Audio Renderer improvements (#210)

* Partial voice implementation on audio renderer

* Implemented audren resampler (based on original impl)

* Fix BiquadFilter struct

* Pause audio playback on last stream buffer

* Split audren/audout files into separate folders, some minor cleanup

* Use AudioRendererParameter on GetWorkBufferSize aswell

* Bump audren version to REV4, name a few things, increase sample buffer size

* Remove useless new lines

6 files changed, 132 insertions, 59 deletions

diff --git a/Ryujinx.Audio/Adpcm/AdpcmDecoder.cs b/Ryujinx.Audio/Adpcm/AdpcmDecoder.cs
new file mode 100644
index 00000000..24455b41
--- /dev/null
+++ b/Ryujinx.Audio/Adpcm/AdpcmDecoder.cs
@@ -0,0 +1,91 @@
+namespace Ryujinx.Audio.Adpcm
+{
+    public static class AdpcmDecoder
+    {
+        private const int SamplesPerFrame = 14;
+        private const int BytesPerFrame   = 8;
+
+        public static int[] Decode(byte[] Buffer, AdpcmDecoderContext Context)
+        {
+            int Samples = GetSamplesCountFromSize(Buffer.Length);
+
+            int[] Pcm = new int[Samples * 2];
+
+            short History0 = Context.History0;
+            short History1 = Context.History1;
+
+            int InputOffset  = 0;
+            int OutputOffset = 0;
+
+            while (InputOffset < Buffer.Length)
+            {
+                byte Header = Buffer[InputOffset++];
+
+                int Scale = 0x800 << (Header & 0xf);
+
+                int CoeffIndex = (Header >> 4) & 7;
+
+                short Coeff0 = Context.Coefficients[CoeffIndex * 2 + 0];
+                short Coeff1 = Context.Coefficients[CoeffIndex * 2 + 1];
+
+                int FrameSamples = SamplesPerFrame;
+
+                if (FrameSamples > Samples)
+                {
+                    FrameSamples = Samples;
+                }
+
+                int Value = 0;
+
+                for (int SampleIndex = 0; SampleIndex < FrameSamples; SampleIndex++)
+                {
+                    int Sample;
+
+                    if ((SampleIndex & 1) == 0)
+                    {
+                        Value = Buffer[InputOffset++];
+
+                        Sample = (Value << 24) >> 28;
+                    }
+                    else
+                    {
+                        Sample = (Value << 28) >> 28;
+                    }
+
+                    int Prediction = Coeff0 * History0 + Coeff1 * History1;
+
+                    Sample = (Sample * Scale + Prediction + 0x400) >> 11;
+
+                    short SaturatedSample = DspUtils.Saturate(Sample);
+
+                    History1 = History0;
+                    History0 = SaturatedSample;
+
+                    Pcm[OutputOffset++] = SaturatedSample;
+                    Pcm[OutputOffset++] = SaturatedSample;
+                }
+
+                Samples -= FrameSamples;
+            }
+
+            Context.History0 = History0;
+            Context.History1 = History1;
+
+            return Pcm;
+        }
+
+        public static long GetSizeFromSamplesCount(int SamplesCount)
+        {
+            int Frames = SamplesCount / SamplesPerFrame;
+
+            return Frames * BytesPerFrame;
+        }
+
+        public static int GetSamplesCountFromSize(long Size)
+        {
+            int Frames = (int)(Size / BytesPerFrame);
+
+            return Frames * SamplesPerFrame;
+        }
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.Audio/Adpcm/AdpcmDecoderContext.cs b/Ryujinx.Audio/Adpcm/AdpcmDecoderContext.cs
new file mode 100644
index 00000000..91730333
--- /dev/null
+++ b/Ryujinx.Audio/Adpcm/AdpcmDecoderContext.cs
@@ -0,0 +1,10 @@
+namespace Ryujinx.Audio.Adpcm
+{
+    public class AdpcmDecoderContext
+    {
+        public short[] Coefficients;
+
+        public short History0;
+        public short History1;
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.Audio/AudioFormat.cs b/Ryujinx.Audio/AudioFormat.cs
deleted file mode 100644
index 8250d136..00000000
--- a/Ryujinx.Audio/AudioFormat.cs
+++ /dev/null
@@ -1,13 +0,0 @@
-namespace Ryujinx.Audio
-{
-    public enum AudioFormat
-    {
-        Invalid  = 0,
-        PcmInt8  = 1,
-        PcmInt16 = 2,
-        PcmImt24 = 3,
-        PcmImt32 = 4,
-        PcmFloat = 5,
-        Adpcm    = 6
-    }
-}
\ No newline at end of file
diff --git a/Ryujinx.Audio/DspUtils.cs b/Ryujinx.Audio/DspUtils.cs
new file mode 100644
index 00000000..c048161d
--- /dev/null
+++ b/Ryujinx.Audio/DspUtils.cs
@@ -0,0 +1,16 @@
+namespace Ryujinx.Audio.Adpcm
+{
+    public static class DspUtils
+    {
+        public static short Saturate(int Value)
+        {
+            if (Value > short.MaxValue)
+                Value = short.MaxValue;
+
+            if (Value < short.MinValue)
+                Value = short.MinValue;
+
+            return (short)Value;
+        }
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.Audio/IAalOutput.cs b/Ryujinx.Audio/IAalOutput.cs
index f9978ee4..e903c5c5 100644
--- a/Ryujinx.Audio/IAalOutput.cs
+++ b/Ryujinx.Audio/IAalOutput.cs
@@ -2,11 +2,7 @@ namespace Ryujinx.Audio
 {
     public interface IAalOutput
     {
-        int OpenTrack(
-            int             SampleRate,
-            int             Channels,
-            ReleaseCallback Callback,
-            out AudioFormat Format);
+        int OpenTrack(int SampleRate, int Channels, ReleaseCallback Callback);
 
