1 files changed, 78 insertions, 0 deletions
diff --git a/Ryujinx.HLE/Loaders/Compression/Lz4.cs b/Ryujinx.HLE/Loaders/Compression/Lz4.cs
new file mode 100644
index 00000000..cfb49551
--- /dev/null
+++ b/Ryujinx.HLE/Loaders/Compression/Lz4.cs
@@ -0,0 +1,78 @@
+using System;
+
+namespace Ryujinx.HLE.Loaders.Compression
+{
+    static class Lz4
+    {
+        public static byte[] Decompress(byte[] Cmp, int DecLength)
+        {
+            byte[] Dec = new byte[DecLength];
+
+            int CmpPos = 0;
+            int DecPos = 0;
+
+            int GetLength(int Length)
+            {
+                byte Sum;
+
+                if (Length == 0xf)
+                {
+                    do
+                    {
+                        Length += (Sum = Cmp[CmpPos++]);
+                    }
+                    while (Sum == 0xff);
+                }
+
+                return Length;
+            }
+
+            do
+            {
+                byte Token = Cmp[CmpPos++];
+
+                int EncCount = (Token >> 0) & 0xf;
+                int LitCount = (Token >> 4) & 0xf;
+
+                //Copy literal chunck
+                LitCount = GetLength(LitCount);
+
+                Buffer.BlockCopy(Cmp, CmpPos, Dec, DecPos, LitCount);
+
+                CmpPos += LitCount;
+                DecPos += LitCount;
+
+                if (CmpPos >= Cmp.Length)
+                {
+                    break;
+                }
+
+                //Copy compressed chunck
+                int Back = Cmp[CmpPos++] << 0 |
+                           Cmp[CmpPos++] << 8;
+
+                EncCount = GetLength(EncCount) + 4;
+
+                int EncPos = DecPos - Back;
+
+                if (EncCount <= Back)
+                {
+                    Buffer.BlockCopy(Dec, EncPos, Dec, DecPos, EncCount);
+
+                    DecPos += EncCount;
+                }
+                else
+                {
+                    while (EncCount-- > 0)
+                    {
+                        Dec[DecPos++] = Dec[EncPos++];
+                    }
+                }
+            }
+            while (CmpPos < Cmp.Length &&
+                   DecPos < Dec.Length);
+
+            return Dec;
+        }
+    }
+}
+\ No newline at end of file