Esempio n. 1
0
        /// <summary>
        /// The Initialize Audio Client
        /// </summary>
        /// <param name="audioFlow"></param>
        /// <param name="_deviceEnumerator"></param>
        private void InitializeAudioClient()
        {
            //Get Audio Client from device
            COMResult result = _audioDevice.Activate(typeof(IAudioClient).GUID, 0, IntPtr.Zero, out object obj);

            _audioClient = (IAudioClient)obj;
            //Get Audio Meter from device
            result      = _audioDevice.Activate(typeof(IAudioMeterInformation).GUID, 0, IntPtr.Zero, out obj);
            _audioMeter = (IAudioMeterInformation)obj;
            //Get Audio End Point
            result = _audioDevice.Activate(typeof(IAudioEndpointVolume).GUID, 0, IntPtr.Zero, out obj);
            _audioEndpointVolume = (IAudioEndpointVolume)obj;
            _audioEndpointVolume.RegisterControlChangeNotify(classCallBack);
            //Initialize Audio Client.
            _sessionGuid = new Guid();
            result       = _audioClient.GetMixFormat(out waveFormat);
            AudioClientStreamFlags streamFlag = AudioClientStreamFlags.None;

            if (_audioDataFlow == AudioDataFlow.eRender)
            {
                streamFlag = AudioClientStreamFlags.Loopback;
            }
            result = _audioClient.Initialize(AudioClientMode.Shared, streamFlag, 10000000, 0, waveFormat, ref _sessionGuid);
            result = _audioClient.Start();
            //Change wave format here
            SetupWaveFormat(waveFormat);

            result = _audioEndpointVolume.GetChannelCount(out _channelCount);
        }
        private void InitializeAudio(AudioDataFlow audioFlow, IMMDeviceEnumerator deviceEnumerator)
        {
            //Get Audio Device
            COMResult result = deviceEnumerator.GetDefaultAudioEndpoint(audioFlow, EndPointRole.eMultimedia, out _audioDevice);

            //Register End point notification
            _notifyClient = new MMNotificationClient();
            result        = deviceEnumerator.RegisterEndpointNotificationCallback(_notifyClient);
            //Get Audio Client from device
            result       = _audioDevice.Activate(typeof(IAudioClient).GUID, 0, IntPtr.Zero, out object obj);
            _audioClient = (IAudioClient)obj;
            //Get Audio Meter from device
            result      = _audioDevice.Activate(typeof(IAudioMeterInformation).GUID, 0, IntPtr.Zero, out obj);
            _audioMeter = (IAudioMeterInformation)obj;
            //Initialize Audio Client.
            _sessionGuid = new Guid();
            result       = _audioClient.GetMixFormat(out waveFormat);
            AudioClientStreamFlags streamFlag = AudioClientStreamFlags.None;

            if (audioFlow == AudioDataFlow.eRender)
            {
                streamFlag = AudioClientStreamFlags.Loopback;
            }
            result = _audioClient.Initialize(AudioClientMode.Shared, streamFlag, 10000000, 0, waveFormat, ref _sessionGuid);
            //Get Capture Client.
            result = _audioClient.GetService(typeof(IAudioCaptureClient).GUID, out obj);
            Marshal.ThrowExceptionForHR((int)result);
            _audioCaptureClient = (IAudioCaptureClient)obj;
            result = _audioClient.Start();
            //Change wave format here
            SetupWaveFormat(waveFormat);
        }
Esempio n. 3
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 /// <summary>
 /// Initialize the Audio Client
 /// </summary>
 /// <param name="shareMode">Share Mode</param>
 /// <param name="streamFlags">Stream Flags</param>
 /// <param name="bufferDuration">Buffer Duration</param>
 /// <param name="periodicity">Periodicity</param>
 /// <param name="waveFormat">Wave Format</param>
 /// <param name="audioSessionGuid">Audio Session GUID (can be null)</param>
 public void Initialize(AudioClientShareMode shareMode,
                        AudioClientStreamFlags streamFlags,
                        long bufferDuration,
                        long periodicity,
                        WaveFormat waveFormat,
                        Guid audioSessionGuid)
 {
     audioClientInterface.Initialize(shareMode, streamFlags, bufferDuration, periodicity, waveFormat, ref audioSessionGuid);
     // may have changed the mix format so reset it
     mixFormat = null;
 }
Esempio n. 4
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        /// <summary>
        /// Initializes the Audio Client
        /// </summary>
        /// <param name="shareMode">Share Mode</param>
        /// <param name="streamFlags">Stream Flags</param>
        /// <param name="bufferDuration">Buffer Duration</param>
        /// <param name="periodicity">Periodicity</param>
        /// <param name="waveFormat">Wave Format</param>
        /// <param name="audioSessionGuid">Audio Session GUID (can be null)</param>
        public void Initialize(AudioClientShareMode shareMode,
                               AudioClientStreamFlags streamFlags,
                               long bufferDuration,
                               long periodicity,
                               WaveFormatProvider waveFormat,
                               Guid audioSessionGuid)
        {
            int hresult = audioClientInterface.Initialize(shareMode, streamFlags, bufferDuration, periodicity, waveFormat, ref audioSessionGuid);

