[[ Bug 21471 ]] Fix revIsSpeaking function on Windows

Ian Macphail · Ian Macphail · commit 29e420f6052f · 2020-11-03T13:38:55.000Z
This patch updates the implementation of revIsSpeaking on Windows to
replace the use of ISpVoice::GetStatus which does not return correct
values when streaming speech to an audio output device. Instead, we now
process speech events to determine when speaking starts &amp; stops.
diff --git a/revspeech/src/w32sapi5speech.cpp b/revspeech/src/w32sapi5speech.cpp
@@ -390,19 +390,55 @@ bool WindowsSAPI5Narrator::Busy(void)
 	if (!bInited)
 		return false;
 
-	SPVOICESTATUS spstat;
-	HRESULT hr = m_cpVoice->GetStatus(&spstat,NULL);
+	if (!ProcessEvents())
+		return false;
 
-    if( SUCCEEDED( hr ) )
+	return isspeaking;
+}
+
+inline void free_speech_event(SPEVENT &p_event)
+{
+	switch (p_event.elParamType)
 	{
-		isspeaking = (spstat.dwRunningState & SPRS_IS_SPEAKING) != 0;
-		
-		return isspeaking;
+	case SPET_LPARAM_IS_POINTER:
+	case SPET_LPARAM_IS_STRING:
+		CoTaskMemFree(reinterpret_cast<void*>(p_event.lParam));
+		break;
+	case SPET_LPARAM_IS_TOKEN:
+	case SPET_LPARAM_IS_OBJECT:
+		reinterpret_cast<IUnknown*>(p_event.lParam)->Release();
+		break;
 	}
-	else
-	{
+	MCMemoryClear(&p_event, sizeof(SPEVENT));
+}
+
+bool WindowsSAPI5Narrator::ProcessEvents(void)
+{
+	if (!bInited)
 		return false;
+
+	SPEVENT t_event;
+	ULONG t_fetched;
+	HRESULT t_result = S_OK;
+	while (t_result == S_OK)
+	{
+		t_result = m_cpVoice->GetEvents(1, &t_event, &t_fetched);
+		if (t_result == S_OK)
+		{
+			switch (t_event.eEventId)
+			{
+			case SPEI_START_INPUT_STREAM:
+				isspeaking = true;
+				break;
+			case SPEI_END_INPUT_STREAM:
+				isspeaking = false;
+				break;
+			}
+			free_speech_event(t_event);
+		}
 	}
+
+	return SUCCEEDED(t_result);
 }
 
 // Parameters
diff --git a/revspeech/src/w32sapi5speech.h b/revspeech/src/w32sapi5speech.h
@@ -62,6 +62,9 @@ class WindowsSAPI5Narrator: public INarrator
 	// Last Error Message
 	char m_strLastError[256];
 
+	// Process events to track speech output status
+	bool ProcessEvents(void);
+
 	// Internal Error Message
 	void Error( WCHAR* pText ){wcscpy((WCHAR *)m_strLastError, pText); };
 	void Error( WCHAR* pText, HRESULT hr){ sprintf(m_strLastError,"%s Error Code:0x%x", pText, hr); };
