audacity/lib-src/portaudio-v19/wasapi-loopback.patch

diff --git a/lib-src/portaudio-v19/include/pa_win_wasapi.h b/lib-src/portaudio-v19/include/pa_win_wasapi.h
index a4416b121..1999e8dad 100644
--- a/lib-src/portaudio-v19/include/pa_win_wasapi.h
+++ b/lib-src/portaudio-v19/include/pa_win_wasapi.h
@@ -564,6 +564,15 @@ const wchar_t *PaWasapi_GetInputDeviceID( PaStream *s );
 */
 const wchar_t *PaWasapi_GetOutputDeviceID( PaStream *s );
 
+/** Returns device loopback indicator.
+
+ @param nDevice device index.
+
+ @return 0 = Not loopback, 1 = loopback, < 0 = PaErrorCode
+         if PortAudio is not initialized or an error is encountered.
+*/
+int PaWasapi_IsLoopback( PaDeviceIndex nDevice );
+
 
 /*
     IMPORTANT:
diff --git a/lib-src/portaudio-v19/src/hostapi/wasapi/pa_win_wasapi.c b/lib-src/portaudio-v19/src/hostapi/wasapi/pa_win_wasapi.c
index f64049ad5..4b28f7f0b 100644
--- a/lib-src/portaudio-v19/src/hostapi/wasapi/pa_win_wasapi.c
+++ b/lib-src/portaudio-v19/src/hostapi/wasapi/pa_win_wasapi.c
@@ -449,6 +449,9 @@ typedef struct PaWasapiDeviceInfo
 
 	// Formfactor
 	EndpointFormFactor formFactor;
+
+	// Loopback indicator
+	int loopBack;
 }
 PaWasapiDeviceInfo;
 
@@ -1674,6 +1677,8 @@ static PaError CreateDeviceList(PaWasapiHostApiRepresentation *paWasapi, PaHostA
 	IMMDeviceEnumerator *pEnumerator = NULL;
 #endif
 	IAudioClient *tmpClient;
+	UINT renderCount;
+	INT devIndex;
 
 	// Make sure device list empty
 	if ((paWasapi->deviceCount != 0) || (hostApi->info.deviceCount != 0))
@@ -1738,6 +1743,19 @@ static PaError CreateDeviceList(PaWasapiHostApiRepresentation *paWasapi, PaHostA
         }
     }
 
+	hr = IMMDeviceEnumerator_EnumAudioEndpoints(pEnumerator, eRender, DEVICE_STATE_ACTIVE, &pEndPoints);
+	// We need to set the result to a value otherwise we will return paNoError
+	// [IF_FAILED_JUMP(hResult, error);]
+	IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);
+
+	hr = IMMDeviceCollection_GetCount(pEndPoints, &renderCount);
+	// We need to set the result to a value otherwise we will return paNoError
+	// [IF_FAILED_JUMP(hResult, error);]
+	IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);
+
+	SAFE_RELEASE(pEndPoints);
+	pEndPoints = NULL;
+
     hr = IMMDeviceEnumerator_EnumAudioEndpoints(pEnumerator, eAll, DEVICE_STATE_ACTIVE, &pEndPoints);
 	// We need to set the result to a value otherwise we will return paNoError
 	// [IF_FAILED_JUMP(hResult, error);]
@@ -1748,6 +1766,7 @@ static PaError CreateDeviceList(PaWasapiHostApiRepresentation *paWasapi, PaHostA
 	// [IF_FAILED_JUMP(hResult, error);]
 	IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);
 
+	paWasapi->deviceCount += renderCount;
 #else
 	// Determine number of available devices by activating AudioClient for render and capture data flows
 	if (SUCCEEDED(ActivateAudioInterface_WINRT(eRender, GetAudioClientIID(), &tmpClient)))
@@ -1797,7 +1816,7 @@ static PaError CreateDeviceList(PaWasapiHostApiRepresentation *paWasapi, PaHostA
         }
 		memset(deviceInfoArray, 0, sizeof(PaDeviceInfo) * deviceCount);
 
-        for (i = 0; i < paWasapi->deviceCount; ++i)
+        for (devIndex = 0, i = 0; i < paWasapi->deviceCount; ++i, ++devIndex)
 		{
             PaDeviceInfo *deviceInfo  = &deviceInfoArray[i];
             deviceInfo->structVersion = 2;
@@ -1807,7 +1826,7 @@ static PaError CreateDeviceList(PaWasapiHostApiRepresentation *paWasapi, PaHostA
 			PA_DEBUG(("WASAPI: ---------------\n"));
 
