Update audio renderer to REV12: Add support for splitter biquad filter (#6813)

* Update audio renderer to REV12: Add support for splitter biquad filter

* Formatting

* Official names

* Update BiquadFilterState size + other fixes

* Update tests

* Update comment for version 2

* Size test for SplitterDestinationVersion2

* Should use Volume1 if no ramp

src/Ryujinx.Audio/Renderer/Common/VoiceUpdateState.cs

@@ -15,7 +15,6 @@ namespace Ryujinx.Audio.Renderer.Common
     {
         public const int Align = 0x10;
         public const int BiquadStateOffset = 0x0;
-        public const int BiquadStateSize = 0x10;
 
         /// <summary>
         /// The state of the biquad filters of this voice.

src/Ryujinx.Audio/Renderer/Dsp/BiquadFilterHelper.cs

@@ -16,10 +16,15 @@ namespace Ryujinx.Audio.Renderer.Dsp
         /// <param name="parameter">The biquad filter parameter</param>
         /// <param name="state">The biquad filter state</param>
         /// <param name="outputBuffer">The output buffer to write the result</param>
-        /// <param name="inputBuffer">The input buffer to write the result</param>
+        /// <param name="inputBuffer">The input buffer to read the samples from</param>
         /// <param name="sampleCount">The count of samples to process</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static void ProcessBiquadFilter(ref BiquadFilterParameter parameter, ref BiquadFilterState state, Span<float> outputBuffer, ReadOnlySpan<float> inputBuffer, uint sampleCount)
+        public static void ProcessBiquadFilter(
+            ref BiquadFilterParameter parameter,
+            ref BiquadFilterState state,
+            Span<float> outputBuffer,
+            ReadOnlySpan<float> inputBuffer,
+            uint sampleCount)
         {
             float a0 = FixedPointHelper.ToFloat(parameter.Numerator[0], FixedPointPrecisionForParameter);
             float a1 = FixedPointHelper.ToFloat(parameter.Numerator[1], FixedPointPrecisionForParameter);
@@ -41,23 +46,24 @@ namespace Ryujinx.Audio.Renderer.Dsp
         }
 
         /// <summary>
-        /// Apply multiple biquad filter.
+        /// Apply a single biquad filter and mix the result into the output buffer.
         /// </summary>
         /// <remarks>This is implemented with a direct form 1.</remarks>
-        /// <param name="parameters">The biquad filter parameter</param>
-        /// <param name="states">The biquad filter state</param>
+        /// <param name="parameter">The biquad filter parameter</param>
+        /// <param name="state">The biquad filter state</param>
         /// <param name="outputBuffer">The output buffer to write the result</param>
-        /// <param name="inputBuffer">The input buffer to write the result</param>
+        /// <param name="inputBuffer">The input buffer to read the samples from</param>
         /// <param name="sampleCount">The count of samples to process</param>
+        /// <param name="volume">Mix volume</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static void ProcessBiquadFilter(ReadOnlySpan<BiquadFilterParameter> parameters, Span<BiquadFilterState> states, Span<float> outputBuffer, ReadOnlySpan<float> inputBuffer, uint sampleCount)
+        public static void ProcessBiquadFilterAndMix(
+            ref BiquadFilterParameter parameter,
+            ref BiquadFilterState state,
+            Span<float> outputBuffer,
+            ReadOnlySpan<float> inputBuffer,
+            uint sampleCount,
+            float volume)
         {
-            for (int stageIndex = 0; stageIndex < parameters.Length; stageIndex++)
-            {
-                BiquadFilterParameter parameter = parameters[stageIndex];
-
-                ref BiquadFilterState state = ref states[stageIndex];
-
             float a0 = FixedPointHelper.ToFloat(parameter.Numerator[0], FixedPointPrecisionForParameter);
             float a1 = FixedPointHelper.ToFloat(parameter.Numerator[1], FixedPointPrecisionForParameter);
             float a2 = FixedPointHelper.ToFloat(parameter.Numerator[2], FixedPointPrecisionForParameter);
@@ -75,9 +81,227 @@ namespace Ryujinx.Audio.Renderer.Dsp
                 state.State3 = state.State2;
                 state.State2 = output;
 
+                outputBuffer[i] += FloatingPointHelper.MultiplyRoundUp(output, volume);
+            }
+        }
+
+        /// <summary>
+        /// Apply a single biquad filter and mix the result into the output buffer with volume ramp.
+        /// </summary>
+        /// <remarks>This is implemented with a direct form 1.</remarks>
+        /// <param name="parameter">The biquad filter parameter</param>
+        /// <param name="state">The biquad filter state</param>
+        /// <param name="outputBuffer">The output buffer to write the result</param>
+        /// <param name="inputBuffer">The input buffer to read the samples from</param>
+        /// <param name="sampleCount">The count of samples to process</param>
+        /// <param name="volume">Initial mix volume</param>
+        /// <param name="ramp">Volume increment step</param>
+        /// <returns>Last filtered sample value</returns>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float ProcessBiquadFilterAndMixRamp(
+            ref BiquadFilterParameter parameter,
+            ref BiquadFilterState state,
+            Span<float> outputBuffer,
+            ReadOnlySpan<float> inputBuffer,
+            uint sampleCount,
+            float volume,
+            float ramp)
+        {
+            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);
+
+            float mixState = 0f;
+
+            for (int i = 0; i < sampleCount; i++)
+            {
+                float input = inputBuffer[i];
+                float output = input * a0 + state.State0 * a1 + state.State1 * a2 + state.State2 * b1 + state.State3 * b2;
+
+                state.State1 = state.State0;
+                state.State0 = input;
+                state.State3 = state.State2;
+                state.State2 = output;
+
+                mixState = FloatingPointHelper.MultiplyRoundUp(output, volume);
+
+                outputBuffer[i] += mixState;
+                volume += ramp;
+            }
+
+            return mixState;
+        }
+
+        /// <summary>
+        /// Apply multiple biquad filter.
+        /// </summary>
+        /// <remarks>This is implemented with a direct form 1.</remarks>
+        /// <param name="parameters">The biquad filter parameter</param>
+        /// <param name="states">The biquad filter state</param>
+        /// <param name="outputBuffer">The output buffer to write the result</param>
+        /// <param name="inputBuffer">The input buffer to read the samples from</param>
+        /// <param name="sampleCount">The count of samples to process</param>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ProcessBiquadFilter(
+            ReadOnlySpan<BiquadFilterParameter> parameters,
+            Span<BiquadFilterState> states,
+            Span<float> outputBuffer,
+            ReadOnlySpan<float> inputBuffer,
+            uint sampleCount)
+        {
+            for (int stageIndex = 0; stageIndex < parameters.Length; stageIndex++)
+            {
+                BiquadFilterParameter parameter = parameters[stageIndex];
+
+                ref BiquadFilterState state = ref states[stageIndex];
+
+                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);
+
+                for (int i = 0; i < sampleCount; i++)
+                {
+                    float input = stageIndex != 0 ? outputBuffer[i] : inputBuffer[i];
+                    float output = input * a0 + state.State0 * a1 + state.State1 * a2 + state.State2 * b1 + state.State3 * b2;
+
+                    state.State1 = state.State0;
+                    state.State0 = input;
+                    state.State3 = state.State2;
+                    state.State2 = output;
+
                     outputBuffer[i] = output;
                 }
             }
         }
+
+        /// <summary>
+        /// Apply double biquad filter and mix the result into the output buffer.
+        /// </summary>
+        /// <remarks>This is implemented with a direct form 1.</remarks>
+        /// <param name="parameters">The biquad filter parameter</param>
+        /// <param name="states">The biquad filter state</param>
+        /// <param name="outputBuffer">The output buffer to write the result</param>
+        /// <param name="inputBuffer">The input buffer to read the samples from</param>
+        /// <param name="sampleCount">The count of samples to process</param>
+        /// <param name="volume">Mix volume</param>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ProcessDoubleBiquadFilterAndMix(
+            ref BiquadFilterParameter parameter0,
+            ref BiquadFilterParameter parameter1,
+            ref BiquadFilterState state0,
+            ref BiquadFilterState state1,
+            Span<float> outputBuffer,
+            ReadOnlySpan<float> inputBuffer,
+            uint sampleCount,
+            float volume)
+        {
+            float a00 = FixedPointHelper.ToFloat(parameter0.Numerator[0], FixedPointPrecisionForParameter);
+            float a10 = FixedPointHelper.ToFloat(parameter0.Numerator[1], FixedPointPrecisionForParameter);
+            float a20 = FixedPointHelper.ToFloat(parameter0.Numerator[2], FixedPointPrecisionForParameter);
+
+            float b10 = FixedPointHelper.ToFloat(parameter0.Denominator[0], FixedPointPrecisionForParameter);
+            float b20 = FixedPointHelper.ToFloat(parameter0.Denominator[1], FixedPointPrecisionForParameter);
+
+            float a01 = FixedPointHelper.ToFloat(parameter1.Numerator[0], FixedPointPrecisionForParameter);
+            float a11 = FixedPointHelper.ToFloat(parameter1.Numerator[1], FixedPointPrecisionForParameter);
+            float a21 = FixedPointHelper.ToFloat(parameter1.Numerator[2], FixedPointPrecisionForParameter);
+
+            float b11 = FixedPointHelper.ToFloat(parameter1.Denominator[0], FixedPointPrecisionForParameter);
+            float b21 = FixedPointHelper.ToFloat(parameter1.Denominator[1], FixedPointPrecisionForParameter);
+
+            for (int i = 0; i < sampleCount; i++)
+            {
+                float input = inputBuffer[i];
+                float output = input * a00 + state0.State0 * a10 + state0.State1 * a20 + state0.State2 * b10 + state0.State3 * b20;
+
+                state0.State1 = state0.State0;
+                state0.State0 = input;
+                state0.State3 = state0.State2;
+                state0.State2 = output;
+
+                input = output;
+                output = input * a01 + state1.State0 * a11 + state1.State1 * a21 + state1.State2 * b11 + state1.State3 * b21;
+
+                state1.State1 = state1.State0;
+                state1.State0 = input;
+                state1.State3 = state1.State2;
+                state1.State2 = output;
+
+                outputBuffer[i] += FloatingPointHelper.MultiplyRoundUp(output, volume);
+            }
+        }
+
+        /// <summary>
+        /// Apply double biquad filter and mix the result into the output buffer with volume ramp.
+        /// </summary>
+        /// <remarks>This is implemented with a direct form 1.</remarks>
+        /// <param name="parameters">The biquad filter parameter</param>
+        /// <param name="states">The biquad filter state</param>
+        /// <param name="outputBuffer">The output buffer to write the result</param>
+        /// <param name="inputBuffer">The input buffer to read the samples from</param>
+        /// <param name="sampleCount">The count of samples to process</param>
+        /// <param name="volume">Initial mix volume</param>
+        /// <param name="ramp">Volume increment step</param>
+        /// <returns>Last filtered sample value</returns>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float ProcessDoubleBiquadFilterAndMixRamp(
+            ref BiquadFilterParameter parameter0,
+            ref BiquadFilterParameter parameter1,
+            ref BiquadFilterState state0,
+            ref BiquadFilterState state1,
+            Span<float> outputBuffer,
+            ReadOnlySpan<float> inputBuffer,
+            uint sampleCount,
+            float volume,
+            float ramp)
+        {
+            float a00 = FixedPointHelper.ToFloat(parameter0.Numerator[0], FixedPointPrecisionForParameter);
+            float a10 = FixedPointHelper.ToFloat(parameter0.Numerator[1], FixedPointPrecisionForParameter);
+            float a20 = FixedPointHelper.ToFloat(parameter0.Numerator[2], FixedPointPrecisionForParameter);
+
+            float b10 = FixedPointHelper.ToFloat(parameter0.Denominator[0], FixedPointPrecisionForParameter);
+            float b20 = FixedPointHelper.ToFloat(parameter0.Denominator[1], FixedPointPrecisionForParameter);
+
+            float a01 = FixedPointHelper.ToFloat(parameter1.Numerator[0], FixedPointPrecisionForParameter);
+            float a11 = FixedPointHelper.ToFloat(parameter1.Numerator[1], FixedPointPrecisionForParameter);
+            float a21 = FixedPointHelper.ToFloat(parameter1.Numerator[2], FixedPointPrecisionForParameter);
+
+            float b11 = FixedPointHelper.ToFloat(parameter1.Denominator[0], FixedPointPrecisionForParameter);
+            float b21 = FixedPointHelper.ToFloat(parameter1.Denominator[1], FixedPointPrecisionForParameter);
+
+            float mixState = 0f;
+
+            for (int i = 0; i < sampleCount; i++)
+            {
+                float input = inputBuffer[i];
+                float output = input * a00 + state0.State0 * a10 + state0.State1 * a20 + state0.State2 * b10 + state0.State3 * b20;
+
+                state0.State1 = state0.State0;
+                state0.State0 = input;
+                state0.State3 = state0.State2;
+                state0.State2 = output;
+
+                input = output;
+                output = input * a01 + state1.State0 * a11 + state1.State1 * a21 + state1.State2 * b11 + state1.State3 * b21;
+
+                state1.State1 = state1.State0;
+                state1.State0 = input;
+                state1.State3 = state1.State2;
+                state1.State2 = output;
+
+                mixState = FloatingPointHelper.MultiplyRoundUp(output, volume);
+
+                outputBuffer[i] += mixState;
+                volume += ramp;
+            }
+
+            return mixState;
+        }
     }
 }

src/Ryujinx.Audio/Renderer/Dsp/Command/BiquadFilterAndMixCommand.cs

@@ -0,0 +1,123 @@
+using Ryujinx.Audio.Renderer.Common;
+using Ryujinx.Audio.Renderer.Dsp.State;
+using Ryujinx.Audio.Renderer.Parameter;
+using System;
+
+namespace Ryujinx.Audio.Renderer.Dsp.Command
+{
+    public class BiquadFilterAndMixCommand : ICommand
+    {
+        public bool Enabled { get; set; }
+
+        public int NodeId { get; }
+
+        public CommandType CommandType => CommandType.BiquadFilterAndMix;
+
+        public uint EstimatedProcessingTime { get; set; }
+
+        public ushort InputBufferIndex { get; }
+        public ushort OutputBufferIndex { get; }
+
+        private BiquadFilterParameter _parameter;
+
+        public Memory<BiquadFilterState> BiquadFilterState { get; }
+        public Memory<BiquadFilterState> PreviousBiquadFilterState { get; }
+
+        public Memory<VoiceUpdateState> State { get; }
+
+        public int LastSampleIndex { get; }
+
+        public float Volume0 { get; }
+        public float Volume1 { get; }
+
+        public bool NeedInitialization { get; }
+        public bool HasVolumeRamp { get; }
+        public bool IsFirstMixBuffer { get; }
+
+        public BiquadFilterAndMixCommand(
+            float volume0,
+            float volume1,
+            uint inputBufferIndex,
+            uint outputBufferIndex,
+            int lastSampleIndex,
+            Memory<VoiceUpdateState> state,
+            ref BiquadFilterParameter filter,
+            Memory<BiquadFilterState> biquadFilterState,
+            Memory<BiquadFilterState> previousBiquadFilterState,
+            bool needInitialization,
+            bool hasVolumeRamp,
+            bool isFirstMixBuffer,
+            int nodeId)
+        {
+            Enabled = true;
+            NodeId = nodeId;
+
+            InputBufferIndex = (ushort)inputBufferIndex;
+            OutputBufferIndex = (ushort)outputBufferIndex;
+
+            _parameter = filter;
+            BiquadFilterState = biquadFilterState;
+            PreviousBiquadFilterState = previousBiquadFilterState;
+
+            State = state;
+            LastSampleIndex = lastSampleIndex;
+
+            Volume0 = volume0;
+            Volume1 = volume1;
+
+            NeedInitialization = needInitialization;
+            HasVolumeRamp = hasVolumeRamp;
+            IsFirstMixBuffer = isFirstMixBuffer;
+        }
+
+        public void Process(CommandList context)
+        {
+            ReadOnlySpan<float> inputBuffer = context.GetBuffer(InputBufferIndex);
+            Span<float> outputBuffer = context.GetBuffer(OutputBufferIndex);
+
+            if (NeedInitialization)
+            {
+                // If there is no previous state, initialize to zero.
+
+                BiquadFilterState.Span[0] = new BiquadFilterState();
+            }
+            else if (IsFirstMixBuffer)
+            {
+                // This is the first buffer, set previous state to current state.
+
+                PreviousBiquadFilterState.Span[0] = BiquadFilterState.Span[0];
+            }
+            else
+            {
+                // Rewind the current state by copying back the previous state.
+
+                BiquadFilterState.Span[0] = PreviousBiquadFilterState.Span[0];
+            }
+
+            if (HasVolumeRamp)
+            {
+                float volume = Volume0;
+                float ramp = (Volume1 - Volume0) / (int)context.SampleCount;
+
+                State.Span[0].LastSamples[LastSampleIndex] = BiquadFilterHelper.ProcessBiquadFilterAndMixRamp(
+                    ref _parameter,
+                    ref BiquadFilterState.Span[0],
+                    outputBuffer,
+                    inputBuffer,
+                    context.SampleCount,
+                    volume,
+                    ramp);
+            }
+            else
+            {
+                BiquadFilterHelper.ProcessBiquadFilterAndMix(
+                    ref _parameter,
+                    ref BiquadFilterState.Span[0],
+                    outputBuffer,
+                    inputBuffer,
+                    context.SampleCount,
+                    Volume1);
+            }
+        }
+    }
+}

src/Ryujinx.Audio/Renderer/Dsp/Command/CommandType.cs

@@ -30,8 +30,10 @@ namespace Ryujinx.Audio.Renderer.Dsp.Command
         CopyMixBuffer,
         LimiterVersion1,
         LimiterVersion2,
-        GroupedBiquadFilter,
+        MultiTapBiquadFilter,
         CaptureBuffer,
         Compressor,
+        BiquadFilterAndMix,
+        MultiTapBiquadFilterAndMix,
     }
 }

