audioFrame);
     }
 }