1 files changed, 95 insertions, 0 deletions
diff --git a/Ryujinx.Audio/Renderer/Dsp/PcmHelper.cs b/Ryujinx.Audio/Renderer/Dsp/PcmHelper.cs
new file mode 100644
index 00000000..12c1d475
--- /dev/null
+++ b/Ryujinx.Audio/Renderer/Dsp/PcmHelper.cs
@@ -0,0 +1,95 @@
+//
+// Copyright (c) 2019-2021 Ryujinx
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+
+using System;
+using System.Runtime.CompilerServices;
+
+namespace Ryujinx.Audio.Renderer.Dsp
+{
+    public static class PcmHelper
+    {
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static int GetCountToDecode(int startSampleOffset, int endSampleOffset, int offset, int count)
+        {
+            return Math.Min(count, endSampleOffset - startSampleOffset - offset);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static ulong GetBufferOffset<T>(int startSampleOffset, int offset, int channelCount) where T : unmanaged
+        {
+            return (ulong)(Unsafe.SizeOf<T>() * channelCount * (startSampleOffset + offset));
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static int GetBufferSize<T>(int startSampleOffset, int endSampleOffset, int offset, int count) where T : unmanaged
+        {
+            return GetCountToDecode(startSampleOffset, endSampleOffset, offset, count) * Unsafe.SizeOf<T>();
+        }
+
+        [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)
+            {
+                return 0;
+            }
+
+            int decodedCount = input.Length / channelCount;
+
+            for (int i = 0; i < decodedCount; i++)
+            {
+                output[i] = input[i * channelCount + channelIndex];
+            }
+
+            return decodedCount;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static int Decode(Span<short> output, ReadOnlySpan<float> input, int startSampleOffset, int endSampleOffset, int channelIndex, int channelCount)
+        {
+            if (input.IsEmpty || endSampleOffset < startSampleOffset)
+            {
+                return 0;
+            }
+
+            int decodedCount = input.Length / channelCount;
+
+            for (int i = 0; i < decodedCount; i++)
+            {
+                output[i] = (short)(input[i * channelCount + channelIndex] * short.MaxValue);
+            }
+
+            return decodedCount;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static short Saturate(float value)
+        {
+            if (value > short.MaxValue)
+            {
+                return short.MaxValue;
+            }
+
+            if (value < short.MinValue)
+            {
+                return short.MinValue;
+            }
+
+            return (short)value;
+        }
+    }
+}