            Marshal.ThrowExceptionForHR(hresult);
            // may have changed the mix format so reset it
            mixFormat = null;
        }
Esempio n. 5
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        /// <summary>
        /// Initializes the Audio Client
        /// </summary>
        /// <param name="shareMode">Share Mode</param>
        /// <param name="streamFlags">Stream Flags</param>
        /// <param name="bufferDuration">Buffer Duration</param>
        /// <param name="periodicity">Periodicity</param>
        /// <param name="waveFormat">Wave Format</param>
        /// <param name="audioSessionGuid">Audio Session GUID (can be null)</param>
        public int Initialize(ShareMode shareMode,
                              StreamFlags streamFlags,
                              long bufferDuration,
                              long periodicity,
                              WaveFormat waveFormat,
                              Guid audioSessionGuid)
        {
            this.shareMode = shareMode;
            int hret = audioClientInterface.Initialize(shareMode, streamFlags, bufferDuration, periodicity, waveFormat, ref audioSessionGuid);

            mixFormat = null;
            return(hret);
        }
Esempio n. 6
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        public void  Initialize(EAudioClientShareMode shareMode,
                                EAudioClientStreamFlags streamFlags,
                                long bufferDuration,
                                long periodicity,
                                WaveFormat format,
                                Guid audioSessionGuid)
        {
            var hresult = _realAudioClient.Initialize(shareMode, streamFlags, bufferDuration, periodicity, format, ref audioSessionGuid);

            Marshal.ThrowExceptionForHR(hresult);
            // may have changed the mix format so reset it
            mixFormat = null;
        }
Esempio n. 7
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        /// <summary>
        /// Initialize the Audio Client
        /// </summary>
        /// <param name="shareMode">Share Mode</param>
        /// <param name="streamFlags">Stream Flags</param>
        /// <param name="bufferDuration">Buffer Duration</param>
        /// <param name="periodicity">Periodicity</param>
        /// <param name="waveFormat">Wave Format</param>
        /// <param name="audioSessionGuid">Audio Session GUID (can be null)</param>
        public int Initialize(AudioClientShareMode shareMode,
                              AudioClientStreamFlags streamFlags,
                              long bufferDuration,
                              long periodicity,
                              ref WaveFormatExtensible waveFormat,
                              Guid audioSessionGuid)
        {
            int hresult = 0;

            hresult = audioClientInterface.Initialize(shareMode, streamFlags, bufferDuration, periodicity, ref waveFormat, ref audioSessionGuid);

            if (hresult != 0)
            {
                this.EventWriterDLL.WriteLine(EventWriterDLL.SeverityTypes.Error, 0x01, "Error Code in AudioClient::Initialize: " + hresult);
            }
            // may have changed the mix format so reset it
            mixFormat = new WaveFormatExtensible();
            return(hresult);
        }
Esempio n. 8
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        private void StartSilenceGeneration()
        {
            IntPtr mixFormatPtr = IntPtr.Zero;

            try
            {
                Checked(_endpoint.Activate(ref IAudioClientId, ClsCtxEnum.All, IntPtr.Zero, out var obj), "Silence.Activate");
                _audioClientForRendering = (IAudioClient)obj;

                Checked(_audioClientForRendering.GetMixFormat(out mixFormatPtr), "Silence.GetMixFormat");
                WaveFormatEx format = (WaveFormatEx)Marshal.PtrToStructure(mixFormatPtr, typeof(WaveFormatEx));

                CheckFormat(format);

                Checked(_audioClientForRendering.Initialize(AudioClientShareModeEnum.Shared, AudioClientStreamFlagsEnum.None, 10_000_000 * 5, 0, mixFormatPtr, Guid.Empty), "Silence.Initialize");
                Checked(_audioClientForRendering.GetBufferSize(out var bufferSize), "Silence.GetBufferSize");
                Checked(_audioClientForRendering.GetService(IAudioRenderClientId, out var renderObj), "Silence.GetService");