src/Ryujinx.Audio/Renderer/Dsp/Command/MixRampGroupedCommand.cs

@@ -24,7 +24,14 @@ namespace Ryujinx.Audio.Renderer.Dsp.Command
 
         public Memory<VoiceUpdateState> State { get; }
 
-        public MixRampGroupedCommand(uint mixBufferCount, uint inputBufferIndex, uint outputBufferIndex, Span<float> volume0, Span<float> volume1, Memory<VoiceUpdateState> state, int nodeId)
+        public MixRampGroupedCommand(
+            uint mixBufferCount,
+            uint inputBufferIndex,
+            uint outputBufferIndex,
+            ReadOnlySpan<float> volume0,
+            ReadOnlySpan<float> volume1,
+            Memory<VoiceUpdateState> state,
+            int nodeId)
         {
             Enabled = true;
             MixBufferCount = mixBufferCount;
@@ -48,7 +55,12 @@ namespace Ryujinx.Audio.Renderer.Dsp.Command
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private static float ProcessMixRampGrouped(Span<float> outputBuffer, ReadOnlySpan<float> inputBuffer, float volume0, float volume1, int sampleCount)
+        private static float ProcessMixRampGrouped(
+            Span<float> outputBuffer,
+            ReadOnlySpan<float> inputBuffer,
+            float volume0,
+            float volume1,
+            int sampleCount)
         {
             float ramp = (volume1 - volume0) / sampleCount;
             float volume = volume0;

src/Ryujinx.Audio/Renderer/Dsp/Command/MultiTapBiquadFilterAndMixCommand.cs

@@ -0,0 +1,145 @@
+using Ryujinx.Audio.Renderer.Common;
+using Ryujinx.Audio.Renderer.Dsp.State;
+using Ryujinx.Audio.Renderer.Parameter;
+using System;
+
+namespace Ryujinx.Audio.Renderer.Dsp.Command
+{
+    public class MultiTapBiquadFilterAndMixCommand : ICommand
+    {
+        public bool Enabled { get; set; }
+
+        public int NodeId { get; }
+
+        public CommandType CommandType => CommandType.MultiTapBiquadFilterAndMix;
+
+        public uint EstimatedProcessingTime { get; set; }
+
+        public ushort InputBufferIndex { get; }
+        public ushort OutputBufferIndex { get; }
+
+        private BiquadFilterParameter _parameter0;
+        private BiquadFilterParameter _parameter1;
+
+        public Memory<BiquadFilterState> BiquadFilterState0 { get; }
+        public Memory<BiquadFilterState> BiquadFilterState1 { get; }
+        public Memory<BiquadFilterState> PreviousBiquadFilterState0 { get; }
+        public Memory<BiquadFilterState> PreviousBiquadFilterState1 { get; }
+
+        public Memory<VoiceUpdateState> State { get; }
+
+        public int LastSampleIndex { get; }
+
+        public float Volume0 { get; }
+        public float Volume1 { get; }
+
+        public bool NeedInitialization0 { get; }
+        public bool NeedInitialization1 { get; }
+        public bool HasVolumeRamp { get; }
+        public bool IsFirstMixBuffer { get; }
+
+        public MultiTapBiquadFilterAndMixCommand(
+            float volume0,
+            float volume1,
+            uint inputBufferIndex,
+            uint outputBufferIndex,
+            int lastSampleIndex,
+            Memory<VoiceUpdateState> state,
+            ref BiquadFilterParameter filter0,
+            ref BiquadFilterParameter filter1,
+            Memory<BiquadFilterState> biquadFilterState0,
+            Memory<BiquadFilterState> biquadFilterState1,
+            Memory<BiquadFilterState> previousBiquadFilterState0,
+            Memory<BiquadFilterState> previousBiquadFilterState1,
+            bool needInitialization0,
+            bool needInitialization1,
+            bool hasVolumeRamp,
+            bool isFirstMixBuffer,
+            int nodeId)
+        {
+            Enabled = true;
+            NodeId = nodeId;
+
+            InputBufferIndex = (ushort)inputBufferIndex;
+            OutputBufferIndex = (ushort)outputBufferIndex;
+
+            _parameter0 = filter0;
+            _parameter1 = filter1;
+            BiquadFilterState0 = biquadFilterState0;
+            BiquadFilterState1 = biquadFilterState1;
+            PreviousBiquadFilterState0 = previousBiquadFilterState0;
+            PreviousBiquadFilterState1 = previousBiquadFilterState1;
+
+            State = state;
+            LastSampleIndex = lastSampleIndex;
+
+            Volume0 = volume0;
+            Volume1 = volume1;
+
+            NeedInitialization0 = needInitialization0;
+            NeedInitialization1 = needInitialization1;
+            HasVolumeRamp = hasVolumeRamp;
+            IsFirstMixBuffer = isFirstMixBuffer;
+        }
+
+        private void UpdateState(Memory<BiquadFilterState> state, Memory<BiquadFilterState> previousState, bool needInitialization)
+        {
+            if (needInitialization)
+            {
+                // If there is no previous state, initialize to zero.
+
+                state.Span[0] = new BiquadFilterState();
+            }
+            else if (IsFirstMixBuffer)
+            {
+                // This is the first buffer, set previous state to current state.
+
+                previousState.Span[0] = state.Span[0];
+            }
+            else
+            {
+                // Rewind the current state by copying back the previous state.
+
+                state.Span[0] = previousState.Span[0];
+            }
+        }
+
+        public void Process(CommandList context)
+        {
+            ReadOnlySpan<float> inputBuffer = context.GetBuffer(InputBufferIndex);
+            Span<float> outputBuffer = context.GetBuffer(OutputBufferIndex);
+
+            UpdateState(BiquadFilterState0, PreviousBiquadFilterState0, NeedInitialization0);
+            UpdateState(BiquadFilterState1, PreviousBiquadFilterState1, NeedInitialization1);
+
+            if (HasVolumeRamp)
+            {
+                float volume = Volume0;
+                float ramp = (Volume1 - Volume0) / (int)context.SampleCount;
+
+                State.Span[0].LastSamples[LastSampleIndex] = BiquadFilterHelper.ProcessDoubleBiquadFilterAndMixRamp(
+                    ref _parameter0,
+                    ref _parameter1,
+                    ref BiquadFilterState0.Span[0],
+                    ref BiquadFilterState1.Span[0],
+                    outputBuffer,
+                    inputBuffer,
+                    context.SampleCount,
+                    volume,
+                    ramp);
+            }
+            else
+            {
+                BiquadFilterHelper.ProcessDoubleBiquadFilterAndMix(
+                    ref _parameter0,
+                    ref _parameter1,
+                    ref BiquadFilterState0.Span[0],
+                    ref BiquadFilterState1.Span[0],
+                    outputBuffer,
+                    inputBuffer,
+                    context.SampleCount,
+                    Volume1);
+            }
+        }
+    }
+}

src/Ryujinx.Audio/Renderer/Dsp/Command/MultiTapBiquadFilterCommand.cs

@@ -4,13 +4,13 @@ using System;
 
 namespace Ryujinx.Audio.Renderer.Dsp.Command
 {
-    public class GroupedBiquadFilterCommand : ICommand
+    public class MultiTapBiquadFilterCommand : ICommand
     {
         public bool Enabled { get; set; }
 
         public int NodeId { get; }
 
-        public CommandType CommandType => CommandType.GroupedBiquadFilter;
+        public CommandType CommandType => CommandType.MultiTapBiquadFilter;
 
         public uint EstimatedProcessingTime { get; set; }
 
@@ -20,7 +20,7 @@ namespace Ryujinx.Audio.Renderer.Dsp.Command
         private readonly int _outputBufferIndex;
         private readonly bool[] _isInitialized;
 
-        public GroupedBiquadFilterCommand(int baseIndex, ReadOnlySpan<BiquadFilterParameter> filters, Memory<BiquadFilterState> biquadFilterStateMemory, int inputBufferOffset, int outputBufferOffset, ReadOnlySpan<bool> isInitialized, int nodeId)
+        public MultiTapBiquadFilterCommand(int baseIndex, ReadOnlySpan<BiquadFilterParameter> filters, Memory<BiquadFilterState> biquadFilterStateMemory, int inputBufferOffset, int outputBufferOffset, ReadOnlySpan<bool> isInitialized, int nodeId)
         {
             _parameters = filters.ToArray();
             _biquadFilterStates = biquadFilterStateMemory;

src/Ryujinx.Audio/Renderer/Dsp/State/BiquadFilterState.cs

@@ -2,12 +2,16 @@ using System.Runtime.InteropServices;
 
 namespace Ryujinx.Audio.Renderer.Dsp.State
 {
-    [StructLayout(LayoutKind.Sequential, Pack = 1, Size = 0x10)]
+    [StructLayout(LayoutKind.Sequential, Pack = 1, Size = 0x20)]
     public struct BiquadFilterState
     {
         public float State0;
         public float State1;
         public float State2;
         public float State3;
+        public float State4;
+        public float State5;
+        public float State6;
+        public float State7;
     }
 }

src/Ryujinx.Audio/Renderer/Parameter/ISplitterDestinationInParameter.cs

@@ -0,0 +1,43 @@
+using Ryujinx.Common.Memory;
+using System;
+
+namespace Ryujinx.Audio.Renderer.Parameter
+{
+    /// <summary>
+    /// Generic interface for the splitter destination parameters.
+    /// </summary>
+    public interface ISplitterDestinationInParameter
+    {
+        /// <summary>
+        /// Target splitter destination data id.
+        /// </summary>
+        int Id { get; }
+
+        /// <summary>
+        /// The mix to output the result of the splitter.
+        /// </summary>
+        int DestinationId { get; }
+
+        /// <summary>
+        /// Biquad filter parameters.
+        /// </summary>
+        Array2<BiquadFilterParameter> BiquadFilters { get; }
+
+        /// <summary>
+        /// Set to true if in use.
+        /// </summary>
+        bool IsUsed { get; }
+
+        /// <summary>
+        /// Mix buffer volumes.
+        /// </summary>
+        /// <remarks>Used when a splitter id is specified in the mix.</remarks>
+        Span<float> MixBufferVolume { get; }
+
+        /// <summary>
+        /// Check if the magic is valid.
+        /// </summary>
+        /// <returns>Returns true if the magic is valid.</returns>
+        bool IsMagicValid();
+    }
+}

src/Ryujinx.Audio/Renderer/Parameter/SplitterDestinationInParameterVersion1.cs

@@ -1,3 +1,4 @@
+using Ryujinx.Common.Memory;
 using Ryujinx.Common.Utilities;
 using System;
 using System.Runtime.InteropServices;
@@ -5,10 +6,10 @@ using System.Runtime.InteropServices;
 namespace Ryujinx.Audio.Renderer.Parameter
 {
     /// <summary>
-    /// Input header for a splitter destination update.
+    /// Input header for a splitter destination version 1 update.
     /// </summary>
     [StructLayout(LayoutKind.Sequential, Pack = 1)]
-    public struct SplitterDestinationInParameter
+    public struct SplitterDestinationInParameterVersion1 : ISplitterDestinationInParameter
     {
         /// <summary>
         /// Magic of the input header.
@@ -41,7 +42,7 @@ namespace Ryujinx.Audio.Renderer.Parameter
         /// </summary>
         private unsafe fixed byte _reserved[3];
 
-        [StructLayout(LayoutKind.Sequential, Size = 4 * Constants.MixBufferCountMax, Pack = 1)]
+        [StructLayout(LayoutKind.Sequential, Size = sizeof(float) * Constants.MixBufferCountMax, Pack = 1)]
         private struct MixArray { }
 
         /// <summary>
@@ -50,6 +51,14 @@ namespace Ryujinx.Audio.Renderer.Parameter
         /// <remarks>Used when a splitter id is specified in the mix.</remarks>
         public Span<float> MixBufferVolume => SpanHelpers.AsSpan<MixArray, float>(ref _mixBufferVolume);
 
+        readonly int ISplitterDestinationInParameter.Id => Id;
+
+        readonly int ISplitterDestinationInParameter.DestinationId => DestinationId;
+
+        readonly Array2<BiquadFilterParameter> ISplitterDestinationInParameter.BiquadFilters => default;
+
+        readonly bool ISplitterDestinationInParameter.IsUsed => IsUsed;
+
         /// <summary>
         /// The expected constant of any input header.
         /// </summary>

src/Ryujinx.Audio/Renderer/Parameter/SplitterDestinationInParameterVersion2.cs

@@ -0,0 +1,81 @@
+using Ryujinx.Common.Memory;
+using Ryujinx.Common.Utilities;
+using System;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.Audio.Renderer.Parameter
+{
+    /// <summary>
+    /// Input header for a splitter destination version 2 update.
+    /// </summary>
+    [StructLayout(LayoutKind.Sequential, Pack = 1)]
+    public struct SplitterDestinationInParameterVersion2 : ISplitterDestinationInParameter
+    {
+        /// <summary>
+        /// Magic of the input header.
+        /// </summary>
+        public uint Magic;
+
+        /// <summary>
+        /// Target splitter destination data id.
+        /// </summary>
+        public int Id;
+
+        /// <summary>
+        /// Mix buffer volumes storage.
+        /// </summary>
+        private MixArray _mixBufferVolume;
+
+        /// <summary>
+        /// The mix to output the result of the splitter.
+        /// </summary>
+        public int DestinationId;
+
+        /// <summary>
+        /// Biquad filter parameters.
+        /// </summary>
+        public Array2<BiquadFilterParameter> BiquadFilters;
+
+        /// <summary>
+        /// Set to true if in use.
+        /// </summary>
+        [MarshalAs(UnmanagedType.I1)]
+        public bool IsUsed;
+
+        /// <summary>
+        /// Reserved/padding.
+        /// </summary>
+        private unsafe fixed byte _reserved[11];
+
+        [StructLayout(LayoutKind.Sequential, Size = sizeof(float) * Constants.MixBufferCountMax, Pack = 1)]
+        private struct MixArray { }
+
+        /// <summary>
+        /// Mix buffer volumes.
+        /// </summary>
+        /// <remarks>Used when a splitter id is specified in the mix.</remarks>
+        public Span<float> MixBufferVolume => SpanHelpers.AsSpan<MixArray, float>(ref _mixBufferVolume);
+
+        readonly int ISplitterDestinationInParameter.Id => Id;
+
+        readonly int ISplitterDestinationInParameter.DestinationId => DestinationId;
+
+        readonly Array2<BiquadFilterParameter> ISplitterDestinationInParameter.BiquadFilters => BiquadFilters;
+
+        readonly bool ISplitterDestinationInParameter.IsUsed => IsUsed;
+
+        /// <summary>
+        /// The expected constant of any input header.
+        /// </summary>
+        private const uint ValidMagic = 0x44444E53;
+
+        /// <summary>
+        /// Check if the magic is valid.
+        /// </summary>
+        /// <returns>Returns true if the magic is valid.</returns>
+        public readonly bool IsMagicValid()
+        {
+            return Magic == ValidMagic;
+        }
+    }
+}

src/Ryujinx.Audio/Renderer/Server/AudioRenderSystem.cs

@@ -1,6 +1,7 @@
 using Ryujinx.Audio.Integration;
 using Ryujinx.Audio.Renderer.Common;
 using Ryujinx.Audio.Renderer.Dsp.Command;
+using Ryujinx.Audio.Renderer.Dsp.State;
 using Ryujinx.Audio.Renderer.Parameter;
 using Ryujinx.Audio.Renderer.Server.Effect;
 using Ryujinx.Audio.Renderer.Server.MemoryPool;
@@ -173,6 +174,22 @@ namespace Ryujinx.Audio.Renderer.Server
                 return ResultCode.WorkBufferTooSmall;
             }
 
+            Memory<BiquadFilterState> splitterBqfStates = Memory<BiquadFilterState>.Empty;
+
+            if (_behaviourContext.IsBiquadFilterParameterForSplitterEnabled() &&
+                parameter.SplitterCount > 0 &&
+                parameter.SplitterDestinationCount > 0)
+            {
+                splitterBqfStates = workBufferAllocator.Allocate<BiquadFilterState>(parameter.SplitterDestinationCount * SplitterContext.BqfStatesPerDestination, 0x10);
+
+                if (splitterBqfStates.IsEmpty)
+                {
+                    return ResultCode.WorkBufferTooSmall;
+                }
+
+                splitterBqfStates.Span.Clear();
+            }
+
             // Invalidate DSP cache on what was currently allocated with workBuffer.
             AudioProcessorMemoryManager.InvalidateDspCache(_dspMemoryPoolState.Translate(workBuffer, workBufferAllocator.Offset), workBufferAllocator.Offset);
 
@@ -292,7 +309,7 @@ namespace Ryujinx.Audio.Renderer.Server
                 state = MemoryPoolState.Create(MemoryPoolState.LocationType.Cpu);
             }
 
-            if (!_splitterContext.Initialize(ref _behaviourContext, ref parameter, workBufferAllocator))
+            if (!_splitterContext.Initialize(ref _behaviourContext, ref parameter, workBufferAllocator, splitterBqfStates))
             {
                 return ResultCode.WorkBufferTooSmall;
             }
@@ -775,6 +792,13 @@ namespace Ryujinx.Audio.Renderer.Server
             // Splitter
             size = SplitterContext.GetWorkBufferSize(size, ref behaviourContext, ref parameter);
 
