3 files changed, 149 insertions, 29 deletions
diff --git a/Ryujinx.Audio/Backends/CompatLayer/CompatLayerHardwareDeviceDriver.cs b/Ryujinx.Audio/Backends/CompatLayer/CompatLayerHardwareDeviceDriver.cs
index b6f45a3e..fbdfe18f 100644
--- a/Ryujinx.Audio/Backends/CompatLayer/CompatLayerHardwareDeviceDriver.cs
+++ b/Ryujinx.Audio/Backends/CompatLayer/CompatLayerHardwareDeviceDriver.cs
@@ -51,6 +51,40 @@ namespace Ryujinx.Audio.Backends.CompatLayer
             };
         }
 
+        private SampleFormat SelectHardwareSampleFormat(SampleFormat targetSampleFormat)
+        {
+            if (_realDriver.SupportsSampleFormat(targetSampleFormat))
+            {
+                return targetSampleFormat;
+            }
+
+            // Attempt conversion from PCM16.
+            if (targetSampleFormat == SampleFormat.PcmInt16)
+            {
+                // Prefer PCM32 if we need to convert.
+                if (_realDriver.SupportsSampleFormat(SampleFormat.PcmInt32))
+                {
+                    return SampleFormat.PcmInt32;
+                }
+
+                // If not supported, PCM float provides the best quality with a cost lower than PCM24.
+                if (_realDriver.SupportsSampleFormat(SampleFormat.PcmFloat))
+                {
+                    return SampleFormat.PcmFloat;
+                }
+
+                // TODO: Implement PCM24 conversion.
+
+                // If nothing is truly supported, attempt PCM8 at the cost of loosing quality.
+                if (_realDriver.SupportsSampleFormat(SampleFormat.PcmInt8))
+                {
+                    return SampleFormat.PcmInt8;
+                }
+            }
+
+            throw new ArgumentException("No valid sample format configuration found!");
+        }
+
         public IHardwareDeviceSession OpenDeviceSession(Direction direction, IVirtualMemoryManager memoryManager, SampleFormat sampleFormat, uint sampleRate, uint channelCount, float volume)
         {
             if (channelCount == 0)
@@ -77,15 +111,26 @@ namespace Ryujinx.Audio.Backends.CompatLayer
                 throw new NotImplementedException();
             }
 
+            SampleFormat hardwareSampleFormat = SelectHardwareSampleFormat(sampleFormat);
             uint hardwareChannelCount = SelectHardwareChannelCount(channelCount);
 
-            IHardwareDeviceSession realSession = _realDriver.OpenDeviceSession(direction, memoryManager, sampleFormat, sampleRate, hardwareChannelCount, volume);
+            IHardwareDeviceSession realSession = _realDriver.OpenDeviceSession(direction, memoryManager, hardwareSampleFormat, sampleRate, hardwareChannelCount, volume);
 
-            if (hardwareChannelCount == channelCount)
+            if (hardwareChannelCount == channelCount && hardwareSampleFormat == sampleFormat)
             {
                 return realSession;
             }
 
+            if (hardwareSampleFormat != sampleFormat)
+            {
+                Logger.Warning?.Print(LogClass.Audio, $"{sampleFormat} isn't supported by the audio device, conversion to {hardwareSampleFormat} will happen.");
+
+                if (hardwareSampleFormat < sampleFormat)
+                {
+                    Logger.Warning?.Print(LogClass.Audio, $"{hardwareSampleFormat} has lower quality than {sampleFormat}, expect some loss in audio fidelity.");
+                }
+            }
+
             if (direction == Direction.Input)
             {
                 Logger.Warning?.Print(LogClass.Audio, $"The selected audio backend doesn't support the requested audio input configuration, fallback to dummy...");
@@ -103,7 +148,7 @@ namespace Ryujinx.Audio.Backends.CompatLayer
             }
 
             // If we need to do post processing before sending to the hardware device, wrap around it.
-            return new CompatLayerHardwareDeviceSession(realSessionOutputBase, channelCount);
+            return new CompatLayerHardwareDeviceSession(realSessionOutputBase, sampleFormat, channelCount);
         }
 
         public bool SupportsChannelCount(uint channelCount)
diff --git a/Ryujinx.Audio/Backends/CompatLayer/CompatLayerHardwareDeviceSession.cs b/Ryujinx.Audio/Backends/CompatLayer/CompatLayerHardwareDeviceSession.cs
index ff3b0988..ca6090fe 100644
--- a/Ryujinx.Audio/Backends/CompatLayer/CompatLayerHardwareDeviceSession.cs
+++ b/Ryujinx.Audio/Backends/CompatLayer/CompatLayerHardwareDeviceSession.cs
@@ -1,5 +1,6 @@
 using Ryujinx.Audio.Backends.Common;
 using Ryujinx.Audio.Common;
+using Ryujinx.Audio.Renderer.Dsp;
 using System;
 using System.Runtime.InteropServices;
 
