1 files changed, 68 insertions, 0 deletions
diff --git a/src/Ryujinx.Audio/Renderer/Dsp/Command/DownMixSurroundToStereoCommand.cs b/src/Ryujinx.Audio/Renderer/Dsp/Command/DownMixSurroundToStereoCommand.cs
new file mode 100644
index 00000000..79cefcc5
--- /dev/null
+++ b/src/Ryujinx.Audio/Renderer/Dsp/Command/DownMixSurroundToStereoCommand.cs
@@ -0,0 +1,68 @@
+using System;
+using System.Runtime.CompilerServices;
+
+namespace Ryujinx.Audio.Renderer.Dsp.Command
+{
+    public class DownMixSurroundToStereoCommand : ICommand
+    {
+        public bool Enabled { get; set; }
+
+        public int NodeId { get; }
+
+        public CommandType CommandType => CommandType.DownMixSurroundToStereo;
+
+        public uint EstimatedProcessingTime { get; set; }
+
+        public ushort[] InputBufferIndices { get; }
+        public ushort[] OutputBufferIndices { get; }
+
+        public float[] Coefficients { get; }
+
+        public DownMixSurroundToStereoCommand(uint bufferOffset, Span<byte> inputBufferOffset, Span<byte> outputBufferOffset, float[] downMixParameter, int nodeId)
+        {
+            Enabled = true;
+            NodeId = nodeId;
+
+            InputBufferIndices = new ushort[Constants.VoiceChannelCountMax];
+            OutputBufferIndices = new ushort[Constants.VoiceChannelCountMax];
+
+            for (int i = 0; i < Constants.VoiceChannelCountMax; i++)
+            {
+                InputBufferIndices[i] = (ushort)(bufferOffset + inputBufferOffset[i]);
+                OutputBufferIndices[i] = (ushort)(bufferOffset + outputBufferOffset[i]);
+            }
+
+            Coefficients = downMixParameter;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static float DownMixSurroundToStereo(ReadOnlySpan<float> coefficients, float back, float lfe, float center, float front)
+        {
+            return FloatingPointHelper.RoundUp(coefficients[3] * back + coefficients[2] * lfe + coefficients[1] * center + coefficients[0] * front);
+        }
+
+        public void Process(CommandList context)
+        {
+            ReadOnlySpan<float> frontLeft = context.GetBuffer(InputBufferIndices[0]);
+            ReadOnlySpan<float> frontRight = context.GetBuffer(InputBufferIndices[1]);
+            ReadOnlySpan<float> frontCenter = context.GetBuffer(InputBufferIndices[2]);
+            ReadOnlySpan<float> lowFrequency = context.GetBuffer(InputBufferIndices[3]);
+            ReadOnlySpan<float> backLeft = context.GetBuffer(InputBufferIndices[4]);
+            ReadOnlySpan<float> backRight = context.GetBuffer(InputBufferIndices[5]);
+
+            Span<float> stereoLeft = context.GetBuffer(OutputBufferIndices[0]);
+            Span<float> stereoRight = context.GetBuffer(OutputBufferIndices[1]);
+
+            for (int i = 0; i < context.SampleCount; i++)
+            {
+                stereoLeft[i] = DownMixSurroundToStereo(Coefficients, backLeft[i], lowFrequency[i], frontCenter[i], frontLeft[i]);
+                stereoRight[i] = DownMixSurroundToStereo(Coefficients, backRight[i], lowFrequency[i], frontCenter[i], frontRight[i]);
+            }
+
+            context.ClearBuffer(OutputBufferIndices[2]);
+            context.ClearBuffer(OutputBufferIndices[3]);
+            context.ClearBuffer(OutputBufferIndices[4]);
+            context.ClearBuffer(OutputBufferIndices[5]);
+        }
+    }
+}
+\ No newline at end of file