Program.cs

?using System;

namespace ConsoleApp1
{
    class Program
    {
        const int offsetstart = 0x2c;
        const int expecteddatasize = 4032000; //4032000; // original task:4032000, Assignment1=2293200
        const int numsamples = expecteddatasize >> 2; // 4 bytes per sample (2 left, 2 right)

        struct sampleLR
        {
            public Int16 left;
            public Int16 right;
        };

        static void FindText(int type, sampleLR[] s, int startoffset, int distance)
        {
            Console.WriteLine();
            Console.WriteLine("FindText-type=" + type.ToString() + ", offset=" + startoffset.ToString() + ", distance=" + distance.ToString());
            byte assembledbyte = 0;
            int numbitsgot = 0;
            for(int i = startoffset; i < numsamples; i += distance)
            {
                if (i >= numsamples)
                    break;
                byte l = (byte)(UInt16)((UInt16)s[i].left & (UInt16)0x01);
                byte r = (byte)(UInt16)((UInt16)s[i].right & (UInt16)0x01);
                if (type == 1)
                {
                    assembledbyte = (byte)((byte)(assembledbyte << 1) | l);
                    assembledbyte = (byte)((byte)(assembledbyte << 1) | r);
                    numbitsgot += 2;
                }
                if (type == 2)
                {
                    assembledbyte = (byte)((byte)(assembledbyte << 1) | r);
                    assembledbyte = (byte)((byte)(assembledbyte << 1) | l);
                    numbitsgot += 2;
                }
                if (type == 3)
                {
                    assembledbyte = (byte)((byte)(assembledbyte << 1) | l);
                    numbitsgot++;
                }
                if (type == 4)
                {
                    assembledbyte = (byte)((byte)(assembledbyte << 1) | r);
                    numbitsgot++;
                }
                if (type == 5)
                {
                    assembledbyte = (byte)((byte)(assembledbyte >> 1) | (byte)(l<<7));
                    assembledbyte = (byte)((byte)(assembledbyte >> 1) | (byte)(r<<7));
                    numbitsgot += 2;
                }
                if (type == 6)
                {
                    assembledbyte = (byte)((byte)(assembledbyte >> 1) | (byte)(r << 7));
                    assembledbyte = (byte)((byte)(assembledbyte >> 1) | (byte)(l << 7));
                    numbitsgot += 2;
                }
                if (type == 7)
                {
                    assembledbyte = (byte)((byte)(assembledbyte >> 1) | (byte)(l << 7));
                    numbitsgot++;
                }
                if (type == 8)
                {
                    assembledbyte = (byte)((byte)(assembledbyte >> 1) | (byte)(r << 7));
                    numbitsgot++;
                }
                if (numbitsgot > 8)
                    throw new Exception("more than 8 bits!");
                if (numbitsgot >= 8)
                {
                    //if(assembledbyte>=32&&assembledbyte<=126)
                        Console.Write((char)assembledbyte);
                    assembledbyte = 0;
                    numbitsgot = 0;
                }
            }
        }