+            if (behaviourContext.IsBiquadFilterParameterForSplitterEnabled() &&
+                parameter.SplitterCount > 0 &&
+                parameter.SplitterDestinationCount > 0)
+            {
+                size = WorkBufferAllocator.GetTargetSize<BiquadFilterState>(size, parameter.SplitterDestinationCount * SplitterContext.BqfStatesPerDestination, 0x10);
+            }
+
             // DSP Voice
             size = WorkBufferAllocator.GetTargetSize<VoiceUpdateState>(size, parameter.VoiceCount, VoiceUpdateState.Align);
 

src/Ryujinx.Audio/Renderer/Server/BehaviourContext.cs

@@ -45,7 +45,6 @@ namespace Ryujinx.Audio.Renderer.Server
         /// <see cref="Parameter.RendererInfoOutStatus"/> was added to supply the count of update done sent to the DSP.
         /// A new version of the command estimator was added to address timing changes caused by the voice changes.
         /// Additionally, the rendering limit percent was incremented to 80%.
-        ///
         /// </summary>
         /// <remarks>This was added in system update 6.0.0</remarks>
         public const int Revision5 = 5 << 24;
@@ -101,10 +100,18 @@ namespace Ryujinx.Audio.Renderer.Server
         /// <remarks>This was added in system update 14.0.0 but some changes were made in 15.0.0</remarks>
         public const int Revision11 = 11 << 24;
 
+        /// <summary>
+        /// REV12:
+        /// Two new commands were added to for biquad filtering and mixing (with optinal volume ramp) on the same command.
+        /// Splitter destinations can now specify up to two biquad filtering parameters, used for filtering the buffer before mixing.
+        /// </summary>
+        /// <remarks>This was added in system update 17.0.0</remarks>
+        public const int Revision12 = 12 << 24;
+
         /// <summary>
         /// Last revision supported by the implementation.
         /// </summary>
-        public const int LastRevision = Revision11;
+        public const int LastRevision = Revision12;
 
         /// <summary>
         /// Target revision magic supported by the implementation.
@@ -354,7 +361,7 @@ namespace Ryujinx.Audio.Renderer.Server
         /// Check if the audio renderer should use an optimized Biquad Filter (Direct Form 1) in case of two biquad filters are defined on a voice.
         /// </summary>
         /// <returns>True if the audio renderer should use the optimization.</returns>
-        public bool IsBiquadFilterGroupedOptimizationSupported()
+        public bool UseMultiTapBiquadFilterProcessing()
         {
             return CheckFeatureSupported(UserRevision, BaseRevisionMagic + Revision10);
         }
@@ -368,6 +375,15 @@ namespace Ryujinx.Audio.Renderer.Server
             return CheckFeatureSupported(UserRevision, BaseRevisionMagic + Revision11);
         }
 
+        /// <summary>
+        /// Check if the audio renderer should support biquad filter on splitter.
+        /// </summary>
+        /// <returns>True if the audio renderer support biquad filter on splitter</returns>
+        public bool IsBiquadFilterParameterForSplitterEnabled()
+        {
+            return CheckFeatureSupported(UserRevision, BaseRevisionMagic + Revision12);
+        }
+
         /// <summary>
         /// Get the version of the <see cref="ICommandProcessingTimeEstimator"/>.
         /// </summary>

src/Ryujinx.Audio/Renderer/Server/CommandBuffer.cs

@@ -204,7 +204,7 @@ namespace Ryujinx.Audio.Renderer.Server
         }
 
         /// <summary>
-        /// Create a new <see cref="GroupedBiquadFilterCommand"/>.
+        /// Create a new <see cref="MultiTapBiquadFilterCommand"/>.
         /// </summary>
         /// <param name="baseIndex">The base index of the input and output buffer.</param>
         /// <param name="filters">The biquad filter parameters.</param>
@@ -213,9 +213,9 @@ namespace Ryujinx.Audio.Renderer.Server
         /// <param name="outputBufferOffset">The output buffer offset.</param>
         /// <param name="isInitialized">Set to true if the biquad filter state is initialized.</param>
         /// <param name="nodeId">The node id associated to this command.</param>
-        public void GenerateGroupedBiquadFilter(int baseIndex, ReadOnlySpan<BiquadFilterParameter> filters, Memory<BiquadFilterState> biquadFilterStatesMemory, int inputBufferOffset, int outputBufferOffset, ReadOnlySpan<bool> isInitialized, int nodeId)
+        public void GenerateMultiTapBiquadFilter(int baseIndex, ReadOnlySpan<BiquadFilterParameter> filters, Memory<BiquadFilterState> biquadFilterStatesMemory, int inputBufferOffset, int outputBufferOffset, ReadOnlySpan<bool> isInitialized, int nodeId)
         {
-            GroupedBiquadFilterCommand command = new(baseIndex, filters, biquadFilterStatesMemory, inputBufferOffset, outputBufferOffset, isInitialized, nodeId);
+            MultiTapBiquadFilterCommand command = new(baseIndex, filters, biquadFilterStatesMemory, inputBufferOffset, outputBufferOffset, isInitialized, nodeId);
 
             command.EstimatedProcessingTime = _commandProcessingTimeEstimator.Estimate(command);
 
@@ -232,7 +232,7 @@ namespace Ryujinx.Audio.Renderer.Server
         /// <param name="volume">The new volume.</param>
         /// <param name="state">The <see cref="VoiceUpdateState"/> to generate the command from.</param>
         /// <param name="nodeId">The node id associated to this command.</param>
-        public void GenerateMixRampGrouped(uint mixBufferCount, uint inputBufferIndex, uint outputBufferIndex, Span<float> previousVolume, Span<float> volume, Memory<VoiceUpdateState> state, int nodeId)
+        public void GenerateMixRampGrouped(uint mixBufferCount, uint inputBufferIndex, uint outputBufferIndex, ReadOnlySpan<float> previousVolume, ReadOnlySpan<float> volume, Memory<VoiceUpdateState> state, int nodeId)
         {
             MixRampGroupedCommand command = new(mixBufferCount, inputBufferIndex, outputBufferIndex, previousVolume, volume, state, nodeId);
 
@@ -260,6 +260,120 @@ namespace Ryujinx.Audio.Renderer.Server
             AddCommand(command);
         }
 
+        /// <summary>
+        /// Generate a new <see cref="BiquadFilterAndMixCommand"/>.
+        /// </summary>
+        /// <param name="previousVolume">The previous volume.</param>
+        /// <param name="volume">The new volume.</param>
+        /// <param name="inputBufferIndex">The input buffer index.</param>
+        /// <param name="outputBufferIndex">The output buffer index.</param>
+        /// <param name="lastSampleIndex">The index in the <see cref="VoiceUpdateState.LastSamples"/> array to store the ramped sample.</param>
+        /// <param name="state">The <see cref="VoiceUpdateState"/> to generate the command from.</param>
+        /// <param name="filter">The biquad filter parameter.</param>
+        /// <param name="biquadFilterState">The biquad state.</param>
+        /// <param name="previousBiquadFilterState">The previous biquad state.</param>
+        /// <param name="needInitialization">Set to true if the biquad filter state needs to be initialized.</param>
+        /// <param name="hasVolumeRamp">Set to true if the mix has volume ramp, and <paramref name="previousVolume"/> should be taken into account.</param>
+        /// <param name="isFirstMixBuffer">Set to true if the buffer is the first mix buffer.</param>
+        /// <param name="nodeId">The node id associated to this command.</param>
+        public void GenerateBiquadFilterAndMix(
+            float previousVolume,
+            float volume,
+            uint inputBufferIndex,
+            uint outputBufferIndex,
+            int lastSampleIndex,
+            Memory<VoiceUpdateState> state,
+            ref BiquadFilterParameter filter,
+            Memory<BiquadFilterState> biquadFilterState,
+            Memory<BiquadFilterState> previousBiquadFilterState,
+            bool needInitialization,
+            bool hasVolumeRamp,
+            bool isFirstMixBuffer,
+            int nodeId)
+        {
+            BiquadFilterAndMixCommand command = new(
+                previousVolume,
+                volume,
+                inputBufferIndex,
+                outputBufferIndex,
+                lastSampleIndex,
+                state,
+                ref filter,
+                biquadFilterState,
+                previousBiquadFilterState,
+                needInitialization,
+                hasVolumeRamp,
+                isFirstMixBuffer,
+                nodeId);
+
+            command.EstimatedProcessingTime = _commandProcessingTimeEstimator.Estimate(command);
+
+            AddCommand(command);
+        }
+
+        /// <summary>
+        /// Generate a new <see cref="MultiTapBiquadFilterAndMixCommand"/>.
+        /// </summary>
+        /// <param name="previousVolume">The previous volume.</param>
+        /// <param name="volume">The new volume.</param>
+        /// <param name="inputBufferIndex">The input buffer index.</param>
+        /// <param name="outputBufferIndex">The output buffer index.</param>
+        /// <param name="lastSampleIndex">The index in the <see cref="VoiceUpdateState.LastSamples"/> array to store the ramped sample.</param>
+        /// <param name="state">The <see cref="VoiceUpdateState"/> to generate the command from.</param>
+        /// <param name="filter0">First biquad filter parameter.</param>
+        /// <param name="filter1">Second biquad filter parameter.</param>
+        /// <param name="biquadFilterState0">First biquad state.</param>
+        /// <param name="biquadFilterState1">Second biquad state.</param>
+        /// <param name="previousBiquadFilterState0">First previous biquad state.</param>
+        /// <param name="previousBiquadFilterState1">Second previous biquad state.</param>
+        /// <param name="needInitialization0">Set to true if the first biquad filter state needs to be initialized.</param>
+        /// <param name="needInitialization1">Set to true if the second biquad filter state needs to be initialized.</param>
+        /// <param name="hasVolumeRamp">Set to true if the mix has volume ramp, and <paramref name="previousVolume"/> should be taken into account.</param>
+        /// <param name="isFirstMixBuffer">Set to true if the buffer is the first mix buffer.</param>
+        /// <param name="nodeId">The node id associated to this command.</param>
+        public void GenerateMultiTapBiquadFilterAndMix(
+            float previousVolume,
+            float volume,
+            uint inputBufferIndex,
+            uint outputBufferIndex,
+            int lastSampleIndex,
+            Memory<VoiceUpdateState> state,
+            ref BiquadFilterParameter filter0,
+            ref BiquadFilterParameter filter1,
+            Memory<BiquadFilterState> biquadFilterState0,
+            Memory<BiquadFilterState> biquadFilterState1,
+            Memory<BiquadFilterState> previousBiquadFilterState0,
+            Memory<BiquadFilterState> previousBiquadFilterState1,
+            bool needInitialization0,
+            bool needInitialization1,
+            bool hasVolumeRamp,
+            bool isFirstMixBuffer,
+            int nodeId)
+        {
+            MultiTapBiquadFilterAndMixCommand command = new(
+                previousVolume,
+                volume,
+                inputBufferIndex,
+                outputBufferIndex,
+                lastSampleIndex,
+                state,
+                ref filter0,
+                ref filter1,
+                biquadFilterState0,
+                biquadFilterState1,
+                previousBiquadFilterState0,
+                previousBiquadFilterState1,
+                needInitialization0,
+                needInitialization1,
+                hasVolumeRamp,
+                isFirstMixBuffer,
+                nodeId);
+
+            command.EstimatedProcessingTime = _commandProcessingTimeEstimator.Estimate(command);
+
+            AddCommand(command);
+        }
+
         /// <summary>
         /// Generate a new <see cref="DepopForMixBuffersCommand"/>.
         /// </summary>
@@ -268,7 +382,7 @@ namespace Ryujinx.Audio.Renderer.Server
         /// <param name="bufferCount">The buffer count.</param>
         /// <param name="nodeId">The node id associated to this command.</param>
         /// <param name="sampleRate">The target sample rate in use.</param>
-        public void GenerateDepopForMixBuffersCommand(Memory<float> depopBuffer, uint bufferOffset, uint bufferCount, int nodeId, uint sampleRate)
+        public void GenerateDepopForMixBuffers(Memory<float> depopBuffer, uint bufferOffset, uint bufferCount, int nodeId, uint sampleRate)
         {
             DepopForMixBuffersCommand command = new(depopBuffer, bufferOffset, bufferCount, nodeId, sampleRate);
 

src/Ryujinx.Audio/Renderer/Server/CommandGenerator.cs

@@ -12,6 +12,7 @@ using Ryujinx.Audio.Renderer.Server.Voice;
 using Ryujinx.Audio.Renderer.Utils;
 using System;
 using System.Diagnostics;
+using System.Runtime.CompilerServices;
 
 namespace Ryujinx.Audio.Renderer.Server
 {
@@ -46,7 +47,8 @@ namespace Ryujinx.Audio.Renderer.Server
             {
                 ref MixState mix = ref _mixContext.GetState(voiceState.MixId);
 
-                _commandBuffer.GenerateDepopPrepare(dspState,
+                _commandBuffer.GenerateDepopPrepare(
+                    dspState,
                     _rendererContext.DepopBuffer,
                     mix.BufferCount,
                     mix.BufferOffset,
@@ -59,15 +61,13 @@ namespace Ryujinx.Audio.Renderer.Server
 
                 while (true)
                 {
-                    Span<SplitterDestination> destinationSpan = _splitterContext.GetDestination((int)voiceState.SplitterId, destinationId++);
+                    SplitterDestination destination = _splitterContext.GetDestination((int)voiceState.SplitterId, destinationId++);
 
-                    if (destinationSpan.IsEmpty)
+                    if (destination.IsNull)
                     {
                         break;
                     }
 
-                    ref SplitterDestination destination = ref destinationSpan[0];
-
                     if (destination.IsConfigured())
                     {
                         int mixId = destination.DestinationId;
@@ -76,7 +76,8 @@ namespace Ryujinx.Audio.Renderer.Server
                         {
                             ref MixState mix = ref _mixContext.GetState(mixId);
 
-                            _commandBuffer.GenerateDepopPrepare(dspState,
+                            _commandBuffer.GenerateDepopPrepare(
+                                dspState,
                                 _rendererContext.DepopBuffer,
                                 mix.BufferCount,
                                 mix.BufferOffset,
@@ -95,7 +96,8 @@ namespace Ryujinx.Audio.Renderer.Server
 
                 if (_rendererContext.BehaviourContext.IsWaveBufferVersion2Supported())
                 {
-                    _commandBuffer.GenerateDataSourceVersion2(ref voiceState,
+                    _commandBuffer.GenerateDataSourceVersion2(
+                        ref voiceState,
                         dspState,
                         (ushort)_rendererContext.MixBufferCount,
                         (ushort)channelIndex,
@@ -106,21 +108,24 @@ namespace Ryujinx.Audio.Renderer.Server
                     switch (voiceState.SampleFormat)
                     {
                         case SampleFormat.PcmInt16:
-                            _commandBuffer.GeneratePcmInt16DataSourceVersion1(ref voiceState,
+                            _commandBuffer.GeneratePcmInt16DataSourceVersion1(
+                                ref voiceState,
                                 dspState,
                                 (ushort)_rendererContext.MixBufferCount,
                                 (ushort)channelIndex,
                                 voiceState.NodeId);
                             break;
                         case SampleFormat.PcmFloat:
-                            _commandBuffer.GeneratePcmFloatDataSourceVersion1(ref voiceState,
+                            _commandBuffer.GeneratePcmFloatDataSourceVersion1(
+                                ref voiceState,
                                 dspState,
                                 (ushort)_rendererContext.MixBufferCount,
                                 (ushort)channelIndex,
                                 voiceState.NodeId);
                             break;
                         case SampleFormat.Adpcm:
-                            _commandBuffer.GenerateAdpcmDataSourceVersion1(ref voiceState,
+                            _commandBuffer.GenerateAdpcmDataSourceVersion1(
+                                ref voiceState,
                                 dspState,
                                 (ushort)_rendererContext.MixBufferCount,
                                 voiceState.NodeId);
@@ -134,14 +139,14 @@ namespace Ryujinx.Audio.Renderer.Server
 
         private void GenerateBiquadFilterForVoice(ref VoiceState voiceState, Memory<VoiceUpdateState> state, int baseIndex, int bufferOffset, int nodeId)
         {
-            bool supportsOptimizedPath = _rendererContext.BehaviourContext.IsBiquadFilterGroupedOptimizationSupported();
+            bool supportsOptimizedPath = _rendererContext.BehaviourContext.UseMultiTapBiquadFilterProcessing();
 
             if (supportsOptimizedPath && voiceState.BiquadFilters[0].Enable && voiceState.BiquadFilters[1].Enable)
             {
-                Memory<byte> biquadStateRawMemory = SpanMemoryManager<byte>.Cast(state)[..(VoiceUpdateState.BiquadStateSize * Constants.VoiceBiquadFilterCount)];
+                Memory<byte> biquadStateRawMemory = SpanMemoryManager<byte>.Cast(state)[..(Unsafe.SizeOf<BiquadFilterState>() * Constants.VoiceBiquadFilterCount)];
                 Memory<BiquadFilterState> stateMemory = SpanMemoryManager<BiquadFilterState>.Cast(biquadStateRawMemory);
 
-                _commandBuffer.GenerateGroupedBiquadFilter(baseIndex, voiceState.BiquadFilters.AsSpan(), stateMemory, bufferOffset, bufferOffset, voiceState.BiquadFilterNeedInitialization, nodeId);
+                _commandBuffer.GenerateMultiTapBiquadFilter(baseIndex, voiceState.BiquadFilters.AsSpan(), stateMemory, bufferOffset, bufferOffset, voiceState.BiquadFilterNeedInitialization, nodeId);
             }
             else
             {
@@ -151,11 +156,11 @@ namespace Ryujinx.Audio.Renderer.Server
 
                     if (filter.Enable)
                     {
-                        Memory<byte> biquadStateRawMemory = SpanMemoryManager<byte>.Cast(state)[..(VoiceUpdateState.BiquadStateSize * Constants.VoiceBiquadFilterCount)];
-
+                        Memory<byte> biquadStateRawMemory = SpanMemoryManager<byte>.Cast(state)[..(Unsafe.SizeOf<BiquadFilterState>() * Constants.VoiceBiquadFilterCount)];
                         Memory<BiquadFilterState> stateMemory = SpanMemoryManager<BiquadFilterState>.Cast(biquadStateRawMemory);
 
