BaseNcoding.Base4096.Decode C# (CSharp) Метод

        public override byte[] Decode(string data)
        {
            unchecked
            {
                if (string.IsNullOrEmpty(data))
                    return new byte[0];

                int lastSpecialInd = data.Length;
                while (data[lastSpecialInd - 1] == Special)
                    lastSpecialInd--;
                int tailLength = data.Length - lastSpecialInd;

                byte[] result = new byte[data.Length / 2 * 3 - tailLength];

                int i, srcInd = 0;
                int x1, x2;
                int length5 = (data.Length / 2 - 1) * 3;
                for (i = 0; i < length5; i += 3)
                {
                    x1 = InvAlphabet[data[srcInd++]];
                    x2 = InvAlphabet[data[srcInd++]];

                    result[i] = (byte)x1;
                    result[i + 1] = (byte)((x1 >> 8) & 0x0F | (x2 << 4));
                    result[i + 2] = (byte)(x2 >> 4);
                }
                if (tailLength == 0)
                {
                    x1 = InvAlphabet[data[srcInd++]];
                    x2 = InvAlphabet[data[srcInd++]];

                    result[i] = (byte)x1;
                    result[i + 1] = (byte)((x1 >> 8) & 0x0F | (x2 << 4));
                    result[i + 2] = (byte)(x2 >> 4);
                }

                switch (tailLength)
                {
                    case 2:
                        x1 = InvAlphabet[data[srcInd++]];

                        result[i] = (byte)x1;
                        break;
                    case 1:
                        x1 = InvAlphabet[data[srcInd++]];
                        x2 = InvAlphabet[data[srcInd++]];

                        result[i] = (byte)x1;
                        result[i + 1] = (byte)((x1 >> 8) & 0x0F | (x2 << 4));
                        break;
                }

                return result;
            }
        }