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

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;
+        }
+    }
+}