-                        _commandBuffer.GenerateBiquadFilter(baseIndex,
+                        _commandBuffer.GenerateBiquadFilter(
+                            baseIndex,
                             ref filter,
                             stateMemory.Slice(i, 1),
                             bufferOffset,
@@ -167,11 +172,112 @@ namespace Ryujinx.Audio.Renderer.Server
             }
         }
 
-        private void GenerateVoiceMix(Span<float> mixVolumes, Span<float> previousMixVolumes, Memory<VoiceUpdateState> state, uint bufferOffset, uint bufferCount, uint bufferIndex, int nodeId)
+        private void GenerateVoiceMixWithSplitter(
+            SplitterDestination destination,
+            Memory<VoiceUpdateState> state,
+            uint bufferOffset,
+            uint bufferCount,
+            uint bufferIndex,
+            int nodeId)
+        {
+            ReadOnlySpan<float> mixVolumes = destination.MixBufferVolume;
+            ReadOnlySpan<float> previousMixVolumes = destination.PreviousMixBufferVolume;
+
+            ref BiquadFilterParameter bqf0 = ref destination.GetBiquadFilterParameter(0);
+            ref BiquadFilterParameter bqf1 = ref destination.GetBiquadFilterParameter(1);
+
+            Memory<BiquadFilterState> bqfState = _splitterContext.GetBiquadFilterState(destination);
+
+            bool isFirstMixBuffer = true;
+
+            for (int i = 0; i < bufferCount; i++)
+            {
+                float previousMixVolume = previousMixVolumes[i];
+                float mixVolume = mixVolumes[i];
+
+                if (mixVolume != 0.0f || previousMixVolume != 0.0f)
+                {
+                    if (bqf0.Enable && bqf1.Enable)
+                    {
+                        _commandBuffer.GenerateMultiTapBiquadFilterAndMix(
+                            previousMixVolume,
+                            mixVolume,
+                            bufferIndex,
+                            bufferOffset + (uint)i,
+                            i,
+                            state,
+                            ref bqf0,
+                            ref bqf1,
+                            bqfState[..1],
+                            bqfState.Slice(1, 1),
+                            bqfState.Slice(2, 1),
+                            bqfState.Slice(3, 1),
+                            !destination.IsBiquadFilterEnabledPrev(),
+                            !destination.IsBiquadFilterEnabledPrev(),
+                            true,
+                            isFirstMixBuffer,
+                            nodeId);
+
+                        destination.UpdateBiquadFilterEnabledPrev(0);
+                        destination.UpdateBiquadFilterEnabledPrev(1);
+                    }
+                    else if (bqf0.Enable)
+                    {
+                        _commandBuffer.GenerateBiquadFilterAndMix(
+                            previousMixVolume,
+                            mixVolume,
+                            bufferIndex,
+                            bufferOffset + (uint)i,
+                            i,
+                            state,
+                            ref bqf0,
+                            bqfState[..1],
+                            bqfState.Slice(1, 1),
+                            !destination.IsBiquadFilterEnabledPrev(),
+                            true,
+                            isFirstMixBuffer,
+                            nodeId);
+
+                        destination.UpdateBiquadFilterEnabledPrev(0);
+                    }
+                    else if (bqf1.Enable)
+                    {
+                        _commandBuffer.GenerateBiquadFilterAndMix(
+                            previousMixVolume,
+                            mixVolume,
+                            bufferIndex,
+                            bufferOffset + (uint)i,
+                            i,
+                            state,
+                            ref bqf1,
+                            bqfState[..1],
+                            bqfState.Slice(1, 1),
+                            !destination.IsBiquadFilterEnabledPrev(),
+                            true,
+                            isFirstMixBuffer,
+                            nodeId);
+
+                        destination.UpdateBiquadFilterEnabledPrev(1);
+                    }
+
+                    isFirstMixBuffer = false;
+                }
+            }
+        }
+
+        private void GenerateVoiceMix(
+            ReadOnlySpan<float> mixVolumes,
+            ReadOnlySpan<float> previousMixVolumes,
+            Memory<VoiceUpdateState> state,
+            uint bufferOffset,
+            uint bufferCount,
+            uint bufferIndex,
+            int nodeId)
         {
             if (bufferCount > Constants.VoiceChannelCountMax)
             {
-                _commandBuffer.GenerateMixRampGrouped(bufferCount,
+                _commandBuffer.GenerateMixRampGrouped(
+                    bufferCount,
                     bufferIndex,
                     bufferOffset,
                     previousMixVolumes,
@@ -188,7 +294,8 @@ namespace Ryujinx.Audio.Renderer.Server
 
                     if (mixVolume != 0.0f || previousMixVolume != 0.0f)
                     {
-                        _commandBuffer.GenerateMixRamp(previousMixVolume,
+                        _commandBuffer.GenerateMixRamp(
+                            previousMixVolume,
                             mixVolume,
                             bufferIndex,
                             bufferOffset + (uint)i,
@@ -271,7 +378,8 @@ namespace Ryujinx.Audio.Renderer.Server
                         GeneratePerformance(ref performanceEntry, PerformanceCommand.Type.Start, nodeId);
                     }
 
-                    _commandBuffer.GenerateVolumeRamp(voiceState.PreviousVolume,
+                    _commandBuffer.GenerateVolumeRamp(
+                        voiceState.PreviousVolume,
                         voiceState.Volume,
                         _rendererContext.MixBufferCount + (uint)channelIndex,
                         nodeId);
@@ -291,15 +399,13 @@ namespace Ryujinx.Audio.Renderer.Server
 
                             while (true)
                             {
-                                Span<SplitterDestination> destinationSpan = _splitterContext.GetDestination((int)voiceState.SplitterId, destinationId);
+                                SplitterDestination destination = _splitterContext.GetDestination((int)voiceState.SplitterId, destinationId);
 
-                                if (destinationSpan.IsEmpty)
+                                if (destination.IsNull)
                                 {
                                     break;
                                 }
 
-                                ref SplitterDestination destination = ref destinationSpan[0];
-
                                 destinationId += (int)channelsCount;
 
                                 if (destination.IsConfigured())
@@ -310,13 +416,27 @@ namespace Ryujinx.Audio.Renderer.Server
                                     {
                                         ref MixState mix = ref _mixContext.GetState(mixId);
 
-                                        GenerateVoiceMix(destination.MixBufferVolume,
+                                        if (destination.IsBiquadFilterEnabled())
+                                        {
+                                            GenerateVoiceMixWithSplitter(
+                                                destination,
+                                                dspStateMemory,
+                                                mix.BufferOffset,
+                                                mix.BufferCount,
+                                                _rendererContext.MixBufferCount + (uint)channelIndex,
+                                                nodeId);
+                                        }
+                                        else
+                                        {
+                                            GenerateVoiceMix(
+                                                destination.MixBufferVolume,
                                                 destination.PreviousMixBufferVolume,
                                                 dspStateMemory,
                                                 mix.BufferOffset,
                                                 mix.BufferCount,
                                                 _rendererContext.MixBufferCount + (uint)channelIndex,
                                                 nodeId);
+                                        }
 
                                         destination.MarkAsNeedToUpdateInternalState();
                                     }
@@ -337,7 +457,8 @@ namespace Ryujinx.Audio.Renderer.Server
                             GeneratePerformance(ref performanceEntry, PerformanceCommand.Type.Start, nodeId);
                         }
 
-                        GenerateVoiceMix(channelResource.Mix.AsSpan(),
+                        GenerateVoiceMix(
+                            channelResource.Mix.AsSpan(),
                             channelResource.PreviousMix.AsSpan(),
                             dspStateMemory,
                             mix.BufferOffset,
@@ -409,7 +530,8 @@ namespace Ryujinx.Audio.Renderer.Server
                 {
                     if (effect.Parameter.Volumes[i] != 0.0f)
                     {
-                        _commandBuffer.GenerateMix((uint)bufferOffset + effect.Parameter.Input[i],
+                        _commandBuffer.GenerateMix(
+                            (uint)bufferOffset + effect.Parameter.Input[i],
                             (uint)bufferOffset + effect.Parameter.Output[i],
                             nodeId,
                             effect.Parameter.Volumes[i]);
@@ -447,7 +569,8 @@ namespace Ryujinx.Audio.Renderer.Server
                         updateCount = newUpdateCount;
                     }
 
-                    _commandBuffer.GenerateAuxEffect(bufferOffset,
+                    _commandBuffer.GenerateAuxEffect(
+                        bufferOffset,
                         effect.Parameter.Input[i],
                         effect.Parameter.Output[i],
                         ref effect.State,
@@ -512,7 +635,10 @@ namespace Ryujinx.Audio.Renderer.Server
 
                 for (int i = 0; i < effect.Parameter.ChannelCount; i++)
                 {
-                    _commandBuffer.GenerateBiquadFilter((int)bufferOffset, ref parameter, effect.State.Slice(i, 1),
+                    _commandBuffer.GenerateBiquadFilter(
+                        (int)bufferOffset,
+                        ref parameter,
+                        effect.State.Slice(i, 1),
                         effect.Parameter.Input[i],
                         effect.Parameter.Output[i],
                         needInitialization,
@@ -591,7 +717,8 @@ namespace Ryujinx.Audio.Renderer.Server
                         updateCount = newUpdateCount;
                     }
 
-                    _commandBuffer.GenerateCaptureEffect(bufferOffset,
+                    _commandBuffer.GenerateCaptureEffect(
+                        bufferOffset,
                         effect.Parameter.Input[i],
                         effect.State.SendBufferInfo,
                         effect.IsEnabled,
@@ -612,7 +739,8 @@ namespace Ryujinx.Audio.Renderer.Server
         {
             Debug.Assert(effect.Type == EffectType.Compressor);
 
-            _commandBuffer.GenerateCompressorEffect(bufferOffset,
+            _commandBuffer.GenerateCompressorEffect(
+                bufferOffset,
                 effect.Parameter,
                 effect.State,
                 effect.IsEnabled,
@@ -629,8 +757,11 @@ namespace Ryujinx.Audio.Renderer.Server
 
             bool performanceInitialized = false;
 
-            if (_performanceManager != null && _performanceManager.GetNextEntry(out performanceEntry, effect.GetPerformanceDetailType(),
-                                                isFinalMix ? PerformanceEntryType.FinalMix : PerformanceEntryType.SubMix, nodeId))
+            if (_performanceManager != null && _performanceManager.GetNextEntry(
+                out performanceEntry,
+                effect.GetPerformanceDetailType(),
+                isFinalMix ? PerformanceEntryType.FinalMix : PerformanceEntryType.SubMix,
+                nodeId))
             {
                 performanceInitialized = true;
 
@@ -706,6 +837,85 @@ namespace Ryujinx.Audio.Renderer.Server
             }
         }
 
+        private void GenerateMixWithSplitter(
+            uint inputBufferIndex,
+            uint outputBufferIndex,
+            float volume,
+            SplitterDestination destination,
+            ref bool isFirstMixBuffer,
+            int nodeId)
+        {
+            ref BiquadFilterParameter bqf0 = ref destination.GetBiquadFilterParameter(0);
+            ref BiquadFilterParameter bqf1 = ref destination.GetBiquadFilterParameter(1);
+
+            Memory<BiquadFilterState> bqfState = _splitterContext.GetBiquadFilterState(destination);
+
+            if (bqf0.Enable && bqf1.Enable)
+            {
+                _commandBuffer.GenerateMultiTapBiquadFilterAndMix(
+                    0f,
+                    volume,
+                    inputBufferIndex,
+                    outputBufferIndex,
+                    0,
+                    Memory<VoiceUpdateState>.Empty,
+                    ref bqf0,
+                    ref bqf1,
+                    bqfState[..1],
+                    bqfState.Slice(1, 1),
+                    bqfState.Slice(2, 1),
+                    bqfState.Slice(3, 1),
+                    !destination.IsBiquadFilterEnabledPrev(),
+                    !destination.IsBiquadFilterEnabledPrev(),
+                    false,
+                    isFirstMixBuffer,
+                    nodeId);
+
+                destination.UpdateBiquadFilterEnabledPrev(0);
+                destination.UpdateBiquadFilterEnabledPrev(1);
+            }
+            else if (bqf0.Enable)
+            {
+                _commandBuffer.GenerateBiquadFilterAndMix(
+                    0f,
+                    volume,
+                    inputBufferIndex,
+                    outputBufferIndex,
+                    0,
+                    Memory<VoiceUpdateState>.Empty,
+                    ref bqf0,
+                    bqfState[..1],
+                    bqfState.Slice(1, 1),
+                    !destination.IsBiquadFilterEnabledPrev(),
+                    false,
+                    isFirstMixBuffer,
+                    nodeId);
+
+                destination.UpdateBiquadFilterEnabledPrev(0);
+            }
+            else if (bqf1.Enable)
+            {
+                _commandBuffer.GenerateBiquadFilterAndMix(
+                    0f,
+                    volume,
+                    inputBufferIndex,
+                    outputBufferIndex,
+                    0,
+                    Memory<VoiceUpdateState>.Empty,
+                    ref bqf1,
+                    bqfState[..1],
+                    bqfState.Slice(1, 1),
+                    !destination.IsBiquadFilterEnabledPrev(),
+                    false,
+                    isFirstMixBuffer,
+                    nodeId);
+
+                destination.UpdateBiquadFilterEnabledPrev(1);
+            }
+
+            isFirstMixBuffer = false;
+        }
+
         private void GenerateMix(ref MixState mix)
         {
             if (mix.HasAnyDestination())
@@ -722,15 +932,13 @@ namespace Ryujinx.Audio.Renderer.Server
                         {
                             int destinationIndex = destinationId++;
 
-                            Span<SplitterDestination> destinationSpan = _splitterContext.GetDestination((int)mix.DestinationSplitterId, destinationIndex);
+                            SplitterDestination destination = _splitterContext.GetDestination((int)mix.DestinationSplitterId, destinationIndex);
 
-                            if (destinationSpan.IsEmpty)
+                            if (destination.IsNull)
                             {
                                 break;
                             }
 
-                            ref SplitterDestination destination = ref destinationSpan[0];
-
                             if (destination.IsConfigured())
                             {
                                 int mixId = destination.DestinationId;
@@ -741,13 +949,28 @@ namespace Ryujinx.Audio.Renderer.Server
 
                                     uint inputBufferIndex = mix.BufferOffset + ((uint)destinationIndex % mix.BufferCount);
 
+                                    bool isFirstMixBuffer = true;
+
                                     for (uint bufferDestinationIndex = 0; bufferDestinationIndex < destinationMix.BufferCount; bufferDestinationIndex++)
                                     {
                                         float volume = mix.Volume * destination.GetMixVolume((int)bufferDestinationIndex);
 
                                         if (volume != 0.0f)
                                         {
-                                            _commandBuffer.GenerateMix(inputBufferIndex,
+                                            if (destination.IsBiquadFilterEnabled())
+                                            {
+                                                GenerateMixWithSplitter(
+                                                    inputBufferIndex,
+                                                    destinationMix.BufferOffset + bufferDestinationIndex,
+                                                    volume,
+                                                    destination,
+                                                    ref isFirstMixBuffer,
+                                                    mix.NodeId);
+                                            }
+                                            else
+                                            {
+                                                _commandBuffer.GenerateMix(
+                                                    inputBufferIndex,
                                                     destinationMix.BufferOffset + bufferDestinationIndex,
                                                     mix.NodeId,
                                                     volume);
@@ -758,6 +981,7 @@ namespace Ryujinx.Audio.Renderer.Server
                             }
                         }
                     }
+                }
                 else
                 {
                     ref MixState destinationMix = ref _mixContext.GetState(mix.DestinationMixId);
@@ -770,7 +994,8 @@ namespace Ryujinx.Audio.Renderer.Server
 
                             if (volume != 0.0f)
                             {
-                                _commandBuffer.GenerateMix(mix.BufferOffset + bufferIndex,
+                                _commandBuffer.GenerateMix(
+                                    mix.BufferOffset + bufferIndex,
                                     destinationMix.BufferOffset + bufferDestinationIndex,
                                     mix.NodeId,
                                     volume);
@@ -783,7 +1008,8 @@ namespace Ryujinx.Audio.Renderer.Server
 
         private void GenerateSubMix(ref MixState subMix)
         {
-            _commandBuffer.GenerateDepopForMixBuffersCommand(_rendererContext.DepopBuffer,
+            _commandBuffer.GenerateDepopForMixBuffers(
+                _rendererContext.DepopBuffer,
                 subMix.BufferOffset,
                 subMix.BufferCount,
                 subMix.NodeId,
@@ -847,7 +1073,8 @@ namespace Ryujinx.Audio.Renderer.Server
         {
             ref MixState finalMix = ref _mixContext.GetFinalState();
 
-            _commandBuffer.GenerateDepopForMixBuffersCommand(_rendererContext.DepopBuffer,
+            _commandBuffer.GenerateDepopForMixBuffers(
+                _rendererContext.DepopBuffer,
                 finalMix.BufferOffset,
                 finalMix.BufferCount,
                 finalMix.NodeId,
@@ -882,7 +1109,8 @@ namespace Ryujinx.Audio.Renderer.Server
                         GeneratePerformance(ref performanceEntry, PerformanceCommand.Type.Start, nodeId);
                     }
 
-                    _commandBuffer.GenerateVolume(finalMix.Volume,
+                    _commandBuffer.GenerateVolume(
+                        finalMix.Volume,
                         finalMix.BufferOffset + bufferIndex,
                         nodeId);
 