                _audioRenderClient = (IAudioRenderClient)renderObj;

                Checked(_audioClientForRendering.Start(), "Silence.Start");

                _silenceThread      = new Thread(() => SilenceGenerationRoutine(bufferSize, format));
                _silenceThread.Name = "Silence generator";
                _silenceThread.Start();
            }
            catch (Exception e)
            {
                ReleaseComObject(ref _audioClientForRendering);
                ReleaseComObject(ref _audioRenderClient);
                Core.LogError(e, "Faied to StartSilenceGeneration");
            }
            finally
            {
                if (mixFormatPtr != IntPtr.Zero)
                {
                    Marshal.FreeCoTaskMem(mixFormatPtr);
                }
            }
        }
Esempio n. 9
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        public void Initialize(
            AudioClientShareMode shareMode,
            AudioClientStreamFlags streamFlags,
            long bufferDuration, long periodicity,
            WAVEFORMATEXTENSIBLE format, Guid audioSessionGuid)
        {
            int hr = _RealClient.Initialize(shareMode, streamFlags, bufferDuration, periodicity, format, ref audioSessionGuid);

            Marshal.ThrowExceptionForHR(hr);

            if ((streamFlags & AudioClientStreamFlags.EventCallback) != 0)
            {
                _audioSampleReady = new AutoResetEvent(false);
                IntPtr eventHandle = CreateEventEx(IntPtr.Zero, "audioSampleReady", CreateEventFlags.None, AccessRight.Synchronize | AccessRight.EventModifyState);
                _audioSampleReady.SafeWaitHandle = new Microsoft.Win32.SafeHandles.SafeWaitHandle(eventHandle, true);

                hr = _RealClient.SetEventHandle(eventHandle);
                Marshal.ThrowExceptionForHR(hr);

                _audioSampleReadyRegistered = ThreadPool.RegisterWaitForSingleObject(
                    _audioSampleReady, new WaitOrTimerCallback(sampleReady), null, -1, false);
            }
            _isInitialized = true;
        }
Esempio n. 10
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        public CoreAudio(bool microphone = false)
        {
            const uint REFTIMES_PER_SEC     = 10000000;
            const uint CLSCTX_INPROC_SERVER = 1;
            Guid       clsid        = new Guid("BCDE0395-E52F-467C-8E3D-C4579291692E");
            Guid       IID_IUnknown = new Guid("00000000-0000-0000-C000-000000000046");

            oEnumerator = null;
            uint hResult = CoCreateInstance(ref clsid, null, CLSCTX_INPROC_SERVER, ref IID_IUnknown, out oEnumerator);

            if (hResult != 0 || oEnumerator == null)
            {
                throw new Exception("CoCreateInstance() pInvoke failed");
            }

            iMde = oEnumerator as IMMDeviceEnumerator;
            if (iMde == null)
            {
                throw new Exception("COM cast failed to IMMDeviceEnumerator");
            }

            IntPtr pDevice = IntPtr.Zero;

            //iMde.EnumAudioEndpoints(EDataFlow.eCapture, DEVICE_STATE_ACTIVE,ref pDevice);
            int retVal;

            if (microphone)
            {
                retVal = iMde.GetDefaultAudioEndpoint(EDataFlow.eCapture, ERole.eConsole, ref pDevice);
            }
            else
            {
                retVal = iMde.GetDefaultAudioEndpoint(EDataFlow.eRender, ERole.eConsole, ref pDevice);
            }

            if (retVal != 0)
            {
                throw new Exception("IMMDeviceEnumerator.GetDefaultAudioEndpoint()");
            }
            //int dwStateMask = DEVICE_STATE_ACTIVE | DEVICE_STATE_NOTPRESENT | DEVICE_STATE_UNPLUGGED;
            //IntPtr pCollection = IntPtr.Zero;
            //retVal = iMde.EnumAudioEndpoints(EDataFlow.eRender, dwStateMask, ref pCollection);
            //if (retVal != 0)
            //{
            //    throw new Exception("IMMDeviceEnumerator.EnumAudioEndpoints()");
            //}
            imd = (IMMDevice)System.Runtime.InteropServices.Marshal.GetObjectForIUnknown(pDevice);
            if (imd == null)
            {
                throw new Exception("COM cast failed to IMMDevice");
            }

