1 files changed, 89 insertions, 0 deletions
diff --git a/Ryujinx.Audio.Renderer/Dsp/Command/BiquadFilterCommand.cs b/Ryujinx.Audio.Renderer/Dsp/Command/BiquadFilterCommand.cs
new file mode 100644
index 00000000..d00d3371
--- /dev/null
+++ b/Ryujinx.Audio.Renderer/Dsp/Command/BiquadFilterCommand.cs
@@ -0,0 +1,89 @@
+//
+// Copyright (c) 2019-2020 Ryujinx
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+
+using Ryujinx.Audio.Renderer.Dsp.State;
+using Ryujinx.Audio.Renderer.Parameter;
+using System;
+
+namespace Ryujinx.Audio.Renderer.Dsp.Command
+{
+    public class BiquadFilterCommand : ICommand
+    {
+        public bool Enabled { get; set; }
+
+        public int NodeId { get; }
+
+        public CommandType CommandType => CommandType.BiquadFilter;
+
+        public ulong EstimatedProcessingTime { get; set; }
+
+        public BiquadFilterParameter Parameter { get; }
+        public Memory<BiquadFilterState> BiquadFilterState { get; }
+        public int InputBufferIndex { get; }
+        public int OutputBufferIndex { get; }
+        public bool NeedInitialization { get; }
+
+        public BiquadFilterCommand(int baseIndex, ref BiquadFilterParameter filter, Memory<BiquadFilterState> biquadFilterStateMemory, int inputBufferOffset, int outputBufferOffset, bool needInitialization, int nodeId)
+        {
+            Parameter = filter;
+            BiquadFilterState = biquadFilterStateMemory;
+            InputBufferIndex = baseIndex + inputBufferOffset;
+            OutputBufferIndex = baseIndex + outputBufferOffset;
+            NeedInitialization = needInitialization;
+
+            Enabled = true;
+            NodeId = nodeId;
+        }
+
+        private void ProcessBiquadFilter(Span<float> outputBuffer, ReadOnlySpan<float> inputBuffer, uint sampleCount)
+        {
+            const int fixedPointPrecisionForParameter = 14;
+
+            float a0 = FixedPointHelper.ToFloat(Parameter.Numerator[0], fixedPointPrecisionForParameter);
+            float a1 = FixedPointHelper.ToFloat(Parameter.Numerator[1], fixedPointPrecisionForParameter);
+            float a2 = FixedPointHelper.ToFloat(Parameter.Numerator[2], fixedPointPrecisionForParameter);
+
+            float b1 = FixedPointHelper.ToFloat(Parameter.Denominator[0], fixedPointPrecisionForParameter);
+            float b2 = FixedPointHelper.ToFloat(Parameter.Denominator[1], fixedPointPrecisionForParameter);
+
+            ref BiquadFilterState state = ref BiquadFilterState.Span[0];
+
+            for (int i = 0; i < sampleCount; i++)
+            {
+                float input = inputBuffer[i];
+                float output = input * a0 + state.Z1;
+
+                state.Z1 = input * a1 + output * b1 + state.Z2;
+                state.Z2 = input * a2 + output * b2;
+
+                outputBuffer[i] = output;
+            }
+        }
+
+        public void Process(CommandList context)
+        {
+            Span<float> outputBuffer = context.GetBuffer(InputBufferIndex);
+
+            if (NeedInitialization)
+            {
+                BiquadFilterState.Span[0] = new BiquadFilterState();
+            }
+
+            ProcessBiquadFilter(outputBuffer, outputBuffer, context.SampleCount);
+        }
+    }
+}