 		#ifndef PA_WINRT
-            hr = IMMDeviceCollection_Item(pEndPoints, i, &paWasapi->devInfo[i].device);
+            hr = IMMDeviceCollection_Item(pEndPoints, devIndex, &paWasapi->devInfo[i].device);
 			// We need to set the result to a value otherwise we will return paNoError
 			// [IF_FAILED_JUMP(hResult, error);]
 			IF_FAILED_INTERNAL_ERROR_JUMP(hr, result, error);
@@ -2039,6 +2058,42 @@ static PaError CreateDeviceList(PaWasapiHostApiRepresentation *paWasapi, PaHostA
 
             hostApi->deviceInfos[i] = deviceInfo;
             ++hostApi->info.deviceCount;
+
+			if (paWasapi->devInfo[i].flow == eRender)
+			{
+				char *deviceName;
+
+				memcpy(&deviceInfoArray[i + 1], deviceInfo, sizeof(*deviceInfo));
+				memcpy(&paWasapi->devInfo[i + 1], &paWasapi->devInfo[i], sizeof(*paWasapi->devInfo));
+
+				i++;
+				paWasapi->devInfo[i].loopBack = 1;
+
+				deviceInfo = &deviceInfoArray[i];
+
+				deviceInfo->maxInputChannels			= deviceInfo->maxOutputChannels;
+				deviceInfo->defaultHighInputLatency		= deviceInfo->defaultHighOutputLatency;
+				deviceInfo->defaultLowInputLatency		= deviceInfo->defaultLowOutputLatency;
+				deviceInfo->maxOutputChannels			= 0;
+				deviceInfo->defaultHighOutputLatency	= 0;
+				deviceInfo->defaultLowOutputLatency		= 0;
+				PA_DEBUG(("WASAPI:%d| def.SR[%d] max.CH[%d] latency{hi[%f] lo[%f]}\n", i, (UINT32)deviceInfo->defaultSampleRate,
+						 deviceInfo->maxInputChannels, (float)deviceInfo->defaultHighInputLatency, (float)deviceInfo->defaultLowInputLatency));
+
+				IMMDevice_AddRef(paWasapi->devInfo[i].device);
+
+				deviceName = (char *)PaUtil_GroupAllocateMemory(paWasapi->allocations, MAX_STR_LEN + 1);
+				if (deviceName == NULL)
+				{
+					result = paInsufficientMemory;
+					goto error;
+				}
+				_snprintf(deviceName, MAX_STR_LEN-1, "%s (loopback)", deviceInfo->name);
+				deviceInfo->name = deviceName;
+
+				hostApi->deviceInfos[i] = deviceInfo;
+				++hostApi->info.deviceCount;
+			}
         }
 
 	#if defined(PA_WASAPI_MAX_CONST_DEVICE_COUNT) && (PA_WASAPI_MAX_CONST_DEVICE_COUNT > 0)
@@ -2392,6 +2447,29 @@ int PaWasapi_GetDeviceRole( PaDeviceIndex device )
 	return paWasapi->devInfo[ index ].formFactor;
 }
 
+// ------------------------------------------------------------------------------------------
+int PaWasapi_IsLoopback( PaDeviceIndex nDevice )
+{
+	PaError ret;
+	PaDeviceIndex index;
+
+	// Get API
+	PaWasapiHostApiRepresentation *paWasapi = _GetHostApi(&ret);
+	if (paWasapi == NULL)
+		return paNotInitialized;
+
+	// Get device index
+	ret = PaUtil_DeviceIndexToHostApiDeviceIndex(&index, nDevice, &paWasapi->inheritedHostApiRep);
+	if (ret != paNoError)
+		return ret;
+
+	// Validate index
+	if ((UINT32)index >= paWasapi->deviceCount)
+		return paInvalidDevice;
+
+	return paWasapi->devInfo[ index ].loopBack;
+}
+
 // ------------------------------------------------------------------------------------------
 PaError PaWasapi_GetFramesPerHostBuffer( PaStream *pStream, unsigned int *pInput, unsigned int *pOutput )
 {
@@ -3055,7 +3133,7 @@ static HRESULT CreateAudioClient(PaWasapiStream *pStream, PaWasapiSubStream *pSu
 	if ((params->channelCount == 1) && (pSub->wavex.Format.nChannels == 2))
 	{
 		// select mixer
-		pSub->monoMixer = GetMonoToStereoMixer(&pSub->wavex, (pInfo->flow == eRender ? MIX_DIR__1TO2 : MIX_DIR__2TO1_L));
+		pSub->monoMixer = GetMonoToStereoMixer(&pSub->wavex, (output ? MIX_DIR__1TO2 : MIX_DIR__2TO1_L));
 		if (pSub->monoMixer == NULL)
 		{
 			(*pa_error) = paInvalidChannelCount;
@@ -3618,6 +3696,9 @@ static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi,
 			((inputStreamInfo != NULL) && (inputStreamInfo->flags & paWinWasapiAutoConvert)))
 			stream->in.streamFlags |= (AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM | AUDCLNT_STREAMFLAGS_SRC_DEFAULT_QUALITY);
 
+        if (info->flow == eRender)
+            stream->in.streamFlags |= AUDCLNT_STREAMFLAGS_LOOPBACK;
+
 		// Fill parameters for Audio Client creation
 		stream->in.params.device_info       = info;
 		stream->in.params.stream_params     = (*inputParameters);