            Guid   iid               = new Guid("5CDF2C82-841E-4546-9722-0CF74078229A");
            uint   dwClsCtx          = (uint)CLSCTX.CLSCTX_ALL;
            IntPtr pActivationParams = IntPtr.Zero;
            IntPtr pEndPoint         = IntPtr.Zero;

            retVal = imd.Activate(iid, dwClsCtx, pActivationParams, out pEndPoint);
            if (retVal != 0)
            {
                throw new Exception("IMMDevice.Activate()");
            }
            iAudioEndpoint = (IAudioEndpointVolume)System.Runtime.InteropServices.Marshal.GetObjectForIUnknown(pEndPoint);
            if (iAudioEndpoint == null)
            {
                throw new Exception("COM cast failed to IAudioEndpointVolume");
            }

            iid               = new Guid("1CB9AD4C-DBFA-4c32-B178-C2F568A703B2");
            dwClsCtx          = (uint)CLSCTX.CLSCTX_ALL;
            pActivationParams = IntPtr.Zero;
            pEndPoint         = IntPtr.Zero;
            retVal            = imd.Activate(iid, dwClsCtx, pActivationParams, out pEndPoint);
            if (retVal != 0)
            {
                throw new Exception("IAudioClient.Activate() " + Convert.ToString(retVal, 2));
            }

            iAudioClient = (IAudioClient)System.Runtime.InteropServices.Marshal.GetObjectForIUnknown(pEndPoint);
            if (iAudioClient == null)
            {
                throw new Exception("COM cast failed to iAudioClient");
            }
            ulong processInterval;
            ulong minimumInterval;

            retVal = iAudioClient.GetDevicePeriod(out processInterval, out minimumInterval);
            if (retVal != 0)
            {
                throw new Exception("iAudioClient.GetDevicePeriod()");
            }

            waveformat                 = new WAVEFORMATEX();
            waveformat.wFormatTag      = (ushort)WaveFormatEncoding.Pcm;
            waveformat.nChannels       = 2;
            waveformat.nBlockAlign     = 4;
            waveformat.wBitsPerSample  = 16;
            waveformat.nSamplesPerSec  = 44100;
            waveformat.cbSize          = 0;
            waveformat.nAvgBytesPerSec = 176400;
            IntPtr reqForm = Marshal.AllocHGlobal(Marshal.SizeOf(waveformat));

            Marshal.StructureToPtr(waveformat, reqForm, false);

            IntPtr propForm = Marshal.AllocHGlobal(Marshal.SizeOf(waveformat));

            retVal = iAudioClient.IsFormatSupported(AUDCLNT_SHAREMODE.AUDCLNT_SHAREMODE_SHARED, reqForm, out propForm);
            if (retVal != 0)
            {
                throw new Exception("IAudioClient.IsFormatSupported()");
            }

            if (microphone)
            {
                retVal = iAudioClient.Initialize(AUDCLNT_SHAREMODE.AUDCLNT_SHAREMODE_EXCLUSIVE, 0, 2000000, 0, reqForm, Guid.Empty);
            }
            else
            {
                retVal = iAudioClient.Initialize(AUDCLNT_SHAREMODE.AUDCLNT_SHAREMODE_SHARED, AUDCLNT_STREAMFLAGS_LOOPBACK, 2000000, 0, reqForm, Guid.Empty);
            }

            if (retVal != 0)
            {
                throw new Exception("IAudioClient.Initialize() " + retVal);
            }
            uint buffersize = 0;

            retVal = iAudioClient.GetBufferSize(out buffersize);
            if (retVal != 0)
            {
                throw new Exception("IAudioClient.GetBufferSize()");
            }
            iid = new Guid("C8ADBD64-E71E-48a0-A4DE-185C395CD317");
            IntPtr capclient = IntPtr.Zero;

