using System;

using System.Text;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        var riffHeader = RiffHelper.BuildHeader(0, RiffHelper.Channels.One, RiffHelper.SampleRate.Khz8, RiffHelper.SampleSize.Bit8, RiffHelper.Format.MuLaw);

        Console.WriteLine("RIFF Header Hex:");

        Console.WriteLine(BitConverter.ToString(riffHeader));

    }

}

public static class RiffHelper

    {

        public enum Channels

        {

            One = 1,

            Two = 2

        }

​

        public enum SampleRate

        {

            Khz8 = 8000,

            Khz16 = 16000,

            Khz44 = 44000

        }

​

        public enum SampleSize

        {

            Bit8 = 8,

            Bit16 = 16,

            Bit32 = 32

        }

​

        public enum Format

        {

            PCM = 1,

            MuLaw = 7

        }

​

        public static byte[] BuildHeader(int audioDataLengthBytes, Channels channels, SampleRate sampleRate, SampleSize sampleSize, Format format)

        {

            return BuildHeader(audioDataLengthBytes, (short)channels, (int)sampleRate, (short)sampleSize, (short)format);

        }

​

        public static byte[] BuildHeader(int audioDataLengthBytes, short channels, int sampleRate, short sampleSizeBits, short formatCode)

        {

            Console.WriteLine("Building header");

            var header = new byte[44];

​

            Encoding.UTF8.GetBytes("RIFF".ToCharArray()).CopyTo(header, 0);

            BitConverter.GetBytes((int)(audioDataLengthBytes + 44 - 8)).CopyTo(header, 4);// size of entire file minus 8 bytes

            Encoding.UTF8.GetBytes("WAVEfmt ".ToCharArray()).CopyTo(header, 8);

            BitConverter.GetBytes((int)16).CopyTo(header, 16);// size of section 2

​

            //section 2 start

            BitConverter.GetBytes(formatCode).CopyTo(header, 20);// 1 = code for PCM audio, 7 = mulaw

            BitConverter.GetBytes(channels).CopyTo(header, 22);// channels

            BitConverter.GetBytes(sampleRate).CopyTo(header, 24);// sample rate

            BitConverter.GetBytes((int)channels * sampleRate * (sampleSizeBits / 8)).CopyTo(header, 28);// bytes per second

            BitConverter.GetBytes((short)channels * (sampleSizeBits / 8)).CopyTo(header, 32);// block byte size

            BitConverter.GetBytes(sampleSizeBits).CopyTo(header, 34);// how many bits per sample

            //section 2 end

​

            Encoding.UTF8.GetBytes("data".ToCharArray()).CopyTo(header, 36);

            BitConverter.GetBytes(audioDataLengthBytes).CopyTo(header, 40);// audio data length

​

            return header;

        }

​

        public static void ReadHeader(byte[] data, out short channels, out int sampleRate, out short sampleSizeBits, out short formatCode)

        {

            if (data.Length < 44)

                throw new Exception("Invalid header data! Need at least 44 bytes!");

            if (Encoding.UTF8.GetString(data.Take(4).ToArray()) != "RIFF")

                throw new Exception("Invalid header data! Not RIFF!");

​

            channels = BitConverter.ToInt16(data.Skip(22).Take(2).ToArray(), 0);

            sampleRate = BitConverter.ToInt32(data.Skip(24).Take(4).ToArray(), 0);

            sampleSizeBits = BitConverter.ToInt16(data.Skip(34).Take(2).ToArray(), 0);

            formatCode = BitConverter.ToInt16(data.Skip(20).Take(2).ToArray(), 0);

        }

    }