Zelda Ucode partly working without Premix hack.

The code is still completely wrong, and it only outputs some sound,
but the mess is confined to the Zelda Ucode implementation.

Source/Core/Core/HW/DSPHLE/UCodes/UCode_Zelda.cpp

@@ -290,32 +290,14 @@ void CUCode_Zelda::HandleMail_NormalVersion(u32 _uMail)
 			m_SyncFlags[n] = _uMail & 0xFFFF;
 			m_bSyncInProgress = false;
 
-			// Normally, we should mix to the buffers used by the game.
-			// We don't do it currently for a simple reason:
-			// if the game runs fast all the time, then it's OK,
-			// but if it runs slow, sound can become choppy.
-			// This problem won't happen when mixing to the buffer
-			// provided by MixAdd(), because the size of this buffer
-			// is automatically adjusted if the game runs slow.
-#if 0
-			if (m_SyncFlags[n] & 0x8000)
-			{
-				for (; m_CurVoice < m_MaxVoice; m_CurVoice++)
-				{
-					if (m_CurVoice >= m_NumVoices)
-						break;
-
-					MixVoice(m_CurVoice);
-				}
-			}
-			else
-#endif
-				m_CurVoice = m_MaxVoice;
+			m_CurVoice = m_MaxVoice;
 
 			if (m_CurVoice >= m_NumVoices)
 			{
 				m_CurBuffer++;
 
+				MixAudio();
+
 				m_rMailHandler.PushMail(DSP_SYNC);
 				DSP::GenerateDSPInterruptFromDSPEmu(DSP::INT_DSP);
 				m_rMailHandler.PushMail(0xF355FF00 | m_CurBuffer);
@@ -555,9 +537,6 @@ u32 CUCode_Zelda::GetUpdateMs()
 
 void CUCode_Zelda::DoState(PointerWrap &p)
 {
-	// It's bad if we try to save during Mix()
-	std::lock_guard<std::mutex> lk(m_csMix);
-
 	p.Do(m_AFCCoefTable);
 	p.Do(m_MiscTable);
 

Source/Core/Core/HW/DSPHLE/UCodes/UCode_Zelda.h

@@ -125,7 +125,6 @@ public:
 	void HandleMail_LightVersion(u32 _uMail);
 	void HandleMail_SMSVersion(u32 _uMail);
 	void HandleMail_NormalVersion(u32 _uMail);
-
 	void Update(int cycles) override;
 
 	void CopyPBsFromRAM();
@@ -290,4 +289,6 @@ private:
 
 	// Renders a voice and mixes it into LeftBuffer, RightBuffer
 	void RenderAddVoice(ZeldaVoicePB& PB, s32* _LeftBuffer, s32* _RightBuffer, int _Size);
+
+	void MixAudio();
 };

Source/Core/Core/HW/DSPHLE/UCodes/UCode_Zelda_Voice.cpp

@@ -738,18 +738,14 @@ ContinueWithBlock:
 		PB.NeedsReset = 0;
 	}
 }
-#if 0
-// size is in stereo samples.
-void CUCode_Zelda::MixAdd(short *_Buffer, int _Size)
+
+void CUCode_Zelda::MixAudio()
 {
-	std::lock_guard<std::mutex> lk(m_csMix);
-	// Safety check
-	if (_Size > 256 * 1024 - 8)
-		_Size = 256 * 1024 - 8;
+	const int BufferSamples = 5 * 16;
 
 	// Final mix buffers
-	memset(m_LeftBuffer, 0, _Size * sizeof(s32));
-	memset(m_RightBuffer, 0, _Size * sizeof(s32));
+	memset(m_LeftBuffer, 0, BufferSamples * sizeof(s32));
+	memset(m_RightBuffer, 0, BufferSamples * sizeof(s32));
 
 	// For each PB...
 	for (u32 i = 0; i < m_NumVoices; i++)
@@ -769,23 +765,24 @@ void CUCode_Zelda::MixAdd(short *_Buffer, int _Size)
 		if (pb.KeyOff != 0)
 			continue;
 
-		RenderAddVoice(pb, m_LeftBuffer, m_RightBuffer, _Size);
+		RenderAddVoice(pb, m_LeftBuffer, m_RightBuffer, BufferSamples);
 		WritebackVoicePB(m_VoicePBsAddr + (i * 0x180), pb);
 	}
 
 	// Post processing, final conversion.
-	for (int i = 0; i < _Size; i++)
+	s16* left_buffer = (s16*)HLEMemory_Get_Pointer(m_LeftBuffersAddr);
+	s16* right_buffer = (s16*)HLEMemory_Get_Pointer(m_RightBuffersAddr);
+	left_buffer += m_CurBuffer * BufferSamples;
+	right_buffer += m_CurBuffer * BufferSamples;
+	for (int i = 0; i < BufferSamples; i++)
 	{
-		s32 left  = (s32)_Buffer[0] + m_LeftBuffer[i];
-		s32 right = (s32)_Buffer[1] + m_RightBuffer[i];
+		s32 left = m_LeftBuffer[i];
+		s32 right = m_RightBuffer[i];
 
 		MathUtil::Clamp(&left, -32768, 32767);
-		_Buffer[0] = (short)left;
+		left_buffer[i] = Common::swap16((short)left);
 
 		MathUtil::Clamp(&right, -32768, 32767);
-		_Buffer[1] = (short)right;
-
-		_Buffer += 2;
+		right_buffer[i] = Common::swap16((short)right);
 	}
 }
-#endif

Source/Core/Core/HW/DSPHLE/UCodes/UCodes.h

@@ -94,7 +94,6 @@ protected:
 	void DoStateShared(PointerWrap &p);
 
 	CMailHandler& m_rMailHandler;
-	std::mutex m_csMix;
 
 	enum EDSP_Codes
 	{