@@ -8,11 +9,13 @@ namespace Ryujinx.Audio.Backends.CompatLayer
     class CompatLayerHardwareDeviceSession : HardwareDeviceSessionOutputBase
     {
         private HardwareDeviceSessionOutputBase _realSession;
+        private SampleFormat _userSampleFormat;
         private uint _userChannelCount;
 
-        public CompatLayerHardwareDeviceSession(HardwareDeviceSessionOutputBase realSession, uint userChannelCount) : base(realSession.MemoryManager, realSession.RequestedSampleFormat, realSession.RequestedSampleRate, userChannelCount)
+        public CompatLayerHardwareDeviceSession(HardwareDeviceSessionOutputBase realSession, SampleFormat userSampleFormat, uint userChannelCount) : base(realSession.MemoryManager, realSession.RequestedSampleFormat, realSession.RequestedSampleRate, userChannelCount)
         {
             _realSession = realSession;
+            _userSampleFormat = userSampleFormat;
             _userChannelCount = userChannelCount;
         }
 
@@ -38,53 +41,86 @@ namespace Ryujinx.Audio.Backends.CompatLayer
 
         public override void QueueBuffer(AudioBuffer buffer)
         {
+            SampleFormat realSampleFormat = _realSession.RequestedSampleFormat;
+
+            if (_userSampleFormat != realSampleFormat)
+            {
+                if (_userSampleFormat != SampleFormat.PcmInt16)
+                {
+                    throw new NotImplementedException("Converting formats other than PCM16 is not supported.");
+                }
+
+                int userSampleCount = buffer.Data.Length / BackendHelper.GetSampleSize(_userSampleFormat);
+
+                ReadOnlySpan<short> samples = MemoryMarshal.Cast<byte, short>(buffer.Data);
+                byte[] convertedSamples = new byte[BackendHelper.GetSampleSize(realSampleFormat) * userSampleCount];
+
+                switch (realSampleFormat)
+                {
+                    case SampleFormat.PcmInt8:
+                        PcmHelper.Convert(MemoryMarshal.Cast<byte, sbyte>(convertedSamples), samples);
+                        break;
+                    case SampleFormat.PcmInt32:
+                        PcmHelper.Convert(MemoryMarshal.Cast<byte, int>(convertedSamples), samples);
+                        break;
+                    case SampleFormat.PcmFloat:
+                        PcmHelper.ConvertSampleToPcmFloat(MemoryMarshal.Cast<byte, float>(convertedSamples), samples);
+                        break;
+                    default:
+                        throw new NotImplementedException($"Sample format conversion from {_userSampleFormat} to {realSampleFormat} not implemented.");
+                }
+
+                buffer.Data = convertedSamples;
+            }
+
             _realSession.QueueBuffer(buffer);
         }
 
         public override bool RegisterBuffer(AudioBuffer buffer, byte[] samples)
         {
-            if (RequestedSampleFormat != SampleFormat.PcmInt16)
-            {
-                throw new NotImplementedException("Downmixing formats other than PCM16 is not supported.");
-            }
-
             if (samples == null)
             {
                 return false;
             }
 
-            short[] downmixedBufferPCM16;
+            if (_userChannelCount != _realSession.RequestedChannelCount)
+            {
+                if (_userSampleFormat != SampleFormat.PcmInt16)
+                {
+                    throw new NotImplementedException("Downmixing formats other than PCM16 is not supported.");
+                }
 
-            ReadOnlySpan<short> samplesPCM16 = MemoryMarshal.Cast<byte, short>(samples);
+                ReadOnlySpan<short> samplesPCM16 = MemoryMarshal.Cast<byte, short>(samples);
 
-            if (_userChannelCount == 6)
-            {
-                downmixedBufferPCM16 = Downmixing.DownMixSurroundToStereo(samplesPCM16);
+                if (_userChannelCount == 6)
+                {
+                    samplesPCM16 = Downmixing.DownMixSurroundToStereo(samplesPCM16);
 