         void CloseTrack(int Track);
 
@@ -14,7 +10,7 @@ namespace Ryujinx.Audio
 
         long[] GetReleasedBuffers(int Track, int MaxCount);
 
-        void AppendBuffer(int Track, long Tag, byte[] Buffer);
+        void AppendBuffer<T>(int Track, long Tag, T[] Buffer)  where T : struct;
 
         void Start(int Track);
         void Stop(int Track);
diff --git a/Ryujinx.Audio/OpenAL/OpenALAudioOut.cs b/Ryujinx.Audio/OpenAL/OpenALAudioOut.cs
index 2860dc2e..1dd63202 100644
--- a/Ryujinx.Audio/OpenAL/OpenALAudioOut.cs
+++ b/Ryujinx.Audio/OpenAL/OpenALAudioOut.cs
@@ -3,6 +3,7 @@ using OpenTK.Audio.OpenAL;
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
+using System.Runtime.InteropServices;
 using System.Threading;
 
 namespace Ryujinx.Audio.OpenAL
@@ -226,15 +227,9 @@ namespace Ryujinx.Audio.OpenAL
             while (KeepPolling);
         }
 
-        public int OpenTrack(
-            int             SampleRate,
-            int             Channels,
-            ReleaseCallback Callback,
-            out AudioFormat Format)
+        public int OpenTrack(int SampleRate, int Channels, ReleaseCallback Callback)
         {
-            Format = AudioFormat.PcmInt16;
-
-            Track Td = new Track(SampleRate, GetALFormat(Channels, Format), Callback);
+            Track Td = new Track(SampleRate, GetALFormat(Channels), Callback);
 
             for (int Id = 0; Id < MaxTracks; Id++)
             {
@@ -247,38 +242,16 @@ namespace Ryujinx.Audio.OpenAL
             return -1;
         }
 
-        private ALFormat GetALFormat(int Channels, AudioFormat Format)
+        private ALFormat GetALFormat(int Channels)
         {
-            if (Channels == 1)
-            {
-                switch (Format)
-                {
-                    case AudioFormat.PcmInt8:  return ALFormat.Mono8;
-                    case AudioFormat.PcmInt16: return ALFormat.Mono16;
-                }
-            }
-            else if (Channels == 2)
-            {
-                switch (Format)
-                {
-                    case AudioFormat.PcmInt8:  return ALFormat.Stereo8;
-                    case AudioFormat.PcmInt16: return ALFormat.Stereo16;
-                }
-            }
-            else if (Channels == 6)
-            {
-                switch (Format)
-                {
-                    case AudioFormat.PcmInt8:  return ALFormat.Multi51Chn8Ext;
-                    case AudioFormat.PcmInt16: return ALFormat.Multi51Chn16Ext;
-                }
-            }
-            else
+            switch (Channels)
             {
-                throw new ArgumentOutOfRangeException(nameof(Channels));
+                case 1: return ALFormat.Mono16;
+                case 2: return ALFormat.Stereo16;
+                case 6: return ALFormat.Multi51Chn16Ext;
             }
 
-            throw new ArgumentException(nameof(Format));
+            throw new ArgumentOutOfRangeException(nameof(Channels));
         }
 
         public void CloseTrack(int Track)
@@ -309,13 +282,15 @@ namespace Ryujinx.Audio.OpenAL
             return null;
         }
 
-        public void AppendBuffer(int Track, long Tag, byte[] Buffer)
+        public void AppendBuffer<T>(int Track, long Tag, T[] Buffer) where T : struct
         {
             if (Tracks.TryGetValue(Track, out Track Td))
             {
                 int BufferId = Td.AppendBuffer(Tag);
 
-                AL.BufferData(BufferId, Td.Format, Buffer, Buffer.Length, Td.SampleRate);
+                int Size = Buffer.Length * Marshal.SizeOf<T>();
+
+                AL.BufferData<T>(BufferId, Td.Format, Buffer, Size, Td.SampleRate);
 
                 AL.SourceQueueBuffer(Td.SourceId, BufferId);
 
@@ -366,7 +341,5 @@ namespace Ryujinx.Audio.OpenAL
 
             return PlaybackState.Stopped;
         }
-
-
     }
 }
\ No newline at end of file