all CRCs in one place

CUETools.Codecs/CRCs/CRC16.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace CUETools.Codecs
+{
+	public class Crc16
+	{
+		ushort[] table = new ushort[256];
+
+		public ushort ComputeChecksum(byte[] bytes, int pos, int count)
+		{
+			ushort crc = 0;
+			for (int i = pos; i < pos + count; i++)
+			{
+				crc = (ushort)(((crc << 8) & 0xffff) ^ table[(crc >> 8) ^ bytes[i]]);
+			}
+			return crc;
+		}
+
+		public unsafe ushort ComputeChecksum(byte* bytes, int pos, int count)
+		{
+			ushort crc = 0;
+			fixed (ushort* t = table)
+				for (int i = pos; i < pos + count; i++)
+					crc = (ushort)(((crc << 8) & 0xffff) ^ t[(crc >> 8) ^ bytes[i]]);
+			return crc;
+		}
+
+		public Crc16()
+		{
+			int bits = 16;
+			int poly16 = 0x8005;
+			int poly = (poly16 + (1 << bits));
+			for (ushort i = 0; i < table.Length; i++)
+			{
+				int crc = i;
+				for (int j = 0; j < bits; j++)
+				{
+					if ((crc & (1U << (bits - 1))) != 0)
+						crc = ((crc << 1) ^ poly);
+					else
+						crc <<= 1;
+				}
+			        //table[i] = (crc & ((1<<bits)-1));
+				table[i] = (ushort)(crc & 0xffff);
+			}
+		}
+	}
+}

CUETools.Codecs/CRCs/CRC16CCITT.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace CUETools.Codecs
+{
+	public enum InitialCrcValue { Zeros, NonZero1 = 0xffff, NonZero2 = 0x1D0F }
+
+	public class Crc16Ccitt
+	{
+		const ushort poly = 4129;
+		ushort[] table = new ushort[256];
+		ushort initialValue = 0;
+
+		public ushort ComputeChecksum(byte[] bytes, int pos, int count)
+		{
+			ushort crc = this.initialValue;
+			for (int i = pos; i < pos + count; i++)
+			{
+				crc = (ushort)((crc << 8) ^ table[((crc >> 8) ^ (0xff & bytes[i]))]);
+			}
+			return crc;
+		}
+
+		public byte[] ComputeChecksumBytes(byte[] bytes, int pos, int count)
+		{
+			ushort crc = ComputeChecksum(bytes, pos, count);
+			return new byte[] { (byte)(crc >> 8), (byte)(crc & 0x00ff) };
+		}
+
+		public Crc16Ccitt(InitialCrcValue initialValue)
+		{
+			this.initialValue = (ushort)initialValue;
+			ushort temp, a;
+			for (int i = 0; i < table.Length; i++)
+			{
+				temp = 0;
+				a = (ushort)(i << 8);
+				for (int j = 0; j < 8; j++)
+				{
+					if (((temp ^ a) & 0x8000) != 0)
+					{
+						temp = (ushort)((temp << 1) ^ poly);
+					}
+					else
+					{
+						temp <<= 1;
+					}
+					a <<= 1;
+				}
+				table[i] = temp;
+			}
+		}
+	}
+}

CUETools.Codecs/CRCs/CRC32.cs

@@ -0,0 +1,80 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace CUETools.Codecs
+{
+	public class Crc32
+	{
+		uint[] table = new uint[256];
+
+		public uint ComputeChecksum(uint crc, byte val)
+		{
+			return (crc >> 8) ^ table[(crc & 0xff) ^ val];
+		}
+
+		public uint ComputeChecksum(uint crc, byte[] bytes, int pos, int count)
+		{
+			for (int i = pos; i < pos + count; i++)
+				crc = ComputeChecksum(crc, bytes[i]);
+			return crc;
+		}
+
+		public uint ComputeChecksum(uint crc, uint s)
+		{
+			return ComputeChecksum(ComputeChecksum(ComputeChecksum(ComputeChecksum(
+				crc, (byte)s), (byte)(s >> 8)), (byte)(s >> 16)), (byte)(s >> 24));
+		}
+
+		public unsafe uint ComputeChecksum(uint crc, int * samples, uint count)
+		{
+			for (uint i = 0; i < count; i++)
+			{
+				int s1 = samples[2 * i], s2 = samples[2 * i + 1];
+				crc = ComputeChecksum(ComputeChecksum(ComputeChecksum(ComputeChecksum(
+					crc, (byte)s1), (byte)(s1 >> 8)), (byte)s2), (byte)(s2 >> 8));
+			}
+			return crc;
+		}
+
+		public unsafe uint ComputeChecksumWONULL(uint crc, int* samples, uint count)
+		{
+			for (uint i = 0; i < count; i++)
+			{
+				int s1 = samples[2 * i], s2 = samples[2 * i + 1];
+				if (s1 != 0)
+					crc = ComputeChecksum(ComputeChecksum(crc, (byte)s1), (byte)(s1 >> 8));
+				if (s2 != 0)
+					crc = ComputeChecksum(ComputeChecksum(crc, (byte)s2), (byte)(s2 >> 8));
+			}
+			return crc;
+		}
+
+		uint Reflect(uint val, int ch)
+		{
+			uint value = 0;
+			// Swap bit 0 for bit 7
+			// bit 1 for bit 6, etc.
+			for (int i = 1; i < (ch + 1); i++)
+			{
+				if (0 != (val & 1))
+					value |= 1U << (ch - i);
+				val >>= 1;
+			}
+			return value;
+		}
+
+		const uint ulPolynomial = 0x04c11db7;
+
+		public Crc32()
+		{
+			for (uint i = 0; i < table.Length; i++)
+			{
+				table[i] = Reflect(i, 8) << 24;
+				for (int j = 0; j < 8; j++)
+					table[i] = (table[i] << 1) ^ ((table[i] & (1U << 31)) == 0 ? 0 : ulPolynomial);
+				table[i] = Reflect(table[i], 32);
+			}
+		}
+	}
+}

CUETools.Codecs/CRCs/CRC8.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace CUETools.Codecs
+{
+
+	public class Crc8
+	{
+		const ushort poly8 = 0x07;
+		ushort[] table = new ushort[256];
+
+		public byte ComputeChecksum(byte[] bytes, int pos, int count)
+		{
+			ushort crc = 0;
+			for (int i = pos; i < pos + count; i++)
+				crc = table[crc ^ bytes[i]];
+			return (byte) crc;
+		}
+
+		public unsafe byte ComputeChecksum(byte * bytes, int pos, int count)
+		{
+			ushort crc = 0;
+			for (int i = pos; i < pos + count; i++)
+				crc = table[crc ^ bytes[i]];
+			return (byte)crc;
+		}
+
+		public Crc8()
+		{
+			int bits = 8;
+			ushort poly = (ushort) (poly8 + (1U << bits));
+			for (ushort i = 0; i < table.Length; i++)
+			{
+				ushort crc = i;
+				for (int j = 0; j < bits; j++)
+				{
+					if ((crc & (1U << (bits - 1))) != 0)
+						crc = (ushort)((crc << 1) ^ poly);
+					else
+						crc <<= 1;
+				}
+				table[i] = (ushort)(crc & 0x00ff);
+			}
+		}
+	}
+}