            retVal = iAudioClient.GetService(iid, out capclient);
            if (retVal != 0)
            {
                throw new Exception("IAudioClient.GetService()");
            }
            iAudioCaptureClient = (IAudioCaptureClient)System.Runtime.InteropServices.Marshal.GetObjectForIUnknown(capclient);
            if (iAudioCaptureClient == null)
            {
                throw new Exception("COM cast failed to iAudioCaptureClient");
            }
            hnsActualDuration            = (double)(REFTIMES_PER_SEC * buffersize / waveformat.nSamplesPerSec); // 8391 smallest possible value
            recordingthread              = new Thread(recordingloop);
            recordingthread.IsBackground = false;
            recordingthread.Start();
        }
Esempio n. 11
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 protected void InternalSetup(int dataFlow, int flags, int bufferSize = 0)
 {
     lock (mutex)
     {
         int hr; object obj; Guid guid;
         if (endpoint == null)
         {
             if (enumerator == null)
             {
                 enumerator = Activator.CreateInstance(typeof(MMDeviceEnumerator)) as IMMDeviceEnumerator;
                 if (enumerator == null)
                 {
                     throw new NotSupportedException();
                 }
             }
             hr = enumerator.GetDefaultAudioEndpoint((DataFlowEnum)dataFlow, RoleEnum.Multimedia, out endpoint);
             if (hr != 0)
             {
                 Marshal.ThrowExceptionForHR(hr);
             }
             if (endpoint == null)
             {
                 throw new NotSupportedException();
             }
         }
         if (audioClient != null)
         {
             Marshal.ReleaseComObject(audioClient); audioClient = null;
         }
         guid = IID_IAudioClient;
         hr   = endpoint.Activate(ref guid, ClsCtxEnum.ALL, IntPtr.Zero, out obj);
         if (hr != 0)
         {
             Marshal.ThrowExceptionForHR(hr);
         }
         audioClient = obj as IAudioClient;
         if (audioClient == null)
         {
             throw new NotSupportedException();
         }
         IntPtr mixFormatPtr = IntPtr.Zero;
         try
         {
             hr = audioClient.GetMixFormat(out mixFormatPtr);
             if (hr != 0)
             {
                 Marshal.ThrowExceptionForHR(hr);
             }
             WaveFormat outputFormat = (WaveFormat)Marshal.PtrToStructure(mixFormatPtr, typeof(WaveFormat));
             outputIsFloat = false;
             if (outputFormat.ExtraSize >= WaveFormatEx.WaveFormatExExtraSize)
             {
                 WaveFormatEx ex = (WaveFormatEx)Marshal.PtrToStructure(mixFormatPtr, typeof(WaveFormatEx));
                 if (ex.SubFormat == IeeeFloat)
                 {
                     outputIsFloat = true;
                 }
             }
             sampleRate    = outputFormat.SampleRate;
             channelCount  = outputFormat.Channels;
             bitsPerSample = outputFormat.BitsPerSample;
             if (bufferSize <= 0)
             {
                 bufferSize = 8192;
             }
             latencyMs = (int)(bufferSize * 500 / sampleRate);
             if (latencyMs <= 0)
             {
                 latencyMs = 1;
             }
             hr = audioClient.Initialize(AudioClientShareModeEnum.Shared, (AudioClientStreamFlagsEnum)flags,
                                         latencyMs * 40000, 0, mixFormatPtr, Guid.Empty);
             if (hr != 0)
             {
                 Marshal.ThrowExceptionForHR(hr);
             }
         }
         finally
         {
             if (mixFormatPtr != IntPtr.Zero)
             {
                 Marshal.FreeCoTaskMem(mixFormatPtr);
             }
         }
         hr = audioClient.GetBufferSize(out outputBufferSize);
         if (hr != 0)
         {
             Marshal.ThrowExceptionForHR(hr);
         }
         this.bufferSize = bufferSize;
         buffers         = new float[channelCount][];
         for (int i = 0; i < buffers.Length; i++)
         {
             buffers[i] = new float[bufferSize];
         }
         isInited = true;
     }
 }
        internal static unsafe Factory_WindowsCoreApi.IAudioClient CreateClient(IMMDevice IDevice, out WAVEFORMATEX format, out Type dataFormat)
        {
            Factory_WindowsCoreApi.IAudioClient IAudioClient;
            IDevice.Activate(Factory_WindowsCoreApi.IID_IAudioClient, (uint)PlaybackClient_WindowsCoreApi.CLSCTX.CLSCTX_ALL, new IntPtr(0), out IAudioClient);

            IntPtr rawFormatPtr = new IntPtr();

            IAudioClient.GetMixFormat(out rawFormatPtr);
            WAVEFORMATEX *pFormat = (WAVEFORMATEX *)rawFormatPtr.ToPointer();

            if (pFormat->wBitsPerSample % 8 != 0)
            {
                throw new Exception("Unsupported bits per sample value");
            }
            dataFormat = typeof(byte);
            if (pFormat->wFormatTag == 0xFFFE)
            {
                WAVEFORMATEXTENSIBLE *pFormatEx = (WAVEFORMATEXTENSIBLE *)pFormat;
                if (pFormatEx->SubFormat == FormatEx_IEEE)
                {
                    switch (pFormat->wBitsPerSample)
                    {
                    case 0:
                    case 32: dataFormat = typeof(float); break;