        static void Main(string[] args)
        {
            System.IO.FileStream fs = new System.IO.FileStream("C:\\TEMP\\CTF_moocfi_2019\\SomethingSoundsOff\\woods_a.wav", System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read);
            byte[] b=new byte[expecteddatasize];
            long sr = fs.Seek(offsetstart, System.IO.SeekOrigin.Begin);
            int readresult=fs.Read(b, 0, expecteddatasize);
            fs.Close();
            if(readresult== expecteddatasize)
            {
                Console.WriteLine("File read successfully.");
                sampleLR[] s = new sampleLR[numsamples];
                for(int i = 0; i < numsamples; i++)
                {
                    byte b0 = b[4 * i];
                    byte b1 = b[4 * i + 1];
                    byte b2 = b[4 * i + 2];
                    byte b3 = b[4 * i + 3];
                    Int16 left = (Int16)((UInt16)b1 << 8 | (UInt16)b0);
                    Int16 right= (Int16)((UInt16)b3 << 8 | (UInt16)b2);
                    s[i].left = left;
                    s[i].right = right;
                }
                Console.WriteLine("Copied samples successfully.");
                int startoffset = 0;
                int distance = 1;
                FindText(1, s, startoffset, distance); // 1=left, right, bits 0...7
                //FindText(2, s, startoffset, distance); // 2=right, left, bits 0...7
                //FindText(3, s, startoffset, distance); // 3=left only, bits 0...7
                //FindText(4, s, startoffset, distance); // 3=right only, bits 0...7
                //FindText(5, s, startoffset, distance); // 1=left, right, bits 7...0
                //FindText(6, s, startoffset, distance); // 2=right, left, bits 7...0
                //FindText(7, s, startoffset, distance); // 3=left only, bits 7...0
                //FindText(8, s, startoffset, distance); // 3=right only, bits 7...0
                //startoffset = 1;
                //FindText(1, s, startoffset, distance); // 1=left, right, bits 0...7
                //FindText(2, s, startoffset, distance); // 2=right, left, bits 0...7
                //FindText(3, s, startoffset, distance); // 3=left only, bits 0...7
                //FindText(4, s, startoffset, distance); // 3=right only, bits 0...7
                //FindText(5, s, startoffset, distance); // 1=left, right, bits 7...0
                //FindText(6, s, startoffset, distance); // 2=right, left, bits 7...0
                //FindText(7, s, startoffset, distance); // 3=left only, bits 7...0
                //FindText(8, s, startoffset, distance); // 3=right only, bits 7...0
                //startoffset = 2;
                //FindText(1, s, startoffset, distance); // 1=left, right, bits 0...7
                //FindText(2, s, startoffset, distance); // 2=right, left, bits 0...7
                //FindText(3, s, startoffset, distance); // 3=left only, bits 0...7
                //FindText(4, s, startoffset, distance); // 3=right only, bits 0...7
                //FindText(5, s, startoffset, distance); // 1=left, right, bits 7...0
                //FindText(6, s, startoffset, distance); // 2=right, left, bits 7...0
                //FindText(7, s, startoffset, distance); // 3=left only, bits 7...0
                //FindText(8, s, startoffset, distance); // 3=right only, bits 7...0
                //startoffset = 3;
                //FindText(1, s, startoffset, distance); // 1=left, right, bits 0...7
                //FindText(2, s, startoffset, distance); // 2=right, left, bits 0...7
                //FindText(3, s, startoffset, distance); // 3=left only, bits 0...7
                //FindText(4, s, startoffset, distance); // 3=right only, bits 0...7
                //FindText(5, s, startoffset, distance); // 1=left, right, bits 7...0
                //FindText(6, s, startoffset, distance); // 2=right, left, bits 7...0
                //FindText(7, s, startoffset, distance); // 3=left only, bits 7...0
                //FindText(8, s, startoffset, distance); // 3=right only, bits 7...0
                //startoffset = 4;
                //FindText(1, s, startoffset, distance); // 1=left, right, bits 0...7
                //FindText(2, s, startoffset, distance); // 2=right, left, bits 0...7
                //FindText(3, s, startoffset, distance); // 3=left only, bits 0...7
                //FindText(4, s, startoffset, distance); // 3=right only, bits 0...7
                //FindText(5, s, startoffset, distance); // 1=left, right, bits 7...0
                //FindText(6, s, startoffset, distance); // 2=right, left, bits 7...0
                //FindText(7, s, startoffset, distance); // 3=left only, bits 7...0
                //FindText(8, s, startoffset, distance); // 3=right only, bits 7...0
                //startoffset = 5;
                //FindText(1, s, startoffset, distance); // 1=left, right, bits 0...7
                //FindText(2, s, startoffset, distance); // 2=right, left, bits 0...7
                //FindText(3, s, startoffset, distance); // 3=left only, bits 0...7
                //FindText(4, s, startoffset, distance); // 3=right only, bits 0...7
                //FindText(5, s, startoffset, distance); // 1=left, right, bits 7...0
                //FindText(6, s, startoffset, distance); // 2=right, left, bits 7...0
                //FindText(7, s, startoffset, distance); // 3=left only, bits 7...0
                //FindText(8, s, startoffset, distance); // 3=right only, bits 7...0
                //startoffset = 6;
                //FindText(1, s, startoffset, distance); // 1=left, right, bits 0...7
                //FindText(2, s, startoffset, distance); // 2=right, left, bits 0...7
                //FindText(3, s, startoffset, distance); // 3=left only, bits 0...7
                //FindText(4, s, startoffset, distance); // 3=right only, bits 0...7
                //FindText(5, s, startoffset, distance); // 1=left, right, bits 7...0
                //FindText(6, s, startoffset, distance); // 2=right, left, bits 7...0
                //FindText(7, s, startoffset, distance); // 3=left only, bits 7...0
                //FindText(8, s, startoffset, distance); // 3=right only, bits 7...0
                //startoffset = 7;
                //FindText(1, s, startoffset, distance); // 1=left, right, bits 0...7
                //FindText(2, s, startoffset, distance); // 2=right, left, bits 0...7
                //FindText(3, s, startoffset, distance); // 3=left only, bits 0...7
                //FindText(4, s, startoffset, distance); // 3=right only, bits 0...7
                //FindText(5, s, startoffset, distance); // 1=left, right, bits 7...0
                //FindText(6, s, startoffset, distance); // 2=right, left, bits 7...0
                //FindText(7, s, startoffset, distance); // 3=left only, bits 7...0
                //FindText(8, s, startoffset, distance); // 3=right only, bits 7...0
            }
            else
            {
                Console.WriteLine("Error reading file.");
            }
        }
    }
}