@@ -938,7 +1166,8 @@ namespace Ryujinx.Audio.Renderer.Server
 
             if (useCustomDownMixingCommand)
             {
-                _commandBuffer.GenerateDownMixSurroundToStereo(finalMix.BufferOffset,
+                _commandBuffer.GenerateDownMixSurroundToStereo(
+                    finalMix.BufferOffset,
                     sink.Parameter.Input.AsSpan(),
                     sink.Parameter.Input.AsSpan(),
                     sink.DownMixCoefficients,
@@ -947,7 +1176,8 @@ namespace Ryujinx.Audio.Renderer.Server
             // NOTE: We do the downmixing at the DSP level as it's easier that way.
             else if (_rendererContext.ChannelCount == 2 && sink.Parameter.InputCount == 6)
             {
-                _commandBuffer.GenerateDownMixSurroundToStereo(finalMix.BufferOffset,
+                _commandBuffer.GenerateDownMixSurroundToStereo(
+                    finalMix.BufferOffset,
                     sink.Parameter.Input.AsSpan(),
                     sink.Parameter.Input.AsSpan(),
                     Constants.DefaultSurroundToStereoCoefficients,
@@ -958,7 +1188,8 @@ namespace Ryujinx.Audio.Renderer.Server
 
             if (sink.UpsamplerState != null)
             {
-                _commandBuffer.GenerateUpsample(finalMix.BufferOffset,
+                _commandBuffer.GenerateUpsample(
+                    finalMix.BufferOffset,
                     sink.UpsamplerState,
                     sink.Parameter.InputCount,
                     sink.Parameter.Input.AsSpan(),
@@ -968,7 +1199,8 @@ namespace Ryujinx.Audio.Renderer.Server
                     Constants.InvalidNodeId);
             }
 
-            _commandBuffer.GenerateDeviceSink(finalMix.BufferOffset,
+            _commandBuffer.GenerateDeviceSink(
+                finalMix.BufferOffset,
                 sink,
                 _rendererContext.SessionId,
                 commandList.Buffers,

src/Ryujinx.Audio/Renderer/Server/CommandProcessingTimeEstimatorVersion1.cs

@@ -170,7 +170,7 @@ namespace Ryujinx.Audio.Renderer.Server
             return 0;
         }
 
-        public uint Estimate(GroupedBiquadFilterCommand command)
+        public uint Estimate(MultiTapBiquadFilterCommand command)
         {
             return 0;
         }
@@ -184,5 +184,15 @@ namespace Ryujinx.Audio.Renderer.Server
         {
             return 0;
         }
+
+        public uint Estimate(BiquadFilterAndMixCommand command)
+        {
+            return 0;
+        }
+
+        public uint Estimate(MultiTapBiquadFilterAndMixCommand command)
+        {
+            return 0;
+        }
     }
 }

src/Ryujinx.Audio/Renderer/Server/CommandProcessingTimeEstimatorVersion2.cs

@@ -462,7 +462,7 @@ namespace Ryujinx.Audio.Renderer.Server
             return 0;
         }
 
-        public uint Estimate(GroupedBiquadFilterCommand command)
+        public uint Estimate(MultiTapBiquadFilterCommand command)
         {
             return 0;
         }
@@ -476,5 +476,15 @@ namespace Ryujinx.Audio.Renderer.Server
         {
             return 0;
         }
+
+        public uint Estimate(BiquadFilterAndMixCommand command)
+        {
+            return 0;
+        }
+
+        public uint Estimate(MultiTapBiquadFilterAndMixCommand command)
+        {
+            return 0;
+        }
     }
 }

src/Ryujinx.Audio/Renderer/Server/CommandProcessingTimeEstimatorVersion3.cs

@@ -632,7 +632,7 @@ namespace Ryujinx.Audio.Renderer.Server
             };
         }
 
-        public virtual uint Estimate(GroupedBiquadFilterCommand command)
+        public virtual uint Estimate(MultiTapBiquadFilterCommand command)
         {
             return 0;
         }
@@ -646,5 +646,15 @@ namespace Ryujinx.Audio.Renderer.Server
         {
             return 0;
         }
+
+        public virtual uint Estimate(BiquadFilterAndMixCommand command)
+        {
+            return 0;
+        }
+
+        public virtual uint Estimate(MultiTapBiquadFilterAndMixCommand command)
+        {
+            return 0;
+        }
     }
 }

src/Ryujinx.Audio/Renderer/Server/CommandProcessingTimeEstimatorVersion4.cs

@@ -10,7 +10,7 @@ namespace Ryujinx.Audio.Renderer.Server
     {
         public CommandProcessingTimeEstimatorVersion4(uint sampleCount, uint bufferCount) : base(sampleCount, bufferCount) { }
 
-        public override uint Estimate(GroupedBiquadFilterCommand command)
+        public override uint Estimate(MultiTapBiquadFilterCommand command)
         {
             Debug.Assert(SampleCount == 160 || SampleCount == 240);
 

src/Ryujinx.Audio/Renderer/Server/CommandProcessingTimeEstimatorVersion5.cs

@@ -210,5 +210,53 @@ namespace Ryujinx.Audio.Renderer.Server
                 _ => throw new NotImplementedException($"{command.Parameter.ChannelCount}"),
             };
         }
+
+        public override uint Estimate(BiquadFilterAndMixCommand command)
+        {
+            Debug.Assert(SampleCount == 160 || SampleCount == 240);
+
+            if (command.HasVolumeRamp)
+            {
+                if (SampleCount == 160)
+                {
+                    return 5204;
+                }
+
+                return 6683;
+            }
+            else
+            {
+                if (SampleCount == 160)
+                {
+                    return 3427;
+                }
+
+                return 4752;
+            }
+        }
+
+        public override uint Estimate(MultiTapBiquadFilterAndMixCommand command)
+        {
+            Debug.Assert(SampleCount == 160 || SampleCount == 240);
+
+            if (command.HasVolumeRamp)
+            {
+                if (SampleCount == 160)
+                {
+                    return 7939;
+                }
+
+                return 10669;
+            }
+            else
+            {
+                if (SampleCount == 160)
+                {
+                    return 6256;
+                }
+
+                return 8683;
+            }
+        }
     }
 }

src/Ryujinx.Audio/Renderer/Server/ICommandProcessingTimeEstimator.cs

@@ -33,8 +33,10 @@ namespace Ryujinx.Audio.Renderer.Server
         uint Estimate(UpsampleCommand command);
         uint Estimate(LimiterCommandVersion1 command);
         uint Estimate(LimiterCommandVersion2 command);
-        uint Estimate(GroupedBiquadFilterCommand command);
+        uint Estimate(MultiTapBiquadFilterCommand command);
         uint Estimate(CaptureBufferCommand command);
         uint Estimate(CompressorCommand command);
+        uint Estimate(BiquadFilterAndMixCommand command);
+        uint Estimate(MultiTapBiquadFilterAndMixCommand command);
     }
 }

src/Ryujinx.Audio/Renderer/Server/Mix/MixState.cs

@@ -225,11 +225,11 @@ namespace Ryujinx.Audio.Renderer.Server.Mix
 
                     for (int i = 0; i < splitter.DestinationCount; i++)
                     {
-                        Span<SplitterDestination> destination = splitter.GetData(i);
+                        SplitterDestination destination = splitter.GetData(i);
 
-                        if (!destination.IsEmpty)
+                        if (!destination.IsNull)
                         {
-                            int destinationMixId = destination[0].DestinationId;
+                            int destinationMixId = destination.DestinationId;
 
                             if (destinationMixId != UnusedMixId)
                             {

src/Ryujinx.Audio/Renderer/Server/Splitter/SplitterContext.cs

@@ -1,4 +1,5 @@
 using Ryujinx.Audio.Renderer.Common;
+using Ryujinx.Audio.Renderer.Dsp.State;
 using Ryujinx.Audio.Renderer.Parameter;
 using Ryujinx.Audio.Renderer.Utils;
 using Ryujinx.Common;
@@ -15,15 +16,35 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
     /// </summary>
     public class SplitterContext
     {
+        /// <summary>
+        /// Amount of biquad filter states per splitter destination.
+        /// </summary>
+        public const int BqfStatesPerDestination = 4;
+
         /// <summary>
         /// Storage for <see cref="SplitterState"/>.
         /// </summary>
         private Memory<SplitterState> _splitters;
 
         /// <summary>
-        /// Storage for <see cref="SplitterDestination"/>.
+        /// Storage for <see cref="SplitterDestinationVersion1"/>.
         /// </summary>
-        private Memory<SplitterDestination> _splitterDestinations;
+        private Memory<SplitterDestinationVersion1> _splitterDestinationsV1;
+
+        /// <summary>
+        /// Storage for <see cref="SplitterDestinationVersion2"/>.
+        /// </summary>
+        private Memory<SplitterDestinationVersion2> _splitterDestinationsV2;
+
+        /// <summary>
+        /// Splitter biquad filtering states.
+        /// </summary>
+        private Memory<BiquadFilterState> _splitterBqfStates;
+
+        /// <summary>
+        /// Version of the splitter context that is being used, currently can be 1 or 2.
+        /// </summary>
+        public int Version { get; private set; }
 
         /// <summary>
         /// If set to true, trust the user destination count in <see cref="SplitterState.Update(SplitterContext, in SplitterInParameter, ref SequenceReader{byte})"/>.
@@ -36,12 +57,17 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         /// <param name="behaviourContext">The behaviour context.</param>
         /// <param name="parameter">The audio renderer configuration.</param>
         /// <param name="workBufferAllocator">The <see cref="WorkBufferAllocator"/>.</param>
+        /// <param name="splitterBqfStates">Memory to store the biquad filtering state for splitters during processing.</param>
         /// <returns>Return true if the initialization was successful.</returns>
-        public bool Initialize(ref BehaviourContext behaviourContext, ref AudioRendererConfiguration parameter, WorkBufferAllocator workBufferAllocator)
+        public bool Initialize(
+            ref BehaviourContext behaviourContext,
+            ref AudioRendererConfiguration parameter,
+            WorkBufferAllocator workBufferAllocator,
+            Memory<BiquadFilterState> splitterBqfStates)
         {
             if (!behaviourContext.IsSplitterSupported() || parameter.SplitterCount <= 0 || parameter.SplitterDestinationCount <= 0)
             {
-                Setup(Memory<SplitterState>.Empty, Memory<SplitterDestination>.Empty, false);
+                Setup(Memory<SplitterState>.Empty, Memory<SplitterDestinationVersion1>.Empty, Memory<SplitterDestinationVersion2>.Empty, false);
 
                 return true;
             }
@@ -60,23 +86,62 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
                 splitter = new SplitterState(splitterId++);
             }
 
-            Memory<SplitterDestination> splitterDestinations = workBufferAllocator.Allocate<SplitterDestination>(parameter.SplitterDestinationCount,
-                SplitterDestination.Alignment);
+            Memory<SplitterDestinationVersion1> splitterDestinationsV1 = Memory<SplitterDestinationVersion1>.Empty;
+            Memory<SplitterDestinationVersion2> splitterDestinationsV2 = Memory<SplitterDestinationVersion2>.Empty;
 
-            if (splitterDestinations.IsEmpty)
+            if (!behaviourContext.IsBiquadFilterParameterForSplitterEnabled())
+            {
+                Version = 1;
+
+                splitterDestinationsV1 = workBufferAllocator.Allocate<SplitterDestinationVersion1>(parameter.SplitterDestinationCount,
+                    SplitterDestinationVersion1.Alignment);
+
+                if (splitterDestinationsV1.IsEmpty)
                 {
                     return false;
                 }
 
                 int splitterDestinationId = 0;
-            foreach (ref SplitterDestination data in splitterDestinations.Span)
+                foreach (ref SplitterDestinationVersion1 data in splitterDestinationsV1.Span)
                 {
-                data = new SplitterDestination(splitterDestinationId++);
+                    data = new SplitterDestinationVersion1(splitterDestinationId++);
+                }
+            }
+            else
+            {
+                Version = 2;
+
+                splitterDestinationsV2 = workBufferAllocator.Allocate<SplitterDestinationVersion2>(parameter.SplitterDestinationCount,
+                    SplitterDestinationVersion2.Alignment);
+
+                if (splitterDestinationsV2.IsEmpty)
+                {
+                    return false;
+                }
+
+                int splitterDestinationId = 0;
+                foreach (ref SplitterDestinationVersion2 data in splitterDestinationsV2.Span)
+                {
+                    data = new SplitterDestinationVersion2(splitterDestinationId++);
+                }
+
+                if (parameter.SplitterDestinationCount > 0)
+                {
+                    // Official code stores it in the SplitterDestinationVersion2 struct,
+                    // but we don't to avoid using unsafe code.
+
+                    splitterBqfStates.Span.Clear();
+                    _splitterBqfStates = splitterBqfStates;
+                }
+                else
+                {
+                    _splitterBqfStates = Memory<BiquadFilterState>.Empty;
+                }
             }
 
             SplitterState.InitializeSplitters(splitters.Span);
 
-            Setup(splitters, splitterDestinations, behaviourContext.IsSplitterBugFixed());
+            Setup(splitters, splitterDestinationsV1, splitterDestinationsV2, behaviourContext.IsSplitterBugFixed());
 
             return true;
         }
@@ -93,7 +158,15 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
             if (behaviourContext.IsSplitterSupported())
             {
                 size = WorkBufferAllocator.GetTargetSize<SplitterState>(size, parameter.SplitterCount, SplitterState.Alignment);
-                size = WorkBufferAllocator.GetTargetSize<SplitterDestination>(size, parameter.SplitterDestinationCount, SplitterDestination.Alignment);
+
+                if (behaviourContext.IsBiquadFilterParameterForSplitterEnabled())
+                {
+                    size = WorkBufferAllocator.GetTargetSize<SplitterDestinationVersion2>(size, parameter.SplitterDestinationCount, SplitterDestinationVersion2.Alignment);
+                }
+                else
+                {
+                    size = WorkBufferAllocator.GetTargetSize<SplitterDestinationVersion1>(size, parameter.SplitterDestinationCount, SplitterDestinationVersion1.Alignment);
+                }
 
                 if (behaviourContext.IsSplitterBugFixed())
                 {
@@ -110,12 +183,18 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         /// Setup the <see cref="SplitterContext"/> instance.
         /// </summary>
         /// <param name="splitters">The <see cref="SplitterState"/> storage.</param>
-        /// <param name="splitterDestinations">The <see cref="SplitterDestination"/> storage.</param>
+        /// <param name="splitterDestinationsV1">The <see cref="SplitterDestinationVersion1"/> storage.</param>
+        /// <param name="splitterDestinationsV2">The <see cref="SplitterDestinationVersion2"/> storage.</param>
         /// <param name="isBugFixed">If set to true, trust the user destination count in <see cref="SplitterState.Update(SplitterContext, in SplitterInParameter, ref SequenceReader{byte})"/>.</param>
-        private void Setup(Memory<SplitterState> splitters, Memory<SplitterDestination> splitterDestinations, bool isBugFixed)
+        private void Setup(
+            Memory<SplitterState> splitters,
+            Memory<SplitterDestinationVersion1> splitterDestinationsV1,
+            Memory<SplitterDestinationVersion2> splitterDestinationsV2,
+            bool isBugFixed)
         {
             _splitters = splitters;
-            _splitterDestinations = splitterDestinations;
+            _splitterDestinationsV1 = splitterDestinationsV1;
+            _splitterDestinationsV2 = splitterDestinationsV2;
             IsBugFixed = isBugFixed;
         }
 
@@ -141,7 +220,9 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
                 return 0;
             }
 
-            return _splitterDestinations.Length / _splitters.Length;
+            int length = _splitterDestinationsV2.IsEmpty ? _splitterDestinationsV1.Length : _splitterDestinationsV2.Length;
+
+            return length / _splitters.Length;
         }
 
         /// <summary>
@@ -178,7 +259,39 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         }
 
         /// <summary>
-        /// Update one or multiple <see cref="SplitterDestination"/> from user parameters.
+        /// Update one splitter destination data from user parameters.
+        /// </summary>
+        /// <param name="input">The raw data after the splitter header.</param>
+        /// <returns>True if the update was successful, false otherwise</returns>
+        private bool UpdateData<T>(ref SequenceReader<byte> input) where T : unmanaged, ISplitterDestinationInParameter
+        {
+            ref readonly T parameter = ref input.GetRefOrRefToCopy<T>(out _);
+
+            Debug.Assert(parameter.IsMagicValid());
+
+            if (parameter.IsMagicValid())
+            {
+                int length = _splitterDestinationsV2.IsEmpty ? _splitterDestinationsV1.Length : _splitterDestinationsV2.Length;
+
+                if (parameter.Id >= 0 && parameter.Id < length)
+                {
+                    SplitterDestination destination = GetDestination(parameter.Id);
+
+                    destination.Update(parameter);
+                }
+
+                return true;
+            }
+            else
+            {
+                input.Rewind(Unsafe.SizeOf<T>());
+
+                return false;
+            }
+        }
+
+        /// <summary>
+        /// Update one or multiple splitter destination data from user parameters.
         /// </summary>
         /// <param name="inputHeader">The splitter header.</param>
         /// <param name="input">The raw data after the splitter header.</param>
@@ -186,23 +299,23 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         {
             for (int i = 0; i < inputHeader.SplitterDestinationCount; i++)
             {
-                ref readonly SplitterDestinationInParameter parameter = ref input.GetRefOrRefToCopy<SplitterDestinationInParameter>(out _);
-
-                Debug.Assert(parameter.IsMagicValid());
-
-                if (parameter.IsMagicValid())
+                if (Version == 1)
                 {
-                    if (parameter.Id >= 0 && parameter.Id < _splitterDestinations.Length)
+                    if (!UpdateData<SplitterDestinationInParameterVersion1>(ref input))
                     {
-                        ref SplitterDestination destination = ref GetDestination(parameter.Id);
-
-                        destination.Update(parameter);
+                        break;
+                    }
+                }
+                else if (Version == 2)
+                {
+                    if (!UpdateData<SplitterDestinationInParameterVersion2>(ref input))
+                    {
+                        break;
                     }
                 }
                 else
                 {
-                    input.Rewind(Unsafe.SizeOf<SplitterDestinationInParameter>());
-                    break;
+                    Debug.Fail($"Invalid splitter context version {Version}.");
                 }
             }
         }
@@ -214,7 +327,7 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         /// <returns>Return true if the update was successful.</returns>
         public bool Update(ref SequenceReader<byte> input)
         {
-            if (_splitterDestinations.IsEmpty || _splitters.IsEmpty)
+            if (!UsingSplitter())
             {
                 return true;
             }
@@ -251,45 +364,52 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         }
 
