cellAudio(Out): properly implement all downmixing modes (#12252)

rpcs3/Emu/Audio/AudioBackend.h

@@ -136,7 +136,7 @@ public:
 	static void normalize(u32 sample_cnt, const f32* src, f32* dst);
 
 	/*
-	 * Returns the channel count and the downmix mode.
+	 * Returns the output channel count and downmix mode.
 	 */
 	static std::pair<AudioChannelCnt, AudioChannelCnt> get_channel_count_and_downmixer(u32 device_index);
 

rpcs3/Emu/Cell/Modules/cellAudio.cpp

@@ -845,17 +845,55 @@ void cell_audio_thread::operator()()
 		// Mix
 		float* buf = ringbuffer->get_current_buffer();
 
+		switch (cfg.audio_channels)
+		{
+		case 2:
 			switch (cfg.audio_downmix)
 			{
+			case AudioChannelCnt::SURROUND_7_1:
+				mix<AudioChannelCnt::STEREO, AudioChannelCnt::SURROUND_7_1>(buf);
+				break;
 			case AudioChannelCnt::STEREO:
-			mix<AudioChannelCnt::STEREO>(buf);
+				mix<AudioChannelCnt::STEREO, AudioChannelCnt::STEREO>(buf);
 				break;
 			case AudioChannelCnt::SURROUND_5_1:
-			mix<AudioChannelCnt::SURROUND_5_1>(buf);
+				mix<AudioChannelCnt::STEREO, AudioChannelCnt::SURROUND_5_1>(buf);
 				break;
+			}
+			break;
+
+		case 6:
+			switch (cfg.audio_downmix)
+			{
 			case AudioChannelCnt::SURROUND_7_1:
-			mix<AudioChannelCnt::SURROUND_7_1>(buf);
+				mix<AudioChannelCnt::SURROUND_5_1, AudioChannelCnt::SURROUND_7_1>(buf);
 				break;
+			case AudioChannelCnt::STEREO:
+				mix<AudioChannelCnt::SURROUND_5_1, AudioChannelCnt::STEREO>(buf);
+				break;
+			case AudioChannelCnt::SURROUND_5_1:
+				mix<AudioChannelCnt::SURROUND_5_1, AudioChannelCnt::SURROUND_5_1>(buf);
+				break;
+			}
+			break;
+
+		case 8:
+			switch (cfg.audio_downmix)
+			{
+			case AudioChannelCnt::SURROUND_7_1:
+				mix<AudioChannelCnt::SURROUND_7_1, AudioChannelCnt::SURROUND_7_1>(buf);
+				break;
+			case AudioChannelCnt::STEREO:
+				mix<AudioChannelCnt::SURROUND_7_1, AudioChannelCnt::STEREO>(buf);
+				break;
+			case AudioChannelCnt::SURROUND_5_1:
+				mix<AudioChannelCnt::SURROUND_7_1, AudioChannelCnt::SURROUND_5_1>(buf);
+				break;
+			}
+			break;
+
+		default:
+			fmt::throw_exception("Unsupported channel count in cell_audio_config: %d", static_cast<u32>(cfg.audio_channels));
 		}
 
 		// Enqueue
@@ -882,13 +920,13 @@ audio_port* cell_audio_thread::open_port()
 	return nullptr;
 }
 
-template <AudioChannelCnt downmix>
+template <AudioChannelCnt channels, AudioChannelCnt downmix>
 void cell_audio_thread::mix(float* out_buffer, s32 offset)
 {
 	AUDIT(out_buffer != nullptr);
 
-	constexpr u32 channels = static_cast<u32>(downmix);
+	constexpr u32 out_channels = static_cast<u32>(channels);
-	constexpr u32 out_buffer_sz = channels * AUDIO_BUFFER_SAMPLES;
+	constexpr u32 out_buffer_sz = out_channels * AUDIO_BUFFER_SAMPLES;
 
 	const float master_volume = g_cfg.audio.volume / 100.0f;
 
@@ -928,7 +966,7 @@ void cell_audio_thread::mix(float* out_buffer, s32 offset)
 
 		if (port.num_channels == 2)
 		{
-			for (u32 out = 0, in = 0; out < out_buffer_sz; out += channels, in += 2)
+			for (u32 out = 0, in = 0; out < out_buffer_sz; out += out_channels, in += 2)
 			{
 				step_volume(port);
 