-                if (_realSession.RequestedChannelCount == 1)
+                    if (_realSession.RequestedChannelCount == 1)
+                    {
+                        samplesPCM16 = Downmixing.DownMixStereoToMono(samplesPCM16);
+                    }
+                }
+                else if (_userChannelCount == 2 && _realSession.RequestedChannelCount == 1)
                 {
-                    downmixedBufferPCM16 = Downmixing.DownMixStereoToMono(downmixedBufferPCM16);
+                    samplesPCM16 = Downmixing.DownMixStereoToMono(samplesPCM16);
+                }
+                else
+                {
+                    throw new NotImplementedException($"Downmixing from {_userChannelCount} to {_realSession.RequestedChannelCount} not implemented.");
                 }
-            }
-            else if (_userChannelCount == 2 && _realSession.RequestedChannelCount == 1)
-            {
-                downmixedBufferPCM16 = Downmixing.DownMixStereoToMono(samplesPCM16);
-            }
-            else
-            {
-                throw new NotImplementedException($"Downmixing from {_userChannelCount} to {_realSession.RequestedChannelCount} not implemented.");
-            }
 
-            byte[] downmixedBuffer = MemoryMarshal.Cast<short, byte>(downmixedBufferPCM16).ToArray();
+                samples = MemoryMarshal.Cast<short, byte>(samplesPCM16).ToArray();
+            }
 
             AudioBuffer fakeBuffer = new AudioBuffer
             {
                 BufferTag = buffer.BufferTag,
                 DataPointer = buffer.DataPointer,
-                DataSize = (ulong)downmixedBuffer.Length
+                DataSize = (ulong)samples.Length
             };
 
-            bool result = _realSession.RegisterBuffer(fakeBuffer, downmixedBuffer);
+            bool result = _realSession.RegisterBuffer(fakeBuffer, samples);
 
             if (result)
             {
diff --git a/Ryujinx.Audio/Renderer/Dsp/PcmHelper.cs b/Ryujinx.Audio/Renderer/Dsp/PcmHelper.cs
index 1eec3e41..1459e3a0 100644
--- a/Ryujinx.Audio/Renderer/Dsp/PcmHelper.cs
+++ b/Ryujinx.Audio/Renderer/Dsp/PcmHelper.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Numerics;
 using System.Runtime.CompilerServices;
 
 namespace Ryujinx.Audio.Renderer.Dsp
@@ -24,6 +25,44 @@ namespace Ryujinx.Audio.Renderer.Dsp
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float ConvertSampleToPcmFloat(short sample)
+        {
+            return (float)sample / short.MaxValue;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static short ConvertSampleToPcmInt16(float sample)
+        {
+            return Saturate(sample * short.MaxValue);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static TOutput ConvertSample<TInput, TOutput>(TInput value) where TInput: INumber<TInput>, IMinMaxValue<TInput> where TOutput : INumber<TOutput>, IMinMaxValue<TOutput>
+        {
+            TInput conversionRate = TInput.CreateSaturating(TOutput.MaxValue / TOutput.CreateSaturating(TInput.MaxValue));
+
+            return TOutput.CreateSaturating(value * conversionRate);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void Convert<TInput, TOutput>(Span<TOutput> output, ReadOnlySpan<TInput> input) where TInput : INumber<TInput>, IMinMaxValue<TInput> where TOutput : INumber<TOutput>, IMinMaxValue<TOutput>
+        {
+            for (int i = 0; i < input.Length; i++)
+            {
+                output[i] = ConvertSample<TInput, TOutput>(input[i]);
+            }
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ConvertSampleToPcmFloat(Span<float> output, ReadOnlySpan<short> input)
+        {
+            for (int i = 0; i < input.Length; i++)
+            {
+                output[i] = ConvertSampleToPcmFloat(input[i]);
+            }
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static int Decode(Span<short> output, ReadOnlySpan<short> input, int startSampleOffset, int endSampleOffset, int channelIndex, int channelCount)
         {
             if (input.IsEmpty || endSampleOffset < startSampleOffset)
@@ -53,7 +92,7 @@ namespace Ryujinx.Audio.Renderer.Dsp
 
             for (int i = 0; i < decodedCount; i++)
             {
-                output[i] = (short)(input[i * channelCount + channelIndex] * short.MaxValue);
+                output[i] = ConvertSampleToPcmInt16(input[i * channelCount + channelIndex]);
             }
 
             return decodedCount;