         /// <summary>
-        /// Get a reference to a <see cref="SplitterDestination"/> at the given <paramref name="id"/>.
+        /// Get a reference to the splitter destination data at the given <paramref name="id"/>.
         /// </summary>
         /// <param name="id">The index to use.</param>
-        /// <returns>A reference to a <see cref="SplitterDestination"/> at the given <paramref name="id"/>.</returns>
-        public ref SplitterDestination GetDestination(int id)
+        /// <returns>A reference to the splitter destination data at the given <paramref name="id"/>.</returns>
+        public SplitterDestination GetDestination(int id)
         {
-            return ref SpanIOHelper.GetFromMemory(_splitterDestinations, id, (uint)_splitterDestinations.Length);
+            if (_splitterDestinationsV2.IsEmpty)
+            {
+                return new SplitterDestination(ref SpanIOHelper.GetFromMemory(_splitterDestinationsV1, id, (uint)_splitterDestinationsV1.Length));
+            }
+            else
+            {
+                return new SplitterDestination(ref SpanIOHelper.GetFromMemory(_splitterDestinationsV2, id, (uint)_splitterDestinationsV2.Length));
+            }
         }
 
         /// <summary>
-        /// Get a <see cref="Memory{SplitterDestination}"/> at the given <paramref name="id"/>.
-        /// </summary>
-        /// <param name="id">The index to use.</param>
-        /// <returns>A <see cref="Memory{SplitterDestination}"/> at the given <paramref name="id"/>.</returns>
-        public Memory<SplitterDestination> GetDestinationMemory(int id)
-        {
-            return SpanIOHelper.GetMemory(_splitterDestinations, id, (uint)_splitterDestinations.Length);
-        }
-
-        /// <summary>
-        /// Get a <see cref="Span{SplitterDestination}"/> in the <see cref="SplitterState"/> at <paramref name="id"/> and pass <paramref name="destinationId"/> to <see cref="SplitterState.GetData(int)"/>.
+        /// Get a <see cref="SplitterDestination"/> in the <see cref="SplitterState"/> at <paramref name="id"/> and pass <paramref name="destinationId"/> to <see cref="SplitterState.GetData(int)"/>.
         /// </summary>
         /// <param name="id">The index to use to get the <see cref="SplitterState"/>.</param>
         /// <param name="destinationId">The index of the <see cref="SplitterDestination"/>.</param>
-        /// <returns>A <see cref="Span{SplitterDestination}"/>.</returns>
-        public Span<SplitterDestination> GetDestination(int id, int destinationId)
+        /// <returns>A <see cref="SplitterDestination"/>.</returns>
+        public SplitterDestination GetDestination(int id, int destinationId)
         {
             ref SplitterState splitter = ref GetState(id);
 
             return splitter.GetData(destinationId);
         }
 
+        /// <summary>
+        /// Gets the biquad filter state for a given splitter destination.
+        /// </summary>
+        /// <param name="destination">The splitter destination.</param>
+        /// <returns>Biquad filter state for the specified destination.</returns>
+        public Memory<BiquadFilterState> GetBiquadFilterState(SplitterDestination destination)
+        {
+            return _splitterBqfStates.Slice(destination.Id * BqfStatesPerDestination, BqfStatesPerDestination);
+        }
+
         /// <summary>
         /// Return true if the audio renderer has any splitters.
         /// </summary>
         /// <returns>True if the audio renderer has any splitters.</returns>
         public bool UsingSplitter()
         {
-            return !_splitters.IsEmpty && !_splitterDestinations.IsEmpty;
+            return !_splitters.IsEmpty && (!_splitterDestinationsV1.IsEmpty || !_splitterDestinationsV2.IsEmpty);
         }
 
         /// <summary>

src/Ryujinx.Audio/Renderer/Server/Splitter/SplitterDestination.cs

@@ -1,115 +1,198 @@
 using Ryujinx.Audio.Renderer.Parameter;
-using Ryujinx.Common.Utilities;
 using System;
 using System.Diagnostics;
-using System.Runtime.InteropServices;
+using System.Runtime.CompilerServices;
 
 namespace Ryujinx.Audio.Renderer.Server.Splitter
 {
     /// <summary>
     /// Server state for a splitter destination.
     /// </summary>
-    [StructLayout(LayoutKind.Sequential, Size = 0xE0, Pack = Alignment)]
-    public struct SplitterDestination
+    public ref struct SplitterDestination
     {
-        public const int Alignment = 0x10;
+        private ref SplitterDestinationVersion1 _v1;
+        private ref SplitterDestinationVersion2 _v2;
 
         /// <summary>
-        /// The unique id of this <see cref="SplitterDestination"/>.
+        /// Checks if the splitter destination data reference is null.
         /// </summary>
-        public int Id;
+        public bool IsNull => Unsafe.IsNullRef(ref _v1) && Unsafe.IsNullRef(ref _v2);
+
+        /// <summary>
+        /// The splitter unique id.
+        /// </summary>
+        public int Id
+        {
+            get
+            {
+                if (Unsafe.IsNullRef(ref _v2))
+                {
+                    if (Unsafe.IsNullRef(ref _v1))
+                    {
+                        return 0;
+                    }
+                    else
+                    {
+                        return _v1.Id;
+                    }
+                }
+                else
+                {
+                    return _v2.Id;
+                }
+            }
+        }
 
         /// <summary>
         /// The mix to output the result of the splitter.
         /// </summary>
-        public int DestinationId;
-
-        /// <summary>
-        /// Mix buffer volumes storage.
-        /// </summary>
-        private MixArray _mix;
-        private MixArray _previousMix;
-
-        /// <summary>
-        /// Pointer to the next linked element.
-        /// </summary>
-        private unsafe SplitterDestination* _next;
-
-        /// <summary>
-        /// Set to true if in use.
-        /// </summary>
-        [MarshalAs(UnmanagedType.I1)]
-        public bool IsUsed;
-
-        /// <summary>
-        /// Set to true if the internal state need to be updated.
-        /// </summary>
-        [MarshalAs(UnmanagedType.I1)]
-        public bool NeedToUpdateInternalState;
-
-        [StructLayout(LayoutKind.Sequential, Size = 4 * Constants.MixBufferCountMax, Pack = 1)]
-        private struct MixArray { }
+        public int DestinationId
+        {
+            get
+            {
+                if (Unsafe.IsNullRef(ref _v2))
+                {
+                    if (Unsafe.IsNullRef(ref _v1))
+                    {
+                        return 0;
+                    }
+                    else
+                    {
+                        return _v1.DestinationId;
+                    }
+                }
+                else
+                {
+                    return _v2.DestinationId;
+                }
+            }
+        }
 
         /// <summary>
         /// Mix buffer volumes.
         /// </summary>
         /// <remarks>Used when a splitter id is specified in the mix.</remarks>
-        public Span<float> MixBufferVolume => SpanHelpers.AsSpan<MixArray, float>(ref _mix);
+        public Span<float> MixBufferVolume
+        {
+            get
+            {
+                if (Unsafe.IsNullRef(ref _v2))
+                {
+                    if (Unsafe.IsNullRef(ref _v1))
+                    {
+                        return Span<float>.Empty;
+                    }
+                    else
+                    {
+                        return _v1.MixBufferVolume;
+                    }
+                }
+                else
+                {
+                    return _v2.MixBufferVolume;
+                }
+            }
+        }
 
         /// <summary>
         /// Previous mix buffer volumes.
         /// </summary>
         /// <remarks>Used when a splitter id is specified in the mix.</remarks>
-        public Span<float> PreviousMixBufferVolume => SpanHelpers.AsSpan<MixArray, float>(ref _previousMix);
+        public Span<float> PreviousMixBufferVolume
+        {
+            get
+            {
+                if (Unsafe.IsNullRef(ref _v2))
+                {
+                    if (Unsafe.IsNullRef(ref _v1))
+                    {
+                        return Span<float>.Empty;
+                    }
+                    else
+                    {
+                        return _v1.PreviousMixBufferVolume;
+                    }
+                }
+                else
+                {
+                    return _v2.PreviousMixBufferVolume;
+                }
+            }
+        }
 
         /// <summary>
-        /// Get the  <see cref="Span{SplitterDestination}"/> of the next element or <see cref="Span{SplitterDestination}.Empty"/> if not present.
+        /// Get the <see cref="SplitterDestination"/> of the next element or null if not present.
         /// </summary>
-        public readonly Span<SplitterDestination> Next
+        public readonly SplitterDestination Next
         {
             get
             {
                 unsafe
                 {
-                    return _next != null ? new Span<SplitterDestination>(_next, 1) : Span<SplitterDestination>.Empty;
-                }
-            }
-        }
-
-        /// <summary>
-        /// Create a new <see cref="SplitterDestination"/>.
-        /// </summary>
-        /// <param name="id">The unique id of this <see cref="SplitterDestination"/>.</param>
-        public SplitterDestination(int id) : this()
+                    if (Unsafe.IsNullRef(ref _v2))
                     {
-            Id = id;
-            DestinationId = Constants.UnusedMixId;
-
-            ClearVolumes();
+                        if (Unsafe.IsNullRef(ref _v1))
+                        {
+                            return new SplitterDestination();
+                        }
+                        else
+                        {
+                            return new SplitterDestination(ref _v1.Next);
+                        }
+                    }
+                    else
+                    {
+                        return new SplitterDestination(ref _v2.Next);
+                    }
+                }
+            }
         }
 
         /// <summary>
-        /// Update the <see cref="SplitterDestination"/> from user parameter.
+        /// Creates a new splitter destination wrapper for the version 1 splitter destination data.
+        /// </summary>
+        /// <param name="v1">Version 1 splitter destination data</param>
+        public SplitterDestination(ref SplitterDestinationVersion1 v1)
+        {
+            _v1 = ref v1;
+            _v2 = ref Unsafe.NullRef<SplitterDestinationVersion2>();
+        }
+
+        /// <summary>
+        /// Creates a new splitter destination wrapper for the version 2 splitter destination data.
+        /// </summary>
+        /// <param name="v2">Version 2 splitter destination data</param>
+        public SplitterDestination(ref SplitterDestinationVersion2 v2)
+        {
+
+            _v1 = ref Unsafe.NullRef<SplitterDestinationVersion1>();
+            _v2 = ref v2;
+        }
+
+        /// <summary>
+        /// Creates a new splitter destination wrapper for the splitter destination data.
+        /// </summary>
+        /// <param name="v1">Version 1 splitter destination data</param>
+        /// <param name="v2">Version 2 splitter destination data</param>
+        public unsafe SplitterDestination(SplitterDestinationVersion1* v1, SplitterDestinationVersion2* v2)
+        {
+            _v1 = ref Unsafe.AsRef<SplitterDestinationVersion1>(v1);
+            _v2 = ref Unsafe.AsRef<SplitterDestinationVersion2>(v2);
+        }
+
+        /// <summary>
+        /// Update the splitter destination data from user parameter.
         /// </summary>
         /// <param name="parameter">The user parameter.</param>
-        public void Update(SplitterDestinationInParameter parameter)
+        public void Update<T>(in T parameter) where T : ISplitterDestinationInParameter
         {
-            Debug.Assert(Id == parameter.Id);
-
-            if (parameter.IsMagicValid() && Id == parameter.Id)
+            if (Unsafe.IsNullRef(ref _v2))
             {
-                DestinationId = parameter.DestinationId;
-
-                parameter.MixBufferVolume.CopyTo(MixBufferVolume);
-
-                if (!IsUsed && parameter.IsUsed)
-                {
-                    MixBufferVolume.CopyTo(PreviousMixBufferVolume);
-
-                    NeedToUpdateInternalState = false;
+                _v1.Update(parameter);
             }
-
-                IsUsed = parameter.IsUsed;
+            else
+            {
+                _v2.Update(parameter);
             }
         }
 
@@ -118,12 +201,14 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         /// </summary>
         public void UpdateInternalState()
         {
-            if (IsUsed && NeedToUpdateInternalState)
+            if (Unsafe.IsNullRef(ref _v2))
             {
-                MixBufferVolume.CopyTo(PreviousMixBufferVolume);
+                _v1.UpdateInternalState();
+            }
+            else
+            {
+                _v2.UpdateInternalState();
             }
-
-            NeedToUpdateInternalState = false;
         }
 
         /// <summary>
@@ -131,16 +216,23 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         /// </summary>
         public void MarkAsNeedToUpdateInternalState()
         {
-            NeedToUpdateInternalState = true;
+            if (Unsafe.IsNullRef(ref _v2))
+            {
+                _v1.MarkAsNeedToUpdateInternalState();
+            }
+            else
+            {
+                _v2.MarkAsNeedToUpdateInternalState();
+            }
         }
 
         /// <summary>
-        /// Return true if the <see cref="SplitterDestination"/> is used and has a destination.
+        /// Return true if the splitter destination is used and has a destination.
         /// </summary>
-        /// <returns>True if the <see cref="SplitterDestination"/> is used and has a destination.</returns>
+        /// <returns>True if the splitter destination is used and has a destination.</returns>
         public readonly bool IsConfigured()
         {
-            return IsUsed && DestinationId != Constants.UnusedMixId;
+            return Unsafe.IsNullRef(ref _v2) ? _v1.IsConfigured() : _v2.IsConfigured();
         }
 
         /// <summary>
@@ -150,9 +242,17 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         /// <returns>The volume for the given destination.</returns>
         public float GetMixVolume(int destinationIndex)
         {
-            Debug.Assert(destinationIndex >= 0 && destinationIndex < Constants.MixBufferCountMax);
+            return Unsafe.IsNullRef(ref _v2) ? _v1.GetMixVolume(destinationIndex) : _v2.GetMixVolume(destinationIndex);
+        }
 
-            return MixBufferVolume[destinationIndex];
+        /// <summary>
+        /// Get the previous volume for a given destination.
+        /// </summary>
+        /// <param name="destinationIndex">The destination index to use.</param>
+        /// <returns>The volume for the given destination.</returns>
+        public float GetMixVolumePrev(int destinationIndex)
+        {
+            return Unsafe.IsNullRef(ref _v2) ? _v1.GetMixVolumePrev(destinationIndex) : _v2.GetMixVolumePrev(destinationIndex);
         }
 
         /// <summary>
@@ -160,22 +260,33 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         /// </summary>
         public void ClearVolumes()
         {
-            MixBufferVolume.Clear();
-            PreviousMixBufferVolume.Clear();
+            if (Unsafe.IsNullRef(ref _v2))
+            {
+                _v1.ClearVolumes();
+            }
+            else
+            {
+                _v2.ClearVolumes();
+            }
         }
 
         /// <summary>
-        /// Link the next element to the given <see cref="SplitterDestination"/>.
+        /// Link the next element to the given splitter destination.
         /// </summary>
-        /// <param name="next">The given <see cref="SplitterDestination"/> to link.</param>
-        public void Link(ref SplitterDestination next)
+        /// <param name="next">The given splitter destination to link.</param>
+        public void Link(SplitterDestination next)
         {
-            unsafe
+            if (Unsafe.IsNullRef(ref _v2))
             {
-                fixed (SplitterDestination* nextPtr = &next)
-                {
-                    _next = nextPtr;
+                Debug.Assert(!Unsafe.IsNullRef(ref next._v1));
+
+                _v1.Link(ref next._v1);
             }
+            else
+            {
+                Debug.Assert(!Unsafe.IsNullRef(ref next._v2));
+
+                _v2.Link(ref next._v2);
             }
         }
 