@@ -941,7 +979,7 @@ void cell_audio_thread::mix(float* out_buffer, s32 offset)
 		}
 		else if (port.num_channels == 8)
 		{
-			for (u32 out = 0, in = 0; out < out_buffer_sz; out += channels, in += 8)
+			for (u32 out = 0, in = 0; out < out_buffer_sz; out += out_channels, in += 8)
 			{
 				step_volume(port);
 
@@ -965,17 +1003,41 @@ void cell_audio_thread::mix(float* out_buffer, s32 offset)
 				{
 					out_buffer[out + 0] += left;
 					out_buffer[out + 1] += right;
+
+					if constexpr (out_channels >= 6) // Only mix the surround channels into the output if surround output is configured
+					{
 						out_buffer[out + 2] += center;
 						out_buffer[out + 3] += low_freq;
+
+						if constexpr (out_channels == 6)
+						{
 							out_buffer[out + 4] += side_left + rear_left;
 							out_buffer[out + 5] += side_right + rear_right;
 						}
+						else // When using 7.1 ouput, out_buffer[out + 4] and out_buffer[out + 5] are the rear channels, so the side channels need to be mixed into [out + 6] and [out + 7]
+						{
+							out_buffer[out + 6] += side_left + rear_left;
+							out_buffer[out + 7] += side_right + rear_right;
+						}
+					}
+				}
 				else
 				{
 					out_buffer[out + 0] += left;
 					out_buffer[out + 1] += right;
+
+					if constexpr (out_channels >= 6) // Only mix the surround channels into the output if surround output is configured
+					{
 						out_buffer[out + 2] += center;
 						out_buffer[out + 3] += low_freq;
+
+						if constexpr (out_channels == 6)
+						{
+							out_buffer[out + 4] += side_left;
+							out_buffer[out + 5] += side_right;
+						}
+						else
+						{
 							out_buffer[out + 4] += rear_left;
 							out_buffer[out + 5] += rear_right;
 							out_buffer[out + 6] += side_left;
@@ -983,6 +1045,8 @@ void cell_audio_thread::mix(float* out_buffer, s32 offset)
 						}
 					}
 				}
+			}
+		}
 		else
 		{
 			fmt::throw_exception("Unknown channel count (port=%u, channel=%d)", port.number, port.num_channels);

rpcs3/Emu/Cell/Modules/cellAudio.h

@@ -348,7 +348,7 @@ private:
 	void reset_ports(s32 offset = 0);
 	void advance(u64 timestamp);
 	std::tuple<u32, u32, u32, u32> count_port_buffer_tags();
-	template <AudioChannelCnt downmix>
+	template <AudioChannelCnt channels, AudioChannelCnt downmix>
 	void mix(float* out_buffer, s32 offset = 0);
 	void finish_port_volume_stepping();
 

rpcs3/Emu/Cell/Modules/cellAudioOut.cpp

@@ -180,42 +180,27 @@ audio_out_configuration::audio_out_configuration()
 
