ExtractAutoTranslate.cs

// Extracts Auto Tranlate (상용구) from FFXIV chat data
public static List<byte[]> ExtractAutoTranslate(this byte[] rawMessage)
{
    List<byte[]> result = new List<byte[]>();

    /*
     * \u0002 \002E \u0004 \u0002 \u00F0 \u00CF \u0003
     * \u0002 \002E \u0003 \u0002 \u00CA \u0003
     * \u0002 \002E \u0005 \u0004 \u00F2 \u0001 \u0095 \u0003
     */
    for (int i = 0; i < rawMessage.Length; i++)
    {
        if (rawMessage[i].Equals(0x02)) // STX
        {
            if (i + 1 == rawMessage.Length) break; // Bound check
            if (!rawMessage[i + 1].Equals(0x2E)) continue; // it should be char '.'(=0x2E)
            byte range = rawMessage[i + 2];
            if(i + range > rawMessage.Length) continue;

            if(rawMessage[i + range + 2].Equals(0x03)) // ETX
            {// Found AutoTranslate block
                byte[] autoTranslate = new byte[range - 1];
                Array.Copy(rawMessage, i + 3, autoTranslate, 0, range - 1);
                result.Add(autoTranslate);
                i = i + range + 2;
            }
        }
    }

    return result;
}