@@ -184,10 +295,74 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         /// </summary>
         public void Unlink()
         {
-            unsafe
+            if (Unsafe.IsNullRef(ref _v2))
             {
-                _next = null;
-            }
+                _v1.Unlink();
+            }
+            else
+            {
+                _v2.Unlink();
+            }
+        }
+
+        /// <summary>
+        /// Checks if any biquad filter is enabled.
+        /// </summary>
+        /// <returns>True if any biquad filter is enabled.</returns>
+        public bool IsBiquadFilterEnabled()
+        {
+            return !Unsafe.IsNullRef(ref _v2) && _v2.IsBiquadFilterEnabled();
+        }
+
+        /// <summary>
+        /// Checks if any biquad filter was previously enabled.
+        /// </summary>
+        /// <returns>True if any biquad filter was previously enabled.</returns>
+        public bool IsBiquadFilterEnabledPrev()
+        {
+            return !Unsafe.IsNullRef(ref _v2) && _v2.IsBiquadFilterEnabledPrev();
+        }
+
+        /// <summary>
+        /// Gets the biquad filter parameters.
+        /// </summary>
+        /// <param name="index">Biquad filter index (0 or 1).</param>
+        /// <returns>Biquad filter parameters.</returns>
+        public ref BiquadFilterParameter GetBiquadFilterParameter(int index)
+        {
+            Debug.Assert(!Unsafe.IsNullRef(ref _v2));
+
+            return ref _v2.GetBiquadFilterParameter(index);
+        }
+
+        /// <summary>
+        /// Checks if any biquad filter was previously enabled.
+        /// </summary>
+        /// <param name="index">Biquad filter index (0 or 1).</param>
+        public void UpdateBiquadFilterEnabledPrev(int index)
+        {
+            if (!Unsafe.IsNullRef(ref _v2))
+            {
+                _v2.UpdateBiquadFilterEnabledPrev(index);
+            }
+        }
+
+        /// <summary>
+        /// Get the reference for the version 1 splitter destination data, or null if version 2 is being used or the destination is null.
+        /// </summary>
+        /// <returns>Reference for the version 1 splitter destination data.</returns>
+        public ref SplitterDestinationVersion1 GetV1RefOrNull()
+        {
+            return ref _v1;
+        }
+
+        /// <summary>
+        /// Get the reference for the version 2 splitter destination data, or null if version 1 is being used or the destination is null.
+        /// </summary>
+        /// <returns>Reference for the version 2 splitter destination data.</returns>
+        public ref SplitterDestinationVersion2 GetV2RefOrNull()
+        {
+            return ref _v2;
         }
     }
 }

src/Ryujinx.Audio/Renderer/Server/Splitter/SplitterDestinationVersion1.cs

@@ -0,0 +1,206 @@
+using Ryujinx.Audio.Renderer.Parameter;
+using Ryujinx.Common.Utilities;
+using System;
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.Audio.Renderer.Server.Splitter
+{
+    /// <summary>
+    /// Server state for a splitter destination (version 1).
+    /// </summary>
+    [StructLayout(LayoutKind.Sequential, Size = 0xE0, Pack = Alignment)]
+    public struct SplitterDestinationVersion1
+    {
+        public const int Alignment = 0x10;
+
+        /// <summary>
+        /// The unique id of this <see cref="SplitterDestinationVersion1"/>.
+        /// </summary>
+        public int Id;
+
+        /// <summary>
+        /// The mix to output the result of the splitter.
+        /// </summary>
+        public int DestinationId;
+
+        /// <summary>
+        /// Mix buffer volumes storage.
+        /// </summary>
+        private MixArray _mix;
+        private MixArray _previousMix;
+
+        /// <summary>
+        /// Pointer to the next linked element.
+        /// </summary>
+        private unsafe SplitterDestinationVersion1* _next;
+
+        /// <summary>
+        /// Set to true if in use.
+        /// </summary>
+        [MarshalAs(UnmanagedType.I1)]
+        public bool IsUsed;
+
+        /// <summary>
+        /// Set to true if the internal state need to be updated.
+        /// </summary>
+        [MarshalAs(UnmanagedType.I1)]
+        public bool NeedToUpdateInternalState;
+
+        [StructLayout(LayoutKind.Sequential, Size = sizeof(float) * Constants.MixBufferCountMax, Pack = 1)]
+        private struct MixArray { }
+
+        /// <summary>
+        /// Mix buffer volumes.
+        /// </summary>
+        /// <remarks>Used when a splitter id is specified in the mix.</remarks>
+        public Span<float> MixBufferVolume => SpanHelpers.AsSpan<MixArray, float>(ref _mix);
+
+        /// <summary>
+        /// Previous mix buffer volumes.
+        /// </summary>
+        /// <remarks>Used when a splitter id is specified in the mix.</remarks>
+        public Span<float> PreviousMixBufferVolume => SpanHelpers.AsSpan<MixArray, float>(ref _previousMix);
+
+        /// <summary>
+        /// Get the reference of the next element or null if not present.
+        /// </summary>
+        public readonly ref SplitterDestinationVersion1 Next
+        {
+            get
+            {
+                unsafe
+                {
+                    return ref Unsafe.AsRef<SplitterDestinationVersion1>(_next);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Create a new <see cref="SplitterDestinationVersion1"/>.
+        /// </summary>
+        /// <param name="id">The unique id of this <see cref="SplitterDestinationVersion1"/>.</param>
+        public SplitterDestinationVersion1(int id) : this()
+        {
+            Id = id;
+            DestinationId = Constants.UnusedMixId;
+
+            ClearVolumes();
+        }
+
+        /// <summary>
+        /// Update the <see cref="SplitterDestinationVersion1"/> from user parameter.
+        /// </summary>
+        /// <param name="parameter">The user parameter.</param>
+        public void Update<T>(in T parameter) where T : ISplitterDestinationInParameter
+        {
+            Debug.Assert(Id == parameter.Id);
+
+            if (parameter.IsMagicValid() && Id == parameter.Id)
+            {
+                DestinationId = parameter.DestinationId;
+
+                parameter.MixBufferVolume.CopyTo(MixBufferVolume);
+
+                if (!IsUsed && parameter.IsUsed)
+                {
+                    MixBufferVolume.CopyTo(PreviousMixBufferVolume);
+
+                    NeedToUpdateInternalState = false;
+                }
+
+                IsUsed = parameter.IsUsed;
+            }
+        }
+
+        /// <summary>
+        /// Update the internal state of the instance.
+        /// </summary>
+        public void UpdateInternalState()
+        {
+            if (IsUsed && NeedToUpdateInternalState)
+            {
+                MixBufferVolume.CopyTo(PreviousMixBufferVolume);
+            }
+
+            NeedToUpdateInternalState = false;
+        }
+
+        /// <summary>
+        /// Set the update internal state marker.
+        /// </summary>
+        public void MarkAsNeedToUpdateInternalState()
+        {
+            NeedToUpdateInternalState = true;
+        }
+
+        /// <summary>
+        /// Return true if the <see cref="SplitterDestinationVersion1"/> is used and has a destination.
+        /// </summary>
+        /// <returns>True if the <see cref="SplitterDestinationVersion1"/> is used and has a destination.</returns>
+        public readonly bool IsConfigured()
+        {
+            return IsUsed && DestinationId != Constants.UnusedMixId;
+        }
+
+        /// <summary>
+        /// Get the volume for a given destination.
+        /// </summary>
+        /// <param name="destinationIndex">The destination index to use.</param>
+        /// <returns>The volume for the given destination.</returns>
+        public float GetMixVolume(int destinationIndex)
+        {
+            Debug.Assert(destinationIndex >= 0 && destinationIndex < Constants.MixBufferCountMax);
+
+            return MixBufferVolume[destinationIndex];
+        }
+
+        /// <summary>
+        /// Get the previous volume for a given destination.
+        /// </summary>
+        /// <param name="destinationIndex">The destination index to use.</param>
+        /// <returns>The volume for the given destination.</returns>
+        public float GetMixVolumePrev(int destinationIndex)
+        {
+            Debug.Assert(destinationIndex >= 0 && destinationIndex < Constants.MixBufferCountMax);
+
+            return PreviousMixBufferVolume[destinationIndex];
+        }
+
+        /// <summary>
+        /// Clear the volumes.
+        /// </summary>
+        public void ClearVolumes()
+        {
+            MixBufferVolume.Clear();
+            PreviousMixBufferVolume.Clear();
+        }
+
+        /// <summary>
+        /// Link the next element to the given <see cref="SplitterDestinationVersion1"/>.
+        /// </summary>
+        /// <param name="next">The given <see cref="SplitterDestinationVersion1"/> to link.</param>
+        public void Link(ref SplitterDestinationVersion1 next)
+        {
+            unsafe
+            {
+                fixed (SplitterDestinationVersion1* nextPtr = &next)
+                {
+                    _next = nextPtr;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Remove the link to the next element.
+        /// </summary>
+        public void Unlink()
+        {
+            unsafe
+            {
+                _next = null;
+            }
+        }
+    }
+}

src/Ryujinx.Audio/Renderer/Server/Splitter/SplitterDestinationVersion2.cs

@@ -0,0 +1,250 @@
+using Ryujinx.Audio.Renderer.Parameter;
+using Ryujinx.Common.Memory;
+using Ryujinx.Common.Utilities;
+using System;
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.Audio.Renderer.Server.Splitter
+{
+    /// <summary>
+    /// Server state for a splitter destination (version 2).
+    /// </summary>
+    [StructLayout(LayoutKind.Sequential, Size = 0x110, Pack = Alignment)]
+    public struct SplitterDestinationVersion2
+    {
+        public const int Alignment = 0x10;
+
+        /// <summary>
+        /// The unique id of this <see cref="SplitterDestinationVersion2"/>.
+        /// </summary>
+        public int Id;
+
+        /// <summary>
+        /// The mix to output the result of the splitter.
+        /// </summary>
+        public int DestinationId;
+
+        /// <summary>
+        /// Mix buffer volumes storage.
+        /// </summary>
+        private MixArray _mix;
+        private MixArray _previousMix;
+
+        /// <summary>
+        /// Pointer to the next linked element.
+        /// </summary>
+        private unsafe SplitterDestinationVersion2* _next;
+
+        /// <summary>
+        /// Set to true if in use.
+        /// </summary>
+        [MarshalAs(UnmanagedType.I1)]
+        public bool IsUsed;
+
+        /// <summary>
+        /// Set to true if the internal state need to be updated.
+        /// </summary>
+        [MarshalAs(UnmanagedType.I1)]
+        public bool NeedToUpdateInternalState;
+
+        [StructLayout(LayoutKind.Sequential, Size = sizeof(float) * Constants.MixBufferCountMax, Pack = 1)]
+        private struct MixArray { }
+
+        /// <summary>
+        /// Mix buffer volumes.
+        /// </summary>
+        /// <remarks>Used when a splitter id is specified in the mix.</remarks>
+        public Span<float> MixBufferVolume => SpanHelpers.AsSpan<MixArray, float>(ref _mix);
+
+        /// <summary>
+        /// Previous mix buffer volumes.
+        /// </summary>
+        /// <remarks>Used when a splitter id is specified in the mix.</remarks>
+        public Span<float> PreviousMixBufferVolume => SpanHelpers.AsSpan<MixArray, float>(ref _previousMix);
+
+        /// <summary>
+        /// Get the reference of the next element or null if not present.
+        /// </summary>
+        public readonly ref SplitterDestinationVersion2 Next
+        {
+            get
+            {
+                unsafe
+                {
+                    return ref Unsafe.AsRef<SplitterDestinationVersion2>(_next);
+                }
+            }
+        }
+
+        private Array2<BiquadFilterParameter> _biquadFilters;
+
+        private Array2<bool> _isPreviousBiquadFilterEnabled;
+
+        /// <summary>
+        /// Create a new <see cref="SplitterDestinationVersion2"/>.
+        /// </summary>
+        /// <param name="id">The unique id of this <see cref="SplitterDestinationVersion2"/>.</param>
+        public SplitterDestinationVersion2(int id) : this()
+        {
+            Id = id;
+            DestinationId = Constants.UnusedMixId;
+
+            ClearVolumes();
+        }
+
+        /// <summary>
+        /// Update the <see cref="SplitterDestinationVersion2"/> from user parameter.
+        /// </summary>
+        /// <param name="parameter">The user parameter.</param>
+        public void Update<T>(in T parameter) where T : ISplitterDestinationInParameter
+        {
+            Debug.Assert(Id == parameter.Id);
+
+            if (parameter.IsMagicValid() && Id == parameter.Id)
+            {
+                DestinationId = parameter.DestinationId;
+
+                parameter.MixBufferVolume.CopyTo(MixBufferVolume);
+
+                _biquadFilters = parameter.BiquadFilters;
+
+                if (!IsUsed && parameter.IsUsed)
+                {
+                    MixBufferVolume.CopyTo(PreviousMixBufferVolume);
+
+                    NeedToUpdateInternalState = false;
+                }
+
+                IsUsed = parameter.IsUsed;
+            }
+        }
+
+        /// <summary>
+        /// Update the internal state of the instance.
+        /// </summary>
+        public void UpdateInternalState()
+        {
+            if (IsUsed && NeedToUpdateInternalState)
+            {
+                MixBufferVolume.CopyTo(PreviousMixBufferVolume);
+            }
+
+            NeedToUpdateInternalState = false;
+        }
+
+        /// <summary>
+        /// Set the update internal state marker.
+        /// </summary>
+        public void MarkAsNeedToUpdateInternalState()
+        {
+            NeedToUpdateInternalState = true;
+        }
+
+        /// <summary>
+        /// Return true if the <see cref="SplitterDestinationVersion2"/> is used and has a destination.
+        /// </summary>
+        /// <returns>True if the <see cref="SplitterDestinationVersion2"/> is used and has a destination.</returns>
+        public readonly bool IsConfigured()
+        {
+            return IsUsed && DestinationId != Constants.UnusedMixId;
+        }
+
+        /// <summary>
+        /// Get the volume for a given destination.
+        /// </summary>
+        /// <param name="destinationIndex">The destination index to use.</param>
+        /// <returns>The volume for the given destination.</returns>
+        public float GetMixVolume(int destinationIndex)
+        {
+            Debug.Assert(destinationIndex >= 0 && destinationIndex < Constants.MixBufferCountMax);
+
+            return MixBufferVolume[destinationIndex];
+        }
+
+        /// <summary>
+        /// Get the previous volume for a given destination.
+        /// </summary>
+        /// <param name="destinationIndex">The destination index to use.</param>
+        /// <returns>The volume for the given destination.</returns>
+        public float GetMixVolumePrev(int destinationIndex)
+        {
+            Debug.Assert(destinationIndex >= 0 && destinationIndex < Constants.MixBufferCountMax);
+
+            return PreviousMixBufferVolume[destinationIndex];
+        }
+
+        /// <summary>
+        /// Clear the volumes.
+        /// </summary>
+        public void ClearVolumes()
+        {
+            MixBufferVolume.Clear();
+            PreviousMixBufferVolume.Clear();
+        }
+
+        /// <summary>
+        /// Link the next element to the given <see cref="SplitterDestinationVersion2"/>.
+        /// </summary>
+        /// <param name="next">The given <see cref="SplitterDestinationVersion2"/> to link.</param>
+        public void Link(ref SplitterDestinationVersion2 next)
+        {
+            unsafe
+            {
+                fixed (SplitterDestinationVersion2* nextPtr = &next)
+                {
+                    _next = nextPtr;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Remove the link to the next element.
+        /// </summary>
+        public void Unlink()
+        {
+            unsafe
+            {
+                _next = null;
+            }
+        }
+
+        /// <summary>
+        /// Checks if any biquad filter is enabled.
+        /// </summary>
+        /// <returns>True if any biquad filter is enabled.</returns>
+        public bool IsBiquadFilterEnabled()
+        {
+            return _biquadFilters[0].Enable || _biquadFilters[1].Enable;
+        }
+
+        /// <summary>
+        /// Checks if any biquad filter was previously enabled.
+        /// </summary>
+        /// <returns>True if any biquad filter was previously enabled.</returns>
+        public bool IsBiquadFilterEnabledPrev()
+        {
+            return _isPreviousBiquadFilterEnabled[0];
+        }
+
+        /// <summary>
+        /// Gets the biquad filter parameters.
+        /// </summary>
+        /// <param name="index">Biquad filter index (0 or 1).</param>
+        /// <returns>Biquad filter parameters.</returns>
+        public ref BiquadFilterParameter GetBiquadFilterParameter(int index)
+        {
+            return ref _biquadFilters[index];
+        }
+
+        /// <summary>
+        /// Checks if any biquad filter was previously enabled.
+        /// </summary>
+        /// <param name="index">Biquad filter index (0 or 1).</param>
+        public void UpdateBiquadFilterEnabledPrev(int index)
+        {
+            _isPreviousBiquadFilterEnabled[index] = _biquadFilters[index].Enable;
+        }
+    }
+}

src/Ryujinx.Audio/Renderer/Server/Splitter/SplitterState.cs

@@ -15,6 +15,8 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
     {
         public const int Alignment = 0x10;
 
+        private delegate void SplitterDestinationAction(SplitterDestination destination, int index);
+
         /// <summary>
         /// The unique id of this <see cref="SplitterState"/>.
         /// </summary>
@@ -26,7 +28,7 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         public uint SampleRate;
 
         /// <summary>
-        /// Count of splitter destinations (<see cref="SplitterDestination"/>).
+        /// Count of splitter destinations.
         /// </summary>
         public int DestinationCount;
 
@@ -37,20 +39,25 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         public bool HasNewConnection;
 
         /// <summary>
-        /// Linked list of <see cref="SplitterDestination"/>.
+        /// Linked list of <see cref="SplitterDestinationVersion1"/>.
         /// </summary>
-        private unsafe SplitterDestination* _destinationsData;
+        private unsafe SplitterDestinationVersion1* _destinationDataV1;
 
         /// <summary>
-        /// Span to the first element of the linked list of <see cref="SplitterDestination"/>.
+        /// Linked list of <see cref="SplitterDestinationVersion2"/>.
         /// </summary>
-        public readonly Span<SplitterDestination> Destinations
+        private unsafe SplitterDestinationVersion2* _destinationDataV2;
+
+        /// <summary>
+        /// First element of the linked list of splitter destinations data.
+        /// </summary>
+        public readonly SplitterDestination Destination
         {
             get
             {
                 unsafe
                 {
-                    return (IntPtr)_destinationsData != IntPtr.Zero ? new Span<SplitterDestination>(_destinationsData, 1) : Span<SplitterDestination>.Empty;
+                    return new SplitterDestination(_destinationDataV1, _destinationDataV2);
                 }
             }
         }
@@ -64,20 +71,20 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
             Id = id;
         }
 
-        public readonly Span<SplitterDestination> GetData(int index)
+        public readonly SplitterDestination GetData(int index)
         {
             int i = 0;
 
-            Span<SplitterDestination> result = Destinations;
+            SplitterDestination result = Destination;
 
             while (i < index)
             {
-                if (result.IsEmpty)
+                if (result.IsNull)
                 {
                     break;
                 }
 
-                result = result[0].Next;
+                result = result.Next;
                 i++;
             }
 
@@ -93,25 +100,25 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         }
 
         /// <summary>
-        /// Utility function to apply a given <see cref="SpanAction{T, TArg}"/> to all <see cref="Destinations"/>.
+        /// Utility function to apply an action to all <see cref="Destination"/>.
         /// </summary>
         /// <param name="action">The action to execute on each elements.</param>
-        private readonly void ForEachDestination(SpanAction<SplitterDestination, int> action)
+        private readonly void ForEachDestination(SplitterDestinationAction action)
         {
-            Span<SplitterDestination> temp = Destinations;
+            SplitterDestination temp = Destination;
 
             int i = 0;
 
             while (true)
             {
-                if (temp.IsEmpty)
+                if (temp.IsNull)
                 {
                     break;
                 }
 