 std::pair<AudioChannelCnt, AudioChannelCnt> audio_out_configuration::audio_out::get_channel_count_and_downmixer() const
 {
+	std::pair<AudioChannelCnt, AudioChannelCnt> ret;
+
+	switch (sound_mode.channel)
+	{
+	case 2: ret.first = AudioChannelCnt::STEREO; break;
+	case 6: ret.first = AudioChannelCnt::SURROUND_5_1; break;
+	case 8: ret.first = AudioChannelCnt::SURROUND_7_1; break;
+	default:
+		fmt::throw_exception("Unsupported channel count in cellAudioOut sound_mode: %d", sound_mode.channel);
+	}
+
 	switch (downmixer)
 	{
-	case CELL_AUDIO_OUT_DOWNMIXER_NONE:
+	case CELL_AUDIO_OUT_DOWNMIXER_NONE: ret.second = AudioChannelCnt::SURROUND_7_1; break;
-	{
+	case CELL_AUDIO_OUT_DOWNMIXER_TYPE_A: ret.second = AudioChannelCnt::STEREO; break;
-		switch (channels)
+	case CELL_AUDIO_OUT_DOWNMIXER_TYPE_B: ret.second = AudioChannelCnt::SURROUND_5_1; break;
-		{
-		case 2: return { AudioChannelCnt::STEREO, AudioChannelCnt::STEREO };
-		case 6: return { AudioChannelCnt::SURROUND_5_1, AudioChannelCnt::SURROUND_5_1 };
-		case 8: return { AudioChannelCnt::SURROUND_7_1, AudioChannelCnt::SURROUND_7_1 };
 	default:
-			fmt::throw_exception("Unsupported channel count in cellAudioOut config: %d", channels);
+		fmt::throw_exception("Unsupported downmixer in cellAudioOut config: %d", downmixer);
-		}
-	}
-	case CELL_AUDIO_OUT_DOWNMIXER_TYPE_A:
-	{
-		switch (channels)
-		{
-		case 2:
-			return { AudioChannelCnt::SURROUND_7_1, AudioChannelCnt::STEREO };
-		default:
-			fmt::throw_exception("Unsupported channel count for CELL_AUDIO_OUT_DOWNMIXER_TYPE_A in cellAudioOut config: %d", channels);
-		}
-	}
-	case CELL_AUDIO_OUT_DOWNMIXER_TYPE_B:
-	{
-		switch (channels)
-		{
-		case 6:
-			return { AudioChannelCnt::SURROUND_7_1, AudioChannelCnt::SURROUND_5_1 };
-		default:
-			fmt::throw_exception("Unsupported channel count for CELL_AUDIO_OUT_DOWNMIXER_TYPE_B in cellAudioOut config: %d", channels);
-		}
-	}
-	default:
-		fmt::throw_exception("Unknown downmixer in cellAudioOut config: %d", downmixer);
 	}
+
+	return ret;
 }
 
 error_code cellAudioOutGetNumberOfDevice(u32 audioOut);
@@ -361,34 +346,26 @@ error_code cellAudioOutConfigure(u32 audioOut, vm::ptr<CellAudioOutConfiguration
 		audio_out_configuration::audio_out& out = cfg.out.at(audioOut);
 
 		// Apparently the set config does not necessarily have to exist in the list of sound modes.
-		// For example 8 channels are used if the downMixer is set even if the PS3 only supports 2 channel output.
 
 		if (out.channels != config->channel || out.encoder != config->encoder || out.downmixer != config->downMixer)
 		{
 			out.channels = config->channel;
 			out.encoder = config->encoder;
+
+			if (config->downMixer > CELL_AUDIO_OUT_DOWNMIXER_TYPE_B) // PS3 ignores invalid downMixer values and keeps the previous valid one instead
+			{
+				cellSysutil.warning("cellAudioOutConfigure: Invalid downmixing mode configured: %d. Keeping old mode: downMixer=%d",
+					config->downMixer, out.downmixer);
+			}
+			else
+			{
 				out.downmixer = config->downMixer;
+			}
 
 			// Try to find the best sound mode for this configuration
-			const auto [channels, downmixer] = out.get_channel_count_and_downmixer();
+			const auto it = std::find_if(out.sound_modes.cbegin(), out.sound_modes.cend(), [&out](const CellAudioOutSoundMode& mode)
-			const auto it = std::find_if(out.sound_modes.cbegin(), out.sound_modes.cend(), [channels = channels, &out](const CellAudioOutSoundMode& mode)
 				{
-				if (mode.type != out.encoder)
+					return mode.type == out.encoder && mode.channel == out.channels;
-				{
-					return false;
-				}
-
-				if (out.downmixer == CELL_AUDIO_OUT_DOWNMIXER_TYPE_A)
-				{
-					return mode.channel == CELL_AUDIO_OUT_CHNUM_2;
-				}
-
-				if (out.downmixer == CELL_AUDIO_OUT_DOWNMIXER_TYPE_B)
-				{
-					return mode.channel == CELL_AUDIO_OUT_CHNUM_6;
-				}
-
-				return mode.channel == static_cast<u8>(channels);
 				});
 
 			if (it != out.sound_modes.cend())
@@ -398,7 +375,7 @@ error_code cellAudioOutConfigure(u32 audioOut, vm::ptr<CellAudioOutConfiguration
 			else
 			{
 				cellSysutil.warning("cellAudioOutConfigure: Could not find an ideal sound mode for %d channel output. Keeping old mode: channels=%d, encoder=%d, fs=%d",
-					static_cast<u32>(channels), out.sound_mode.channel, out.sound_mode.type, out.sound_mode.fs);
+					config->channel, out.sound_mode.channel, out.sound_mode.type, out.sound_mode.fs);
 			}
 
 			needs_reset = true;