                    case 64: dataFormat = typeof(double); break;

                    default: throw new Exception("Unsupported underlying data format");
                    }
                }
                else if (pFormatEx->SubFormat == FormatEx_PCM)
                {
                    switch (pFormat->wBitsPerSample)
                    {
                    case 8: dataFormat = typeof(byte); break;

                    case 16: dataFormat = typeof(Int16); break;

                    case 32: dataFormat = typeof(Int32); break;

                    case 64: dataFormat = typeof(Int64); break;

                    default: throw new Exception("Unsupported underlying data format");
                    }
                }
            }
            else
            {
                switch ((WAVE_FORMAT)pFormat->wFormatTag)
                {
                case WAVE_FORMAT.PCM:
                    switch (pFormat->wBitsPerSample)
                    {
                    case 8: dataFormat = typeof(byte); break;

                    case 16: dataFormat = typeof(Int16); break;

                    case 32: dataFormat = typeof(Int32); break;

                    case 64: dataFormat = typeof(Int64); break;

                    default: throw new Exception("Unsupported underlying data format");
                    }
                    break;

                case WAVE_FORMAT.IEEE:
                    switch (pFormat->wBitsPerSample)
                    {
                    case 0:
                    case 32: dataFormat = typeof(float); break;

                    case 64: dataFormat = typeof(double); break;

                    default: throw new Exception("Unsupported underlying data format");
                    }
                    break;
                }
            }
            try
            {
                IAudioClient.Initialize(Factory_WindowsCoreApi.AUDCLNT_SHAREMODE.AUDCLNT_SHAREMODE_SHARED, 0, 10000000, 0, new IntPtr(pFormat), Guid.Empty);
            }
            catch { throw new Exception("Unexpected error when creating the client"); }

            format = *pFormat;
            return(IAudioClient);
        }
Esempio n. 13
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        public WaveFormatEx Open()
        {
            StopSilenceThread();

            Log.Information("Opening DesktopAudio");
            IMMDeviceEnumerator deviceEnumerator = null;
            IntPtr mixFormatPtr = IntPtr.Zero;

            try
            {
                bool render = true;
                deviceEnumerator = Activator.CreateInstance(typeof(MMDeviceEnumerator)) as IMMDeviceEnumerator;
                var res = deviceEnumerator.GetDefaultAudioEndpoint(
                    render ? DataFlowEnum.Render : DataFlowEnum.Capture,
                    render ? RoleEnum.Console : RoleEnum.Communications,
                    out _endpoint);

                if (render)
                {
                    StartSilenceGeneration();
                }

                Checked(_endpoint.Activate(ref IAudioClientId, ClsCtxEnum.All, IntPtr.Zero, out var obj), "Activate");
                _audioClient = (IAudioClient)obj;

                Checked(_audioClient.GetMixFormat(out mixFormatPtr), "GetMixFormat");
                WaveFormatEx outputFormat = (WaveFormatEx)Marshal.PtrToStructure(mixFormatPtr, typeof(WaveFormatEx));

                if (!render) // for render it is checked in the StartSilenceGeneration();
                {
                    CheckFormat(outputFormat);
                }

                _bytesPerFrame = outputFormat.BlockAlign;

                var flags = AudioClientStreamFlagsEnum.StreamFlagsEventCallback | (render ? AudioClientStreamFlagsEnum.StreamFlagsLoopback : AudioClientStreamFlagsEnum.None);
                Checked(_audioClient.Initialize(AudioClientShareModeEnum.Shared, flags, 10_000_000 * 5, 0, mixFormatPtr, Guid.Empty), "Initialize");

                Checked(_audioClient.GetService(IAudioCaptureClientId, out var captureObj), "GetService");
                _audioCaptureClient = (IAudioCaptureClient)captureObj;

#pragma warning disable CS0618 // Type or member is obsolete
                Checked(_audioClient.SetEventHandle(_dataAvailable.Handle), "SetEventHandle");
#pragma warning restore CS0618 // Type or member is obsolete
                Checked(_audioClient.Start(), "Start");

                return(outputFormat);
            }
            catch (Exception e)
            {
                Core.LogError(e, "Open desktop audio failed");
                StopSilenceThread();

                ReleaseComFields();
                throw;
            }
            finally
            {
                if (mixFormatPtr != IntPtr.Zero)
                {
                    Marshal.FreeCoTaskMem(mixFormatPtr);
                }

                ReleaseComObject(ref deviceEnumerator);
            }
        }