-                Span<SplitterDestination> next = temp[0].Next;
+                SplitterDestination next = temp.Next;
 
-                action.Invoke(temp, i++);
+                action(temp, i++);
 
                 temp = next;
             }
@@ -142,9 +149,9 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
             {
                 input.ReadLittleEndian(out int destinationId);
 
-                Memory<SplitterDestination> destination = context.GetDestinationMemory(destinationId);
+                SplitterDestination destination = context.GetDestination(destinationId);
 
-                SetDestination(ref destination.Span[0]);
+                SetDestination(destination);
 
                 DestinationCount = destinationCount;
 
@@ -152,9 +159,9 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
                 {
                     input.ReadLittleEndian(out destinationId);
 
-                    Memory<SplitterDestination> nextDestination = context.GetDestinationMemory(destinationId);
+                    SplitterDestination nextDestination = context.GetDestination(destinationId);
 
-                    destination.Span[0].Link(ref nextDestination.Span[0]);
+                    destination.Link(nextDestination);
                     destination = nextDestination;
                 }
             }
@@ -174,16 +181,21 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         }
 
         /// <summary>
-        /// Set the head of the linked list of <see cref="Destinations"/>.
+        /// Set the head of the linked list of <see cref="Destination"/>.
         /// </summary>
-        /// <param name="newValue">A reference to a <see cref="SplitterDestination"/>.</param>
-        public void SetDestination(ref SplitterDestination newValue)
+        /// <param name="newValue">New destination value.</param>
+        public void SetDestination(SplitterDestination newValue)
         {
             unsafe
             {
-                fixed (SplitterDestination* newValuePtr = &newValue)
+                fixed (SplitterDestinationVersion1* newValuePtr = &newValue.GetV1RefOrNull())
                 {
-                    _destinationsData = newValuePtr;
+                    _destinationDataV1 = newValuePtr;
+                }
+
+                fixed (SplitterDestinationVersion2* newValuePtr = &newValue.GetV2RefOrNull())
+                {
+                    _destinationDataV2 = newValuePtr;
                 }
             }
         }
@@ -193,19 +205,20 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
         /// </summary>
         public readonly void UpdateInternalState()
         {
-            ForEachDestination((destination, _) => destination[0].UpdateInternalState());
+            ForEachDestination((destination, _) => destination.UpdateInternalState());
         }
 
         /// <summary>
-        /// Clear all links from the <see cref="Destinations"/>.
+        /// Clear all links from the <see cref="Destination"/>.
         /// </summary>
         public void ClearLinks()
         {
-            ForEachDestination((destination, _) => destination[0].Unlink());
+            ForEachDestination((destination, _) => destination.Unlink());
 
             unsafe
             {
-                _destinationsData = (SplitterDestination*)IntPtr.Zero;
+                _destinationDataV1 = null;
+                _destinationDataV2 = null;
             }
         }
 
@@ -219,7 +232,8 @@ namespace Ryujinx.Audio.Renderer.Server.Splitter
             {
                 unsafe
                 {
-                    splitter._destinationsData = (SplitterDestination*)IntPtr.Zero;
+                    splitter._destinationDataV1 = null;
+                    splitter._destinationDataV2 = null;
                 }
 
                 splitter.DestinationCount = 0;

src/Ryujinx.Tests/Audio/Renderer/Server/BehaviourContextTests.cs

@@ -52,7 +52,9 @@ namespace Ryujinx.Tests.Audio.Renderer.Server
             Assert.IsFalse(behaviourContext.IsMixInParameterDirtyOnlyUpdateSupported());
             Assert.IsFalse(behaviourContext.IsWaveBufferVersion2Supported());
             Assert.IsFalse(behaviourContext.IsEffectInfoVersion2Supported());
-            Assert.IsFalse(behaviourContext.IsBiquadFilterGroupedOptimizationSupported());
+            Assert.IsFalse(behaviourContext.UseMultiTapBiquadFilterProcessing());
+            Assert.IsFalse(behaviourContext.IsNewEffectChannelMappingSupported());
+            Assert.IsFalse(behaviourContext.IsBiquadFilterParameterForSplitterEnabled());
 
             Assert.AreEqual(0.70f, behaviourContext.GetAudioRendererProcessingTimeLimit());
             Assert.AreEqual(1, behaviourContext.GetCommandProcessingTimeEstimatorVersion());
@@ -78,7 +80,9 @@ namespace Ryujinx.Tests.Audio.Renderer.Server
             Assert.IsFalse(behaviourContext.IsMixInParameterDirtyOnlyUpdateSupported());
             Assert.IsFalse(behaviourContext.IsWaveBufferVersion2Supported());
             Assert.IsFalse(behaviourContext.IsEffectInfoVersion2Supported());
-            Assert.IsFalse(behaviourContext.IsBiquadFilterGroupedOptimizationSupported());
+            Assert.IsFalse(behaviourContext.UseMultiTapBiquadFilterProcessing());
+            Assert.IsFalse(behaviourContext.IsNewEffectChannelMappingSupported());
+            Assert.IsFalse(behaviourContext.IsBiquadFilterParameterForSplitterEnabled());
 
             Assert.AreEqual(0.70f, behaviourContext.GetAudioRendererProcessingTimeLimit());
             Assert.AreEqual(1, behaviourContext.GetCommandProcessingTimeEstimatorVersion());
@@ -104,7 +108,9 @@ namespace Ryujinx.Tests.Audio.Renderer.Server
             Assert.IsFalse(behaviourContext.IsMixInParameterDirtyOnlyUpdateSupported());
             Assert.IsFalse(behaviourContext.IsWaveBufferVersion2Supported());
             Assert.IsFalse(behaviourContext.IsEffectInfoVersion2Supported());
-            Assert.IsFalse(behaviourContext.IsBiquadFilterGroupedOptimizationSupported());
+            Assert.IsFalse(behaviourContext.UseMultiTapBiquadFilterProcessing());
+            Assert.IsFalse(behaviourContext.IsNewEffectChannelMappingSupported());
+            Assert.IsFalse(behaviourContext.IsBiquadFilterParameterForSplitterEnabled());
 
             Assert.AreEqual(0.70f, behaviourContext.GetAudioRendererProcessingTimeLimit());
             Assert.AreEqual(1, behaviourContext.GetCommandProcessingTimeEstimatorVersion());
@@ -130,7 +136,9 @@ namespace Ryujinx.Tests.Audio.Renderer.Server
             Assert.IsFalse(behaviourContext.IsMixInParameterDirtyOnlyUpdateSupported());
             Assert.IsFalse(behaviourContext.IsWaveBufferVersion2Supported());
             Assert.IsFalse(behaviourContext.IsEffectInfoVersion2Supported());
-            Assert.IsFalse(behaviourContext.IsBiquadFilterGroupedOptimizationSupported());
+            Assert.IsFalse(behaviourContext.UseMultiTapBiquadFilterProcessing());
+            Assert.IsFalse(behaviourContext.IsNewEffectChannelMappingSupported());
+            Assert.IsFalse(behaviourContext.IsBiquadFilterParameterForSplitterEnabled());
 
             Assert.AreEqual(0.75f, behaviourContext.GetAudioRendererProcessingTimeLimit());
             Assert.AreEqual(1, behaviourContext.GetCommandProcessingTimeEstimatorVersion());
@@ -156,7 +164,9 @@ namespace Ryujinx.Tests.Audio.Renderer.Server
             Assert.IsFalse(behaviourContext.IsMixInParameterDirtyOnlyUpdateSupported());
             Assert.IsFalse(behaviourContext.IsWaveBufferVersion2Supported());
             Assert.IsFalse(behaviourContext.IsEffectInfoVersion2Supported());
-            Assert.IsFalse(behaviourContext.IsBiquadFilterGroupedOptimizationSupported());
+            Assert.IsFalse(behaviourContext.UseMultiTapBiquadFilterProcessing());
+            Assert.IsFalse(behaviourContext.IsNewEffectChannelMappingSupported());
+            Assert.IsFalse(behaviourContext.IsBiquadFilterParameterForSplitterEnabled());
 
             Assert.AreEqual(0.80f, behaviourContext.GetAudioRendererProcessingTimeLimit());
             Assert.AreEqual(2, behaviourContext.GetCommandProcessingTimeEstimatorVersion());
@@ -182,7 +192,9 @@ namespace Ryujinx.Tests.Audio.Renderer.Server
             Assert.IsFalse(behaviourContext.IsMixInParameterDirtyOnlyUpdateSupported());
             Assert.IsFalse(behaviourContext.IsWaveBufferVersion2Supported());
             Assert.IsFalse(behaviourContext.IsEffectInfoVersion2Supported());
-            Assert.IsFalse(behaviourContext.IsBiquadFilterGroupedOptimizationSupported());
+            Assert.IsFalse(behaviourContext.UseMultiTapBiquadFilterProcessing());
+            Assert.IsFalse(behaviourContext.IsNewEffectChannelMappingSupported());
+            Assert.IsFalse(behaviourContext.IsBiquadFilterParameterForSplitterEnabled());
 
             Assert.AreEqual(0.80f, behaviourContext.GetAudioRendererProcessingTimeLimit());
             Assert.AreEqual(2, behaviourContext.GetCommandProcessingTimeEstimatorVersion());
@@ -208,7 +220,9 @@ namespace Ryujinx.Tests.Audio.Renderer.Server
             Assert.IsTrue(behaviourContext.IsMixInParameterDirtyOnlyUpdateSupported());
             Assert.IsFalse(behaviourContext.IsWaveBufferVersion2Supported());
             Assert.IsFalse(behaviourContext.IsEffectInfoVersion2Supported());
-            Assert.IsFalse(behaviourContext.IsBiquadFilterGroupedOptimizationSupported());
+            Assert.IsFalse(behaviourContext.UseMultiTapBiquadFilterProcessing());
+            Assert.IsFalse(behaviourContext.IsNewEffectChannelMappingSupported());
+            Assert.IsFalse(behaviourContext.IsBiquadFilterParameterForSplitterEnabled());
 
             Assert.AreEqual(0.80f, behaviourContext.GetAudioRendererProcessingTimeLimit());
             Assert.AreEqual(2, behaviourContext.GetCommandProcessingTimeEstimatorVersion());
@@ -234,7 +248,9 @@ namespace Ryujinx.Tests.Audio.Renderer.Server
             Assert.IsTrue(behaviourContext.IsMixInParameterDirtyOnlyUpdateSupported());
             Assert.IsTrue(behaviourContext.IsWaveBufferVersion2Supported());
             Assert.IsFalse(behaviourContext.IsEffectInfoVersion2Supported());
-            Assert.IsFalse(behaviourContext.IsBiquadFilterGroupedOptimizationSupported());
+            Assert.IsFalse(behaviourContext.UseMultiTapBiquadFilterProcessing());
+            Assert.IsFalse(behaviourContext.IsNewEffectChannelMappingSupported());
+            Assert.IsFalse(behaviourContext.IsBiquadFilterParameterForSplitterEnabled());
 
             Assert.AreEqual(0.80f, behaviourContext.GetAudioRendererProcessingTimeLimit());
             Assert.AreEqual(3, behaviourContext.GetCommandProcessingTimeEstimatorVersion());
@@ -260,7 +276,9 @@ namespace Ryujinx.Tests.Audio.Renderer.Server
             Assert.IsTrue(behaviourContext.IsMixInParameterDirtyOnlyUpdateSupported());
             Assert.IsTrue(behaviourContext.IsWaveBufferVersion2Supported());
             Assert.IsTrue(behaviourContext.IsEffectInfoVersion2Supported());
-            Assert.IsFalse(behaviourContext.IsBiquadFilterGroupedOptimizationSupported());
+            Assert.IsFalse(behaviourContext.UseMultiTapBiquadFilterProcessing());
+            Assert.IsFalse(behaviourContext.IsNewEffectChannelMappingSupported());
+            Assert.IsFalse(behaviourContext.IsBiquadFilterParameterForSplitterEnabled());
 
             Assert.AreEqual(0.80f, behaviourContext.GetAudioRendererProcessingTimeLimit());
             Assert.AreEqual(3, behaviourContext.GetCommandProcessingTimeEstimatorVersion());
@@ -286,11 +304,69 @@ namespace Ryujinx.Tests.Audio.Renderer.Server
             Assert.IsTrue(behaviourContext.IsMixInParameterDirtyOnlyUpdateSupported());
             Assert.IsTrue(behaviourContext.IsWaveBufferVersion2Supported());
             Assert.IsTrue(behaviourContext.IsEffectInfoVersion2Supported());
-            Assert.IsTrue(behaviourContext.IsBiquadFilterGroupedOptimizationSupported());
+            Assert.IsTrue(behaviourContext.UseMultiTapBiquadFilterProcessing());
+            Assert.IsFalse(behaviourContext.IsNewEffectChannelMappingSupported());
+            Assert.IsFalse(behaviourContext.IsBiquadFilterParameterForSplitterEnabled());
 
             Assert.AreEqual(0.80f, behaviourContext.GetAudioRendererProcessingTimeLimit());
             Assert.AreEqual(4, behaviourContext.GetCommandProcessingTimeEstimatorVersion());
             Assert.AreEqual(2, behaviourContext.GetPerformanceMetricsDataFormat());
         }
+
+        [Test]
+        public void TestRevision11()
+        {
+            BehaviourContext behaviourContext = new();
+
+            behaviourContext.SetUserRevision(BehaviourContext.BaseRevisionMagic + BehaviourContext.Revision11);
+
+            Assert.IsTrue(behaviourContext.IsAdpcmLoopContextBugFixed());
+            Assert.IsTrue(behaviourContext.IsSplitterSupported());
+            Assert.IsTrue(behaviourContext.IsLongSizePreDelaySupported());
+            Assert.IsTrue(behaviourContext.IsAudioUsbDeviceOutputSupported());
+            Assert.IsTrue(behaviourContext.IsFlushVoiceWaveBuffersSupported());
+            Assert.IsTrue(behaviourContext.IsSplitterBugFixed());
+            Assert.IsTrue(behaviourContext.IsElapsedFrameCountSupported());
+            Assert.IsTrue(behaviourContext.IsDecodingBehaviourFlagSupported());
+            Assert.IsTrue(behaviourContext.IsBiquadFilterEffectStateClearBugFixed());
+            Assert.IsTrue(behaviourContext.IsMixInParameterDirtyOnlyUpdateSupported());
+            Assert.IsTrue(behaviourContext.IsWaveBufferVersion2Supported());
+            Assert.IsTrue(behaviourContext.IsEffectInfoVersion2Supported());
+            Assert.IsTrue(behaviourContext.UseMultiTapBiquadFilterProcessing());
+            Assert.IsTrue(behaviourContext.IsNewEffectChannelMappingSupported());
+            Assert.IsFalse(behaviourContext.IsBiquadFilterParameterForSplitterEnabled());
+
+            Assert.AreEqual(0.80f, behaviourContext.GetAudioRendererProcessingTimeLimit());
+            Assert.AreEqual(5, behaviourContext.GetCommandProcessingTimeEstimatorVersion());
+            Assert.AreEqual(2, behaviourContext.GetPerformanceMetricsDataFormat());
+        }
+
+        [Test]
+        public void TestRevision12()
+        {
+            BehaviourContext behaviourContext = new();
+
+            behaviourContext.SetUserRevision(BehaviourContext.BaseRevisionMagic + BehaviourContext.Revision12);
+
+            Assert.IsTrue(behaviourContext.IsAdpcmLoopContextBugFixed());
+            Assert.IsTrue(behaviourContext.IsSplitterSupported());
+            Assert.IsTrue(behaviourContext.IsLongSizePreDelaySupported());
+            Assert.IsTrue(behaviourContext.IsAudioUsbDeviceOutputSupported());
+            Assert.IsTrue(behaviourContext.IsFlushVoiceWaveBuffersSupported());
+            Assert.IsTrue(behaviourContext.IsSplitterBugFixed());
+            Assert.IsTrue(behaviourContext.IsElapsedFrameCountSupported());
+            Assert.IsTrue(behaviourContext.IsDecodingBehaviourFlagSupported());
+            Assert.IsTrue(behaviourContext.IsBiquadFilterEffectStateClearBugFixed());
+            Assert.IsTrue(behaviourContext.IsMixInParameterDirtyOnlyUpdateSupported());
+            Assert.IsTrue(behaviourContext.IsWaveBufferVersion2Supported());
+            Assert.IsTrue(behaviourContext.IsEffectInfoVersion2Supported());
+            Assert.IsTrue(behaviourContext.UseMultiTapBiquadFilterProcessing());
+            Assert.IsTrue(behaviourContext.IsNewEffectChannelMappingSupported());
+            Assert.IsTrue(behaviourContext.IsBiquadFilterParameterForSplitterEnabled());
+
+            Assert.AreEqual(0.80f, behaviourContext.GetAudioRendererProcessingTimeLimit());
+            Assert.AreEqual(5, behaviourContext.GetCommandProcessingTimeEstimatorVersion());
+            Assert.AreEqual(2, behaviourContext.GetPerformanceMetricsDataFormat());
+        }
     }
 }

src/Ryujinx.Tests/Audio/Renderer/Server/SplitterDestinationTests.cs

@@ -9,7 +9,8 @@ namespace Ryujinx.Tests.Audio.Renderer.Server
         [Test]
         public void EnsureTypeSize()
         {
-            Assert.AreEqual(0xE0, Unsafe.SizeOf<SplitterDestination>());
+            Assert.AreEqual(0xE0, Unsafe.SizeOf<SplitterDestinationVersion1>());
+            Assert.AreEqual(0x110, Unsafe.SizeOf<SplitterDestinationVersion2>());
         }
     }
 }