fix(sndDevices): handle device reconnection and filter capture events in OnDeviceStateChanged

audiopassthru/include/sndDevices.h

@@ -427,6 +427,9 @@ struct sndDevicesHdlType {
 	// Module common status flag, set by functions that can't complete their requestion operation
 	int function_status;
 
+	wchar_t reconnectedDeviceGuid[PT_MAX_GENERIC_STRLEN];
+	BOOL hasReconnectedDevice;
+
 	void (*deviceChangeCallback)();
 };
 

audiopassthru/src/sndDevices/sndDevicesDeviceCallbacks.cpp

@@ -200,13 +200,43 @@ HRESULT STDMETHODCALLTYPE CsndDevicesMMNotificationClient::OnDeviceStateChanged(
 {
   struct sndDevicesHdlType *cast_handle;
   int type;
-
+  IMMDevice *pDevice = NULL;
+  IMMDeviceEnumerator *pEnumerator = NULL;
+  IMMEndpoint *pEndpoint = NULL;
+  EDataFlow flow;
+  HRESULT hr;
+
   cast_handle = (struct sndDevicesHdlType *)g_sndDevicesCallbacks_hdl;
 
   if (cast_handle == NULL)
     return(S_OK);
 
-  //SLOUT_FIRST_LINE(L"CsndDevicesMMNotificationClient::OnDeviceStateChanged() enters");
+  // Only react to render (playback) device changes, not capture (input) devices
+  if (pwstrDeviceId != NULL)
+  {
+	  hr = CoCreateInstance(cast_handle->CLSID_MMDeviceEnumerator, NULL, CLSCTX_ALL, cast_handle->IID_IMMDeviceEnumerator, (void**)&pEnumerator);
+	  if (SUCCEEDED(hr) && pEnumerator != NULL)
+	  {
+		  hr = pEnumerator->GetDevice(pwstrDeviceId, &pDevice);
+		  if (SUCCEEDED(hr) && pDevice != NULL)
+		  {
+			  hr = pDevice->QueryInterface(__uuidof(IMMEndpoint), (void**)&pEndpoint);
+			  if (SUCCEEDED(hr) && pEndpoint != NULL)
+			  {
+				  hr = pEndpoint->GetDataFlow(&flow);
+				  if (pEndpoint) pEndpoint->Release();
+				  if (SUCCEEDED(hr) && flow != eRender)
+				  {
+					  if (pDevice) pDevice->Release();
+					  if (pEnumerator) pEnumerator->Release();
+					  return S_OK;
+				  }
+			  }
+			  if (pDevice) pDevice->Release();
+		  }
+		  if (pEnumerator) pEnumerator->Release();
+	  }
+  }
 
   switch (dwNewState)
   {
@@ -224,14 +254,22 @@ HRESULT STDMETHODCALLTYPE CsndDevicesMMNotificationClient::OnDeviceStateChanged(
       break;
   }
 
-  // Ignore identical callbacks from the same guid. Since device must be disconnected after being connected,
-  // we should never miss a connect or disconnect event.
   if( pwstrDeviceId != NULL )
-		if( (wcscmp(pwstrDeviceId, cast_handle->lastDeviceAddCallbackGuid) == 0) && ( dwNewState == cast_handle->lastDeviceAddCallbackGuidtype ) )
-		{
-			SLOUT_FIRST_LINE(L"CsndDevicesMMNotificationClient::OnDeviceStateChanged() ignoring identical callback");
-		   return(S_OK);
-		}
+  {
+	  // Track reconnected device: when state changes to ACTIVE from a non-active state,
+	  // this is a device reconnection (e.g., Bluetooth headset connects after being paired/disconnected)
+	  if (dwNewState == DEVICE_STATE_ACTIVE)
+	  {
+		  wcscpy(cast_handle->reconnectedDeviceGuid, pwstrDeviceId);
+		  cast_handle->hasReconnectedDevice = TRUE;
+	  }
+
+	  // Ignore identical callbacks from the same guid (prevents callback storms)
+	  if( (wcscmp(pwstrDeviceId, cast_handle->lastDeviceAddCallbackGuid) == 0) && ( dwNewState == cast_handle->lastDeviceAddCallbackGuidtype ) )
+	  {
+		  return(S_OK);
+	  }
+  }
 
   if( pwstrDeviceId == NULL )
 		wcscpy(cast_handle->lastDeviceAddCallbackGuid, L"");

audiopassthru/src/sndDevices/sndDevicesImplementDeviceRules.cpp

@@ -231,6 +231,42 @@ int PT_DECLSPEC sndDevicesImplementDeviceRules(PT_HANDLE *hp_sndDevices, int *ip
 		}
 	}
 
+	// Check if a previously disconnected device has reconnected (state transitioned to ACTIVE).
+	// This handles the case where a paired Bluetooth device was in UNPLUGGED state and now connects:
+	// the device count stays the same (it was already enumerated), so the count-based check above
+	// would miss it. The reconnection is instead detected via OnDeviceStateChanged callback.
+	if (cast_handle->hasReconnectedDevice)
+	{
+		cast_handle->hasReconnectedDevice = FALSE;
+		for (i = 0; i < cast_handle->numRealDevices; i++)
+		{
+			if (wcscmp(cast_handle->reconnectedDeviceGuid, cast_handle->pwszIDRealDevices[i]) == 0)
+			{
+				if (SND_DEVICES_MONO_BUG_SKIP_MONO_DEVICES)
+				{
+					if (sndDevicesGetNumberOfChannelsFromID(hp_sndDevices, cast_handle->pwszIDRealDevices[i], &i_numChannels, &i_resultFlag) != OKAY)
+						return(NOT_OKAY);
+
+					if (i_numChannels < 2)
+					{
+						break;
+					}
+				}
+
+				if (sndDevices_UtilsGetIndexFromID(hp_sndDevices, cast_handle->pwszIDRealDevices[i], &deviceIndex) != OKAY)
+					return(NOT_OKAY);
+
+				if (deviceIndex != SND_DEVICES_DEVICE_NOT_PRESENT)
+				{
+					cast_handle->playbackDeviceNum = deviceIndex;
+					WritePreviousDefault = 1;
+					goto PlaybackDeviceIsSelected;
+				}
+				break;
+			}
+		}
+	}
+
 	// If we got here we have more than one real playback device and either the user hasn't manually selected one or
 	// the selected device is not present. Use rules to select the playback device based on the default device setting and history.
 	// First check to see if the current default device is not one of the DFX devices.

audiopassthru/src/sndDevices/sndDevicesReInit.cpp

@@ -81,6 +81,9 @@ int PT_DECLSPEC sndDevicesReInit(PT_HANDLE *hp_sndDevices, int i_initType, int *
 
 	wcscpy(cast_handle->lastDeviceAddCallbackGuid, L"");
 	cast_handle->lastDeviceAddCallbackGuidtype = 0;
+
+	wcscpy(cast_handle->reconnectedDeviceGuid, L"");
+	cast_handle->hasReconnectedDevice = FALSE;
 
 	cast_handle->noBufferCount = 0;
 	cast_handle->MeasuredVirtualSilentBufferCount = 0;
@@ -375,7 +378,7 @@ int PT_DECLSPEC sndCheckDeviceChanges(PT_HANDLE* hp_sndDevices, BOOL* bp_deviceC
 			{
 				deviceFound = TRUE;
 
-				// Device ID matched � now check if its state has changed
+				// Device ID matched � now check if its state has changed
 				DWORD currentState = 0;
 				hr = pDevice->GetState(&currentState);
 				if (SUCCEEDED(hr) && currentState != cast_handle->deviceState[j])